eBay Reground Cam

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I can't get sense of your degreeing numbers. I keep coming up with an impossible installed centerline of 120*
From your numbers, that cam measures;
280/275/115.75LSA/installed at 120.
The ICA of 80* seems to be the culprit,

From your .050 numbers, the durations are
212 intake/211 exhaust/115.25LSA/ installed at 114
From your overlap numbers; the cam looks to be installed fairly close to straight up, whatever that may be.
 
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AJ/FormS said:
I can't get sense of your degreeing numbers. I keep coming up with an impossible installed centerline of 120*
From your numbers, that cam measures;
280/275/115.75LSA/installed at 120.
The ICA of 80* seems to be the culprit,

From your .050 numbers, the durations are
212 intake/211 exhaust/115.25LSA/ installed at 114
From your overlap numbers; the cam looks to be installed fairly close to straight up, whatever that may be.
Click to expand...


Yup...his numbers looked off to me too.
 
Further proof the cam is crap? I rotated the engine multiple times to verify the numbers. i pushed down on the lifter while closing to make sure it wasn't hanging up.
 
Probably not the cam, friend.
Like said, the DI indicator tip has to move on the same axis as the lifter, and NOT crawl around in the push-rod cup, or be pushed around in or by it.
I fabricated a metal slug, to fit in the lifter bore, with the top and bottom machined flat and parallel to eliminate the cup problem. But that does not prevent the DI tip from scrubbing sideways. So I have to be extremely careful in the set up.

Comp has some interesting tools; Hughes Engines as well, probably Jegs or Summit
4925_600.jpg
778-66830.jpg

Proform Cam Lobe Checking Fixture and Tools | JEGS
 
indirect_connection said:
Further proof the cam is crap? I rotated the engine multiple times to verify the numbers. i pushed down on the lifter while closing to make sure it wasn't hanging up.
Click to expand...

Take an old pushrod and cut it off just above the deck about a 1/4 inch. Make it parallel to the lifter and stick the dial indicator in the end of the pushrod.

It’s crazy doing it the way you are doing it, and unless you degree cams for a living, you don’t need an expensive tool.
 
like most machining of used metal - it is reground until it cleans up. with that cam being small I wonder if it has been ground down beyond factory heat treat? Is it cast or forged?
 
I know that I'm an amateur at this, but my methods are improving. This attempt was done with tip extensions on the indicator centered in the lifter. I also used the magnetic base instead of the flexible vice grip mount. I made sure that the indicator was in line with the lifter. I did have one case where the tip rode up on the cup, and caught it right away because my readings completely changed. In my experience with dial indicators is that if you have things moving around, the reading will be all over the board. I was returning to zero (+/- .001) every time.
 
Measuring with a decent caliper can be accurate. I would question cam hardness . Since cam was directly measured with caliper we know
 
indirect_connection said:
Pulled cam and measured with vernier calipers (no micrometers at home). Similar. Coming out at about .305. So at 1.6 rocker ratio I’m going from .536 lift down to .488. Seems significant.
Click to expand...
Assuming you are happy with the final #'s on the cam, you could go with a 1.7 on the exhaust to gain back some lift.
 
indirect_connection said:
I made my first attempt at degreeing a cam this past weekend. Magnum 360 block I'm attempting to rehab on the cheap. My cam core was pitted/flaked on a few lobes, plus I wanted to run a mechanical fuel pump, so I purchased a LA roller regrind off of ebay. Same seller and similar to this one: Hydraulic Roller Camshaft Mopar LA HR-268-SBMd 318 340 360 Demon b | eBay

The specs are as follows:

Advertised Duration
In. 268
Ex. 276

Duration @ .050
In. .215
Ex. .218

Valve Lift 1.5
In. .489
Ex. .503

Lobe Lift
In. .326
Ex. .335

LSA
112

After much fiddling, I finally got the degree wheel set to TDC and the flexible dial indicator mount steady. The tip of the dial indicator was centered in the pushrod cup of the lifter. The duration at .050 looked right on for the intake, but exhaust was low. I was also reading over .300 lift on the intake, but only .280 on the exhaust.

View attachment 1715522572 View attachment 1715522573

I was starting to doubt my measures. I pulled the lifters on Cylinder 1, and disassembled one. I stacked washers inside and put the lifter cup back on. I also used a magnetic base instead of the flexible one. The exhaust lifter must have been loose, because my readings came up to .290 lift, but intake stayed the same.

Now this is well below the specifications. I'm running no name Edelbrock heads I purchased from Mancini, which should be good to .550 lift. I feel I'm leaving a lot on the table.

So my question is, have I eliminated all variables to my measuring? I'm about ready to pull the cam, and try and get my money back through paypal.
Click to expand...

Did the cam Grinder from Texas ever get back to you through eBay?
 
Jadaharabi said:
Did the cam Grinder from Texas ever get back to you through eBay?
Click to expand...

No. I even sent another message asking if they would accept a return even though the time had passed. No response at all. Paypal just refers to ebay. Im going to try to dispute the charge through my credit card. I can't bring myself to run it
 
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