Over Sized Valves - Reduced P2V?
Thread Starter
Teching In
Joined: Mar 2012
Posts: 7
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Over Sized Valves - Reduced P2V? Hello,
Im in the middle of doing heads and cam on a LS6 and keep coming up with very tight P2V clearances.
IN .010"
Ex .070"
I am using both dial indicator and clay method. Could oversized valves make such a big difference?
Stock ls6 block, stock pistons
243 Heads milled .020", 2.020" IN valve, 1.57" EX valve.
TSP MS3 112LSA Cam
The procedure used to set up the valve train is as follows:
Welded solid lifters
Install push rod 'checker' rods
Tighten down rockers snug
Expand checker rod till zero lash
Head is bolted down snug using the old stock GM head gasket.
Is this correct? am i missing something?
Thanks in advance.
Im in the middle of doing heads and cam on a LS6 and keep coming up with very tight P2V clearances.
IN .010"
Ex .070"
I am using both dial indicator and clay method. Could oversized valves make such a big difference?
Stock ls6 block, stock pistons
243 Heads milled .020", 2.020" IN valve, 1.57" EX valve.
TSP MS3 112LSA Cam
The procedure used to set up the valve train is as follows:
Welded solid lifters
Install push rod 'checker' rods
Tighten down rockers snug
Expand checker rod till zero lash
Head is bolted down snug using the old stock GM head gasket.
Is this correct? am i missing something?
Thanks in advance.
Hello,
Im in the middle of doing heads and cam on a LS6 and keep coming up with very tight P2V clearances.
IN .010"
Ex .070"
I am using both dial indicator and clay method. Could oversized valves make such a big difference?
Stock ls6 block, stock pistons
243 Heads milled .020", 2.020" IN valve, 1.57" EX valve.
TSP MS3 112LSA Cam
The procedure used to set up the valve train is as follows:
Welded solid lifters
Install push rod 'checker' rods
Tighten down rockers snug
Expand checker rod till zero lash
Head is bolted down snug using the old stock GM head gasket.
Is this correct? am i missing something?
Thanks in advance.
Im in the middle of doing heads and cam on a LS6 and keep coming up with very tight P2V clearances.
IN .010"
Ex .070"
I am using both dial indicator and clay method. Could oversized valves make such a big difference?
Stock ls6 block, stock pistons
243 Heads milled .020", 2.020" IN valve, 1.57" EX valve.
TSP MS3 112LSA Cam
The procedure used to set up the valve train is as follows:
Welded solid lifters
Install push rod 'checker' rods
Tighten down rockers snug
Expand checker rod till zero lash
Head is bolted down snug using the old stock GM head gasket.
Is this correct? am i missing something?
Thanks in advance.
If you haven't already, degree the cam and verify your centerlines. Make sure you don't have the cam in too far advanced.
Thread Starter
Teching In
Joined: Mar 2012
Posts: 7
Likes: 0
Cam gear is dot to dot. I have double checked that.
Cam is spot on with centerline at 110 deg. IN at 237 and EX at 243 which is +/- 1 deg per specs.
Can someone double check my valve train set up procedure please.
welded solid lifter
used GM gasket
Head bolted snug
Comp 'checker' push rod
Cam on base lobe
Rocker bolted snug
Extend 'checker' push rod till zero lash
Dial indicator on retainer of valve spring
I feel like oversized valves and .020" mill should not reduce the P2V this much.
Cam is spot on with centerline at 110 deg. IN at 237 and EX at 243 which is +/- 1 deg per specs.
Can someone double check my valve train set up procedure please.
welded solid lifter
used GM gasket
Head bolted snug
Comp 'checker' push rod
Cam on base lobe
Rocker bolted snug
Extend 'checker' push rod till zero lash
Dial indicator on retainer of valve spring
I feel like oversized valves and .020" mill should not reduce the P2V this much.
Shouldn't the intake CL be like 108 on that cam with an LSA of 112? So, Roll through the clay, take off the head, cut and measure the clay. As mentioned, you should strongly consider a degree wheel, you could find absolute TDC and not guess at where your came is installed
Thread Starter
Teching In
Joined: Mar 2012
Posts: 7
Likes: 0
Cam card has IN centerline at 110.
Everything is being checked with a degree wheel and dial indicator.
Also, not mentioned, i am using checker springs.
Im confident the cam is in spec. I would like more verification on the procedure used for setting up the valve train mentioned above.
Everything is being checked with a degree wheel and dial indicator.
Also, not mentioned, i am using checker springs.
Im confident the cam is in spec. I would like more verification on the procedure used for setting up the valve train mentioned above.
Cam card has IN centerline at 110.
Everything is being checked with a degree wheel and dial indicator.
Also, not mentioned, i am using checker springs.
Im confident the cam is in spec. I would like more verification on the procedure used for setting up the valve train mentioned above.
Everything is being checked with a degree wheel and dial indicator.
Also, not mentioned, i am using checker springs.
Im confident the cam is in spec. I would like more verification on the procedure used for setting up the valve train mentioned above.
Thread Starter
Teching In
Joined: Mar 2012
Posts: 7
Likes: 0
Thanks KCS.
Checker push rod was only just snug enough to remove lash. No spring compression.
I guess i could double check this by setting up the dial indicator before extending the checker push rod.
Those checker springs are soft after all.
Checker push rod was only just snug enough to remove lash. No spring compression.
I guess i could double check this by setting up the dial indicator before extending the checker push rod.
Those checker springs are soft after all.
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Teching In
Joined: Mar 2012
Posts: 7
Likes: 0
So I ended up moving forward with fly cutting. Went .080" on IN and EX.
Double checked P2V afterwards. Perfect.
Now I have a question on radial clearance.
Does this look sufficient?
Also, does it make a difference if 806 heads were used for fly cutting, but i will be using 243 heads on the car?
Intake:
Exhaust:
Double checked P2V afterwards. Perfect.
Now I have a question on radial clearance.
Does this look sufficient?
Also, does it make a difference if 806 heads were used for fly cutting, but i will be using 243 heads on the car?
Intake:
Exhaust: