compression ratio question

[markmitchinnh]

Just curious if the TBI computers can handle a bit more compression and will it improve the engine in any way. I was thinking of having the heads shaved a small amount. I would also look into doing a home port matching between the heads and intake manifold.

[1Gary]

Rule of thumb is within 10%.Need you you to figure the static compression ratio or SCR.

viewtopic.php?f=4&t=6252

We have found without a 5 position CNC program best hope port to port by hand to match is only 25%.So it is very real to end up with a rich cylinder and then a lean cylinder and so on.Then head to head or side to side gets really complicated.Trace gasket outlines have proven to be very in-actuate.Flow bench time and a steady hand is the road to that only 25% result.Yes I know we all have been doing hand porting since the stone age.And been doing it wrong. #-o

[1Gary]

One other thing to consider.The feature of Vortec heads is the ruff surface of the intake runners.It is that to keep the gas molecules(sp) suspended.Smoothing that out destroys the advantage of Vortec heads.

[markmitchinnh]

I don't have vortec heads that is way to expensive for an intake manifold.