bore/compression ratio Q's...

[Vanilla Sky]

ok.. with an a20a1, the bore/stroke is 2.25x3.58, with a compression ration of 9.1:1

a20a3 has a bore/stroke of 3.25x3.58 with a 9.3:1 compression ratio...

1: would the a20a1 with an efi conversion have the same power as an a20a3?

2: which would handle nitrous/turbo better, the a20a1 with efi, or the a20a3?

3: since the bore is smaller for the a1 block, it would take different pistons, correct?

4: can the a20a1/a3 be bored out, or stroked?

please get back to me on this.... these specs are from my chilton's manual

Derick

[pric]

these specs are from my chilton's manual

That book is only about 90% accurate.

The bore & stroke are the same for both A20A1/3 3.25x3.58.

No, it would not put out the same power if you convert to EFI it will be close but not the same.

Yes, the lower comp. ratio it better when turbo/N2O only if you are going with high boost or a big shot. Also the 87 A20A3 has a 8.8 comp. ratio even safer to boost higher.

[Vanilla Sky]

still want #4 answered... can you bore/stroke the a20?


Derick

[MoonScryer]

Yes, you can. Some people on here have 10:1 pistons in their A20's, and I have been told of an ol' boy down south of me and slighty east of you that runs 11.5:1 pistons in his; I'm trying to contact him now through a guy I met at the track.
It can be done, but you got to match pistons with need, as far as stroking it, that is a different matter.

[Vanilla Sky]

well, i'm fine with the compression ratio, but i would like a larger combustion chamber... that's why i'd like to bore it our and stroke it.. this project would be a while down the road, because i would do it to a spare motor to reduce downtime

i wanna see how much power i can get from the old a20 engine before i do a GSR or an old school b20 swap

Derick

[guaynabo89]

If you make the combustion chamber larger it will lower the comp ratio.:flash:

[shepherd79]

if you stick with 2L and increase the stroke, you will increase the compretion ratio.
i don't think you can bore out much with our engine.
plus if you do what are you going to use for pisons and rods?
bigger bore and stock rods you will lose the compressio for sure.

[Vanilla Sky]

when i said i'm fine with the compression ratio, i mean i don't particurly car, unless i drop below 8.5:1... or i run nitrous... the coupe i'll be getting has an engine, but it's been ripped down already... i can ust that block and head and see if i can do anything with it... and for pistons and roda, i'm probably gonna end up using pistons and rods...:flipa: serioulsy, if i end up boring or stroking, i'll get JE pistons (do they make rods also?) and go at that

Derick

[shepherd79]

man, why are you gonna waist your money on A20 when you said you gonna do the GSR or B20(us specs) with B16 head and JE pistons. that would work hell a lot better than A20. don't waist your money on something you will trush after a while, unless you have unlimited supply of money.

[Vanilla Sky]

well, the more i spend, the more i feel like i really do have money, so i just spend :lol

i'm just pondering things... curious to if there was a crank that could swap in easy and on the cheap... i may just save and go with an engine worth more than the car is... lol at least it would be fast

BTW, how good are the mods for the GSR?

Derick

[smufguy]

anything with a bigger displacement is good, thats why some of us have an eye on the B20 shit. if ur real careful, u can be running a turbo on a B20 like the dude ( i forgot his name) who sold his engine in here. i feel for that dude though. man...... his site has all this amazing things and details up and i saved up his pics and shit. man......... i would be devastated if i was him. But god be with him.

derick, the B series dont have much torque, u see the A20 efi motor with a 9.3 compression had a stock spec peak torque of 122 ft-lbs. See if u get a motor more than that or close to it cause u dont really wanna go lower than ur stock torque.

I would prefer a bigger bore or a higher compression on our existing motor if no engine (that is easily available) would be to our selectiveness.

[Vanilla Sky]

i could always do an h series, but i'm wanting to hold that off for my current car... i'm just lookin for something to keep me busy

Derick