SBE LS2 build opinons,advice please
12-10-2019, 09:18 AM
#21
Originally Posted by Know It All
Did you measure that with checking springs? I would be okay with .074" but if it makes you feel better, the real springs will cause a little bit of deflection and increase that PTV.
Don't forget that you do have an adjustable timing set. You could always retard the cam a degree to give up a little exhaust PTV to gain some intake PTV.
Don't forget that you do have an adjustable timing set. You could always retard the cam a degree to give up a little exhaust PTV to gain some intake PTV.
I was using check springs. Makes sense that you would lose some lift with real springs.
I had some difficulty adjusting the cam timing precisely. I kept changing by a degree or two each time I made an adjustment. When I finally got within a degree off I said close enough but it is on the advanced side of the specified icl.
I'll try retarding that a degree and see what clearance that gives.
12-15-2019, 07:29 PM
#24
I double checked everything and I'm not sure why I posted that the intake clearance was .074, that was at 5 degrees atdc. It was actually .067 at 8 degrees where it was tightest . This was with the intake centerline at about 110.5 degrees. Also the shims I was using are more like .056 so thicker than the stock gasket.
I adjusted the intake centerline to 111.5, (cam card calls for 111), it changed the clearance to .069 at 8 atdc. Tightest point again.
I think I'm going to do a .030 relief cut and run the .041 gaskets.
Doing the math like this: .056 shim when measuring - .041 gasket = .015
Clearance as measured = .069 - .015 gasket thickness adjustment = .054 existing clearance
Desired clearance = .080 - existing clearance .054 = .026 minimum relief cut
What size cutter should I use? I have the stock 2.00" valves. I'm thinking 2.10"
I adjusted the intake centerline to 111.5, (cam card calls for 111), it changed the clearance to .069 at 8 atdc. Tightest point again.
I think I'm going to do a .030 relief cut and run the .041 gaskets.
Doing the math like this: .056 shim when measuring - .041 gasket = .015
Clearance as measured = .069 - .015 gasket thickness adjustment = .054 existing clearance
Desired clearance = .080 - existing clearance .054 = .026 minimum relief cut
What size cutter should I use? I have the stock 2.00" valves. I'm thinking 2.10"
12-15-2019, 08:13 PM
#25
ModSquad
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I double checked everything and I'm not sure why I posted that the intake clearance was .074, that was at 5 degrees atdc. It was actually .067 at 8 degrees where it was tightest . This was with the intake centerline at about 110.5 degrees. Also the shims I was using are more like .056 so thicker than the stock gasket.
I adjusted the intake centerline to 111.5, (cam card calls for 111), it changed the clearance to .069 at 8 atdc. Tightest point again.
I think I'm going to do a .030 relief cut and run the .041 gaskets.
Doing the math like this: .056 shim when measuring - .041 gasket = .015
Clearance as measured = .069 - .015 gasket thickness adjustment = .054 existing clearance
Desired clearance = .080 - existing clearance .054 = .026 minimum relief cut
What size cutter should I use? I have the stock 2.00" valves. I'm thinking 2.10"
I adjusted the intake centerline to 111.5, (cam card calls for 111), it changed the clearance to .069 at 8 atdc. Tightest point again.
I think I'm going to do a .030 relief cut and run the .041 gaskets.
Doing the math like this: .056 shim when measuring - .041 gasket = .015
Clearance as measured = .069 - .015 gasket thickness adjustment = .054 existing clearance
Desired clearance = .080 - existing clearance .054 = .026 minimum relief cut
What size cutter should I use? I have the stock 2.00" valves. I'm thinking 2.10"
12-16-2019, 08:01 AM
#26
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I double checked everything and I'm not sure why I posted that the intake clearance was .074, that was at 5 degrees atdc. It was actually .067 at 8 degrees where it was tightest . This was with the intake centerline at about 110.5 degrees. Also the shims I was using are more like .056 so thicker than the stock gasket.
I adjusted the intake centerline to 111.5, (cam card calls for 111), it changed the clearance to .069 at 8 atdc. Tightest point again.
I think I'm going to do a .030 relief cut and run the .041 gaskets.
Doing the math like this: .056 shim when measuring - .041 gasket = .015
Clearance as measured = .069 - .015 gasket thickness adjustment = .054 existing clearance
Desired clearance = .080 - existing clearance .054 = .026 minimum relief cut
What size cutter should I use? I have the stock 2.00" valves. I'm thinking 2.10"
I adjusted the intake centerline to 111.5, (cam card calls for 111), it changed the clearance to .069 at 8 atdc. Tightest point again.
I think I'm going to do a .030 relief cut and run the .041 gaskets.
Doing the math like this: .056 shim when measuring - .041 gasket = .015
Clearance as measured = .069 - .015 gasket thickness adjustment = .054 existing clearance
Desired clearance = .080 - existing clearance .054 = .026 minimum relief cut
What size cutter should I use? I have the stock 2.00" valves. I'm thinking 2.10"
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12-31-2019, 08:14 AM
#29
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Nice job