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Old 09-22-2019, 07:34 AM   #1
JRN1967
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Default How to check a Model B Cam?

Last year I picked up a Model B engine. It was all cracked but I did save this camshaft and tappets. Still have the intake and carb too.

Where do I measure to see if the cam is not worn out?
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File Type: jpg B-Cam2.jpg (21.3 KB, 57 views)
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Old 09-22-2019, 09:39 AM   #2
nick c
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Default Re: How to check a Model B Cam?

Go to ford garage.com, click on camshaft, measure heal to nose, subtract base circle, that's the lift, if its an A or B cam, it can be reground.
carry on
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Old 09-22-2019, 10:48 AM   #3
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Default Re: How to check a Model B Cam?

Clean it up with extra fine scotch brite pad..measure actual lobe tip to heel,then side to side..subtract one from the other will give you measured lift. Measured lift early B is .302 or so,late B (c grind) is .319..measure the bearing surface as well.Measured C grind on right,early a 5 bearing cam on left.



http://www.fordgarage.com/pages/camshaftspecs.htm

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Old 09-22-2019, 11:02 AM   #4
johnneilson
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Default Re: How to check a Model B Cam?

There is more to checking than just the lobes.
Yes, they are going to vary some, I doubt that .010 difference on the cam lobe will make any difference in performance. The main concern on the lobe is to make sure it is not going to eat the lifter, either from damage or spalling.
The main concern I see is/are the bearing journals. Typically, the center bearing will be worn. How much is too much? Some grinders will not accept anything worn under 1.555
(stk 1.560)
If you are looking to modify the motor beyond using "B" cam and manifold, you are probably going to want to contact Jim Brierley, he has the Winfield masters and grinds.

John
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Old 09-22-2019, 12:11 PM   #5
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Default Re: How to check a Model B Cam?

As John says, I do regrinds. I suggest 1.556" as a minimum bearing size, the center brg. is the most likely to wear. B cams came in .305", 319" and 339" lifts. Some were copper plated, some not. That is for heat rejection in the heat-treating of the cam, means nothing if going to be re-ground. B tappets are larger than A's, a good thing. They can be re-surfaced if needed too. e-mail me at jimb4e4@gmail if interested. The nose of the cam often wears, and the area where the gear attaches is sometimes buggered, these will be corrected before re-grinding. Measuring lift as railcar suggests works on stock cams but not necessarily on performance grinds.
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Old 09-22-2019, 03:47 PM   #6
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Default Re: How to check a Model B Cam?

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Im curious Mr B,my measurement works on stockers...but not on performance grinds? is that because you offset the center line?.
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Old 09-22-2019, 04:49 PM   #7
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Default Re: How to check a Model B Cam?

Railcar,

Generally speaking, the performance grinds have much more duration and measuring more than likely will be of the opening/closing ramps, not the base circle.

Typically perf cams are measured in a fixture like a bench center with a degree wheel and indicator. I use an old block with crank so I can measure all the lobes and check lobe centers.

Also, never try to use the old "rule of 9" when lashing up valves when big cam is used.
Again, lobe centers and duration come into play.
J
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Old 09-23-2019, 11:38 AM   #8
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Default Re: How to check a Model B Cam?

Railcar, as John says. Duration is greater, ramps are often longer. Doing it your way gives an indication but is not totally accurate on most performance grinds.
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Old 09-23-2019, 02:57 PM   #9
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Default Re: How to check a Model B Cam?

Here are the cam readings I took today.
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Old 09-23-2019, 03:09 PM   #10
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Default Re: How to check a Model B Cam?

Thank you..
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Old 09-23-2019, 09:47 PM   #11
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Default Re: How to check a Model B Cam?

Bill Stipe told me that the best core specs before grinding would be 1.557 center bearing diameter . Lobe diameter at 1.225 . This is the dimension that I look for when I go through my cores . Bill said that he would do the best that he could with what ever I sent him . Good cam cores that are good for a regrind are scarce in my neck of the woods . I am well pleased with the two Winfield grind cams that Stipe machine ground for me !!!
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Old 09-24-2019, 05:37 AM   #12
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Default Re: How to check a Model B Cam?

Quote:
Originally Posted by Purdy Swoft View Post
Bill Stipe told me that the best core specs before grinding would be 1.557 center bearing diameter . Lobe diameter at 1.225 . This is the dimension that I look for when I go through my cores . Bill said that he would do the best that he could with what ever I sent him . Good cam cores that are good for a regrind are scarce in my neck of the woods . I am well pleased with the two Winfield grind cams that Stipe machine ground for me !!!
Yesterday I posted my measurements, but it may be just a little under. Could you take a look and tell me if it would be a waist of time to bother with that cam?

Thanks
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Old 09-24-2019, 12:26 PM   #13
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Default Re: How to check a Model B Cam?

The center journal can be sleeved back to standard but it is usually cheaper to find another core.
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Old 09-24-2019, 12:46 PM   #14
Railcarmover
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Default Re: How to check a Model B Cam?

I'd run that cam you have.In my opinion modern engine oil additives to increase load will tolerate more clearance
Diesel grade 15/40 rotella or the like have superior shear and load characteristics than the oils used by ford when the specs were set.
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Old 09-24-2019, 01:46 PM   #15
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Default Re: How to check a Model B Cam?

JRN,


the dimensions provided show some wear, not too bad.
the pics originally posted show a well used cam, again, not too bad.


the real question is, "what are you trying to do?"


J
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Old 09-24-2019, 02:24 PM   #16
Purdy Swoft
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Default Re: How to check a Model B Cam?

Quote:
Originally Posted by JRN1967 View Post
Yesterday I posted my measurements, but it may be just a little under. Could you take a look and tell me if it would be a waist of time to bother with that cam?

Thanks

The cam that is pictured in the first post appears to be worn . There doesn't appear to be much of any heel left on the lobes . It could have been reground . Usually the heel gets ground away to get more lift . The measurements didn't show up here . I won't say that it is worn out . It would be best to have a cam grinder look at it . I would call who ever I wanted to grind the cam and let them tell me the required measurements for the core . I use a caliper to measure cams . If you don't have a caliper , Harbor Freight sells them very reasonably . I think the last one that I bought was on sale and priced under twenty dollars .

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Old 09-24-2019, 09:36 PM   #17
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Default Re: How to check a Model B Cam?

Center cam bearing wear minimum is kind of moot. There is a max clearance however if you measure the wear in the block even a cam with standard bearings can exceed limits.
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Old 09-25-2019, 05:27 AM   #18
JRN1967
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Default Re: How to check a Model B Cam?

Thank you all for help to understand how to check camshafts. I learned a lot.
Looks like mine is just on the edge of good/bad for a regrind.

I'll need to consider if its worth the cost of a regrind versus buying one already done.

Thanks again, John
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