Shoud I relieve my block

[Tim Ayers]

Originally Posted by Ol' Ron

I can understand why relieving the block works do well. most of the cylinder heads have very little transfer area so relieving is there to make up the difference. I was just looking at my Hydro engines, They rak well over 5K and when they came out of the water Pegged the needle, Somebody here suggested Monkey see, monkey do, Yes, I can see how it might work My Grancore heads used apopu piston In my Bvill engine I used 3 3/4 stroke pistons on a 4" crank

Originally Posted by Pete

Here is a size comparison of a rough finish port to a stock one.. There is about .030 more to finish size.

Pete,

I understand what you mean now. Issues with the a large D port not sealing on raised intake block due to the lack of material would be the "lowered" section in the direction towards the deck surface. Never thought of it that way, but I guess you are right.

Regarding D shaped ports, do you guys do this on a mill or freehand? If freehand, any useful tips or tricks?