Mopar Performance Lifters

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daddio4048

Daddios72
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Anybody have any issues with the hydraulic lifters that came in the old Purple Camshaft kits?
 
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No problems whatsoever. I have always found them to be a high quality lifter and have pretty much done everything I've asked to do RPM range. I've had two sets in my motor over the last 20 years. I have ran them with both factory style and roller rockers,, but just like any hydraulic lifter you need to keep the spring rate reasonable.
 
Hyd.? Never an issue though multiple different camshafts from mild to wild, street grinds to oval track grinds to 12 sec. bracket cams.
 
Being that the Hyd lifted is self adjusting the pushrod has to be the correct length. If you swapped out a cam with higher lift, it is possible that the pushrod is to short or to long. This depends on the lift of the cam and how it was ground. If the stock diameter of the base circle of the cam is stock, then the added lift (if enough) makes the pushrod to long. If the base circle of the cam is ground smaller than stock, then the pushrod is to short.

Other measurements that can effect the pushrod length is if the block was milled and/or the heads were milled. Head gasket thickness is also a factor as well as between the stock stamped rockers or adjustable rocker arms.

I had a block and head set milled so much, when I was ordering pushrods I was asked to double check & asked if this was for a different engine because the length was so odd.
 
What kind of issues are you having?
Got engine going & did the usual 20 minute break in on the cam & everything was good. Did a couple more start ups with different RPM changes & motor ran great. Went to start back up the other day & noticed a lifter tap on driver's side that I didn't have before. I have Toth Aluminum heads with adjustable rockers. I'm figuring things are just settling in & that I need to go back & adjust the valves again.
 
Probably. lifters went in, not to tight? Easy slide up and down well beyond there normal traveling limits? Un obstructed oil flow tongue lifter?
 
Probably. lifters went in, not to tight? Easy slide up and down well beyond there normal traveling limits? Un obstructed oil flow tongue lifter?
It was just one lifter doing this. I took the lifter out & took it apart & found no issues. I'm thinking just soak it oil again,pump it up,& reinstall it. Maybe things just settling in?
 
The only thing I ever noticed is sometimes they get jammed up. Why? IDK. Settling in? I don’t see it that way. I’m not sure how they would have to settle in.
 
The only thing I ever noticed is sometimes they get jammed up. Why? IDK. Settling in? I don’t see it that way. I’m not sure how they would have to settle in.
I'm just thinking about the spring in the lifter may just settled just enough to start the tapping. How much do you adjust your adjustable rockers? I know everybody has different ways but I know some have that certain way that seems to work better than just the normal way!
 
Screw showing 1-1/2 threads with the pushrod depressing the lifter approximately. .050. However, some lifter manufacturers or cam grinders or performance shops like Hughesengines will suggest a certain amount of lifter depression and/or thread count showing for THERE material. Also a lifter like a variable duration or other catch name will suggest something else.

Have the rocker shafts been shimmed?
This could also change pushrod length.
 
I have always found Mopar performance lifters to like very little preload 0.50 or less. As mentioned earlier I have run direct connections / Mopar performance lifters almost exclusively and are currently running them in my 340. I would truly hesitate to think that it's lifter failure unless something weird happened during break-in. I will tell you that I have had those lifters clatter around for a while after a cam replacement for the first few startups and then just settle in and perlite kittens for no apparent reason. Also when I went from stock to adjustable rocker arms it took a while to get it dialed in.
 
How did you adjust your preload. Bring your cam around to the base circle and reduce pressure on the push rod till you have zero preload. You shouldn't be able to move the push rod up or down but should be able to twist it gently with your fingers. And screw your rocker adjustment down 1/2 to 3/4 of a turn and lock it in. Some adjustments might very slightly but that should put you definitely in the ballpark to rock and roll.
 
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