Budget Parkerizing flat tappet cams at shop

[fabr]

Correct me if I'm wrong but isn't the purpose of the parkerizing to allow the lobes to retain oil/moly/whatever long enough during initial startup to prevent lobe/lifter failure?

[CamKing]

Correct me if I'm wrong but isn't the purpose of the parkerizing to allow the lobes to retain oil/moly/whatever long enough during initial startup to prevent lobe/lifter failure?

Parcorizing is a surface treatment of iron and manganese phosphates formulated to produce non-metallic, oil-absorptive coatings on iron and steel bearing surfaces.

Benefits:
Removes any remaining light metal scratches from machining operations
Permits rapid break-in of moving parts without scuffing or welding by preventing metal-to-metal contact
Increases lubrication of treated surfaces
Inhibits corrosion

[BillK]

I would be more inclined to suspect the lifters rather than the cam on that engine. The picture on the Melling website looks like it is parkerized. Was it the 22116 cam ? I would try to find a set of NOS GM lifters or old stock TRW etc.

I have been trying my best to convert everything over to hydraulic roller but you cant do it on everything. I have been using the Driven assembly lube on the lobes and lifter bottoms and the Driven break in oil and so far so good. I just finished a 425 Olds so we will see.

[liqu]

Hi guys, I've been reading this, now I'm starting to change my thinking on break in and oils

https://540ratblog.wordpress.com/

[Schurkey]

How about using a nitrided cam instead of Parkerized? Not a "D-I-Y" coating, and not cheap. My impression is very favorable, but I'm no expert.

[In-Tech]

Nitriding can cause all kinds of issues on a cast core. I'm sure Mike will chime in with way more experience than I.

[PRH]

It certainly doesn’t seem like the OP’s application should require any “extraordinary measures” to get a cam to live.

Some people get lucky, and the motor doesn’t eat the cam...... even when it probably should have.
The lifter in the pic was one of several that came out of a 360 Mopar that looked like this.
Mild hyd cam....... that had a max of .0005” taper on any lobes...... some where just about zero.
The pattern on this lifter looks like it probably didn’t have 3 revolutions on it before it stopped turning(it had been used in the motor for two seasons).
Didn’t eat the lobes, or the lifters. The motor was still running fine.
The reason it came out was for a bump in performance.

32D1F58C-FDB7-4EC2-8DD0-EF2C37402322.jpeg

[ProPower engines]

I have to agree with Mike on checking and confirming the lobe taper for issues.
I just looked at a pair of merc.165 cams for the GM 250 engines and they were basically flat or straight. No Lobe Taper!!!

Since these are basically the same cam just longer but suffer from the same issues.
Since these are not really common engines anymore but with the factories cranking out stuff I bet the QC is suffering bad.
And these engines are real easy on cams to start with but you mention the 140Hp version.

These are a 181 CID engine to replace the 153 120/130Hp versions.
Do these engines use a 1 piece rear seal and counter weighted flywheel like the newer engines or 2 piece seals??
the 140 has a 4" bore the 120/130 has a 3.875 bore

FYI if thats the case the cams differ somewhat compared to the older engines. More lift.
Also the rods use a spit hole to help lube the cylinders as well as the cam lobes and if the wrong bearings are used or the wrong rods are used then the cam will lack lube while running. Seen this many times as I have had to file groves in the rod and cap to convert newer rods to lube the cam for low speed operation.

FWIW I either send the cams out for re-grind if they are not worn bad or send the new cams out as good cores for a tune up on the lobe taper.
New springs are only 85 lbs closed and about 175-185 open which is really easy on lobe wear as long as they have enough lube and lobe taper to keep them spinning.

WE also use the comp lifter bore grooving tool to groove the lifter bores to force lube the lobe at point of contact to help stop scuffing the lifters during break in.

[F-BIRD'88]

When these camshafts are in the block do the cam lobes sit centered under each tappet? Or offcenter like a SBC?
If they are all centered under the tappets when running they won't spin.. Thus no taper ground in the lobe profile.

[lefty o]

looks like its been parkerized.

No, this is parkerized.

F.T. cam.jpg

i could be wrong, but was more talking the steel between the lobes, that shade of gray does not look like its raw.

[jeff swisher]

Cam shop in OKC got 2 crates of those 4 cylinder cams from a company that builds those little engines and these cams were not spinning the lifters and cam and lifters were failing. Compressor and forklifts were the use.
They brought the cams in and a bunch of lifters in to have more lobe taper ground into them and the lifters ground with a bit more taper.

The reports were lifters are now spinning very well and no more failed cams.
The crates are 3x3 foot and just about 2 foot tall.

That is a lot of cams that were destined to fail.

[In-Tech]

It's referred to many times as "minutes" of rotation. Load and rpm are the factors that control how many "minutes"(Like a clock) of rotation is needed.

[PRH]

Several years ago, before the crate motor thing took over the local circle track scene, we had a freshly built 350 on the dyno.
This was for one of the mid-level classes.
Stock small valve heads, stock 2bbl intake, ex manifolds, hyd cams, stock rockers, etc.
One of the cams we had success in that class with was a pretty plain Jane grind.
Never had any unusual wear with them in the past(springs at 120/280).
We get a few pulls into the session and I can hear some tapping.
Pull the covers, one valve has some lash.
We determine it’s not a problem “up top”, so we pull the intake.
That lifter is already cupped noticeably(not terrible, but visible)

When the cam comes out, that lobe is toast.
The other 15 lifters and lobes are perfect.

Slide another cam in and check for rotation on the offending bore..... there is none.
All others have adequate rotation.
Checked new cam...... .0015” lobe taper.

I order a cam done with .003” taper.
Get new cam........ 15 lifters are really whipping around...... but the one still has essentially no rotation.

Didn’t really feel like pulling it down and replacing block or bushing the lifter bores.

Then......Light build came on!!!

Bought one Schubek lifter. Problem solved. No rotation necessary.

[ProPower engines]

Are those lifters even available??>
While the spring load you noted is not even close to what they can handle having used them years ago before they were outlawed in some class's.
They would be a solution albeit a costly substitute but since we are most likely referring to a GM factory block why did it live a long life in a vehicle. Was GM doing something different with their cams back then we don't know about??
Or was the oils used just so full of additives they had no choice but live in the slicker environment?

I have seen the same issues on stock stuff where after a stock cam replacement getting the lifters to spin is a challenge.

We had a cam grinder re-grind some stuff for the shop with more lobe taper which for the most part solved the issues of premature wear but if the lifter bore is that far off how do they even live as long as they do from the factory??

Makes you wonder don't it

[PRH]

Those lifters were no problem to get back when that engine was built.