Trick flow 215
Trick flow 215 I have a set of trick flow 215s I bought and then found out they are 57cc. I want to run them in my street car at 60cc or more. Is it a bad idea to sink the valves and fly cut to gain that extra volume to lower the compression? Would there be a lot of valve train geometry issues? Also does gm make a thicker gasket?
TECH Senior Member
Joined: Feb 2009
Posts: 5,445
Likes: 4
you would need to measure for the correct length push rod after the heads are on.the valve stem tip would be higher in the head ,but the thicker gasket would make up for some of that.you better call and find out how much you can sink the valve seat.consider a after market head gasket if gm dose not have one thick enough.talk to chrs1313 about fly cutting pistons ,he can help you figure out how it will help you lower compression.
flycutting is only going to drop you around 1.1cc and that it is with a .110 cut on both intake and exhaust...
my heads are at 57.5cc and i run a cometic .040 compression is around 11.95:1 and with the cam i have the DCR is close to 9.0:1...and it will run on 93 with no knock, even on a 80+degree summer day
The major thing to worry about is the DCR and that is dipicted by the cam size...and split lsa
my cam is a 239/243 on 110+3 when degreed
The larger the duration on the intake valve @ .006 the more it will bleed off the pressure and lower DCR, also a wider split (higher lsa) will help with this too...
So you can definitely run the heads the way they are now, just depends on the cam choice...
But take a look at partick g's 500rwhp thread it explains it pretty well on how quench is important... so a motor with a stock mls .051-.053 gasket at 11.5:1 is more prone to knock than the same motor with a tighter quench and running a .040 gasket at 11.9:1...
Also the chambers on these heads are very effiecient and that helps resist knock too...
If you still feel uncomfortable about the heads shoot me a price and I will most likely take them off your hands, got a friend who is in the market for some heads...
Chris
my heads are at 57.5cc and i run a cometic .040 compression is around 11.95:1 and with the cam i have the DCR is close to 9.0:1...and it will run on 93 with no knock, even on a 80+degree summer day
The major thing to worry about is the DCR and that is dipicted by the cam size...and split lsa
my cam is a 239/243 on 110+3 when degreed
The larger the duration on the intake valve @ .006 the more it will bleed off the pressure and lower DCR, also a wider split (higher lsa) will help with this too...
So you can definitely run the heads the way they are now, just depends on the cam choice...
But take a look at partick g's 500rwhp thread it explains it pretty well on how quench is important... so a motor with a stock mls .051-.053 gasket at 11.5:1 is more prone to knock than the same motor with a tighter quench and running a .040 gasket at 11.9:1...
Also the chambers on these heads are very effiecient and that helps resist knock too...
If you still feel uncomfortable about the heads shoot me a price and I will most likely take them off your hands, got a friend who is in the market for some heads...
Chris
