Eurospec 944s and US-Spec 944s, compression difference in pistons or stroke?
09-12-2002, 01:32 PM
#1
Official Bay Area Patriot
Fuse 24 Assassin
Rennlist Member
Fuse 24 Assassin
Rennlist Member
Thread Starter
Eurospec 944s and US-Spec 944s, compression difference in pistons or stroke?
Ok this question concerns the parts I am going to order for a motor i will be building. My goal is to achieve 10.6:1 compression by having the head shaved, high lift camshaft, and the motor stroked up.
I was looking for parts yesterday and I had the idea of using eurospec pistons on the motor instead of stroking up since the Eurocars are 10.2:1. But I wonder if the pistons are the same with no real changes to the surface between the 2 cars. Is the Euro 944's compression high because of stroke, or because of the piston surface???
If anyone knows please tell me, if you have a picture i really appreciate it, thanks.
<img src="graemlins/burnout.gif" border="0" alt="[burnout]" />
I was looking for parts yesterday and I had the idea of using eurospec pistons on the motor instead of stroking up since the Eurocars are 10.2:1. But I wonder if the pistons are the same with no real changes to the surface between the 2 cars. Is the Euro 944's compression high because of stroke, or because of the piston surface???
If anyone knows please tell me, if you have a picture i really appreciate it, thanks.
<img src="graemlins/burnout.gif" border="0" alt="[burnout]" />
09-12-2002, 03:09 PM
#2
Race Director
The cars are basicly designed as euro motors with euro compression. They reduced compresson on US -spec cars by dishing the piston.
So euro pistons with stock US head will give you euro compression. Of course then you need to ensure you have a euro chip to ensure proper A/F ratios & timing for the euro compression to get max power.
Euro pistons are $$$$$. That is why it is cheaper to shave the head to get more compression from a US motor.
Chaning stroke does not a good way to impact compression ratio. If you want a 2.8L motor just to go to John Anderson and have him build it. It is far to easy to mess-up if you start mixing and matching parts. A good engine builder will be able to match the right compression with right stroke and the right cam for the type of engine you want.
So euro pistons with stock US head will give you euro compression. Of course then you need to ensure you have a euro chip to ensure proper A/F ratios & timing for the euro compression to get max power.
Euro pistons are $$$$$. That is why it is cheaper to shave the head to get more compression from a US motor.
Chaning stroke does not a good way to impact compression ratio. If you want a 2.8L motor just to go to John Anderson and have him build it. It is far to easy to mess-up if you start mixing and matching parts. A good engine builder will be able to match the right compression with right stroke and the right cam for the type of engine you want.
