AU XR8 220 heads, how many cc's?

crakrz · 19-07-2009, 07:13 PM

Just wondering if anyone can tell me how many cc's the Yella Terra modified GT40p heads are? And how much can be removed of the decks safely?

Thanks,

-Craig

RG · 21-07-2009, 08:59 AM

58cc IIRC, and not too much. Compression is already in the 10's.

CRAIGAU3220 · 21-07-2009, 08:45 PM

Quote:

Originally Posted by RG

58cc IIRC, and not too much. Compression is already in the 10's.

I thought compression is 9.4

RG · 21-07-2009, 08:50 PM

Quote:

Originally Posted by CRAIGAU3220

I thought compression is 9.4

That was the 185 and 200, it was bumped up to mid 10's for the 220.

crakrz · 23-07-2009, 07:06 PM

Well I spoke to Yella terra today, they weren't sure of how many cc's the chambers are, but they took .020" of the heads. They said that they are safe to take off another .020" but cam choice and piston to valve clearance can become an issue.
As well as the machining done in the combustion chambers and ports, they also told me that they machined the spring bases too, but that was more to suit the springs that were bieng used as they interfered with the guide boss or the step on the spring base, or something similar to that. They couldn't tell me what springs were used as they just got the machining dimensions.

As for the comp ratio, all the specs that I have, from the service book and original brochure tell me that the 220kw motor was 9.4:1.

I know that there are some really knowledgeable people on these forums that can either verify, expand or correct the info that I have been given. So feel free to pick the crap out of it.

Thanks,

Craig.

BlacklistedXR · 23-07-2009, 07:26 PM

Quote:

Originally Posted by crakrz

Well I spoke to Yella terra today, they weren't sure of how many cc's the chambers are, but they took .020" of the heads. They said that they are safe to take off another .020" but cam choice and piston to valve clearance can become an issue.
As well as the machining done in the combustion chambers and ports, they also told me that they machined the spring bases too, but that was more to suit the springs that were bieng used as they interfered with the guide boss or the step on the spring base, or something similar to that. They couldn't tell me what springs were used as they just got the machining dimensions.

As for the comp ratio, all the specs that I have, from the service book and original brochure tell me that the 220kw motor was 9.4:1.

I know that there are some really knowledgeable people on these forums that can either verify, expand or correct the info that I have been given. So feel free to pick the crap out of it.

Thanks,

Craig.

9.4:1 is the correct compression for the AU 220 XR8s:
http://www.fpv.com.au/theheritage/fa...onxr8-220.aspx

Mr_4.0 · 23-07-2009, 08:16 PM

whats actually required to put gt40 heads on and e-series motor.

obviously inlet manifold. but what about lifters, cam etc? is sticking the e-series MAF sensor in the au housing going to work ok?

im looking at an ef 5l, and i have a mate selling gt40 heads, extractors, and inlet manifold. i want to put a cam in there at the same time though.
also, different plugs?

sorry to high jack this thread, lol