The M20B25 885 head has intake/outlet valves 2mm bigger in diameter than those found on the 731 head.
I have heard of people using the bigger valves on the 731 without sleeving the head, although it looks a bit tight. Any problems doing this?
Normally I would presume the 885 would be aligned the same as the 731 so therefore its fine, but the 885 has a slightly bigger combustion chamber so perhaps its valves are seated back a bit giving more meat around the valve seats. I am probably wrong about this but thought to ask first.
Then there is also clearance issues. This is not an ETA block build, but just for the standard M20B23 bottom end.
I have heard of people using the bigger valves on the 731 without sleeving the head, although it looks a bit tight. Any problems doing this?
Normally I would presume the 885 would be aligned the same as the 731 so therefore its fine, but the 885 has a slightly bigger combustion chamber so perhaps its valves are seated back a bit giving more meat around the valve seats. I am probably wrong about this but thought to ask first.
Then there is also clearance issues. This is not an ETA block build, but just for the standard M20B23 bottom end.