Head Port and Polish

[decoupe]

I will be pulling the head this winter (an AMC casting from an unknown series) in order to match or at least improve the flow from the b35 intake manifold runners to the combustion chamber. The intake port on the head is much taller but not as wide as seen here http://s54.photobucket.com/user/decoupe/media/M30B35 EFI/P1050645.jpg.html?sort=6&o=15

At the same time I've looked into the head porting services at a couple of BMW specialists with the goal to get the best airflow through the head. Are there other people or shops that anyone has used and can recommend?

Miller offers https://www.millerperformancecars.c...age=flypage.tpl&product_id=106&category_id=61

Metric Mechanic has a similar service with similar increase in flow but you have to go with their cam as well which I'm not interested in at this point.

The engine is 3.5l Euro block, flat Arias forged 9:1 (or slightly less) CR pistons, 282 "shrick Pattern" regrind cam and is programable EFI.

I will post the dyno output using the same test machine as before after it's back on the road (summer next year I hope...).

Thanks

 

[TodB]

I'd also reach out to Paul Burke. He has opinions and lots of experience with these heads.

 

[rsporsche]

from past experience, Korman

 

[Polariscsl]

I would definitely speak to a variety of experts on this before you spend on extensive porting. Personally I question if you will see much benefit given the relatively low 9:1 compression. From my experience these engines need lots of squish to provide high enough gas speeds to make porting worthwhile.

 

[sfdon]

If you went with the euro block, euro 10:1 pistons and a M 30 B 35 head with that cam you would be in heaven. No porting needed. Final compression is 9:1.
M30 b35 Head comes with bigger intake valves, double valve springs, bigger ports- 26 hp more than the head you have stock on 87 octane. With your setup you can run 93 octane and more aggressive maps and get 240 hp + for cheap.

 

[decoupe]

Porting (or other ideas)

Sfdon,

Any idea what the head I have is from given the shape of the intake ports?

Changing to a b35 head hadn't occurred to me - not a lot to chose from around here but worth considering. The plan is to leave the bottom end for a bit and possibly go the boost route in which case the low CR is a good thing.

PM coming your way.

Doug