piston to valve clearance..
Thread Starter
11 Second Club
iTrader: (3)
Joined: Aug 2005
Posts: 239
Likes: 0
From: sweet home CS/ baytown
piston to valve clearance.. -already tried the search with no luck.
i pretty sure i have seen a formula posted before to calculate piston to valve clearance.
can someone give me some information on this.. i want to know if a 236/236 .585/.585 112 cam will fit in a stock cube. the heads are tsp ls6's.
i pretty sure i have seen a formula posted before to calculate piston to valve clearance.
can someone give me some information on this.. i want to know if a 236/236 .585/.585 112 cam will fit in a stock cube. the heads are tsp ls6's.
Originally Posted by brad8266
Should fit without a problem.
There is no formula to calculate PTVC, you have to measure it yourself if you want to know.
There is no formula to calculate PTVC, you have to measure it yourself if you want to know.
Originally Posted by JPH
there is a formula, but it is never right. computers can't measure all the variables, just numbers. just put the cam in and check it, that's the only way to know for sure.
Might as well be no formula. I just checked mine by claying it, gave me piece of mind.
Originally Posted by brad8266
Well a formula that doesnt work is worthless. Might as well be no formula. I just checked mine by claying it, gave me piece of mind.
Might as well be no formula. I just checked mine by claying it, gave me piece of mind. Thread Starter
11 Second Club
iTrader: (3)
Joined: Aug 2005
Posts: 239
Likes: 0
From: sweet home CS/ baytown
what are the varius methods for checking clearance..
i assume once the heads and cam are in you could roll the motor over by hand, but it seems like there is better way..
i have experiance with heads/cam installs. i did the job about 4 different times in my last car, but clearance was never an issue. the shop assurred me of clearance.
i assume once the heads and cam are in you could roll the motor over by hand, but it seems like there is better way..
i have experiance with heads/cam installs. i did the job about 4 different times in my last car, but clearance was never an issue. the shop assurred me of clearance.
Trending Topics
Originally Posted by dirty2kTA
what are the varius methods for checking clearance..
i assume once the heads and cam are in you could roll the motor over by hand, but it seems like there is better way..
i have experiance with heads/cam installs. i did the job about 4 different times in my last car, but clearance was never an issue. the shop assurred me of clearance.
i assume once the heads and cam are in you could roll the motor over by hand, but it seems like there is better way..
i have experiance with heads/cam installs. i did the job about 4 different times in my last car, but clearance was never an issue. the shop assurred me of clearance.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?
Pouria Savadkouei
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
So when you say 'you clayed the heads' do you put a peice of modeling clay at a specific thickness on the piston, rebolt down the heads and then manually turn the motor over, repull the head and check to see if the valves left an eyebrow in the clay?
I get that, but can you buy clay at a predetermined thickness? I'm guessing you would need it be pretty uniform thickness in order to be an accurate measurement.
My issue is a little different. I've got a TR 224 on a 112lsa but my heads are milled, and I have 2.05 intake valves, and I'd like to go down a thinner head gasket, but don't want to throw an intake valve threw a piston...
I get that, but can you buy clay at a predetermined thickness? I'm guessing you would need it be pretty uniform thickness in order to be an accurate measurement.
My issue is a little different. I've got a TR 224 on a 112lsa but my heads are milled, and I have 2.05 intake valves, and I'd like to go down a thinner head gasket, but don't want to throw an intake valve threw a piston...
Originally Posted by The Alchemist
So when you say 'you clayed the heads' do you put a peice of modeling clay at a specific thickness on the piston, rebolt down the heads and then manually turn the motor over, repull the head and check to see if the valves left an eyebrow in the clay?
I get that, but can you buy clay at a predetermined thickness? I'm guessing you would need it be pretty uniform thickness in order to be an accurate measurement.
My issue is a little different. I've got a TR 224 on a 112lsa but my heads are milled, and I have 2.05 intake valves, and I'd like to go down a thinner head gasket, but don't want to throw an intake valve threw a piston...
I get that, but can you buy clay at a predetermined thickness? I'm guessing you would need it be pretty uniform thickness in order to be an accurate measurement.
My issue is a little different. I've got a TR 224 on a 112lsa but my heads are milled, and I have 2.05 intake valves, and I'd like to go down a thinner head gasket, but don't want to throw an intake valve threw a piston...
Brad you got the numbers mixed up. you want .080" on teh intake side, and .100 on the exhaust. the reason for the difference is the exh. valve gets hotter then the intake valve due to the incomeing air/fuel cooling the valve down.
anyways I got some pics for you from when I did mine. you want modeling clay because it will not "spring" back up after the valve has compressed it. somewhere around .25" thick is what you want. too much and it'll stick to the head and peel up when you lift off the head. I cleaned the piston top really good, and oiled the combustion chamber and valves so the clay would not stick to the clay. carefully cut the clay down the deepest part of the indentation and remove the outer half. you can use either feeler gauges, or the point of a dial caliper to measure the depth. also, you'll want to use either checking springs in place of the valve springs so the plunger in the lifter doesnt colapse and give you a false reading, or just do like I did. use modified stock lifters that have solid internals, and NO plunger movement. I dissasembled some old stock lifters and filled them with epoxy and reassembled. then just add your preload.
that should help you picture what your goin to do. I used some putty instead of modeling clay. its not as easy to work with, but it still works just fine. you can get modeling clay at hobby stores. wish I would have known that before. couldnt figure out who the F@@@ sold that stuff.
anyways I got some pics for you from when I did mine. you want modeling clay because it will not "spring" back up after the valve has compressed it. somewhere around .25" thick is what you want. too much and it'll stick to the head and peel up when you lift off the head. I cleaned the piston top really good, and oiled the combustion chamber and valves so the clay would not stick to the clay. carefully cut the clay down the deepest part of the indentation and remove the outer half. you can use either feeler gauges, or the point of a dial caliper to measure the depth. also, you'll want to use either checking springs in place of the valve springs so the plunger in the lifter doesnt colapse and give you a false reading, or just do like I did. use modified stock lifters that have solid internals, and NO plunger movement. I dissasembled some old stock lifters and filled them with epoxy and reassembled. then just add your preload.
that should help you picture what your goin to do. I used some putty instead of modeling clay. its not as easy to work with, but it still works just fine. you can get modeling clay at hobby stores. wish I would have known that before. couldnt figure out who the F@@@ sold that stuff.
Originally Posted by Irocss85
Brad you got the numbers mixed up. you want .080" on teh intake side, and .100 on the exhaust. the reason for the difference is the exh. valve gets hotter then the intake valve due to the incomeing air/fuel cooling the valve down.
anyways I got some pics for you from when I did mine. you want modeling clay because it will not "spring" back up after the valve has compressed it. somewhere around .25" thick is what you want. too much and it'll stick to the head and peel up when you lift off the head. I cleaned the piston top really good, and oiled the combustion chamber and valves so the clay would not stick to the clay. carefully cut the clay down the deepest part of the indentation and remove the outer half. you can use either feeler gauges, or the point of a dial caliper to measure the depth. also, you'll want to use either checking springs in place of the valve springs so the plunger in the lifter doesnt colapse and give you a false reading, or just do like I did. use modified stock lifters that have solid internals, and NO plunger movement. I dissasembled some old stock lifters and filled them with epoxy and reassembled. then just add your preload.
that should help you picture what your goin to do. I used some putty instead of modeling clay. its not as easy to work with, but it still works just fine. you can get modeling clay at hobby stores. wish I would have known that before. couldnt figure out who the F@@@ sold that stuff.
anyways I got some pics for you from when I did mine. you want modeling clay because it will not "spring" back up after the valve has compressed it. somewhere around .25" thick is what you want. too much and it'll stick to the head and peel up when you lift off the head. I cleaned the piston top really good, and oiled the combustion chamber and valves so the clay would not stick to the clay. carefully cut the clay down the deepest part of the indentation and remove the outer half. you can use either feeler gauges, or the point of a dial caliper to measure the depth. also, you'll want to use either checking springs in place of the valve springs so the plunger in the lifter doesnt colapse and give you a false reading, or just do like I did. use modified stock lifters that have solid internals, and NO plunger movement. I dissasembled some old stock lifters and filled them with epoxy and reassembled. then just add your preload.
that should help you picture what your goin to do. I used some putty instead of modeling clay. its not as easy to work with, but it still works just fine. you can get modeling clay at hobby stores. wish I would have known that before. couldnt figure out who the F@@@ sold that stuff.
I knew what i meant, I just typed it backwards, i do that all the time. I know, Im constantly swithcing letters around while Im typing. see what I mean? I left that just to prove my point. I think the backspace button gets used more then the return key.lol.
Originally Posted by dirty2kTA
what are the varius methods for checking clearance..
i assume once the heads and cam are in you could roll the motor over by hand, but it seems like there is better way..
i have experiance with heads/cam installs. i did the job about 4 different times in my last car, but clearance was never an issue. the shop assurred me of clearance.
i assume once the heads and cam are in you could roll the motor over by hand, but it seems like there is better way..
i have experiance with heads/cam installs. i did the job about 4 different times in my last car, but clearance was never an issue. the shop assurred me of clearance.
12 Second Club
iTrader: (13)
Joined: Feb 2005
Posts: 1,575
Likes: 1
From: Gateway International Raceway
Found this interesting http://www.centuryperformance.com/piston2valve.asp
http://www.compcams.com/technical/Ca...106-07/381.pdf
2. Check piston to valve clearance.
Insufficient clearance will render the engine inoperable. A minimum clearance
of .100” on the intake valve and .125” on the exhaust must be maintained.
Keep in mind that when you advance or retard the cam, it dramatically
changes clearance. Also, most of our High Energy Cams™, Magnum
Cams, and Xtreme Energy Cams™ are ground with 4 degrees advance already
in them. Always check clearance with the cam degreed in the correct position.
For instructions on checking piston to valve clearance, see our camshaft
installation sections on page 378.
http://www.compcams.com/technical/Ca...106-07/381.pdf
2. Check piston to valve clearance.
Insufficient clearance will render the engine inoperable. A minimum clearance
of .100” on the intake valve and .125” on the exhaust must be maintained.
Keep in mind that when you advance or retard the cam, it dramatically
changes clearance. Also, most of our High Energy Cams™, Magnum
Cams, and Xtreme Energy Cams™ are ground with 4 degrees advance already
in them. Always check clearance with the cam degreed in the correct position.
For instructions on checking piston to valve clearance, see our camshaft
installation sections on page 378.
Last edited by ExceSSive; May 9, 2007 at 08:30 PM.
There is a formula you can use if you have all of your motor specs.
Freedrop - piton depth - .100 + gasket thickness = total Lift clearance @ tdc
Tappet lift @TDC Lobe CL x rocker ratio = Valve Lift @ tdc.
If your valve lift at TDC if more than the clearance then you have to flycut.
Freedrop - piton depth - .100 + gasket thickness = total Lift clearance @ tdc
Tappet lift @TDC Lobe CL x rocker ratio = Valve Lift @ tdc.
If your valve lift at TDC if more than the clearance then you have to flycut.
