how much flycut to fit G5X-2 cam?
09-23-2003, 12:04 AM
#1
how much flycut to fit G5X-2 cam? ok....I'm coming down to the final planning. The car has in it:
- stock 01 short block
- 5.7 heads milled 0.020" with 2.08/1.60 valves
- TR224/224 .563/.563 112LSA
the current P-to-V clearance is ~ 0.110"
Will I be able to fly cut (with the Isky tool) enough material out of the stock pistons to fit the G5X-2 cam?
I tried to install a Schneider 234/230 .578/.578 112LSA cam the first go around (no fly cuts) and the intake valve hit the piston (say -0.002 P-to-V clearance). I noticed that the G5X-2 is a 232/240 .595/.608 112LSA cam. Since the intake duration is smaller (on G5X-2), will that make up for (give more room for) the added lift?
- stock 01 short block
- 5.7 heads milled 0.020" with 2.08/1.60 valves
- TR224/224 .563/.563 112LSA
the current P-to-V clearance is ~ 0.110"
Will I be able to fly cut (with the Isky tool) enough material out of the stock pistons to fit the G5X-2 cam?
I tried to install a Schneider 234/230 .578/.578 112LSA cam the first go around (no fly cuts) and the intake valve hit the piston (say -0.002 P-to-V clearance). I noticed that the G5X-2 is a 232/240 .595/.608 112LSA cam. Since the intake duration is smaller (on G5X-2), will that make up for (give more room for) the added lift?
09-23-2003, 07:56 AM
#2
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Re: how much flycut to fit G5X-2 cam? .080" minimum PTV clearance with the G5X2. The intake lift on the G5X2 is .120" when the piston is at TDC. Its very easy to check PTV even before you have the cam installed.
#1 Bring the piston to TDC using a dial indicator.
#2 Install the head (with intake valve installed but spring removed) with an old head gasket. Tighten it down just a little, no need to torque it.
#3 Using a caliper, measure the height from the top of the valve stem to the spring seat while pulling up on the valve.
#4 Push the valve down until it touches the top of the piston. Measure the distance again. The total valve drop minus (.120") will give you the PTV clearance. It must be .080" or more. If you need to flycut, let me know, I plan on renting my cutter to those who need it. It won't be available for about 2 weeks though.
#1 Bring the piston to TDC using a dial indicator.
#2 Install the head (with intake valve installed but spring removed) with an old head gasket. Tighten it down just a little, no need to torque it.
#3 Using a caliper, measure the height from the top of the valve stem to the spring seat while pulling up on the valve.
#4 Push the valve down until it touches the top of the piston. Measure the distance again. The total valve drop minus (.120") will give you the PTV clearance. It must be .080" or more. If you need to flycut, let me know, I plan on renting my cutter to those who need it. It won't be available for about 2 weeks though.
09-23-2003, 08:11 AM
#4
Re: how much flycut to fit G5X-2 cam? Only two things I'd add.... .080 on the intake side, .100 on the exhaust side. Also, I'd want to see the #'s at 8* BTDC to TDC, and TDC to 10* ATDC. This is where the overlap is occurring and where you need the given clearance #'s....not just at TDC. Use BergerMans method using the above #'s and you'll be good to go 
