Fly cutting questions
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Teching In
Joined: Oct 2007
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Fly cutting questions Ok, so i am rerady for my head/cam swap. I have a ms4 cam, ls6 heads that have been freshened and milled .010 to true them with 040 gaskets and all of the bolts ons to go along with it. I am aware i am going to need to fly cut.
I have never done this before and i am not afraid of it, but i need to measure properly because i do not want to remove more than i need. this is where i am a little fuzzy, what is the best way to measure ptv clearence?
Also, does anybody have 2.0, 1.55 fly cutters to rent or f/s used?
I have never done this before and i am not afraid of it, but i need to measure properly because i do not want to remove more than i need. this is where i am a little fuzzy, what is the best way to measure ptv clearence?
Also, does anybody have 2.0, 1.55 fly cutters to rent or f/s used?
This is how I checked PTV clearance. It worked pretty well. https://ls1tech.com/forums/showpost....64&postcount=6
You can rent the tools from LG motorsports. If you have 2.0 and 1.55 valves, you'll need cutters a little bigger in diameter.
You can rent the tools from LG motorsports. If you have 2.0 and 1.55 valves, you'll need cutters a little bigger in diameter.
You will get different views on measuring PTVC. When I flycut I used organic modeling clay. It was very easy and as well as measuring I was able to see a visual reference of how much clearance I had.
As for renting cutters, I agree with Xtnct00WS6. I would love to help you out, but my cutters are for 2.02 and 1.575 valves.
Good luck with your project.
R/
Frat
As for renting cutters, I agree with Xtnct00WS6. I would love to help you out, but my cutters are for 2.02 and 1.575 valves.
Good luck with your project.
R/
Frat
The most accurate method is with a dial indicator and degree wheel.
Basic Instructions:
Using low-tension checking springs, assemble the valve train and verify correct lifter preload or valve lash. A hydraulic roller lifter modified to be solid is the best type of lifter to use for this operation. The modified lifter won't bleed down and provides solid repeatable results. Mount a dial indicator on the cylinder head with the plunger's tip on the valve spring retainer.
Hand rotate the engine through a complete cycle (two rotations of the crankshaft), stopping at several points before and after Top Dead Center (TDC) to check valve clearance. The least amount of clearance will usually occur between 15 degrees before TDC and 15 degrees after TDC. This also provides a graphic illustration that gross valve lift does not determine piston-to-valve clearance, as the piston is fairly far down in the cylinder when maximum valve lift is reached.
By pushing the rocker arm down, the valve will contact the piston. The amount of movement shown on the dial indicator is the valve clearance at that point of engine rotation. Rotate the crankshaft a few degrees and re-check the clearance. As the piston moves through this area, the dial indicator reading will decrease, then increase as the engine rotates past the critical point. The smallest recorded reading is the actual piston-to-valve clearance.
Basic Instructions:
Using low-tension checking springs, assemble the valve train and verify correct lifter preload or valve lash. A hydraulic roller lifter modified to be solid is the best type of lifter to use for this operation. The modified lifter won't bleed down and provides solid repeatable results. Mount a dial indicator on the cylinder head with the plunger's tip on the valve spring retainer.
Hand rotate the engine through a complete cycle (two rotations of the crankshaft), stopping at several points before and after Top Dead Center (TDC) to check valve clearance. The least amount of clearance will usually occur between 15 degrees before TDC and 15 degrees after TDC. This also provides a graphic illustration that gross valve lift does not determine piston-to-valve clearance, as the piston is fairly far down in the cylinder when maximum valve lift is reached.
By pushing the rocker arm down, the valve will contact the piston. The amount of movement shown on the dial indicator is the valve clearance at that point of engine rotation. Rotate the crankshaft a few degrees and re-check the clearance. As the piston moves through this area, the dial indicator reading will decrease, then increase as the engine rotates past the critical point. The smallest recorded reading is the actual piston-to-valve clearance.
