S&S Hydraulic Lifters with LT Kit - Travel inconsistent on new Lifters.
- Thread starter Th3InfamousI
- Start date
john sachs
Well-Known Member
If you have a lifter, or lifters that bleed all the way down after sitting for even a month, you'd better replace them.
Travel limiters have nothing to do with long duration cams vs. compression
The proper way to set the lifters with travel limiters is :
Engine at TDC compression stroke.
Adjust p/rod to bottom lifter out.
Loosen the p/rod so you can just turn the lifter with your fingers, or a half turn.
John
Travel limiters have nothing to do with long duration cams vs. compression
The proper way to set the lifters with travel limiters is :
Engine at TDC compression stroke.
Adjust p/rod to bottom lifter out.
Loosen the p/rod so you can just turn the lifter with your fingers, or a half turn.
John
john sachs
Well-Known Member
NO.................
I'd actually like to know his opinion on the LT kit itself and if he uses it. I'm not sure there is a significant benefit on a stock motor...but I could be way wrong. Wouldn't be the first time.
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Last edited:
Olde Man
Active Member
I adjust my lifters from the bottom because using the large valve spring to push the oil out of the lifer and collapse it to the bottom is a lot more positive than hoping that the little spring inside the lifter can pull oil in and send the plunger in the lifter to the top especially when the oil is cold.
Olde Man
Active Member
I am going to try to explain what I meant about the lifter collapsing and hard starting.
If the engine stops with the intake valve open, then the pressure of the valve spring will push the oil out of the lifter sending the lifter plunger to the spacer or the bottom of the lifter. With out the spacer the clearance will be .100 if the lifter is adjusted to the center and will be .043 if the limiters are used. This means that the cam will not lift the valve as far and will close the valve sooner. Closing the valve sooner when the piston is rising on the compression. stroke will increase the dynamic compression ratio dramatically. There are two basic compression ratios. Static is what every one talks about and it is a ratio of the swept volume of the piston compared to the space between the piston and the head. The dynamic compression ratio is the swept volume of the piston after the intake valve is closed compared to the space between the piston and the head. The camshaft duration, specifically the intake valve closing timing ABDC ,after bottom dead center, is the primary player in the scenerio. The 585 cam intake closes at 45deg ABDC and the 600 55deg ABDC. The 585 is built with 9.5cr and the 600 with 10.2cr. They both net about the same cranking resistance. In the collapsed intake lifter situation the dynamic ratio can go high and create starting problems. I previously said that I had removed mine. After writing this mine are going back in.
If the engine stops with the intake valve open, then the pressure of the valve spring will push the oil out of the lifter sending the lifter plunger to the spacer or the bottom of the lifter. With out the spacer the clearance will be .100 if the lifter is adjusted to the center and will be .043 if the limiters are used. This means that the cam will not lift the valve as far and will close the valve sooner. Closing the valve sooner when the piston is rising on the compression. stroke will increase the dynamic compression ratio dramatically. There are two basic compression ratios. Static is what every one talks about and it is a ratio of the swept volume of the piston compared to the space between the piston and the head. The dynamic compression ratio is the swept volume of the piston after the intake valve is closed compared to the space between the piston and the head. The camshaft duration, specifically the intake valve closing timing ABDC ,after bottom dead center, is the primary player in the scenerio. The 585 cam intake closes at 45deg ABDC and the 600 55deg ABDC. The 585 is built with 9.5cr and the 600 with 10.2cr. They both net about the same cranking resistance. In the collapsed intake lifter situation the dynamic ratio can go high and create starting problems. I previously said that I had removed mine. After writing this mine are going back in.
Marky-Marc
Well-Known Member
Just chiming in...I soak NEW lifters in oil overnight before installing them....just my .02......
john sachs
Well-Known Member
All righty then.
If you have a lifter that bleeds down to where it becomes noisy when the motor sits with a valve open you have either a bad lifter or too much valve spring pressure.
Adjustable push rod manufacturers have a spec for proper adjustment based on the threads per inch of the threaded adjuster.
Ideally the lifter should be set in the center of its internal travel.
Travel limiters restrict some of the travel of a hydraulic lifter. Purpose is to help lifter from pumping up at high rpm. That's why they're set differently.
I use limiters in super high compression/high rpm builds. No need for stock or semi-hot builds.
Hope this helps.
John
Soaking lifters overnight without pressurizing them won't usually do much.
If you have a lifter that bleeds down to where it becomes noisy when the motor sits with a valve open you have either a bad lifter or too much valve spring pressure.
Adjustable push rod manufacturers have a spec for proper adjustment based on the threads per inch of the threaded adjuster.
Ideally the lifter should be set in the center of its internal travel.
Travel limiters restrict some of the travel of a hydraulic lifter. Purpose is to help lifter from pumping up at high rpm. That's why they're set differently.
I use limiters in super high compression/high rpm builds. No need for stock or semi-hot builds.
Hope this helps.
John
Soaking lifters overnight without pressurizing them won't usually do much.
Thanks John that's what I thought figured stock to mild build is of no significant use. Granted they are not expensive to add however.
With stock lifters 3.2 turns or 20 flats with S&S pushrods should nail you damn near dead center.
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