Recently I acquired a very nice-looking new T cam. The only markings on it is "114" stamped on the edge of the front flange and on the back end of the cam. There's also marking pen "114" on the front edge and in one of the gaps between lobes. The cam is blackened and coppered except for the bearing areas which are bare metal. According to Stipe, it's not one of theirs. This has been sitting on a shelf for a long time (decades?) and has a green plastic netting sleeve around it.
Any ideas? Just curious! I was told it's a 250 grind (someone measured the lobe heights?).
Well, this is a bump. got out my cheap caliper, and it shows the lobes as having 1.12 lift, so maybe that's what the stamped 114 is about?
Any clues guys? There can't have been many camshaft manufacturers in the past 20 or so years.
No such thing as 1.12 lift. To measure lift, you measure the largest dimension, from the heel to the tip, (which I think is probably the 1.12 dimension you gave), and subtract from that, the smallest dimension, taken from the heel diameter, (or perhaps base diameter).
But there are a good number of people that do regrinds which is what this may be. Just because it has the black and copper does not mean it's new. Originals could have the copper wash between lobes and bearing surfaces.
David, Lift is only one parameter you need to know. You must also measure intake and exhaust open and close numbers at a specific valve clearance (0.010-0.015 in). You can then calculate the duration. I can plug these numbers into my computer dyno and tell you exactly how well the cam will work.
Ah yes, that makes sense and I should have figured that out myself! So "B" is .88, which leaves .24 for the lift--hmm, not even .250! Unless there's already some lift at points B-B, which could be. All the lobes are black, the rest of it, other than the bearing surfaces, which measure .75, are copper.
Mind you, I'm just using a veneer, not a micrometer!
So, does that give any other clues?
It sure looks brand new.
Glenn, I appreciate that, but it will be some time before I have a block I can put this into to check that (I assume one would need to have it in a block to check that). Any chance it's one of yours?
Thinking about this some more, I could, when I have some time, chuck it in my lathe, put a dial indicator on the carriage and measure the lobe. With care I could possibly even come up with the degrees of lift. Hmm, would have to make some sort of indicator for the degrees of rotation of the lathe head. Hmmm.
I have seen many bad grinds. Even my early grinds were not that good, but that was before I found out how to make a good cam. We just used what ever the cam grinder had that had the lift we wanted. Now we know better and have perfected a grind that is optimized for Model T street use and hill climbing.
Most likely that 114 is the lobe separation angle that the cam grinder used when the cam was reground. Does not tell you much about duration but the lift can be measured as above. If its a single pattern cam(and many are) you can use the lobe centerlines to check the lobe separation.
OK Dan, you're losing me, lobe centerlines to check lobe separation? It's been a long time since I studied engine design! (like 40+ years ago!)
And in spite of the like new condition of the bearing areas, and everything else that looks new, this is a regrind?
It's easy to see if it's a regrind - on an original or new cam, the base circle ("B" in the sketch above) would be a little thicker than the shaft itself, while a regrind reduces the base circle to about the same dimension as the shaft besides the lobes.
That's why reground '09-'24 shafts with the longer front bearing may need help by a thrust washer kit towards the timing cover to handle axial forces forward - the long style front bearings has a notch for clearance to the lifter, and when the front lobe gets lined up with that notch, it may get caught there, since the heel of the cam lobe isn't there anymore to help handle thrust forces.
Well stated Roger
OK, OK!! I've taken a picture(s)!!! note that the heels of the cam are very proud of the shaft. The irregularities you see on the bare metal areas is Vaseline I put on to protect the surfaces until I install it.
Camshaft, green netting alongside is the protective sleeve it came in.
Close up of the number stamping
Bump!!! No responses??? Maybe this weekend I can set it in the lathe, but my everyday truck just made grinding noises when I pulled up to a stop sign, so have to deal with that first! And a funeral for the guy that had one of the last "old fashioned" glass shops around here who would cut glass for Ts and other stuff.
It actually looks like a Chaffin's cam. They have that black coating on the lobes when they arrive. I agree that it appears to be NORS.