38 replies to this topic

[speedster]

I trying to source a set of high compression pistons (11:1). I looked for Wiseco and JE Pistons but can't seem to locate any compatible products. Dropped a line to Coutenay but not something they carry.Anybodyany idea where I could pick up a set? I'd prefer a kit with rings and pins. Standard bore (not me the pistons).

 

Thanks,

Stephen

 

 

[2-20]

The Wiseco pistons are 10:1 with a 1mm thick gasket.

If you install a Z22se gasket which is supposed to be at around 0.5 mm you will end up with a 10.5:1 CR.

Shim your head another 0.5 mm and the job is done.

[Rosssco]

Z22YH pistons not suitable?

[Claws]

The Wiseco pistons are 10:1 with a 1mm thick gasket. If you install a Z22se gasket which is supposed to be at around 0.5 mm you will end up with a 10.5:1 CR. Skim your head another 0.5 mm and the job is done.

EFA

[2-20]

Thanks

 

You can also use a Z22YH head gasket which is around 0.4 mm

Edited by 2-20, 28 June 2013 - 09:56 AM.

[TheRealVXed]

0.1mm = 0.1:1 increase in compression ratio?

 

Sounds too good to be true...

 

What is the stroke length on the Z22se?

Edited by VXRed, 28 June 2013 - 10:16 AM.

[siztenboots]

94.6mm , according to the conrod ratios thread , http://www.vx220.org...-conrod-ratios/

 

whats the squish is the next question

[siztenboots]

more information here , http://www.vx220.org...high-rpm/page-2

 

[slindborg]

0.1mm = 0.1:1 increase in compression ratio?

 

Sounds too good to be true...

 

What is the stroke length on the Z22se?

 

 

That would be overly lucky..

 

Plus as the head is a dome, knocking 5 *0.1mm off will alter the volume by a lesser quantity each time.

[speedster]

Z22YH pistons not suitable?

 

Anybody know?

 

Prefer not to get involved in any skimming. Head gaskets I can do.

[vocky]

according to the Mad Doc's calculations you can skim 1mm from the head to get 11:1 CR

 

or just use the 11:1 CR z22yh pistons and rods

[speedster]

according to the Mad Doc's calculations you can skim 1mm from the head to get 11:1 CR

 

or just use the 11:1 CR z22yh pistons and rods

 

Do I need the rods vocky? I have some eagles here I'd like to keep.

[slindborg]

according to the Mad Doc's calculations you can skim 1mm from the head to get 11:1 CR

 

or just use the 11:1 CR z22yh pistons and rods

 

 

Did he do it and measure it? if not then I'd take that with a massive fist of salt

[vocky]

 

according to the Mad Doc's calculations you can skim 1mm from the head to get 11:1 CR

 

or just use the 11:1 CR z22yh pistons and rods

 

Do I need the rods vocky? I have some eagles here I'd like to keep.

 

rods are not interchangeable, due to the gudgen pin being bigger on the z22yh engine.

[vocky]

 

according to the Mad Doc's calculations you can skim 1mm from the head to get 11:1 CR

 

or just use the 11:1 CR z22yh pistons and rods

 

 

Did he do it and measure it? if not then I'd take that with a massive fist of salt

 

I prefer the 11:1 pistons for some reason

[siztenboots]

I'd much prefer high compression turbo engine, with proper mapping , instead of some 80's throwback approach and daft AFR

[Claws]

according to the Mad Doc's calculations you can skim 1mm from the head to get 11:1 CR
 
or just use the 11:1 CR z22yh pistons and rods

 
 
Did he do it and measure it? if not then I'd take that with a massive fist of salt

[speedster]

 

 

according to the Mad Doc's calculations you can skim 1mm from the head to get 11:1 CR

 

or just use the 11:1 CR z22yh pistons and rods

 

Do I need the rods vocky? I have some eagles here I'd like to keep.

 

rods are not interchangeable, due to the gudgen pin being bigger on the z22yh engine.

 

I understand. 

 

Are there no third party high compression pistons for the standard rods out there?

[2-20]

You know, there is a good margin before the combustion chamber starts to be a dome. Then It's not difficult to calculate the CR by yourself

Currently we have (549.5 cm3 + Combustion chamber volume)/ combustion chamber volume =10

It means that 549.5 + CC = 10 CC ---->  549.5= 9CC ---->  CC= 61 cm3 (including the gasket)

If you skim 1mm of a round surface of 86 mm dia , it correspond to 5.8 cm3. so your new volume of CC is 55.2.

(549.5 +55.2) / 55.2 = 10.95

So the Doc was right

[2-20]

About the Z22YH the CR is curiously advertised as 12:1 here and there

 

https://en.wikipedia...II_engine#Z22YH

 

And 11.3:1 for the 2.2 JTS used on Alfa-Romeo