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I have been told to take the travel of the hydraulic lifter off your final measurement in the clay and that it should be fairly accurate.Example if your lifters travel .06 when they pump up ,take .06 off the clay thickness and that should be the clearance.The only 100 % check is the solid roller but the lifter height,roller size must match your hydraulic lifter.
I have been told to take the travel of the hydraulic lifter off your final measurement in the clay and that it should be fairly accurate.Example if your lifters travel .06 when they pump up ,take .06 off the clay thickness and that should be the clearance.The only 100 % check is the solid roller but the lifter height,roller size must match your hydraulic lifter.
Where can I find that information (lifters travel), I can't find it at Comp Cams?
Originally Posted by Danish Shark
I wouldn't. A tiny scratch inside and they are ruined
Ok, what did you do, and are you ready for start up?
Normally hydraulic lifters call for 1/2 to 1 full turn preload.If you have 3/8 studs they have 24 tpi which equals .041666 per turn.If you are using 7/16 studs they have 20 tpi which equals .05 per turn.If you want to be conservative use the .05 for the 7/16 studs as your adjustment to the clay measurement.Comp should state the proper preload on their website.Some of the higher rpm lifters are also rated for limited travel so using the max preload variable should provide a little extra margin of safety.I suggest you may want to shoot Chris Straub a pm or email to verify using this method,he is usually more than willing to help.
Normally hydraulic lifters call for 1/2 to 1 full turn preload.If you have 3/8 studs they have 24 tpi which equals .041666 per turn.If you are using 7/16 studs they have 20 tpi which equals .05 per turn.If you want to be conservative use the .05 for the 7/16 studs as your adjustment to the clay measurement.Comp should state the proper preload on their website.Some of the higher rpm lifters are also rated for limited travel so using the max preload variable should provide a little extra margin of safety.I suggest you may want to shoot Chris Straub a pm or email to verify using this method,he is usually more than willing to help.
Thx.
It is AFR 195 with 3/8 studs.
I will PM Chris.
I did find this:
The following instructions cover the correct procedures for installing COMP Cams® High Energy
Lifters™. The High Energy Lifters™ can be used with adjustable and non-adjustable valve train
setups. Through various testing we have discovered that lifter preload should be set between .030” to
.040” or ½ to ¾ a turn of the wrench past zero for optimal performance.
C3 for your own information u need to take any one of your lifters and and try to force the little cup into the lifter by hand - yes even dry. I used a block of wood to push on the p-rod and all i could do is put a dent in the block of wood. What im saying is the little internal spring that counters the pre-load is plenty strong. Now against a say steel cam lobe force it is more cooperative.
Please try and force in that lifter cup and please, please report back. This a viral misconception on the forums. And i also caution u not to remove that little clip that holds the lifter cup in place. I have and that spring fights like a badger and u may never get the lifter back together again w/o damage. I believe there must be a dedicated tool for this.
So what i'll say is dont even worry 'bout lifter preload for your clay test.
Hope this helps more than hurts.
Last edited by cardo0; 04-25-2015 at 01:07 PM.
Reason: remove spring force
If your using lightweight checking springs, you shouldn't be compressing a hydraulic plunger......should be fine.....watch the plunger when you rotate the motor....I'll bet you see no compresion of the plunger. With stock L-46 forged pistons, you shouldn't have problems with a cam up to around 0.550-0.560" lift 12mm-14mm of lift.
C3 for your own information u need to take any one of your lifters and and try to force the little cup into the lifter by hand - yes even dry. I used a block of wood to push on the p-rod and all i could do is put a dent in the block of wood. What im saying is the little internal spring that counters the pre-load is plenty strong. Now against a say steel cam lobe force it is more cooperative.
Please try and force in that lifter cup and please, please report back. This a viral misconception on the forums. And i also caution u not to remove that little clip that holds the lifter cup in place. I have and that spring fights like a badger and u may never get the lifter back together again w/o damage. I believe there must be a dedicated tool for this.
So what i'll say is dont even worry 'bout lifter preload for your clay test.
Hope this helps more than hurts.
Hi cardo0,
I just tried to push, with a push rod. And I also tried to "press" the check springs.
It is "easy" to press down the piston in the lifter, I would say, it if the same amount of pressure, for the lifters and the check springs.
If your using lightweight checking springs, you shouldn't be compressing a hydraulic plunger......should be fine.....watch the plunger when you rotate the motor....I'll bet you see no compresion of the plunger. With stock L-46 forged pistons, you shouldn't have problems with a cam up to around 0.550-0.560" lift 12mm-14mm of lift.
I use Comp Cams 4758-2 springs.
Low Tension Checking Springs•2/pkg
I just tried to push, with a push rod. And I also tried to "press" the check springs.
It is "easy" to press down the piston in the lifter, I would say, it if the same amount of pressure, for the lifters and the check springs.
Thx.
Wow! Well thx for the test. Dont know what to say. They didnt for me. But i will try again next chance i get. Really surprised here. Well take my word for it dont remove the cup clip.
Wow! Well thx for the test. Dont know what to say. They didnt for me. But i will try again next chance i get. Really surprised here. Well take my word for it dont remove the cup clip.
I used a dial indicator on the top of the valve stem and checked the distance at different angles:
Clay will definitely compress the springs in the lifters. Remember the force of the checking spring add to the force of the clay in compressing the spring in the lifter
Wow! Well thx for the test. Dont know what to say. They didnt for me. But i will try again next chance i get. Really surprised here. Well take my word for it dont remove the cup clip.
I used a dial indicator on the top of the valve stem and checked the distance at different angles:
The checking springs I got with the Summit kit were too strong and would slowly compress the springs in the lifters. I could see the indicator on the dial slowly start creeping down after a while.
Clay will definitely compress the springs. Remember the force of the checking spring add to the force of the clay in compressing the spring in the lifter
As you can see from John's chart TDC is max .035 more clearance on both intake and exhaust. Put the piston @ TDC, remove the springs and let the valve sit on the piston. Measure how far from the top of valve to the spring seat. Then pull the valve closed with your fingers and measure top of valve to the spring seat. Subtract .035. That is about your minimum clearance. You should likely have plenty of margin. I have run +.600 lift cams with dome pistons. If it is to close for comfort do the clay test.
04-25-2015, 12:38 AM
Piston to valve clerance
