Preferred Flat Tappet Lifter

[blykins]

Any idea what it would cost to send one back in to be nitrided?

About 150 smacks.

[plovett]

I was going to say it is about the price of the camshaft.  I was going to say $120-$150.  Brent would know better than me, though.

Not much money in the grand scheme of engine building.

JMO,

paulie

[plovett]

I guess I haven't bought a camshaft in a while. 

[plovett]

Paulie , your wear is more likely pushrod seats, cups and rockers due to the stout pressure.  If you were losing thousandths at the lobe, it would get ugly and especially not be uniform

I think you are probably right.   The wear has been very consistent across all the valves.   It is still disconcerting to me because every couple of thousand miles I have to set it slightly tighter.  Maybe 0.002" tighter?   I do set on the tight side.  I go 0.010" cold so I get about 0.017" hot.  I set intake and exhaust the same even though I know the exhaust is a bit hotter.

paulie

[plovett]

Do you use tool steel lifters on regular cast cams, or nitrided cast cams, or either?

[My427stang]

Cast no special treatment, but I tend to like a lazy lobe if I can manage overlap.

[plovett]

I don't know, but I would think you would want the lifter and cam to be similar in hardness and finish?  You wouldn't want one to be significantly different than the other?  That's why I was asking about the tool steel lifters on the normal cast cam.  Of course I have a nitrided cam with normal cast lifters. 

So, should the cam be harder than the lifters or the lifters harder than the cam, or should they be the same?

paulie


And the lifters are a lot smoother finish?  I am not sure. 

[Falcon67]

Although any bit of oil that dribbles around should be a little better, unless you are going radical, I just haven't seen flat tappet failures, solid or otherwise, after a good break in and good oil.  Admittedly, I run street lobes up to only about .600 lift, but I never think twice about them to tell you the truth

One of the Facebook feeds I'm one, guy just lost a mile hydro flat during break in with all the right parts and oil.

Above discussion is why I'd rather ride the bus than buy any more flat tappet cams.  Roller and done.  Want to change - pull one roller out, put another in.  Done.  No BS.  Lose one cam, now you could have bought the roller business and you still have to hope break in goes well.  No more at this house.  After I lost one running $$$ EDM lifters and real racing oil (proper levels of ZDDP, etc), that was it.  I've been doing things like this since 1974 and I'll not waste my time on less at this point.   

[blykins]

Do you use tool steel lifters on regular cast cams, or nitrided cast cams, or either?

You can use uncoated tool steel lifters on both non-nitrided and nitrided cast core cams.

Coated tool steel lifters go on steel core cams.

[plovett]

Do you use tool steel lifters on regular cast cams, or nitrided cast cams, or either?

You can use uncoated tool steel lifters on both non-nitrided and nitrided cast core cams.


[/quote]

What is the best somewhat economical solution for a somewhat high pressure flat tappet?  Tool steel lifters on a nitrided cam?   

Thanks,

paulie

[blykins]

Yes, nitrided and tool steel.

[plovett]

Thank you, sir.