Camshaft Wear

[johnr]

looking for information on stock camshaft.
I need to know what is standard lift and what would be minimum dimension.

Thank you for your help.

[Scott_Conger]

Nominally .250" lift for all stock cams after around 1912-13

lots of great info you can take to the bank, here: http://mtfctulsa.com/Cams/

[johnr]

Scott
Thanks for the information on cams.
What I really need is how much wear can I have on the tip or nose of the cam
before I would replace it or regrind the cam.
Thank you.

JohnR

[Scott_Conger]

To your specific question: after 1913, a T has a nominal lift of .250. After you figure in loss from lifter clearance (which is far wider than for modern valves) if you manage .220 to .225+ lift at the valve itself, you will be doing well.

T engines are low reving and extraordinarily forgiving of worn cams relative to lift as well as valve events that vary somewhat from cylinder to cylinder.

Remember that the old valves required a very large lash at the lifter, so some lift was already lost. With modern valves which can operate just fine with less lash so if combined with adjustable lifters or ground to match original lifters, you will be regaining some lift right there. That will not ensure absolutely correct valve event timing, so the ultimate answer to your question is "how well does the car run??" If the car has good compression but just won't produce peppy response and is sluggish on hills compared to your friends' T's, then it is probably that worn out cam.

Correct driving methods with a worn cam will often outperform a T with a new cam driven with sloppy technique

If the engine is out for total rebuild, I'd do a complete rebuild. That would include a new good, proven, cam design and I would avoid a regrind or consider it as an absolute last resort. I do not believe that a worn original cam can be reground AND retain its original valve timing...something to consider when you're looking for the best power (and the original grind T cam is a remarkably good cam)

[Art M]

I would consider a reground cam if the donor was a .280 cam ground to a std profile.
My concern is the depth of the hardness case. Is the original depth deep enough. Or is the surface recarburized.

Art Mirtes

[Craig Leach]

I bought two Chaffins regrinds when they where $ 75 + core. I only had early cores so I have to install the spacer to keep it from bouncing
fore & aft. I for one am pleased with the cam. I was concerned with the finish of the lobes, but I have run the one four years until I broke
a low drum & swapped that engine out for the original engine. (wish I had installed the other cam in the original engine) I found the cam
wear was very good ( almost un noticeable) This was in my speedster and I get my moneys worth out of it. I found the power band to be
excellent. I went up Mount Palomar's steep side with stock gearing no Aux. trans or rear end. High compression pistons stock head in high
gear as fast as the turns would let me. The lift is .270 I don't know the profile but I understand it is advanced a little. There was a .290
regrind cam for sale in classifieds a while back. I don't know who ground it. I'm not sure but Stipe may be the only one making new cams.
And I have never heard a bad word about Stipe cams. I will not part with my Chaffins regrinds.
Craig.

[Scott_Conger]

Nice testimonial Craig

I am pleased to hear that kind of report on Chaffin's regrinds