Most hp you normally aspirated guys have put down?

[Accordtheory]

I am rather curious about this, as I know people are regularly approaching and exceeding 200whp with their modded B series VTECs. I haven't done anything to my longblock other than port the head. I have the stock internals/cam with my turbo setup. But I imagine with the ported head, a different cam and valvesprings for higher rpm, decent intake manifold, higher comp pistons , stronger rods for an increased redline, decent header, 2.25 or 2.5" exhaust, and good management, you could maybe up to 170whp? (and then spray) What is the most you guys have gotten? I am talking legit dyno sheets..and if someone says they have 200whp, I'm definitely calling BS. And if you don't have a dyno sheet but the car is still exceptional, that should be reflected in it's quarter mile time..who is in at least the 14s N/A? And I'm not talking all stripped and with "weight reduction"

represent, people

[Vanilla Sky]

theoretically, it's possible to get up to about 200 WHP without really doing a whole lot (in the grand scheme of things)...

P&P, better intake manifold, wild cam, tuned exhaust, bump the compression, dome the head a bit (at least unshroud the valves), and switch to better engine management... yeah, i'm missing some stuff, but i don't see it as a horrible task making 200WHP... doing it reliably is another issue...

i want to get up that high reliably... and i'm not ready to turbo a car... if i did, i'd keep the higher compression and run a really small turbo with very low boost...

[shepherd79]

i don't think you will find many people who can present you with dyno results.
most of us don't have money for dyno or just not interested.

since you are turbo, you should think about 2.75"- 3" exhaust. 2.5" will choke the turbo.
the good part about our motors is that they make nice torque numbers.

http://www.3geez.com/showthread.php?t=38269&highlight=dyno+results
http://www.3geez.com/showthread.php?t=36543&highlight=dyno+results
http://www.3geez.com/showthread.php?t=27388&highlight=dyno+results
http://www.3geez.com/showthread.php?t=15569&highlight=dyno+results
http://www.3geez.com/showthread.php?t=10628&highlight=dyno+results


this one is probably the most i have seen in A20 NA version
http://www.3geez.com/showthread.php?t=2202&highlight=dyno+results

[smufguy]

I beg to differ. A20 is not a wonderful NA motor to begin with even tho its great for a Turbo. The thing is, to get 200whp with a 15% driveline loss, u need to have 235hp minimum at the crank to pull those numbers. and that kinda number is not gonna be possible unless the motor can rev like the amazing S2000 which accomplishes it with Dual Cams, 16V, 12:1 ungodly compression and redline of crazy 9K rpm (the current ones lowered a lil, 8.5 i believe). Those are mere numbers and a purebread drag all motor can be possible with ITBs and extensive head work. Just a simple port and polish and bigger valves is not gonna cut it. Sure as hell, its not gonna be making any power in the lower rpm, which for practical reasons is not gonna work in the street and sure as hell not gonna idle smooth with that much lift. and def the cams need to have 500 or even 550 lift to make the head flow a min of 340cfm.

So yeah, NA on this motor is pretty much limited :(

ps: sorry to just put my views forward, but more or less its the fact.

[NXRacer]

you dont have to have an S2000 that revs to 9.5k to get 200whp. My buddy just dropped a JDM H22 in his 4th gen and it just recently dyno'd at 190whp. just a couple more mods and some tuning on the dyno and he'd be well over 200.

as for the a20, it might be possible to get 200hp out of an a20, but few (if any) have yet to put the time and money into it to find out. It'll probably end up running about the same (if not less) money to boost it then build a crazy N/A motor. Plus, you can keep going with the boost a lot easier (and cheaper).

[AccordEpicenter]

n/a power is way more expensive than turbo. i like my turbo torque too

[rjudgey]

well i'm working on a A20 N/A project, My previous A18 project with 33mm inlet valves, twin modified Weber DCOE's, 2.25" SSteel exhaust, 272 degree cam with 10mm lift, ported and flowed cast header, heavily moddified Cylinder head done by myself, this netted me around 200bhp at the flywheel with bags of torque, power band was from 3-7K 1/4 mile time so far quickest has been 14.6 with quite a bit of traction problem, first tried it with 285 duration cam and this only wielded 180bhp, have a dyno of 176bhp on a first setup dyno run session. Currently using an ET1 engine with an Overbore to 2.0 litre custom inlet manifold with 1.5" long runners with twin Webers, stock valve size but valves are modded in shape and finish, the head is also extensively moddified, 285 duration cam with 10mm lift power the power band is from 4-7.5K but does spin to 8K, again i think the bottleneck is with the cast manifold and the inlet port sizes and carbs.

The A20A4 i'm working on has a Jenvey B18C inlet manifold, which is turned upside down and re-drilled to fit for the correct angle, full head work, 33mm inlet valves custom made with special shape and narrower stems, 45mm inlet ports on the inlet manifold, custom header with equal length long primaries, maybe 2.5" system but will try the 2.25" first, but the real improvement will be the fact i should be able to use a 295 degree cam and have 11mm lift maybe push for 11.5mm lift, but the biggest change will be from running twin webers to Quad bike carbs from a Honda fireblade which have a 42mm bore, this should easily produce over 200whp but will be harder to drive in traffic as the ally flywheel, solid hub clutch disk and 295 degree cam will not like being driven at low revs!!

But from just that gives you some idea how hard it is to produce big numbers on a N/A engine!! Especially when a JDM K20 practically puts that out as standard and can be further modded to 250bhp and supercharged to over 300bhp!!! Which is why i'm looking at getting an Ariel Atom as these have K20's in them as standard in a car that weighs only 500kg!!!!! Now thats a serious power to weight ratio!!!!

Also a long throw Suzuki Hayabusa engine modded puts out 230bhp from 1.5 litres and only has 33mm inlet valves so the biggest mod to change in A20 is to get bigger inlet valves, and the cheapest way to do that is to re-use old exhaust valves and have them machined to 33mm and re-profiled!! Works out a treat but not quite as good as custom as the valve stem is slightly thicker than stock.

[Lok]

Very nice set-up rjudgey!!!!!!!!!!
Maybe you'll create the most powerfull N/A A20???
And some questions, if you have time to answer???
You think that Bike CARBS are much better mod instead off dual DCOE..............through I think that second hand Bike CARBS are much cheaper than
WEBER DCOE?...
Is any problem in the instalation of Bike Carbs, or is something straight forward (if you have the manifold)??
Are you using a fuel pressure regulator aswell??
How much will cost one A20 built in your specs, on U.K ,through this is increadibly powerfull N/A engine ( 200whp)?
One B18C5 swap in Accord 3G, on U.K, will cost about £4000.....................so how much cost your set-up??? I think 200whp(A20 rjudgey specs) is better than 170whp
(jdm B18C 197hp)??

Thank you very much

[Accordtheory]

Damn, that is rather impressive, rjudgey..now I have some questions that you probably know the answers to. First, the A18 is an A20 with a smaller bore, right? So that's even more impressive to generate that much hp. I cannot believe you have taken a stock shortblock to 8k!! If I tried to pull that, i would fully expect to destroy the engine catastrophically. Anyway, what are the stock A20 valve sizes, and what is the stock cam profile? You haven't increased the exhaust valve size? I would have thought that would be a good thing to do, given that the A series only has 4 of them. I don't know how much of a difference that would make with a turbo though, due to the already higher backpressure.
I am basically trying to find out what can be done to improve the efficiency of the engine itself, before a turbo, so I can retain the parts of a high powered N/A combination that are turbo compatible. My head is already ported to match my aftermarket b series intake manifold, maybe now i'll look into larger valves and a higher lift cam. As far as the short block, I just need more strength, not compression. I would be curious to know what my combo would have put down N/A..what would an A20 make with the aebs manifold, ported head, stock cam, stock shortblock, 4-2-1 header with 2.25 or 1.5" exhaust, and of course, good tuning..?

[A20A1]

Bike carb would be somewhat easier I'd assume... the mouting angle isn't as critical as the dcoe's

Do you plan to go with the traditional butterflies or slide throttle? Slide throttle is supposed to have less restriction.

[system-f]

Most hp you normally aspirated guys have put down with a reasonable torque curve ie. real world usable power?

Fixed it for you

IMHO There is no replacement for displacement...

[Vanilla Sky]

the no replacement for displacement argument pretty much ends when you build a race motor... at least while we still measure power by HP... i mean, how many SBC or 5-0 motors do you see revving to 10,000 RPM?

it does feel nice to have a v8 available to your right foot, though...

[guaynabo89]

I am rather curious about this, as I know people are regularly approaching and exceeding 200whp with their modded B series VTECs. I haven't done anything to my longblock other than port the head. I have the stock internals/cam with my turbo setup. But I imagine with the ported head, a different cam and valvesprings for higher rpm, decent intake manifold, higher comp pistons , stronger rods for an increased redline, decent header, 2.25 or 2.5" exhaust, and good management, you could maybe up to 170whp? (and then spray) What is the most you guys have gotten? I am talking legit dyno sheets..and if someone says they have 200whp, I'm definitely calling BS. And if you don't have a dyno sheet but the car is still exceptional, that should be reflected in it's quarter mile time..who is in at least the 14s N/A? And I'm not talking all stripped and with "weight reduction"

represent, people



I put 123whp with a rebuilt stock block p&p heaad bored out tb, stoock cam short ram intake dc headre and 2 1/4 exhaust on 17" wheels with 45 rubber.

Not bad considering this was back in 99 or so.

I'll be pushing the limits of a n/a a20 and hope to have good numbers by summer.

[Accordtheory]

Has anyone flow tested a stock or modified A20 head?

[rjudgey]

The A18 had a re-bore to 2.0litre, stock valve size for any A or E series is 30mm inlet and 35mm exhaust, the exhaust valve size doesn't have to increase in size on a N/A engine as when the fuel mixture is burnt it is reduced in mass to half, so as long as the exhaust valve and port size is greater than half than that will work fine, with Turbo it's slightly different as a lot more air and fuel is being pushed through past the inlet valves, so you need to have as big a exhaust valve as possible.
The bike carbs are what a specialist recommended and said that the best ones are from Honda Fireblade, they have 42mm bore but inlet manifold needs to be custom fabricated to suit the head. I've been told that the bike carbs are better in the lower and mid power range and will give a small increase at the top end overall power isn't much more than DCOE's. But Bike carbs are a lot cheaper than Webers and quite a few people no how to tune them as their still fairly new and current.
An engine re-built to high spec isn't cheap but not that expensive, in parts cost £600 roughly with new pumps, full gaskets, pistons, rings.
Performance cam grind £200.
Machine work around £3-400
Headwork with full port and chamber flowing and manifold matching is about 30-40 hours worth of work donw to my standards.
Done by a specialist i know about £6-800 depending on spec.
Bike carb conversion looking at £500 including fabrication of inlet manifold.
Custom Exhaust header and system about £800-1000.
Exhaust could be done cheaper a pacesetter header and system would be better than stock but would limit power to around 200bhp.

[Accordtheory]

the exhaust valve size doesn't have to increase in size on a N/A engine as when the fuel mixture is burnt it is reduced in mass to half, so as long as the exhaust valve and port size is greater than half than that will work fine The only way you can exchange mass for energy is a nuclear reaction! The amount of mass exiting the cylinder is the same as before it was combusted, it's just in a different molecular arrangement.

[Oldblueaccord]

Has anyone flow tested a stock or modified A20 head?


I'd like some flow numbers as well.



wp

[Vanilla Sky]

i believe sean did, and from what i remember, it flowed pretty well for a stock head

[rjudgey]

Well i'm not a scientist but the combustion process makes it easier for the exhaust gas to be expelled, and is a well tried and tested that exhuast valve size on a N/A engine is not as critical as the inlet valve size, as long as the exhaust valve size is of a reasonable size your fine, as ours are 35mm their fine as they are, you could maybe go 37mm but to be honest with the nasty nature that exhaust gas is your better off having as much metal in the exhuast ports as possible. Also Exhuast valve of that size will cost quite a bit to custom make. The biggest benefit for any N/A engine is to increase the inlet valve size 30mm is not a bad size but if you can increase that to 32-33mm you will gain a lot more especially if you have high duration and lift cams, but at the same time if you don't like high revving engines larger inlet valves combined with a lower spec cam duration will give good low and mid power without overstressing the engine with really high rpms.
As for flow figures most people who aren't a profesional engine builder won't have a flowbench, and those that DIY to a high level won't have accurate figures as we just have a basic rig that works to help us balance each port rather than measure accurately the flow rate. But just bought a new magazine and goes in depth into how to make an accurate DIY flowbench so maybe i might look more into that and get some more accurate measurements.

[Strugglebucket]

The only way you can exchange mass for energy is a nuclear reaction! The amount of mass exiting the cylinder is the same as before it was combusted, it's just in a different molecular arrangement.
i think he was referring to volume.

[A20A1]

Or density...

[Justin86]

from what I remember Sean said the stock head flowed at 132cfm and his ported head with larger valves was pushing 230cfm.
One thing I don't understand is being able to rev to 7-8K on stock bottom end. Looking at piston speeds at 8K its 4776fpm. What is the suppose normal for stock blocks is about 3500fpm and with forged parts around 4000fpm. Going up to around 5000fpm is playing with fire and you can get away with it for a couple sec's, but it is itching to blow. So trying to stay around that 3500fpm limit for stock blocks would be 5860rpms and our redline at 6500rpm the piston speed is 3880fpm.

[rjudgey]

well don't know about the rest of you but my blocks have never blown, and also they are in constant combat mode from 4-7K and with the 285 duartion cam upto 8K, and thats on a more than regular basis for sometimes 30 mins at a time and for a whole day so all in use on track 4-5 hours at combat speed, thats with stock secondhand rod bolts, stock 2nd hand rods that are balanced and stress relieved, stock crank balanced, sealed power cast pistons, but they do only tend to last 15K before needing replacing. But nothing has ever broken or bent? Sure your figures are correct? To be honest i know very few people who have managed to completely destroy an A20/E series engine? I've knackered a few pistons, bearings and heads but thats about it.

[Oldblueaccord]

from what I remember Sean said the stock head flowed at 132cfm and his ported head with larger valves was pushing 230cfm.
One thing I don't understand is being able to rev to 7-8K on stock bottom end. Looking at piston speeds at 8K its 4776fpm. What is the suppose normal for stock blocks is about 3500fpm and with forged parts around 4000fpm. Going up to around 5000fpm is playing with fire and you can get away with it for a couple sec's, but it is itching to blow. So trying to stay around that 3500fpm limit for stock blocks would be 5860rpms and our redline at 6500rpm the piston speed is 3880fpm.


You gotta link to the formula?

I think the type r runs faster than that.


I can't see a head going %100 better flow with just some porting. That of course coming from Sean like most of what he said is unbelievable.

I think 250 cfm at .500 lift is good for about 450hp in a chevy small block. there's a formula for that too. Thats why i have been wondering what the stock flow is.

wp

[smufguy]

well from the last time i talked to him, he flowed 340cfm with .550 lift and i think 230 was with .4xx lift.

[Oldblueaccord]

well from the last time i talked to him, he flowed 340cfm with .550 lift and i think 230 was with .4xx lift.


those are like Big Chief pro stock heads numbers. you could make probably 800 hp power on a v-8 with those. He sell you a bridge with that?
BB Chrysler guys would kill for numbers like those.


wp

[rjudgey]

not being funny but not even the best 16 valve or even 20valve heads flow much over 200cfm i think theirs a formula for flow equals bhp every 3cfm is equal to 1bhp roughly a good head which has been flowed should do around 170-200cfm depending on valve size and lift lets say 31mm inlet with .450 thou lift, no theirs also a calcutaion that lift which is more than 1/4 the size of the valve gives very little extra flow, also 550 thou on A20 head is impossible, i had a cam with 500 thou and the springs compressed way too much and it couldn't even turn, had to do some custom work to get that to work properly 550 thou although you would be able to measure it on a flow bench the reality of actually having that much lift on a wroking head is next to impossible, it's doable but your talking custom springs, platforms and even pocketing the valve spring seat area in the head, that and a 30mm or even 33mm inlet valve with 550 thou lift is a waste of time!! Most you should even consider would be 11.5mm or .450 thou maybe .475 tops.

[Justin86]

well my numbers are correct unless my formula is fubar.

(stroke in inches X rpm)/6 = piston speed in feet per minute

[smufguy]

Oldblueaccord: Bridge? what you mean like the ones you see thats used on dohc motors and domestic motors? well we dont need them since our stock rocker support is good enough.

rjudgey: i know you do a lot of custom work and stuff and have a lot of experience, but i dont think you have experience with building race motors. What sean builds for custom projects, are pretty much full race motors and the numbers he gets are not from his so called theory. he is doing a motor for Elijah and if you want, pm him and ask Elijah to get you the details on the motor and the head. Competition heads start at $400 each and just to flow test a cyl (2v) is $60 minimum from a builder. So yeah, stuff is possible, but its easy for guys who build race motors for a living.

[mykwikcoupe]

hey rjudgey want to get one of those JDM b20a heads and do a nice port job and work your magic on it. Id be willing to makeit worth your while. Itll go on a Carbed JDM B20a, 10.5:1 pistons with a weber 38/38 synchronous. Justins header, msd 6a ignition, auto tranny proabably a 272 cams or so since Im looking mainly for low- mid rpms. Nothing over say 5k since its an auto tranny and all. If your interested let me know and I was planning on something in the 5-800 range for portwork and intake manifold porting if you want to increase valve size i could see going larger from there

[rjudgey]

geez whats with the Auto's!! What me to find you a manual!!
As with previous post, you send me the head, with new guides in 3 angle valve seats with 1.5mm seat backcut valves to match, unless you want custom valves and then you'd be looking at more, the exhaust valves can easily go to 30mm without needing seats, and the inlet valves could go to 34mm without seats but 35mm would be possible but new seats might be a safe idea, with valves that size your looking at a potential of around upwards to 250bhp with the right induction and camshafts.

But the shipping is the killer, you find a head, ship it over on a return shipping ticket, with new guides in the head allready, send over a bag full of sanding drums, carbide tungsten cutter and some grinding stones for Dremel drill i'll do it for free and you can see how it goes, i can gurantee it will be better but howmuch better than a DIY cleanup job i don't know so if you want to be a guinea pig i'll give you my time, but paying me $800 isn't going to cut it a head will set me back $200 then putting new guides, skimming, valve seat cutting and valve backcutting, chemical cleaning, and any other repair work plus the tools for porting and flowing i think i would struggle to break even and then theirs still the shipping cost on something that weighs quite a lot!!

I'm interested but you gotta do the hard work for my free time, also i work hard during the day and only have 2 weekends off fully a month and half that time o spend on the track!! So don't expect 40 plus hours labour to be done in a couple of weeks at best it would take me about 2 months from start to finish maybe a little less if i don't get hassled from work so much!!

But just to give you some ideas of the extent of work i've done, i have a B20A head which is scrap and i've basically dug and drilled as deep as i can go to find out where the metal is and how deep it is to get the best i can from these heads. If finding a B20A head is really that difficult for you i'll have another look and maybe have a word with Civvy but it will cost more although you would save on shipping. If your serious E-mail me and we'll see what i can do and what options you might want or not want!!

As far as seans race heads go i'm sure their great and he does get great numbers from them, but some of those figures just aren't possible and i've seen racing 2.0litre engines with 35mm inlet valves and 30mm exhaust valves 16 in total with some radical cams, and lots of other goodies not even come close to those flow numbers yet the engine still produces 260bhp with 180lb ft torque, and were talking Cosworth XE engine used by Vauxhall and GM group.

Flow bench numbers aren't allways where the powers at anyways, how the head mixes the fuel and air together and the amount of tumble or swirl is just as important as ultimate flow numbers and in some ways more important, with rescent work i've done, the A18/ET head has shown itself to be very good, i know Sean hates them becuase of the offset ports, but with the right cam profile these can be made into real monsters with a killer toruqe curve and torque is just as important as Bhp, after trying my ET1 engine i'm seriously tempted to bolt back up my ET head onto it as i find that the ET1 head is seriouly lacking in low end power and overall just doesn't seem as quick but the last head did have bigger valves so probably just got used to that extra grunt.

Also has anyone actually seen dyno results of Seans N/A engines i know he had great Turbo numbers but thats easy you just turn the boost up as far as you can before the whole lot explodes, i have dyno sheets from basic to full on builds but my latest incarnation is in the build stages and thats gonna be sick with larger valves, bigger ports, better inlet manifold with extra tumble, bigger carbs with 42mm bore, custom exhaust manifold and complete custom grind cam from pipercams in U.K. Gonna be looking at around summer to autumn on that one but should easily hit 230-250bhp hopefully but i think that will be about as far as you can go without needing ITB's with 45-50mm bore and a pukka ECU to go with. But at the moment my 20 year old suspension is in bad need of sorting out can't even brake in a straight line at the moment which is rather scary at 130mph!!

P.S has anyone used a A20A1 manula box on a high output engine? wondering what kinda speeds you guy's get from your cars? Teg box is driving me mad 140mph at 7K is deafening!!

[Oldblueaccord]

Oldblueaccord: Bridge? what you mean like the ones you see thats used on dohc motors and domestic motors? well we dont need them since our stock rocker support is good enough.

rjudgey: i know you do a lot of custom work and stuff and have a lot of experience, but i dont think you have experience with building race motors. What sean builds for custom projects, are pretty much full race motors and the numbers he gets are not from his so called theory. he is doing a motor for Elijah and if you want, pm him and ask Elijah to get you the details on the motor and the head. Competition heads start at $400 each and just to flow test a cyl (2v) is $60 minimum from a builder. So yeah, stuff is possible, but its easy for guys who build race motors for a living.

Meet me in Brooklyn tomorrow I got a beauty to show you. If not I got some beach front propery in Kansas Ill sell you cuz your my buddy.


wp

[Oldblueaccord]

geez whats with the Auto's!! What me to find you a manual!!
As with previous post, you send me the head, with new guides in 3 angle valve seats with 1.5mm seat backcut valves to match, unless you want custom valves and then you'd be looking at more, the exhaust valves can easily go to 30mm without needing seats, and the inlet valves could go to 34mm without seats but 35mm would be possible but new seats might be a safe idea, with valves that size your looking at a potential of around upwards to 250bhp with the right induction and camshafts.

But the shipping is the killer, you find a head, ship it over on a return shipping ticket, with new guides in the head allready, send over a bag full of sanding drums, carbide tungsten cutter and some grinding stones for Dremel drill i'll do it for free and you can see how it goes, i can gurantee it will be better but howmuch better than a DIY cleanup job i don't know so if you want to be a guinea pig i'll give you my time, but paying me $800 isn't going to cut it a head will set me back $200 then putting new guides, skimming, valve seat cutting and valve backcutting, chemical cleaning, and any other repair work plus the tools for porting and flowing i think i would struggle to break even and then theirs still the shipping cost on something that weighs quite a lot!!

I'm interested but you gotta do the hard work for my free time, also i work hard during the day and only have 2 weekends off fully a month and half that time o spend on the track!! So don't expect 40 plus hours labour to be done in a couple of weeks at best it would take me about 2 months from start to finish maybe a little less if i don't get hassled from work so much!!

But just to give you some ideas of the extent of work i've done, i have a B20A head which is scrap and i've basically dug and drilled as deep as i can go to find out where the metal is and how deep it is to get the best i can from these heads. If finding a B20A head is really that difficult for you i'll have another look and maybe have a word with Civvy but it will cost more although you would save on shipping. If your serious E-mail me and we'll see what i can do and what options you might want or not want!!

As far as seans race heads go i'm sure their great and he does get great numbers from them, but some of those figures just aren't possible and i've seen racing 2.0litre engines with 35mm inlet valves and 30mm exhaust valves 16 in total with some radical cams, and lots of other goodies not even come close to those flow numbers yet the engine still produces 260bhp with 180lb ft torque, and were talking Cosworth XE engine used by Vauxhall and GM group.

Flow bench numbers aren't allways where the powers at anyways, how the head mixes the fuel and air together and the amount of tumble or swirl is just as important as ultimate flow numbers and in some ways more important, with rescent work i've done, the A18/ET head has shown itself to be very good, i know Sean hates them becuase of the offset ports, but with the right cam profile these can be made into real monsters with a killer toruqe curve and torque is just as important as Bhp, after trying my ET1 engine i'm seriously tempted to bolt back up my ET head onto it as i find that the ET1 head is seriouly lacking in low end power and overall just doesn't seem as quick but the last head did have bigger valves so probably just got used to that extra grunt.

Also has anyone actually seen dyno results of Seans N/A engines i know he had great Turbo numbers but thats easy you just turn the boost up as far as you can before the whole lot explodes, i have dyno sheets from basic to full on builds but my latest incarnation is in the build stages and thats gonna be sick with larger valves, bigger ports, better inlet manifold with extra tumble, bigger carbs with 42mm bore, custom exhaust manifold and complete custom grind cam from pipercams in U.K. Gonna be looking at around summer to autumn on that one but should easily hit 230-250bhp hopefully but i think that will be about as far as you can go without needing ITB's with 45-50mm bore and a pukka ECU to go with. But at the moment my 20 year old suspension is in bad need of sorting out can't even brake in a straight line at the moment which is rather scary at 130mph!!

P.S has anyone used a A20A1 manula box on a high output engine? wondering what kinda speeds you guy's get from your cars? Teg box is driving me mad 140mph at 7K is deafening!!

Get an old head and chopsaw it up. That way you can see where the metal is at.

As far .500 lift cams true they take head work but sometimes its worth it. Domestic engines guys do it all the time. A good .650/.650 roller cam is nothing now days. I have a set of heads now that need to go in to make the spring pockets deeper so I can run around a .525 lift cam on my 318 Chrysler and run the LS1 beehive type springs.

Big chief chevy heads are totally aftermarket heads not even close to production style so if our heads are flowing close to that then we got a super great head.

Most flow numbers are just quoted at .500 lift 28 inches and the bore size as a standard. Kinda like using the gross lift number on a camshaft.

wp

[Oldblueaccord]

well my numbers are correct unless my formula is fubar.

(stroke in inches X rpm)/6 = piston speed in feet per minute

I wasnt questioning your numbers just how you got them.

I was looking into a 408 stroker motor( 360 cu with a 4 inch stroke crank) for my Chrysler and I remember reading the piston speeds were up to 4000 so I wanted to figure it out. I remeber when the type r came out it advertised as the fastest piston speed in the world.

Our cars have pretty light piston rings and short lands so I think they can go pretty high.

Not really the best for the motor but its doable I think.

wp

['A20A3']

If all goes correctly, byt the end of summer I'll have a built race motor and I'll be hoping to 200+whp. If not, then my friend MR. Turbo will be making the rest...

I'm working on the head right now, the block will hopefully be finished by September.

Built Head

race cam(not sure what gring yet)
titanium valve springs and retainers
adjustable cam gear
3 angle valve job
port & polish, milled


Built Block

10.1:1 compression ratio via Diamond forged pistons
copper head gasket
Eagle forged rods
high performance rod bearings(any suggestions as to a brand??)
high volume oil pump
balanced crank

Not to mention a complete fuel management upgrade, from a fuel pump to a AEM EMS will be installed as well...

[rjudgey]

ACL the best full stop.
As for Fuel system, get some ITB's taper bore from Jenvey from 40-50mm bore size with Electromotive ignition and ECU.
That should do it!!
Oh BTW if you want 200whp your going to need 33mm inlet valves you won't hit that with 30mm and a single plenum style inlet manifold!!

[ICEMAN707]

I am rather curious about this, as I know people are regularly approaching and exceeding 200whp with their modded B series VTECs. I haven't done anything to my longblock ......represent, people

I know of a very reputable company in Alabama that can make 5 stages of our engines as well as hundreds of others.

Stage One (146 hp)
Stage SRE (158 hp)
Stage Two (176 hp)
Stage Three (202 hp)
Stage Four (242 hp)

Forged Balanced Crank
Pistons (custom aluminum)
Copper headgasket
Titanium rods
Chrome-moly rods
Main cap girdle

Of course, the higher the stage, the more aggressive and less streetable and daily driver friendly it is. It will be LOUD and lopy! Of course you can have them build it for turbo with lower compression pistons and have more HP potential (maybe say 500hp?). That's what I would do if I were to spend that kinda money to have an engine built. You would also need one of those big ass dash mounted tachs cus I'm pretty sure the upper stage N/A engines rev pretty high past the stock tach readout. And I'm sure you would need alot of other miscellaneous stuff as well like LSD, 550cc injectors, upgraded fuel pump, MSD ignition, better OBD1 stand-alone or chipped ECU PJ0 (stock), etc.

I found this info on 2nd gen Prelude forums awhile ago and I don't remember exactly the name of the company is nor the spec/parts list for these engines, so don't ask me. Cus from what I hear, it's pretty pricy just like DART B-series engines. So I never really looked into it. Best to do an engine swap for cheaper unless you're really hard-core into the A20A3 then go for it. Would you really pay $4000-$10000 on an engine for a 3gee? :dunno:

[system-f]

the no replacement for displacement argument pretty much ends when you build a race motor... at least while we still measure power by HP... i mean, how many SBC or 5-0 motors do you see revving to 10,000 RPM?

Far from true.. a larger displacment motor turning the same rpm as it's smaller counter part (usually using more cylinders for more balanced motor) will provide more power in most cases and is easier for engineers to work with. Most racing motors ,ex. F1, are small due to displacment regulation.

Depends on what kind of racing, top fuel has lots of larger displacment motors running insane rotations per min. Hell, my good friends 69 Chevelle with a big block turns 6k at the end of the track and it's not special, just built/balanced properly.


natural aspiration has it's limitations. Some people see it as the easy way out ie. less money, others see it as a challenge. no matter what a properly setup forced induction car at an equal weight with an equal driver will always beat the same car naturaly aspirated. Torque number's alone make this possible..especialy the torque at higher rpm available with smaller displacment high boost engines which depending on boost actually equals a larger displacment motor.

[MoonScryer]

Hmmm, well, I've seen the flow numbers from Seans' head, and seen pictures of his port job that flowed 235(8??)cfm from an A20 head - the head didn't look stock anymore in any area air flowed through. The port area had this weird smooth shiny look to it, like it was formed from glass. Most of the work took about two years and nearly a dozen heads to get right.

Sean said eventually he will be offering the heads for sale again, this time ground on CNC machines and not by hand. That is what killed accordcentral; he was making all the harnesses and doing the programming by hand, and farming the fuel injector box out to someone who sucked at timetables and making stuff. It nearly killed him - he just got over another bout of pneumonia, the dumb ass does too much at once.

Anyway, I don't know when the above will happens exactly, but it is still happening. Those that are concerned or want turbo manifolds, well, you can wait, or attempt to make it yourself. With the OBD-1 conversions going on, the hardest part has been solved. Making a manifold is easy if you look around honda-tech or homemadeturbo.

Anyway, I don't know why I even replied to this thread, but I thought I would contribute something in his defense.

[rjudgey]

Now were talking more realistic no that sounds about right with numbers like that easy 250bhp and as for the port finish thats a whole other debate and very hot debate as to what type of finish to use. Personally i have found gains in both a very shiny finish and a very rough finish, i think it all depends on how long your inlet manifold is and where the fuel does it's mixing, i.e ITB's the injectors are much further up so fuel and air is mixed further up inlet manifold should have a rougher finish working it's way down to the head ports getting smoother, stock with plenum with direct port injection the inlet manifold should be polished as much as possible as the fuel and air are not mixed here just air goes through untill it hits the heads inlet ports with the injector sitting their, then the heads inlet ports should have a rougher finish to help mix the air and fuel as much as possible before going into the cylinder. Same priniciple with the carbs as well, longer inlet manifold more polished inlet port shorter inloet manifold rougher finish. If any of you have different ideas on this speak up!! Also as i said before ultimate flow figures is not what allways gives you the best BHP and torque figures, i've seen heads where two people have worked them and one had more CFM then the other and the one with less CFM had better dyno readings because it just mixed and up the fuel and air better!!
Whats your thoughts!!

[Oldblueaccord]

Yes head porting is a black art still today. I guess that’s why I like it so much. Plus on any motor the power is in the heads and the cam. My opinions on flow numbers are based on what I have been reading up on in the last say 10 years or so and sure it changes, evolves all the time. The numbers I quote are just a reference and that’s all.


My way of thinking is Mr. Honda does a lot of good stuff very very well and I’m sure his heads are top notch so….. when I hear flow numbers that are double what they are stock I tend to be a skeptic. It’s not an affront on any said person. Most head porters are happy with anywhere from 20 to 50 cfm gain on the intake side on an aftermarket type head.

I am reading that rule of thumb is 2 hp per 1 cfm as reported at 28 inchs of mercury.

http://www.raceflowdevelopment.com/ this guy I have been following on www.moparts.com quite a bit. Goto his tech section he explains about flow benches etc. The superflow benches are considered industry standard kinda like dynojet is to chasis dynos.

http://board.moparts.org/ubbthreads/showflat.php?Cat=&Number=1611860&page=2&view=collapsed&sb=5&o=7&fpart=1

These are some number on small block Chrysler heads I have been thinking about in the future and a discussion on valve angles and flow.

Totally off topic

Here’s a little write up on a sweet deal on a motor combo im looking at.

http://board.moparts.org/ubbthreads/showflat.php?Cat=&Number=1612080&page=2&view=collapsed&sb=5&o=7&fpart=1&vc=1

CNC ported heads : ) $2500 heh.

Wp

[rjudgey]

thanks for the links,
Yes it is very much a black art but i think also it's very much a good understanding of physics and the law of physics which to some is a black art!!
CNC is the way forward but for many is still way out of their price range and also it's only really for people and race teams who want to squeeze that last 5% outta thei engines, it's just a more accurate way of flow balancing, instead of using a flowbench and measuring each port and matching the figures produced, you have a master port which you do and then that port is then identically copied to the others, in theory they should all then be identical in flow and combustion burning given you a nice balanced firing and extracting the most out your engine as possible, whether that actually in practice happens is another debate!! One would like to think that two identical ports would fire and flow identically!! I know the cost of CNC millind heads is coming down, but i get really good results from my DIY heads which cost me just my time and my makeshift ghetto flow bench works perfectly for port flow balancing it might not give me what the real flow figures are but it gives me an ideaas of if i;m going right or wrong and if all the ports are reaasonably the same, and for me thats fine, if i need a head to be the bollocks then i just pop down to my machinist's place and use his superflow but so far each time i try a new head i allways get a gain but when i starting hunting for that magical 250bhp mark i think i might have to pay him a visit!!
BTW my very first head was done by one of the best in the world with custom everything, 5 angle seats, re-profiled valves, custom aerodynamically shaped guides, race flow, this was on a ET head and it was a Stonker easy put down 190bhp with a stock cast manifold, but unfortunately that set me back £1000 and everything i've done since then has been as good if not better (mainly due to increase in valve size though!!) So i don't see why i should pay anymore for work that doesn't make me go any faster than what i can do myself even if it is Ghetto works for me and i got the dyno's and 1/4mile times to back me up.
I wonder what times Jason Budds A20 does without the NOS?
But i do need to get my arse into gear and get the header dumped for a tubular i reckon im' costing myself 10-15bhp having that thing on not to mention the extra weight of carrying it around!!

[Oldblueaccord]

http://www.theoldone.com/articles/badtothebone/

head flow a little closer to home.

Quote:

With the plenum side in place and a 64mm throttle body, this manifold will out-flow the best individual throttle body combination we've ever tested. At .500" valve lift the head/manifold combination will flow 349cfm @ 28"H20 with equally impressive mid-lift numbers.
We have to use retainers that set-up .060" higher than stock. This can lead to retainer-to-rocker arm contact. It's essential that the clearance between the retainer and the rocker arm be at least .040". We check this clearance on every head we rework and assemble, as failure to do so can result in catastrophic engine damage

End quote:

Thats with an intake on but thats still pretty sweet numbers.


wp

[Accordtheory]

yeah, I was waiting for someone to bring that endyn shit up..

[Oldblueaccord]

yeah, I was waiting for someone to bring that endyn shit up..


I dont 100% buy there bullshit either but its a Honda head with flow numbers. No one I know post/flows there heads with the intake on so like EDIT hes mixing up numbers to get you confused and or not able to compare them to other ported heads.

They take credit for like all of Bob Glidens prostock wins, swirl port heads and a few other things . :bowrofl:

I know for a fact myself the eldebrock heads for Harleys they talk about sucked ass and didnt make any power at all.


wp

[rjudgey]

Well didn't want to say but someone who thinks that Plenum style inlet manifold will out perform an ITB setup on a real working engine needs their brains testing? If they were so good then why don't the race teams use them? Every serious N/A performance engine made has ITB's especially with the newer designs and the bigger sizes that you can get them in upto 55mm!!

[Accordtheory]

I see no way individual throttle bodies can create more power, unless your original manifold is not optimized. The way I look at it, what difference does it make where you place a flow restriction (part throttle) when the flow restriction is removed under full throttle? Imagine a system with no throttle(s) at all. What difference does it make where the throttles Were? ..and with ITBs, you still have a plenum anyway, unless you have a filter on each runner. BMW's valvetronic system has no throttles, it uses computer controlled servo activated variable fulcrum point rocker arm system (still uses a cam) to control the valves. In other words the valves act as the throttles. (VTEC now looks like a pathetic joke).. Individual throttle bodies do allow for a virtually instantaneous throttle response, due to no time required to change the plenum pressure, but that's the only advantage I will give them.
People say the same kind of shit about exhaust sytems too. "Does it have true duals?" As if that's something good when an H pipe makes more power, an X pipe more than that, and yet a properly sized single pipe is weaker than any of those? What gives?

[A20A1]

I think Jason Got 13's without nitrous.

I'm interested in how my manifold will perform Compared to a manifold that keeps the spacing even. On mine there will be a wider pause between each side of the carb as 2 & 1 fire and 3 & 4 fire.

[rjudgey]

well most people who run ITB's or Webers don't have a joined air box and run seperate filters or no filters at all on each runner, the benefit is not from low down, low down and mid power is allways going to be dominated by Plenum manifolds as that's what their good at doing producing low and mid power, ITB's come into their own because at high RPM's 9-15K the air speed velocity is so high that a plenum inblet manifold would severly choke up, that and it's having to get air from a 90 degree bend to the TB where as ITB is a straight shot in their plus with aid of direct air induction is going to get a certain amount of extra air from the forward motion of the car.
All i'm saying is if plenums are so good why aren't race teams using them? Don't see a Ferrari F1 car with a plenum inlet manifold or a BAR Honda? Even Touring cars have ITB's in Germany and U.K. the U.K ones aren't that highly modified like the German ones but they still use ITB's on their engines, if they were better then why is their such a huge performance market in ITB's and not Plenum manifold's? Their would be an awefull lot of company's wasting their money on designing and making better ITB's if all along a plenum stlye inlet manifold is better?
Is this not a valid argument?
Got mothing wrong with plenum style manifolds they have their plus points just like ITB's have their minus's but for outright BHP ITB's are the way to go, flow figures on a head with a plenum inlet manifold are not accurate as it's not a running engine so none of the other cylinders are sharing that same 64mm TB but if you run it on a flow bench it will come up with good figures because at the end of the day it's got a whopping great big 64mm TB to breathe through all by itself.

[Accordtheory]

If you make your plenum volume very large, then you don't have the sharp 90 deg bend of airflow into the runner. Look at any high performance turbo intake manifold, from the SR20 to the TT Supra, they all have huge plenums. Imagine a plenum so large that it is almost equivalent to the atmosphere, in other words, so large that the velocity Across the runners is negligible. Then it becomes identical to ITBs with their throttles fully open. That is what these large plenum manifolds are trying to achieve. In that situation, I don't see any difference in efficiency between that and ITBs. Not to mention, it all becomes irrelevant when you go forced induction, like me, because then you need a plenum..what difference does it make where the throttles are, as long as you keep that velocity across the runners down?

[rjudgey]

well yes for a turbo you do but as air if being forced/pushed in you get minimal loss in power from running a plenum not that you got any other choice, but as most turbo cars are banned from racing and as a lot of people here don't like turbos which are really only good for drag racing or street light racing and for people who like to play the numbers game N/A engines are more difficult to setup but everyone who builds a serious N/A engine all use ITB style induction, look at bike engines do you see plenum chamber on a bike? no? Must be a reason, yes plenums can be made to flow very well don't disagree but no one serious about N/A power uses them? Must be a reason? Also Plenums just don't make the same noise maybe thats what it is!!! You can't beat the sound of 4 cylinders all screaming along together in harmony!!

Well Anyways, Jason Budd uses ITB's and he's the man!!
Apparantly his last engine with the webers when his car was red and yellow was putting down 183whp which isn't that much more than mine and i'm still using stock upper manifold and cast low compression A20A1 pistons, and A18 head with it's twisty effect head!!
So i reckon with my new custom header and new 2.5" mandrel bent system, seriously modded A20 head with huge valves and 4 42mm bike carbs should be good for around 250bhp at the flywheel maybe more if i go ITB's with 45-50mm bore size but were talking huge cost here so i'll try with carbs first i'll use my webers which might goto 250bhp then try the bike carbs.
Will also use either Honda A20A3/4 pistons then deck the block and head a bit to get CR ratio upto around 10:1 but i have a source that can get me some JE 83mm forged pistons hopefully that will be around 11:1 maybe a tad more depends on head gasket!!
Then car goes on a more extreme diet lighter seats, gutted doors, remove sound deadening, lexan side windows, plus anything else that doesn't do a great deal!! Try and save 100-200lb's in weight. Then play with the suspension lower the front more and jack up the rear with some adjustable coil overs then with wider and stickier Toyo R888 should do the job.

[Vanilla Sky]

i do have a couple questions here...

what's the highest compression ratio these engines will hold up to reliably on a daily basis? i'm figuring as long as it's not gonna pre-detonate, it will hold...

also, with increasing the intake valves, would increasing the exhaust valve be of any help? i'm sure there's an application out there it can be pulled from, or worst case scenario, it can be made...

and mr race engine (can't remember your name for anything, so from here on out, "rjudjey" is mr race engine), do you think anything is to be gained on a motor like yours using lightweight moving parts? i mean everything that can be made lightweight and stay reliable... pistons, rods, balanced crank, lighter valves... once you get to that point, is it even worth it?

also, what jettings would you consider a good baseline for a STOCK a20 with 40DCOEs?

[rjudgey]

Right then Mr Vanilla sky,
Lighter parts are better for engine revs and quicker response but the cost is the major factor, looking at titanium wrist pins as the stock ones are very heavy that will help a little, titanium rods are just so expensive i'll leave them till i win the lottery!! I believe Eagle rods might be slightly lighter but i have my stock ones stress relieved and that lightens them a bit especially when finished getting them balanced as well, not a huge amount though to make a huge difference.
Titanium valves aren't really needed either as long as you don't plan on revving past 9K the valve train can handle that the rods and pistons would need uprating though pistons distort after 10-15K at revs higher than 7K and not sure how long the rods would last either not had one break yet upto 8K but you never know better to be safe than sorry as they say!!
Bigger inlet valves help hugely and on N/A engine bigger exhaust valve doens't make that much difference, you could go out to 37mm that would help a little, but that would have to be custom, the inlet valves i used were exhaust valves i had machined down to size but custom would be better from a flow and weight point of view the stock exhaust valves are very heavy and have a thick stem, they are also made from a really tough arse forged stainless steel metal my machinist couldn't believe how hard they were he loved them apart from when he tried to machine them down took him best part of all day to do and quite a few bits for his valve cutter as well!! Cost nearly as much to have machined down to size as new ones to be made!!
Valve springs are a combination of Accord exhaust springs and Prelude inner springs, but i've used earlier ET1 valve springs on stock size valves they work quite well double springs as standard for some reason? But looking at sizes of springs from CAt CAMs to see what i can use from their need to increase lift to 12mm if possible but can only do that with some new aftermarket springs as none of the Honda springs allow lift of more than 11mm.

Jetting size for 40's not to sure as i have 45's but i would guess for a well built A20 go with 50 F6 idle jet 150 main jet F16 emulsion and 180-190 air corrector, pump jets 45-50 and try and get the chokes bored out at a machinist to the biggest they can go, i think 38mm can be machinied out i have 42mm chokes on my 45's which are normally 40mm. Anything smaller that that will impede airflow with a performance cam fitted but 36mm will get you going but don't expect to rev much past 6-6.5K.

As for high compression ratios and Head gaskets lasting not to sure on that, my heads are off quite a bit so i never really get to see how long they last, my CR ratio is quite low as i machine quite a lot of metal out of the combustion chambers to flow them better, that and i use sealed power cast pistons which are heavily dished but the head and deck are both skimmed a little but a guess i reckon i'm only running 9:1 CR ratio so CR isn't everything if you use a quality Head gasket like Felpro should last at least 25-50K but also depends on the revs your pulling as the static CR cause more problems with gaskets going than anything else, Ajusa also make very good Head gasket kits i use those mainly and use Felpro for the earlier ET engines as they have a biiger seal ring for over bored blocks also the Felpro are like £50 a shot where as Ajusa i can buy for £10 each but i do change those every 10-15K i've had them blow across the cylinders but i think thats mainly caused by me running no thermostat so the head and block expanding more than usual and the engine running quite cold most of the time allows gas to creep across and gradually it just tears it apart, if i ran a thermostat i'm sure it would last much longer, but i don't like thermostats and a colder engine produces more power when a HG takes 1 hour to change doens't really bother me too much!! Felpro are suppose to handle upto 11:1 reliably for while but ultimately a Copper gasket with chamber seal shims or ring and grooved block is the way to go for High CR and reliability can get them made for around £100
But their only re-useable a few times so for the moment i'm gonna stick with my Ajusa ones for £10 each!!
The ET1 engine i have with custom inlet weber manifold is only a stop gap engine and a spare for when the main engine is out, still testing with A18 head and will ultimately be looking at A20 head for all out power but also developing B20A engine at the same time using Civvy's car as a test bed as well as my other B20A Lude which i'm still tempted to stck bike carbs on i really hate EFI it's pain when it doesn't work properly!!

[A20A1]

-Turbo Apps.- Wouldn't velocity across the runners drop anyways cause the manifold is pressurised... the place with the most velocity would be near the valves, velocity across the runners would only increase if hypotheicly you had more demand and the boost pressure was drawn off from the plenum. As long as the pressure stays the same or goes up I'm thinking the velocity would be way down.... IMO
Let me know if I need a kick in the arse for sayin somethin stupid. :)

But I see your point where the large plenum comes in handy.