Nitriding a hydraulic flat-tappet camshaft

[Schurkey]

With regard to hydraulic flat tappet camshaft break-in and durability: Aside from special oil and/or oil additives; maintaining RPM for the first half-hour of running time, etc. I am curious about having the camshaft hardened beyond what is typical. The cam company I'm dealing with has suggested a nitriding process; and it sure seems good to me.

This is a mild (~.550 lift, 227/233 @ .050) camshaft with the recommended upgraded beehive valve springs in a Big Block Chevy.

The cam company will send it to their usual subcontractor for nitride treatment, and inspect the camshaft after the nitriding to assure that it meets all specs post-treatment.

What say ye about the durability/value of nitriding a flat-tappet camshaft?

[bigjoe1]

Any even fairly big flat tappet cam I use now days, I allways step up and get the nitride process done to it==I only use the flat tappet cams in very mild engines, where the duration is no longer than 224 at 050= with out this process. I have never had a failure on a flat tappet cam that was nitrided. It is money well spent


JOE SHERMAN RACING ENGINES

[Dodge Freak]

Is there any downside besides costs?

[CamKing]

Is there any downside besides costs?

Yes, it can make the cam brittle.
And it can also cause flaking on the lobes.

We've been nitriding flat tappet cams for years(I use the same heat treater as my biggest competitor), and I only reccommend it, when there is no other options.

[CHT]

Is there any downside besides costs?

Yes, it can make the cam brittle.
And it can also cause flaking on the lobes.

We've been nitriding flat tappet cams for years(I use the same heat treater as my biggest competitor), and I only reccommend it, when there is no other options.

Has Tufftriding been considered Mike, some years ago that was suggested to me by (cant remember who & too darn old to care)

[CamKing]

Is there any downside besides costs?

Yes, it can make the cam brittle.
And it can also cause flaking on the lobes.

We've been nitriding flat tappet cams for years(I use the same heat treater as my biggest competitor), and I only reccommend it, when there is no other options.

Has Tufftriding been considered Mike, some years ago that was suggested to me by (cant remember who & too darn old to care)

We uses to have them sionide nitrided, then when that became illegal, we went to tufftriding, now we have them Ion Nitrided.

[Unkl Ian]

Would it be worthwhile to do the lifters at the same time ?

[CHT]

[/quote]
We uses to have them sionide nitrided, then when that became illegal, we went to tufftriding, now we have them Ion Nitrided.[/quote]
Thanks Mike for clarifiying that.

[CamKing]

Would it be worthwhile to do the lifters at the same time ?

You have to be carefull. You don't want the hardness of the lifter to be the same as the cam.

[Alan Roehrich]

To add to what Mike said, you don't want two metals of the exact same alloy or characteristics together in any sliding interface, as galling will result.

[Unkl Ian]

Got it. Thanks.

[bobqzzi]

Hope this isn't too much of a high jack, but I'm wondering about the process of cam production, heat treating, nitriding etc//

Is the cam finish ground then hardened and/or nitrided because those processes don't distort the final dimensions?

or are they roughed in then hardened and/or nitrided then final ground because those processes do distort the final dimensions?

[bigjoe1]

The cams I have used that were nitrided I got from Comp Cams=They appear almost like the old parkerizing process= I am pretty sure that the cam is finish ground before the nitride process is done, just like the parkerizing was. I think they just polish the cam bearing journals before they ship it out.


JOE SHERMAN RACING

[F-BIRD'88]

"The old parkerizing process"

I was under the assumption that is was routinely done on all new flat tappet cams, still.

Isn't the whole idea of parkerizing and or nitriting a new cam (and lifter foot) to aid in initial breakin.
(used to see the good solid lifters with the blacken foot)
(People would ask me if they should clean off the blacken appearance from the lobes. hell no!)

If this is no longer done, no wonder there seems to be a higher prcentage of new cam/lifters failures.
It seems as soon and the OEM's got away from flat tappets the whole industry/process has come apart.

The Isky I have sitting here appears to be parkerized.

[wbclassics]

You know, it never occured to me, but when we nitride cranks I keep a log of the journal sizes before and after so I've got a record of the growth and this has proven helpful in nailing down the final journal size I want ground PRIOR to nitriding so that I get very close to where I want to be post nitriding w/ a final polish. My data shows that the different journal diameters of the crank grow at different rates.

So how does nitriding impact a cam lobe shape... there is no way it comes out proportioned exactly the same as when it was ground. I routinely see half a thou growth on crank snouts of 1.375" diameter. I've got recorded growth rates of 0.0002"min / 0.0006"max per inch of diameter across all of my recorded data depending on the journal diameter and the composition of the steel being nitrided (the steels with higher nitride forming elements obviously exhibit more growth). If a cam lobe grew by 0.0005", that would be fairly significant, and from my experience, the growth would not be uniform due to the lobe shape.

So how is this being rectified in the cam world?