My cylinder head will be going to the machine shop in the near future for a valve job and Iím trying to finalize a list of all the little things to do that will help this head perform its best. This is not a big power build or a drag car. It will be a fun street car making 350-380 hp max, so I donít want to spend money on things that will be of no benefit for that goal.
Iíve decided to stay with stock size valves. I know 1mm oversize on the intake side could be helpful, but considering that I got a new set of stock intake valves for far less than a set of oversize I decided it wasnít necessarily cost effective. I already have EVO exhaust valves (the sodium filled ones) and EVO beehive springs and retainers, and of course the revised lifters. The casting flaws inside the ports have been cleaned up and things smoothed out a bit but no actual porting/enlarging of the ports. Still need to look at gasket matching the ports. Exhaust ports will be polished, intake ports left slightly rough.
Itís my understanding that at this power level a 5 angle valve job has no advantage over a 3 angle. Unless somebody can give me good reason to go for the 5 angle Iíll save the money and stay with 3 angle. Seats and guides will be replaced as needed based on the machinists inspection.
What is the benefit of polishing the combustion cambers?
Anything else I should consider doing while Iím at it just to make it that little bit better?