Valve sizes

[SUFFRN6]

My heads and engine are at the machine shop and I was wondering about the valves. I am going to put in stainless valves but not sure wether to go with stock valve sizes or go with the 177 and the 150. Which would be better to go with. The car is going to be driven mostly on the street with some track time.

My new engine parts are:
30 over JE pistons
212/212 Comp cams
Te-44 Turbo
Everything in the engine is new except for the connecting rods and the crank. Going to be using an alky kit too. Any suggestions will be greatly appreciated. Thanks in advance. Chris

 

[FJM568]

Bigger valves aren't really going to help unless you are running a 4.1L motor...The 3.8L is a smaller bore and the valves will be shrouded if you go any bigger...That isn't a concern on the 4.1L since the bore is almost 3/16" bigger and the bigger valves will be unshrouded...

You will get more out of doing some clean-up work in the bowls and the ports than you will going with bigger valves...

Just my .01 worth(unemployed and I need the other .01 for bills )

Hope this helps some...

 

[Intercooler]

The stock valve sizes are 1.71/1.50 so the only real upgrade is the intake. It is worth it to go larger on the intake to the 1.77 because you can remove even more meat under the valve in the bowl region. If you have a sharp head porter he can heart shape your combustion chamber and improve the shrouding of the valves (basically opens the bore combustion chamber more). He may be limited if it is stock bore and there is a balance if it has been bored. FWIW Ferrara makes a great undercut valve in its 6000 series that runs $15.50 a piece.

 

[SUFFRN6]

Thanks for the input guys. I think that I will just stick with the stock size valves but in stainless. It doesn't seem that I will gain much more with the 177 valves. Thanks again. Chris

 

[UNGN]

1.77's are worth about 6 CFM (3%) over the stock size intakes based on every back to back test I have seen or read about. It doesn't sound like much, but 6 CFM is 6 CFM.