Don Terrill’s Speed-Talk

Hi all,
I have the valve covers off my small block chevy for maintenance and noticed one rocker firing a column of oil out over the front gaurd and onto the ground while all other rockers flow oil as per normal. What is causing this and can it be fixed by adjusting preload etc or do i need to remove the manifold and replace/repair the lifter? the cylinder is number 4 exhaust. The lifter is a Comp hydraulic flat tappet and is only 200 miles old. oil pressure hot at idle is 35 40psi and 60 psi running using a standard volume and pressure mellings pump.
Cheers
Adrian

Not unusual at all.

novafornow wrote: ↑Fri Dec 18, 2020 6:15 pm Not unusual at all.

X2

I would be worried of no oil...

ok, good to know, does that mean the metering disc under the pushrod cup is unseated or damaged?
I am thinking of lifting the intake manifold to replace one lifter which is not rotating, should i replace this over oiling one at the same time?

The oil going thru the lifters up to the rockers is supposed to be metered.

Sounds like you have one that has a defect in the metering element of the lifter, or perhaps has a piece of debris in it that’s creating a larger space/path for the oil to pass thru.
I would expect it to be fairly noticeable whatever the issue is....... but it will require lifter removal and disassembly........ so, it’s going to be a pita to figure it out.

OTOH, If it’s not causing any other issues........ you could just keep running it as is.

I am thinking of lifting the intake manifold to replace one lifter which is not rotating, should i replace this over oiling one at the same time?

I’d at least disassemble and inspect it, and replace if necessary........ but frankly, I’d be at least as concerned about the condition of the cam lobe that’s paired with the lifter that isn’t turning.
That doesn’t usually end well.

I'm very concerned about the non spinning lifter lobe, but it does only have 200 miles on it. Any tips on a fix not needing cam removal? New lifter with plenty of crown on the face? Any other ideas?

The oil from the other lifter is like a hose out of the engine bay and onto the ground two feet away from the car, I've never seen anything like it! I will disassemble the lifter and inspect for interest sake but will probably install a new one due to the effort involved removing the dizzy, manifolde etc.

A non-spinning lifter IS a worry & could well have wiped a lobe. The cam lobes should be inspected. Unlike rare parts made of un-obtainium, many of today's lifters are made from crap-ainium. I keep mentioning on this forum [ & others ] if you want to be sure your FT lifters will survive, have a set of factory lifters [ or lifters that are 25+ yrs old ] re-faced. They are then as good as new. We have been using re-faced lifters in Australia for DECADES with zero problems.

Agree also that the lifter firing oil like a fire hose is defective.

Curious but how did you work out one lifter isn't rotating?

After the break-in I removed the valve covers and started the engine and set it to idle, I had marked the pushrods with a sharpie pen and watched them while the engine idled, some rotated nice, some rotated slow and one sat in the same spot the whole time.

Assuming the lobe still looks okay, I would verify proper lifter rotation with the new lifters before putting the intake manifold back on.

During assembly, I check for proper lobe taper before I even slide the cam into the block.

I did a cam swap in a SB Mopar a little while back that had a few lifters that weren’t turning.
Surprisingly....... it hadn’t chewed up the lobes or the lifters.

I’ve come across that same situation a couple of times in the past.
In the case of this particular SB Mopar, there was almost no lobe taper(.0005” or less).

I will follow this advice and inspect lifter face and lobe, if lobe looks good I will install the two new lifters and verify rotation on the starter, if all good will reassemble the intake and go from there.
If I have to remove the cam then the job will involve dropping the gearbox and then removing the motor,at which point I'd be crazy to not change to a roller cam so as to stop the russian roulet!
Thanks for all the advice and I will advise how it goes over the xmas break.

JMO

Christmas
x ≠ Christ Jesus

YMMV

Merry Christmas, y'all

Jesus would approve of punching anyone who uses the horrible 'xmas' slur.

I’ll be interested in hearing what you find when you pull the over-oiling lifter apart.

PRH wrote: ↑Sat Dec 19, 2020 12:08 pm Assuming the lobe still looks okay, I would verify proper lifter rotation with the new lifters before putting the intake manifold back on.

During assembly, I check for proper lobe taper before I even slide the cam into the block.

I did a cam swap in a SB Mopar a little while back that had a few lifters that weren’t turning.
Surprisingly....... it hadn’t chewed up the lobes or the lifters.

I’ve come across that same situation a couple of times in the past.
In the case of this particular SB Mopar, there was almost no lobe taper(.0005” or less).
FD49A71D-8ADC-45EA-8FB1-335B1BFA6A90.jpeg

If you put that lifter in a v block and measure the run out on the outer part of the face, I bet it has .0025" or more run out. Once they have that much they will not rotate.