, I show that head as having 44.7 chambers , according to the Ozdat engine calculator. That puts you at 9.7 before shaving off .020. Something is not right here, unless that's a euro e88 that had bigger chambers. Sure you measured right?    

I guess it's a late e88 head 47.8 cc.

I may have mesured wrong, guess so.

Because it has been shaved .020 I guess the chambers would be something like 45cc? 

But then I don't know if the larger valves and changed seats have any effect on the cc?

Car comes from California.

Ok, found some more info about the head.

"when installing bigger n42 valves and unshrouding them you can easily ad 2-4 cc to the combustion chamber"

Anyone who can confirm?

If that's true, my mesure looks right. 

47.8cc to begin with then ad say 3cc do to valves etc. Then there's .020 shaved from the head and I guess that takes away 2cc (not sure about that but close) and were at 48.8cc. So I guess my measured volume of 49 were right.

So I guess I take of another .020 or .030 to get to the 10.0 cr

 

i believe you'll get more poke out of the motor with porting/matching and running full advance than just more CR, and detonation is a bad thing to have to worry about, plus if you shave too much you'll need to shim the cam towers. if you drive it regularly, there may be times when you can't get the best gas, so i'd err on the side of safety w/CR.

will be slightly ported. Towers will be fitted with shims. It already had some shims on.

Even with 10.5 comp i can still run full advance (lots of people do that here in europe) because we have 98 octane at every station here in Sweden. 

Will aim for close to a cr of 10, probobly ill end up slightly less.

On 3/9/2016 at 9:07 PM, moelk said:

I guess it's a late e88 head 47.8 cc.

I may have mesured wrong, guess so.

Because it has been shaved .020 I guess the chambers would be something like 45cc? 

But then I don't know if the larger valves and changed seats have any effect on the cc?

Car comes from California.

Yes it definitely looks to be the late L26 head at 47.8 cc.

With the stage 3 cam you are using, i would shave it more if it were me.

All the engine calculators I have seen list all the E88 heads same at 44.7 cc. They need to 

correct that to add the later L26 head with the bigger volume.

I will take off another .020 so it will be shaved a total of .040

That should put my cr somewere around 9.7

And your right they should correct the e88 head in those engine calculators.

 

Edited March 10, 20169 yr by moelk