engine mods = what compression?

[l1ttle_d3vil]

if a 20v silvertop is running the internals from an AE101 4agze with a 2mm headgasket, what would the compression on it be?

is there any way to be sure its running the 4agze internals without pulling the engine apart? the engine is in a car and running so need another way of confirming! I'm assuming the above method wouldn't be 100% accurate ...

thanks.

[matt dunn]

It is impossible to work out compression ratio from compression pressure.


From my working sheet, ST 20V with AE101 GZE pistons and 2mm Headgasket works out to be 8.56:1 compression ratio.
(asuming ny calculations are correct)

[l1ttle_d3vil]

damn thats pretty low...its only running small boost.

I wasn't really wanting the c/r though. I've seen people before say "if its got xxx pistons, do a compression test and it should be around xxxpsi"

I'm wanting to know what the compression pressure will be if it is running these pistons. otherwise i'm just taking someones word that its got mean strong pistons in the engine!

[Mr Revhead]

ring around some workshops (i suggest ones involved in racing) and see if they have an endoscope. that is a device that you can inspect the chamber. then you will be able to look at the top of the pistons.

[l1ttle_d3vil]

probably don't have any workshops around here with a tool that flash

but if I can get hold of one, what would I be looking for to identify the ae101 gze pistons?

[bluemaumau]

i gues the 4agze pistons will only have four valve cutouts (altho ive never seen them in person)

[l1ttle_d3vil]

uh, yeah...ofcourse I knew that!

[Dell'Orto]

damn thats pretty low...its only running small boost.

I wasn't really wanting the c/r though. I've seen people before say "if its got xxx pistons, do a compression test and it should be around xxxpsi"

I'm wanting to know what the compression pressure will be if it is running these pistons. otherwise i'm just taking someones word that its got mean strong pistons in the engine!

8.5 isnt that low, Gen 3 3SGTE's are that. Try a dirty ol YB at 7:1 Or 930 Porsche with something idiotic like 6.5:1

[matt dunn]

i gues the 4agze pistons will only have four valve cutouts (altho ive never seen them in person)

Yes the AE101 GZE's will only have 4 cut out's

but so will AE92 GTZ
and AW11 GZE one's.

You need to know what your looking at.

Matt

[bluemaumau]

at least youll know its running gze pistons rather than 20v tho!

unless its got N/A 16v pistons in it

[TRD_ZERO]

i gues the 4agze pistons will only have four valve cutouts (altho ive never seen them in person)

Yes the AE101 GZE's will only have 4 cut out's

but so will AE92 GTZ
and AW11 GZE one's.

You need to know what your looking at.

Matt

Then what do those super dished ones come out of?? Seen them on trademe once doesnt look anything like my ae101 gtz ones and they guy said he pulled it out of his ae92 gtz.

[bluemaumau]

i think the dished ones are ae92

[ezy10s]

more likely to be aw11 8.0-1 pistons than ae92 8.9-1 items,

as for finding out if it actually has what the seller is saying- youll just have to ask him a whole lot of questions like who installed them, re they over sized, what block is used, what else was done while it was apart, receipts? etc and try make an educated guess whether he is on the level or not.

[bluemaumau]

i meant the 8.0-1 ae92 ones

my bad