Valve clearance help!

[boostyGST]

Any one ever have issues with 1mm over manley valves with 264/272 cam set up having clearance issues with hitting the piston.

The way I figured I could check this is by sitting the fully decked/completed head down on the block and turn the cam gears to see if I cleared, well the valves are hitting!!

But is this method even plausable, because wouldnt the piston be moving down and the valves are opening up?

Help me out here, and tell me any good, proven method to check to make sure the valves are not going to hit the pistons upon initial start up!!

thks

 

[boostyGST]

anything more specific please WTF ......i mean i am talking a 2000 dollar head here!!!

 

[92awddsm]

anything more specific please WTF ......i mean i am talking a 2000 dolar head here!!!

I run ferrea 1mm os valves, comp 101200, block decked to zero, head cut .010, and a cometic hp hg. Never had any clearance problems. And yes, the intake valves chase the pistons down and the pistons chase the exhaust valves up.

 

[gsx951]

Any one ever have issues with 1mm over manley valves with 264/272 cam set up having clearance issues with hitting the piston.

The way I figured I could check this is by sitting the fully decked/completed head down on the block and turn the cam gears to see if I cleared, well the valves are hitting!!

But is this method even plausable, because wouldnt the piston be moving down and the valves are opening up?

Help me out here, and tell me any good, proven method to check to make sure the valves are not going to hit the pistons upon initial start up!!

thks

Blue the piston tops at the valve relief with dykem or similar machinist blue and install the head and T-belt. turn the motor over with a wrench, then disassemble and inspect. We use machinist blue all over to check for interference in fit ups when rebuilding machine tools. The blue will be scraped off if there is even slight contact.

 

[92awddsm]

Blue the piston tops at the valve relief with dykem or similar machinist blue and install the head and T-belt. turn the motor over with a wrench, then disassemble and inspect. We use machinist blue all over to check for interference in fit ups when rebuilding machine tools. The blue will be scraped off if there is even slight contact.

The best bet would be mock it up with clay in the valve releifs and check to see what clearence really is. The dykem might show clearance but just .003" wont cut it. It should be at least .060" on the exhaust side and thats with good valve springs. The dykem will show interference but not clearance.

Make sure you have a hg installed of equivilent thickness as you plan to run when checking clearance. I have a compressed cometic that you can use if needed, just pm me.

 

[boostyGST]

I run ferrea 1mm os valves, comp 101200, block decked to zero, head cut .010, and a cometic hp hg. Never had any clearance problems. And yes, the intake valves chase the pistons down and the pistons chase the exhaust valves up.

ok that is good that your head is very simular to mine, however what pistons are you running in that engine of yours?

See, i dont know if I am right or not, but dont most aftermarket pistons have a larger dished out surface?

Considering I have stock pistons which hardly have any releif for the valves, this makes me have the queston of clearence issues.

See the funny thing is I will be running a cometic HP gasket, so i know this is going to provide a few thousandths more space over the stocker which i kept on there to check for clearance. The clay and machinists dye I have already thought of, however what is the point when you go to turn the cam gear over and the valves clearly hit the piston?

Should is turn freely evan when piston is TDC or not, because of the way the piston travels in relation to the valves when the engine is turning over?

 

[92awddsm]

ok that is good that your head is very simular to mine, however what pistons are you running in that engine of yours?

See, i dont know if I am right or not, but dont most aftermarket pistons have a larger dished out surface?

Considering I have stock pistons which hardly have any releif for the valves, this makes me have the queston of clearence issues.

See the funny thing is I will be running a cometic HP gasket, so i know this is going to provide a few thousandths more space over the stocker which i kept on there to check for clearance. The clay and machinists dye I have already thought of, however what is the point when you go to turn the cam gear over and the valves clearly hit the piston?

Should is turn freely evan when piston is TDC or not, because of the way the piston travels in relation to the valves when the engine is turning over?

I am running stock pistons also.

If you just set the head on the block, the valves will hit the piston if it is just sitting at tdc. You have to rotate the crank in relation to the cams to keep it from hitting. Your best bet is to install the timing belt and rotate as an assembly because just rotating the cams wont tell you anything about clearance.

 

[Defiant]

The way I figured I could check this is by sitting the fully decked/completed head down on the block and turn the cam gears to see if I cleared, well the valves are hitting!!

It's an interference engine. This is why losing the cam belt bends valves. You can't check valve clearance on any engine unless you're driving the cams and crank in time.

 

[boostyGST]

thks alot guys appreciate it !!