Roller lifter bleed down

[anotheridiot]

off the subject, looking for the next mechanics special, get to some Cherokees with 5.7 hemis and go to learn that those lifters make it thru original warranty, but there is insufficient oiling happening at the rollers. Cam is up higher than what we are used to in small blocks, so the splash from the crank only gets there at higher RPM's. Idle, whatever gets thru the push rod, gets to the lifter and runs off the inner side barely lubing the needle bearings and at the mileage where these are "worthwhile" you are looking at 1500 for cam and lifters. Yeah, I read that a few times, the lifter is supposed to be pumping the oil thru the pushrod to lubricate the rockers.

So it seems like manufacturers know these problems. My question is still the same. You decide, I know this is a problem, but I know Gatermans can take a half turn lash when everybody elses say zero lash. If you squeeze down a lifter not designed for the 1/2 turn, all you are really doing is pushing the oil out faster when the car is turned off, right? The 6 or 8 valves that are closed will push out less, but the ones that are open will push out more.

So considering this hemi problem, are the GM's designed to let more oil thru the lifter so it gets to the needle bearings on the lifter so it makes the lifter noisy at startup but the rollers are lubed? Just made me think of this thread and wonder if this problem is part of the solution.

[anotheridiot]

We are changing injections again, took the manifold off, found the standard rocker arm lock nuts were half tight, half loose. Went back to poly locks. After another few hours of searching found that Howards cams uses Morel lifters and found this article that finally made some sense regarding lash.

https://golenengineservice.com/blog/morel-hydraulic-roller-lifter-adjustment-procedure/

So we have 3/8-24 studs, went to 3/4 turn that should have these only .031 of preload. I still cannot push down the plunger of the lifter to see how far it actually travels, but went around back to one at a time and I could see the plunger down past where it was when the lash was set. I dont know how long until it runs again, but at least this article showed me there is not a simple answer, depends on the combination of block and head, but solidified that you need to preload a lifter.

[fatguyzinc]

dunno why it posted this a page back, but heres a repost---


in street applications..... none of the aftermarket ones will tolerate
extended low speed/idle operations....

sounds familiar... didnt realize OEM ones were like that too, but my
moms brother lost a durango with the 5.7 AND a gmc 4x4 with the
LS motor due to lifter issues..... think the LS the lifter "trays" degraded
and they started turning sideways, not good when theres a directional
wheel on the bottom.

[anotheridiot]

dunno why it posted this a page back, but heres a repost---


in street applications..... none of the aftermarket ones will tolerate
extended low speed/idle operations....

sounds familiar... didnt realize OEM ones were like that too, but my
moms brother lost a durango with the 5.7 AND a gmc 4x4 with the
LS motor due to lifter issues..... think the LS the lifter "trays" degraded
and they started turning sideways, not good when theres a directional
wheel on the bottom.

I ended up getting a hemi cherokee that we need to do the lifter job on. Still looking for an answer before buying any parts. Their issues are poor block oiling and all the aftermarket stuff is non MDS, so its both plugging oil passages and turning MDS off on the computer. People go to the hellcat oil pump and lifters, but those lifters are non MDS anyway. Go straight to mopar since they claim to have made changes and the lifters say, for after 3-15-2016 applications, then to use on pre 3-15-2015 applications. You can pay 1100 thru mopar for the lifters, or go to amazon and get an entire kit, with cam and waterpump, all the gaskets for around 400. Apparently mopars make past warranty so they are not redesigning the block. The melling high volume oil pump seems to be part of the answer, but they only make non MDS replacement lifters too.
Its not like people are buying a hemi to turn it to a 4 cylinder on the highway, but either way MDS or non MDS, they are prone to failure.