AB-B20Vtec

[hondalude86]

So with the depressing facts facing me about the reliability of the A series motors at extreme grip levels I've made the beginning moves for a new motor...

Sure, sure, call me a sell out, I'm going the back to the B series route, but with a twist... High compression (12.5:1) B20 with a B16a (from the white lude) head with basic valve train (supertec kit), Cams (skunk2 pro2 cams), and simple exhaust (skunk2 alpha header)... But here is the twist... Dual DCO 50 SP carbs... Thats right, a carbed, b20vtec in an 86 Honda Prelude... Shit just got real! There is definitly more planned this winter besides an upgrade in reliable power, but stay tuned... It's going to be a wild 4-6 months...

Here is where we are at right now...


Starting from here...


Bad A20, Bad...


DCOE 45's will be up for sale soon, but with my a18/et2 manifold...


Current rear suspension setup, Koni Red (ext adjustable) with 600lbs Eibach race springs, Addco rear sway bar, Si rear calipers with Hawk HP+ pads and Goodrich Stainless Brake Lines...


Current Front suspension setup, Koni Yellows (EF civic) with 500lbs Eibach race springs, stock DX sway bar, ITR calipers with Hawk hp+ pads, ARP extended studs, redrilled 4th gen Prelude rotors, all Chedda J Bushings installed...

Basic overview of plans...

Moar pwr with LSD. Moar grip and better handling (15x10s and New Coilovers), and moar Aero... I hoping for a nationally competitive SMF car... Only time will tell, there is so much to buy just get to get the car running again!

[Dr_Snooz]

Well I can't say I've ever heard of anyone complaining about A-series reliability in any context, but good luck with the build.

[hondalude86]

I'm not sure if you're joking or not... But I'm willing to bet, there isn't a large A series following trying to race on 275 Hoosier A6's... hahahaha

either way, Here is tonights progress... If you can call it that...


A series out...


Subframe out, and all the other shiiiitt.. only a few parts from here are going back in...


Wide open, spaces... yea, this thing is going to get a big cleanup... I'm going to try and clean all the damn wiring up and remove all the non essential bullshit and attempt to integrate the new wiring (for the megajolt) into the factory wiring thats in the engine bay (starter and alternator???). I'll have to modify the harness to make the other silly b-series stuff work, but all in all, should be straight forward. I just want to clean this thing up as much as possible and try to reduce any unnecessary weight. I know I'm going to be picking up some weight with the b-series, but i've got a few things I can do to shrink down the weight! Enjoy! Btw, my goal weight is 2000lbs and as it sat for the Match Tour, I weighed in at 2021lbs.

[Hauntd ca3]

dunno how the vtec will work with the dco carbs, i think it will be a bitch to jet right to suit both lobes.
some vtec eliminator cams would be the go, or just use the b20b head and port the crap out of it with big cams.

[86turbolude]

what happened to the a20?

[2oodoor]

dunno how the vtec will work with the dco carbs, i think it will be a bitch to jet right to suit both lobes.
some vtec eliminator cams would be the go, or just use the b20b head and port the crap out of it with big cams.

X2. This will be interesting and exciting to follow

[hondalude86]

Awe, you guys worry to much, the whole idea behind proper VTEC cross covers with proper cams is maximizing your torque and horsepower. With the way the air correctors work with the mains, there will be some finite adjustment in those two ranges. The interesting part is running it all off the mega jolt. Remember I've got map based ignition tuning...

[hondalude86]

Spun rod bearings in two motors this season, each lasting about 6 races...

[cygnus x-1]

VERY interesting! Can't wait to see how this one works out.

So what's the deal with the spun rod bearings? The B18A1 uses the same bearings and those things rev much higher? Does the B20 use larger bearings? Either way it's hard to argue with the better parts availability.

Been awhile since I had to mess with air correctors, but seems you might be able to have VTEC kick in about the same time as the air correctors. And I do forsee fun times with 50mm carbs and MAP based ignition. Have a feeling you might end up switching to TPS eventually. ;-P

EDIT: Now that I think about it, how ARE you going to switch on VTEC? Does the Megajolt have any aux outputs?

C|

[hondalude86]

the mega jolt has like 4 aux outputs... I believe they are only 5v, but either way, shouldn't be a biggie... I'm thinking about a 5500rpm cross over, but I've gotta play with some numbers...
Yea, spun rod bearings... maybe its the size of the oil galleys in the crank to rod journals, maybe its just an issue with the return from the head back to the block, maybe its alot of things... could even be a volume issue with the oil pumps, but the one thing I know for sure is my b16a never had an issue, ever... And for a while I was driving that thing everywhere... and I've ran the exact same setup on the White Prelude (275/225 hoosiers and identical suspension). I never opened that motor up outside of the initial timing belt parts jazz 9 years ago... the b-series motors can just take abuse that the A simply cannot.
The reason I'm going to run the 50s is because I want a better venturi effect with the choke size i'm going to run. I planning on 41mm chokes (they do have 41mm choke for the 45s). I'm hoping the more pronounced step down will help with my mid range (the most important part). If the Carb route doesn't work decent, I'll just go FI ITB. I'm close to my wits end with carbs, but I want to try it one more time with brand new webers in a more updated version... I'm going to go strictly by the book of jet calculations... and hope for the best. There are tons of ignition maps out there for similiar setups to get me going... hopefully all will go well!

[hondalude86]

in for pics!!! this may be the last update for a while... Still lots of other bullshit to attend (like my fucked up regulator on my 87!!)


Mmmmm...


DoMe!!!




B20B...

I'm getting excited, It's like being one huge step closer!!!

[Hazwan]

ooohhh this gonna be great! How much power you're shooting for with the carbs?

[Hauntd ca3]

spun rod bearings is prob more to do with the stroke length, than oil supply i think.
bearing is along way from crank center line, so is traveling pretty quickly when revving hard.
oil film breaks down, bearing welds to crank, spun bearing.
and imho, vtec on a race car is boardering on pointless.
the btcc accords of the 90's done away with it just because they never revved below 5k and is more reciprocating mass that dosnt need to be there.
just stick big arse cams in it and be done

[hondalude86]

Haunted, Its not that I don't agree with you about the "big arse cams" but this is an appropriated build. I've got a purpose, and just simply making power isn't going to make me faster. I'd love to get the TODA vtec Killer cams, but simply throwing in big cams isn't all you need, nest thing you need are larger valves, then you need badass head porting, then you need CNC'd combustion chambers... it all adds up. If I could make 180-200whp @ this altitude, I'd be sooo pumped... They way I look at it, i could maybe hit 240whp and have the same suspension setup an no aero... The car is a handful with 110whp... another 60+hp without any other provisions won't make me faster, and as embarrassing as it might be to say, I've got about 10k dollars worth of upgrades planned hopefully before next season. When I did just my original plan for just the motor it was 10k... I got lucky with picking up a gently used built b20b... Now hopefully i'm not just all talk right? hahahaha, So if you've got any more cost saving methods that would overall benefit my cause, I'd love to hear them... Just to give everyone else and idea of what the plan is, its looking like this...

Carbed B20Vtec with with basic Skunk2 pro2 cams and alpha header (read cheap) with a moroso uber baffled pan!!! hahaha
APR gt300 Wing with gurney flap and 3 in add on risers (for a total of 16" tall pedestals)
AMR engineering Coilovers (hopefully) with some 15x10, 15x9 949 6ULs

That's the basics in the order of importance... Worst comes to worse I can still run my current suspension and wheel setup, or if the budget semi permits koni race shocks...

[Hauntd ca3]

i know you want to use the 50 dco carbs, but me being an old school four banger guy i know what they cost, and must say that for the price of buying 2 dco carbs, chokes and jetting them, you'd prob find it cheaper to start with the itbs from the get go.
cost me bout 400 to make my itb set up. ok the ecu bit wasnt cheap, but all up the price would prob surprise you.
think was 1200 for itbs and ecu on the motor
prob going to need bigger injectors, but i have the choice of 2jz injectors which keeps price down.
and the prob with carbs, if you go to a track thats closer to sea level, the jetting will be all over the show, where the efi will compensate for baro and altitude

[hondalude86]

the altitude doesn't cause as much of a problem as you think it does...

Acura RSX Type S " K20a2 Vtec Killer - Dual Weber 50-50 " a - YouTube

its about principal, Webers are cheaper than the TWM itbs... Hell, Webers are cheaper than most standalones... Again... Cost effective performance... $1500 is all I need for my weber setup... no biggie... I still have both an a20 and an a18 weber manifold AND some used DCOE45s I can sell...

[carotman]

This is going to be an interesting build!

Can't wait to see more.

It's weird that you mention bearing problems on a A20A. Jason Budd, a local drag racer, used a prelude just like you. His only problem was the A20 transmissions not lasting but the A20A was bulletproof. (Turbo, huge slicks)

He moved on to a Civic and a B series transmission mated to... his original A20A.



http://www.preludepower.com/forums/s...d.php?t=319633

[Dr_Snooz]

^^^ Mon Dieu!

[hondalude86]

Cool story bro!

Anyway... Didn't do much on the car tonight (got my window regulator fixed on the 87 however!!)


perfect running b16a that I'm going to pull apart and use the head (and other parts) on my b20... random side note, the b20b doesn't have a ported block in the rear for the PCV system... weird huh...


random motors everywhere... Good b18c, Bad A20...


some random d16z6 that is living in my damn garage... hahahahaha


A18A1... See I still have A-series love!!!


Won't need this bastard...


mount removed... will have to fab up my own mounts since the carb'd mount bolts straight down, and I need it to go side to side... Some 3/16 steel will work...

[MessyHonda]

Sounds like you also gave up on the A20. Going the B series is the way to go when it comes to parts. with that much compression and displacement with the right tune you can make 220whp+ it will have good torque because the b20 uses the 89mm stroke crank.

[Hazwan]

Put that D in lolol

[hondalude86]

Yeah Jessie, it's been a sad year for the a series at my house. The whole reason I built the et2 was to prove that you could build a reliable, high power a series cheaper than a b swap. I don't even want to think what I actually spent on my a, but I'd guess it's in the 3-4k mark... and as far as road course reliability... hmmm not so much, as far as power either... am I looking at spending more than 3k on my b swap in a carbureted chassis? Yes... am I going to make more power? Yes. I the motor going to be more reliable (last more than 6 races on Hoosiers...) maybe... the biggest reason this is cheaper for me than most has lots to do with having tons of b series parts already!!!

Hazwan, I saw your post joking about d series swap... I'd say go for it.

[cygnus x-1]

the mega jolt has like 4 aux outputs... I believe they are only 5v, but either way, shouldn't be a biggie... I'm thinking about a 5500rpm cross over, but I've gotta play with some numbers...

As long as it has some sort of output it can be converted to whatever.

Yea, spun rod bearings... maybe its the size of the oil galleys in the crank to rod journals, maybe its just an issue with the return from the head back to the block, maybe its alot of things... could even be a volume issue with the oil pumps, but the one thing I know for sure is my b16a never had an issue, ever... And for a while I was driving that thing everywhere... and I've ran the exact same setup on the White Prelude (275/225 hoosiers and identical suspension). I never opened that motor up outside of the initial timing belt parts jazz 9 years ago... the b-series motors can just take abuse that the A simply cannot.

Oil starvation... could be; especially for road racing where you have oil sloshing back and forth in the pan. I seem to recall someone else here on 3geez having problems with oil starvation too. In that case it was oil not draining back to the pan fast enough. I don't know enough about the B engines to know how different the oiling systems are from the A series, but it's probably worth doing some research to see how they compare.

The reason I'm going to run the 50s is because I want a better venturi effect with the choke size i'm going to run. I planning on 41mm chokes (they do have 41mm choke for the 45s). I'm hoping the more pronounced step down will help with my mid range (the most important part). If the Carb route doesn't work decent, I'll just go FI ITB. I'm close to my wits end with carbs, but I want to try it one more time with brand new webers in a more updated version... I'm going to go strictly by the book of jet calculations... and hope for the best. There are tons of ignition maps out there for similiar setups to get me going... hopefully all will go well!

Interesting theory on the venturi sizes. I wouldn't expect much difference in power output with a given venturi size; mostly just a difference in throttle response. The larger throttle plate should in theory give a faster response on the low end. Mid range I really don't know. High end, the 50s might have the edge. Honestly I would tend to go with the smaller carbs but since you already have those, might as well try the larger ones.

The ignition shouldn't be a big deal. The map is just a matter of tuning. The crappy MAP might give you fits but you can always switch to TPS, or even just RPM based timing. RPM only wouldn't be optimal but maybe good enough.

Where's Rich? I want to hear what he has to say!

C|

[cygnus x-1]

spun rod bearings is prob more to do with the stroke length, than oil supply i think.
bearing is along way from crank center line, so is traveling pretty quickly when revving hard.
oil film breaks down, bearing welds to crank, spun bearing.

That's a logical conclusion. However, look at the B18 type R. The rod ratio (1.57) is only marginally better than the A20 (1.51) and the redline is well over 8000RPM.

and imho, vtec on a race car is boardering on pointless.

On an open track certainly. For autox though, not so sure. They spend more time playing the throttle.


C|

[Hauntd ca3]

i dont read to much into r/s ratio myself.
honda get things pretty much right from the get go.
i'd be thinking that a spun bearing in a honda is going to be an oiling or an oil problem, or a flaw with the motor itself.

webers must be cheap in the states.
brand new 45dcoe are like $700 each here, $500 second hand
which is why people like me use 45mm toyota itbs which are $200 with injectors and manifold.
my itbs cost me less to build than 1 second hand dcoe