High Rev A20?

[rjudgey]

Were talking about building engines that put peak power at 7-8k rpm not will rev there whilst flogging the shit out of a dead horse to get there.

I've had engines pulling there power to 8k and i'm sure that with my new head mods and bigger valves and the new cam profiles i have in mind combined with some uprated lightweight rods should be able to see rpms fo around8.5-9k rpm hopefully but we'll see i have so much on my plate at the minute including 2 B20A builds, a B20A head from a member here, a Starlet 5EF3 engine conversion and full modifications, suspension and brake rebuild for my Mint Red 2G prelude, Rover K series engine to be modded and built, and still tinkering with the idea of custom intercooler and exhuast system with hybrid turbo for my BMW 1 series Diesel to try and get it to 250bhp 350lbft toqrue (At around 215bhp at the mo and 310lbft))

So busy busy busy and have to do a full time job on top of all this sometimes i just wish i was retired and had all day to do this shit or what would be better winning the lottery i could get upto some seious projects with the cash and time on my hands!!!

[Bass Man]

Power to 8k would be extremely sweet... I can kick my horse to 7500, but I loose the power at about 5.7k where as my A1 would only give me power to like 5k and never go past 6.2

[gfrg88]

Power to 8k would be extremely sweet... I can kick my horse to 7500, but I loose the power at about 5.7k where as my A1 would only give me power to like 5k and never go past 6.2

we need vids of you hittin 7.5k!!!!

[2oodoor]

Power to 8k would be extremely sweet... I can kick my horse to 7500, but I loose the power at about 5.7k where as my A1 would only give me power to like 5k and never go past 6.2

As an experiment I installed the hogged out manifold and weber 38/38 that I bought to put on the B20A, on the 86 DX BS (eventually to be called A20a1)
It woke that motor the f*ck up, it pulls very strong to redline. This is a bone stock 246k mile motor. I feel no reason to try an push it past that rpm, there is no point, it is so much fun getting there I am ready for it to drop rpm on the next gear to feel it again.
Speculate all you want, but I feel it may have picked up NO LESS than 25 HP by that alone.. probably more.
oh and I still plan on putting it on the B20 unless I can run across a deal on some flatsides.

[Bass Man]

So it went from about 80HP to 105?? lol.

What do you mean by hogged out? Did you take any aluminum out of it or did you just kinda polish it?

Also, I paid closure attention to the RPM's going down the road, and I have nice pull till about 6.4-5k then it's done. I don't like taking it that far because it takes a lot longer to shift gears because of my syncro's.

[2oodoor]

[QUOTE]

So it went from about 80HP to 105?? lol.

that is not funny, Im serious I assume it is more than that

What do you mean by hogged out? Did you take any aluminum out of it or did you just kinda polish it?

yep, another member had it and removed a buttload of material, inside it looks like an speadbore. The 38/38 is not a progressive stage carb like the 32/36, it pulls from both barrels all the time.

[cygnus x-1]

[QUOTE=roodoo2;880916]

yep, another member had it and removed a buttload of material, inside it looks like an speadbore. The 38/38 is not a progressive stage carb like the 32/36, it pulls from both barrels all the time.

I think I can help you here Roo'. This is just too annoying remaining anonymous!

It's my old carb. Here are a couple pics of the manifold taken during modification:

http://bluegreenlabs.com/Prelude/Eng...takePlenum.jpg
http://bluegreenlabs.com/Prelude/Eng...numAdapter.jpg

The 38 has bigger throttle bores, so to really make use of them the intake needs to be matched to the carb. Also, I removed the wall between the bores because it was not symmetrical, meaning you would get more flow from one bore than the other, which is not what you want with the 38. It's a synchronous carb so both bores need to matched as much as possible for best results.
I really need to give some credit to A20A1 for originally suggesting to remove the wall.

C|

[turabaka]

^^ I did the exact same thing to mine. ended up port matching the manifold to the adapter plates, and cutting out the dividing wall. Got the idea from A20A1 as well.

[Bass Man]

So all you did was remove the plenum and match the intake to the carb?? What would this do for the stock carb?

What is that thing between the carb and the intake? Something to do with the choke? Like a thermovalve?

[Bass Man]

that is not funny, Im serious I assume it is more than that

Well, if Cygnus had something to do with it, it's a power increase.

No, I was making a funny about the 245k motor.

Hey, Cygnus, could you tell me the tools you used doing that to the intake?

[cygnus x-1]

Well, if Cygnus had something to do with it, it's a power increase.

No, I was making a funny about the 245k motor.

Hey, Cygnus, could you tell me the tools you used doing that to the intake?

1 Rotozip
1 Rotozip flex attachment
Various cutting bits

I think I also used a drill to drill out as many holes as I could. It took a long ass time, and kinda sucked. A die grinder and some carbide cutters would be infinitely faster, but I don't have a die grinder.

C|

[Bass Man]

Would just clearing the intake out give an outstanding increase in performance, or is it only reccomended for weber setups?

[cygnus x-1]

Would just clearing the intake out give an outstanding increase in performance, or is it only reccomended for weber setups?

I can't say for certain but I doubt it would gain you much with a stock carb. Although taking out that heater plate might help a bit.

C|

[2oodoor]

[QUOTE]

Well, if Cygnus had something to do with it, it's a power increase.

True, and Cygnus the gig is up so I don't have to call you just some dude. It was not really a secret except before I had it in my hands.. LOL

No, I was making a funny about the 245k motor.

Bass you need to understand something, the A20 >>you can take these things apart at 250k miles and see factroy hone marks in the cylinders. Do not underestimate the endurance of these engines. Now if you twist the hell outta them like you did, yep you will let loose a rod, especially not knowing how well the motor was taken care of before you got it and IF IT HAD OIL IN IT. The age factor in the A20 as far as loosing compression and bang bang power is likely going to be found starting with the head, valve seating, again this is my opinion based on observation.

Also in fuel injected cars the intake plenum gets clogged and gunked up resulting in the gradual loss of power, and carbed cars..well you know those oem carbs are not too hot after 200K miles.

[2oodoor]

Would just clearing the intake out give an outstanding increase in performance, or is it only reccomended for weber setups?

I wouldn't do that BAss, cuz you have no way to rejet the OEM carb to get it to pull fuel properly after you open the plemum. Just like you do not want to use a speadbore hi rise under a unmodified Rochester Quad on a chevy, it is asking for trouble. YOU may see gains at WOT, but streetability on the primary side will suffer.

And kudos praise to A20A1 for the education X2

[cubert]

not sure if you were still looking to do bike carbs, but harley wont be any help. Most all of them run a single carb to feed the tow cylinders...no help to you. You should look for a rack of carbs from a Jap inline-4 bike.

[turabaka]

1 Rotozip
1 Rotozip flex attachment
Various cutting bits

I think I also used a drill to drill out as many holes as I could. It took a long ass time, and kinda sucked. A die grinder and some carbide cutters would be infinitely faster, but I don't have a die grinder.

C|

Do not use carbide bits. I tried that at first, and all it ended up doing was melting the aluminum to the bit. Use something intended for soft metals, and woods. I switched to a bit for those things after the carbide didn't work, and they cut right through aluminum like a hot knife through butter.

[2oodoor]

When I did the manifold for the other car for the 32/36 I used a dremel and a all metal bit that looked like something you drill for oil with, it really moved some material. Note that I did not hog out the whole inside like cygnus did on this one, I just cut a step in the separation and some porting. I dressed it off with more of a deburr bit.
Harley carbs would probably work if you used them like DCOE webers one for two cyl. I guess?

[Bass Man]

Hmm... I was acually thinking about running Harley carbs. My dad is a buff on anything Harley.

[cygnus x-1]

Do not use carbide bits. I tried that at first, and all it ended up doing was melting the aluminum to the bit. Use something intended for soft metals, and woods. I switched to a bit for those things after the carbide didn't work, and they cut right through aluminum like a hot knife through butter.

You mean these kind of bits?
http://www.tyrolit.com/page.cfm?vpat...encarbideburrs

Aluminum does have a tendency to stick to cutters, but it seems surprising since these are what lots of people use for headwork. The dremel bits I was using are high speed steel and they would also get some buildup. Adding some coolant/oil would help, but is messy.

C|

[Bass Man]

Quick question... Can I safely remove the EFE heater? That green plastic thing under my carb?

[cygnus x-1]

Quick question... Can I safely remove the EFE heater? That green plastic thing under my carb?

I believe that's for cold starts. I would get rid of it.

C|

[turabaka]

You mean these kind of bits?
http://www.tyrolit.com/page.cfm?vpat...encarbideburrs

Aluminum does have a tendency to stick to cutters, but it seems surprising since these are what lots of people use for headwork. The dremel bits I was using are high speed steel and they would also get some buildup. Adding some coolant/oil would help, but is messy.

C|

yeah don't use those. I tried those with my dad's die grinder, and all it did was gunk up the bit. I ended up using a dremel, and some similar shaped bits that were intended for softer metals, and wood. Those worked perfect. No aluminum buildup at all on the bit.