Mash down of Comp roller lifter

[ThikStik]

How about that for techical term!! Anyway, after another valve job, my moronic machine shop has one of my lifters (I checked pushrod preload) mashing down .100". What is limit of Comp's roller lifter? My cam is PN 69-000-8 206/210 517 lift. Now my other fear is a thin intake valve causing detonation from running hot.
Thanks

 

[WSLN 6]

I would definately invest in a set of adjustable roller rockers like T&D or Harland Sharpe then you will have no more machine shop worries.

 

[bison]

I would definately invest in a set of adjustable roller rockers like T&D or Harland Sharpe then you will have no more machine shop worries.

He needs a different set of rods too. The adjuster wont back out enough to compensate for that much preload. Machine shop should be slapped for that one

 

[ThikStik]

Oh Lord. Would this be the case if the lowest was .060 ? Meaning the preloads range from .060 to .100? Thanks guys. Do yall have a preference on TD's vs HarlandSharpes?

 

[bison]

Oh Lord. Would this be the case if the lowest was .060 ? Meaning the preloads range from .060 to .100? Thanks guys. Do yall have a preference on TD's vs HarlandSharpes?

If they were all at .060 id be less concerned. Ive used T&D with no problems over the years. I only run about .020 preload on comp 885 and no preload on the 885's.

 

[ThikStik]

I talked to Red and went ahead and bought his Harlands, he thinks theyll take up the slop. I hate to admit it, but dont know if my lifters are 885's or 853's even after checking the Comp cam card from Full Throttle. Red thinks I probably have the milder lifter (853's) and will need around 25-40 pre load. I reckon i could get 2 or 3 custom pushrods for the real high stems...the hassle never ends!
bison-What does Kentucky jelly mean?
Thanks

 

[bison]

I talked to Red and went ahead and bought his Harlands, he thinks theyll take up the slop. I hate to admit it, but dont know if my lifters are 885's or 853's even after checking the Comp cam card from Full Throttle. Red thinks I probably have the milder lifter (853's) and will need around 25-40 pre load. I reckon i could get 2 or 3 custom pushrods for the real high stems...the hassle never ends!
bison-What does Kentucky jelly mean?
Thanks

My other post should have been .020 on the 853's. The 885's use a gold colored steel retainer to hold the pushrod plungers down. Others use a snap ring. If the heads are off id just get the tips of the valves ground a little on the high ones

 

[ThikStik]

Just wondering if say I had just bolted on the rockers as they were with the pre loads varying that much. I wonder if it would make for an unbalanced engine....meaning some cylinders would be stronger on low end and vice versa. That would make for parasitic drag between cylinders sapping power Id think. Picture rowers on a boat with some rowing different amounts. Like when checking compression its always said to look for evenness more than #'s. Now of course the 1 stem with the .100 mash down height would likely float a valve. I do remember a guy saying on here that he gained 100 hp from cleaning up the valve train preloads..cant remember the thread.

 

[ThikStik]

Thanks for that info, yea, they got snap rings. Heads are on with RJC gaskets. I almost thought about grinding down with a hand file. They are very close to valve buttons.

 

[bison]

Just wondering if say I had just bolted on the rockers as they were with the pre loads varying that much. I wonder if it would make for an unbalanced engine....meaning some cylinders would be stronger on low end and vice versa. That would make for parasitic drag between cylinders sapping power Id think. Picture rowers on a boat with some rowing different amounts. Like when checking compression its always said to look for evenness more than #'s. Now of course the 1 stem with the .100 mash down height would likely float a valve. I do remember a guy saying on here that he gained 100 hp from cleaning up the valve train preloads..cant remember the thread.

The only way you would gain is if the valves werent closing. Cranking compression wont tell you either. You wont know for sure till it lays down at high rpm. Thats why you shoud resolve it now and get them all close so you dont have to think about it.

 

[ThikStik]

I hear ya , and no doubt some of the previous valve jobs probably have been leaving the pre loads on the sloppy side as no machinist in Birmingham that Ive dealt with will do their jobs right. Ive noticed an amazing thing when doing a running valve adj...it is how much the engine is disturbed by barely moving one polylock on just one valve. Even putting a.010, etc gapper under rocker will disturb motor...then it recovers. Does the lifter mash down as the gap is closed, then recover its original position somewhat as plunger moves back while alittle oil exits lifter internals? Also it is known that more mash down gives alittle more low end and vice versa. Also, say if some poor sap, like me in this case, does have lengths all over the place and assuming it were to stay that way, then in essence, each cylinder has a different cam spec...kinda wild. Which also begs the question...What does a lifter do with its given preload? I imagine it settles out to a fairly predictable lift..maybe until hi rpms. Just thinking out loud, raising more ??? than answers fer suere. Thanks

 

[QUIP'6']

adjustable rockers arent designed to take up the slack of improper preload. sounds like your machine shop did a piss poor valve job. they should all be within one another. that .100 preload is going to mess up your geometry. your roller on the rocker has to be close to the middle of valve stem. sounds like you need shorter pushrods maybe .050 shorter

 

[bison]

adjustable rockers arent designed to take up the slack of improper preload. sounds like your machine shop did a piss poor valve job. they should all be within one another. that .100 preload is going to mess up your geometry. your roller on the rocker has to be close to the middle of valve stem. sounds like you need shorter pushrods maybe .050 shorter

Adjustable rockers may be able to be adjusted but htey wont correct the valvetrain geometry. As far as pre load goes less or more doesnt really matter unless the valve is not closing. Running lash on a hydraulic setup is not good. If you run light preloads you can be more sure the lifter is functioning as it should.

 

[ThikStik]

It was in that thread on here that I saw info on where a guy swears by even valve adj, and that preloads do give differing power peaks...more preload for lowe end and less for power on top. Wish i could remember which thread it was, but i agree, just get tehm even. Does anyone know what each turn of a HS rocker equates to ?
I may ask machine shop if theyll buy back the heads for the $240 they charged me for the job. Ive got about $1200 in them now ...remember it was another shop that cut the exh guides down, so when i took them back, they just sat on them for 1.3 years. The worst valve height (.100) is on the intake side so if i sent to .177's that would clean that one up anyway.
Thanks

 

[bison]

It was in that thread on here that I saw info on where a guy swears by even valve adj, and that preloads do give differing power peaks...more preload for lowe end and less for power on top. Wish i could remember which thread it was, but i agree, just get tehm even. Does anyone know what each turn of a HS rocker equates to ?
I may ask machine shop if theyll buy back the heads for the $240 they charged me for the job. Ive got about $1200 in them now ...remember it was another shop that cut the exh guides down, so when i took them back, they just sat on them for 1.3 years. The worst valve height (.100) is on the intake side so if i sent to .177's that would clean that one up anyway.
Thanks

My total solution to all potential valvetrain problems related to whether or not the valves were closing based on preload was to run comp 885's and zero preload/lash cold. I have run the 853's up to about 6000rpm and they were not a problem either. If you find the thread you were talking about and the person posting has no data supporting what he swears then it doesnt mean dick. Especially if the engine was only revving to a little over 5000rpm. Thousands of us on here have not had problems with the lifters pumping up at those rpm levels. Fwiw i have ran up to .040 and saw zero change as far as quarter mph and no noticeable difference anywhere else in between. The actual a/f was the same and the duty cycle was the same so from that id guess the engine output would be almost identical.

 

[Mike Licht]

Bison, I have seen guys run .080 preload on the 853's with no adverse effects or lifter pump up below 6200 RPM, they make less noise too. .030 to .050 is a good spot as far as I am concerned
Mike