Mellings 041 Cam / Rhoads Lifter Wear
 

In another thread early this summer I posted about discovering two worn lifters, but in frustration just put the car in my back garage bay and covered it until I had time over the holiday to pull the engine and tear it down.

Engine is 1970 455 four bolt main, stock crank 0.010" under, ICON forged pistons 0.040" over, Maxx lite connecting rods, Mellings 041 cam, Rhoads VMax lifters with vertical oil groove, Harland Sharpe 1.65 roller rockers, headers, Cliff Ruggles 800 cfm Qjet, ported '67 stock intake, 6X-8 heads ported per Jim Hands book, SI SS valve with 1.77 exhaust, and 995-16 valve springs at 1.700" height. Compression is 9.4. Did this engine in 2011 for my '67 Firebird, driving it only in the summer not many miles. Over the years I thought it was not as powerful, but this summer it developed a severe miss, so I pulled the valve covers and found two loose rockers. Pulled the intake and yup two worn lifters.

So that I had time over the holiday, I pulled the engine and did a full tear down. The two lifters are worn about 0.170" and the cam lobes about 0.100". The only good thing is I used two Filter Mags on a Baldwin B39 filter and a magnetic drain plug. Cut open the filter and yup metal in there. Upon complete teardown I don't see more metal and the bearing don't look bad, minor scratches but the crank journals look good. I plan to send the block out for cleaning and will install new bearings and a oil pump.

So, why this wear ?
I did everything per sage advice. Correct lube on the cam, break in with no inner springs, oil with zinc, lifters with the Superlube groove. I believed I would never have to open up this engine again, and enjoy this car for the next 30 some odd years, as a cruiser. (Owned the 'bird since 1980)

Any root cause suggestions ?

All lifters rotate, valves move freely, had a reputable shop do the heads and verified the spring pressure / height. I adjusted the preload correctly, triple checked it.

I see in other threads there seems to be two camps; nothing wrong with HFT cams, or go roller. I am willing to spend the money for reliability.
What the latest story with retrofit roller lifters reliability ?

I do not know if you did this or not, but It's very important to NOT prime the lifters with oil before you load them in the Bores.
If you did so then you can never get the .030" to .050" preload right before you fire the motor over, and a good sign of this condition is that the motor does not light off right away!

It does not take much cranking time before and having the motor not fire for damage to be be done even with breakin lube.

Effected lifters were at cylinder 3 ad 4, both intake. All other lifers / cam lobe perfect.
I don't remember if I prime the lifters, but I did follow Rocky's "How to Rebuild a Pontiac V8" step by step.

Still, why wouldn't more lifters / cam locations be wiped out ?

Anyway, strongly thinking about going hydraulic roller cam. Only issue is I have Harland Sharp 1.65 (1.7" ?) roller rockers, and valve spring height is 1.70". Not sure if there an off the shelf cam, or would a custom grind to limit lift.

"Rhoads VMax lifters" - These lifters should be installed similar to solid lifters and don't follow the normal preload procedure.

https://www.rhoadslifters.com/Pages/Installation.html

You can get low lobe lift hyd roller cams.Butler could order one for you.Tom

Lifter Quality Recently
 

When did you obtain the lifters? Were they manufactured recently or a few years ago? I ask because I have heard of similar failures with recently produced lifters in Chevrolet engines, and am wondering if these - lifter and camshaft lobe failures - are a more recent phenononom?

Why not prime the lifters? with pressure on them they will bleed down anyhow, right? I just tighten them down, let them bleed down, then loosen the rocker nut till I see .030-.040 gap under the snap ring. Or am I way off doing that?

This build was in 2011.

I recall that I did adjust the lifter preload per instructions with the intake/ valley pan off, so I was sure cam was on base circle and I could verify the lifter preload measurement.

Not happy as I researched this back then for every detail / best practice known.

Besides cost, are the current hydraulic lifters problematic, or is there something else I am not aware of ?

Agree. Rhoads knows the best way to set lash on their product, and that will have the best chance of the valve train surviving.

The fit and finish of the Rhoads lifters are way above what I have seen from other companies, and I believe they have the best chance of living. A lobe will take out a lifter and vice versa, and when both are ground down it can only be speculation of whether the lobe or lifter failed first.

While you have identified two that failed, I would be willing to bet that additional lobe/lifter combinations are in various degrees of failure -- and it could be these that might tell you where the failure points are. If some of the lifters look like new but you are seeing slight flattening of the lobe crown, I'd say that the cam is taking out the lifters.

We have Rhoads V-Max lifters along with the Crower RAIV reproduction in the 2+2 and it has lasted thousands of miles. Before that combination we had two cam/lifter failures in that engine and mostly out of desperation we went with the two products that seemed to have the least reported problems.

Just for the record, I haven't pulled out a HFT cam on an engine rebuild that I would be comfortable putting back in the engine. That's 100% of the HFT cams in a row that had either gone flat or showed initial signs of failure.

I just had the first HR cam failure come in and it was due to a rivet coming out of a link bar. Haven't heard of any other link bars failing so mostly just bad luck, but flat tappet cams going flat happens all the time.

When you originally installed did you confirm all lifters rotated easily in the bores? I don't mean with engine running but when lifters are first inserted in bore. If they get stuck or barely rotate they can get scuffed and downhill from there. It's a good practice to verify they are spinning once engine is running too. This is done by marking the pushrods and watching for rotation of all 16 at similar speeds.

First Question I would ask Bill S is: What oil were you using with these lifters in the engine you have had for 10 years?

Second Question is Did you use GM EOS on the initial break-in?
I assume you did.

Third Questionis What oil did you have in the original engine 10 years ago and what was the PPM of that oil. Parts per Million of Zinc in oil.


% of Zinc in oil vs PPM | Bob Is The Oil Guy
https://bobistheoilguy.com › forums › threads › of-zinc...

From your posts it appears that you had the failure of the camshaft and lifters over a period of time. A flip of the coin which lifters on what cylinder failed first. Post up that info.

Adding better oil after the failure is on the way will do nothing.

Tom V.

Tom, I coated the cam with the black paste ( don't remember which product, but specified for cam break in), and used Joe Gibbs LS30 5W30 high zinc oil for two years.
I then switched to Quaker state full synthetic 5W30. This decision was based on Rat540 oil blog oil film strength testing.
I had good experience with the Quaker State Ultimate Durability in my 2004 GTO LS1. Just did a cam / lifter swap at 81k miles and the old roller parts looked good.

Funny thing is I posted on his blog about my misfortune, and chastised me for even using the high zinc oil in the first place, stating that cause the wear !

The worn lifters are concaved, not " striped", not sure if that means they were rotating.

So, possibly running that oil on a HFT cam is the cause.

I was told to use the High Zinc oil in my GTO Engine by the British Petroleum Oil Expert.
Not some guy posting in a Blog about using full synthetic oils.
They put that high level of zinc in the cars/trucks/engines in the old days for a reason.

I would read this article: https://www.hemmings.com/stories/201...-older-engines

The internet bites someone in the aze again.

Tom V.

My 72 455 has run a Melling RA4 cam with Rhoads lifters for at least 20yrs. Broken in with Crane cam lube and still has Comp springs. Always used Wix or Baldwin filters with Valvoline 10/30 or straight 30 VR1 oil. This motor has been used and abused for many thousands of miles. I have to wonder about the QS 5w-30 synthetic use. My engine builder would never let me use that. Just checked some records, the springs are Comp 995 and the lifters were original Rhoads.

I run 15/40 Diesel Oil which I purchased in gallon containers before the oil Zinc levels were lowered.
Again based on the BP Engineers suggestion. I have about 200 quarts worth of the oil with a ZDDP (zinc) amount of 1400 ppm.

I also paid 1/4th of the price of the Valvoline VR-1 Racing Oil (per quart) available today.

When they took the ZDDP amount below 1000 ppm per quart, the BP Engineer said you could have camshaft and lifter failures on flat tappet camshaft engines. He knew I was using that design of camshaft.

So I think the OP basically had a issue that was oil related and caused the initial concerns and later failures.

Tom V.

Since both Dished Lifters were Intakes, not Exhausts, the vslve guide tightness with warmup-hot highway stuck guides would get a pass.

YEP.

TV

Took my 6X heads to very reputable engine machine shop / builder last weekend. Had him check the heads over and flow test a intake port, then had him test the valve springs. They all read very low at install height (1.700"), about 70-80 !

Thinking that may have been a contributor to the wear issue. Evidence included beat up spring shims, valve end burrs, and a couple of seats in the heads needing a touchup. I have read about many problems which arise from worn / incorrect springs.

Personal opinion, with 70-80 on the seat, the engine is going to have a lot of unwanted harmonic spring issues especially on the intake side as the intake valve weight is obviously heavier vs the exhaust weight. My 995 springs were quite a bit higher on the seat on my 70 455 engine build.

In the 145# area with the 744 high lift Blue Racer camshaft.

Tom V.

I did a Pontiac engine a couple years ago that only had a couple thousand miles on it from a previous build, and upon tear down, the valves springs were like yours. Lucky to have 80 lbs. on the seats, and it was chewing into the bottom of the retainers, and the locks were taking a beating. There was a good chance after a while that it will drop a valve like that. Probably lucky the cam went flat first.

The valve bouncing on the seat as a result, and unable to control the valvetrain properly, with the lifter likely beating the lobes, is one possible reason for the cam failure.

I also believe the oil is another possible cause. The two combined looks like a good indication.