Jim Fulmer
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- May 6, 2006
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This thread is the best, so much bull****, so many facts, so much smoke and mirrors.
Jim
Jim
My post was meant to be sarcastic:1tooth:
Sorry for the quick little high jack, but I was wondering what a Cummins cam install normal runs Labor wise???
What's the average dollar amount charged in labor for a complete install?? I just don't wanna get taken when I decide to have mine done... Thanks
Narrower lobes? It is a flat tappet cam is it not? Think of how a flat tappet contacts the lobe and it will make sense in adding lift.
I didn't realize teddybear was being sarcastic... I was responding in awe...
then he said he was being sarcastic, then I said my sarcasm detector broke because I was in a foul mood because I'm having to go offshore again
I don't have any problem with anyone on this board. I know I come off as a smartass sometimes, but that's just how I am I guess
Sorry for the quick little high jack, but I was wondering what a Cummins cam install normal runs Labor wise???
What's the average dollar amount charged in labor for a complete install?? I just don't wanna get taken when I decide to have mine done... Thanks
Sorry for the quick little high jack, but I was wondering what a Cummins cam install normal runs Labor wise???
What's the average dollar amount charged in labor for a complete install?? I just don't wanna get taken when I decide to have mine done... Thanks
You hit the nail dead on the head there!!
"The pointy triangle lobe" thats it Man, you are so right.
Couple of things happened on the CR: The duration went way down and the lift came up. Especially on the exhaust.
....
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Lets go back and look at the first post. Have a close look at the factory cam lobe. The lobe has a step in it. This step is on all the B series cams from 94 and up for the Dodge and most other engines as well.
When the factory cams are cast, the iron is poured into a mold that is chilled/very cold in the lobe area. This allows the cam to have a hard and wear resistant surface area on the lobes and still retain a softer less brittle shaft and bearing area. This keeps the main shaft from being too brittle and prone to cracking.
Simple. Simple.
But, like most things there is a trade off on the mix of metals used in any iron alloy. The ductile iron used on the OEM Cummins cam uses more Chromiun in the alloy to do a couple of things: Control the depth of hardening and brittleness that occurs when the iron is poured into the chilled mold and make a more durable material. Controlling the hardness depth is done to help the hard area from pitting and chipping pieces out of the hardened lobe. The hardness only needs to be thick enough to keep the lobe from wearing down and thats it.
Trying to grind a performance cam profile on those little triangle lobes gets down into the softer regions of the lobe. Past the step. Past the hard layer of what is basically white iron produced when it is chilled quickly from liquid iron. This is why so many regrinds rub the lobes flat.
A quick Rockwell test will show the softness is remarkably low after even a mild regrind. Cummins remanufactures all their engines, with remaned rods, cranks, etc, but never uses a reground camshaft. They are always new.
Our Flate Rate is $600
We've indented regrinds here that have been in the 38 Rockwell range. Sad. At that number the tappets plow through the lobes like butter. Thats an exception though. Most mild ones are still sub 45. I suspect the overwhelming numbers of regrind failures are the result of softy lobes from a grinder that wants those lobe centers wider or the lift cranked up. Funny to see those base circles at 38 rockwell, the ramps at 42 and the nose at under 50.
The grinders that try to induction harden those Cummins cams back to spec are pissin up a rope. Just an opinion, of course.