A18 & A20

[OldSchool86]

Does anyone know if i can put an A18 head on my A20A1 block. i want to run the duel side draft carb set up. i got the maifold with carbs, but the intake ports are differant an will not fit on the A20 head? can anyone help?

[2ndGenGuy]

You should be able to no problem. Just make sure it's an A18 and not an ES from an earlier 2g Prelude and you should be good to go.

[cygnus x-1]

Does anyone know if i can put an A18 head on my A20A1 block. i want to run the duel side draft carb set up. i got the maifold with carbs, but the intake ports are differant an will not fit on the A20 head? can anyone help?


So I have to ask, why do you want to run the dual carb setup? They aren't that great and are hard to find parts for. Unless your stock carb is hosed and you happen to have all the A18 parts already it's not worth the trouble. You would be better off keeping your stock head and intake and putting on a Weber carb. Much better carb and less work. There is even a kit you can get.

C|

[OldSchool86]

2 carbs mean more air flow and more fuel..... more power. why run "1" 30,40, or 50 mm weber when i can run "2" 30,40 or 50 mm weber side drafts?

[OldSchool86]

also the A18 head has the same size intake valves as th a20a1 but has a smaller cc port witch will raise my compresion... So higher compression with the same air flow as the a20 means more power aswell.

[cygnus x-1]

Oh, so you have a Weber setup? That's a totally different story then. I thought you were going to use the stock Prelude carbs. Those things aren't any better than the stock Accord single carb. The stock dual carb manifold is also not compatible with anything else, except maybe other motorcycle type carbs.

The compression bump with the A18 head will be minimal. Less than 0.4 points difference. Not worth going out of your way for if that's the only reason you're doing it. But if you're switching to Webers then by all means go for it.

EDIT: If you are really doing this you should also do some work on the A18 head before putting it on. At the very least get a good 3-angle valve job done and put in a reground cam. If you're up for more you can get the ports and combustion chambers worked over, and even put in bigger valves. That's getting pretty spendy though and tricky to get right. It's very easy to ruin a head with overzealous porting.

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[lostforawhile]

RUN as fast as you can from those dual prelude carbs. those are the worst bastardization of carbs ever made. you will have twice the problems and twice the vaccume hoses of the Keihin carbs on the a20. plus you have a computer and all kinds of shit. Sometimes honda will really drop the ball,and thats the ball they dropped. They had trouble getting those to work right when they were brand new.