Distributor cam

[Brianfrench65]

I recently purchased a new distributor cam and being a retired engineer, I thought I would check it before I used it. I took a nice used distributor upper shaft and chucked it in my lathe, in a 4 jaw chuck and indicated it to 0.0005. Then I slid the distributor can on the shaft and tightened the screw. Then by hand I rotated the chuck, expecting to see about equal lobe shape with the indicator. Well....this new cam was not even close to being the precision part I had expected. The differences in lobe height were 0.0052, which would effect the point gap, when those lobes went by the point block. I found an old distributor cam in my pile, and it repeated perfectly.

Lesson to me, it's running good, and a new part is not better than the old one, just because it's new, in this case. I did buy the part from a reputable source in NY.

I don't know, maybe I am over thinking a simple part.

[fiddlybits]

I did almost the same thing when I looked at a cam and realized it was basically a cylinder with four flats.... not at all what I would call a cam.

Picked up a Bill Stipe cam.... it is a real cam with tight tolerances. (of course...installing it showed me the slop in the rest of the distributor so and overhaul followed. Can not say it makes a big difference in performance but I can hear the difference in cadence.)

[Patrick L.]

My question is, who made the cam ? Is it from Stipe ? If not, try one of his.

There is a difference in the aftermarket profiles. Most are made to 'B' specs to allow for more dwell/saturation time.

[Terry, NJ]

If I'm reading this correctly, the bore of the cam is out of concentricity, by .005 to the bore.
Clearly, you will open the points .005 wider than on the other side. This built in point gap difference affects the build up of a charge in the condenser. This is unacceptable. I would return the cam to the vendor with a description of whats wrong with it.
Terry

[BRENT in 10-uh-C]

Originally Posted by Brianfrench65

I recently purchased a new distributor cam .....

I did buy the part from a reputable source in NY.

I don't know, maybe I am over thinking

............... .........


.........

[dlshady]

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I was wondering how long it would take someone to point out the obvious.

[Brianfrench65]

No, this did not come from Stipe, likely an offshore part.

Yes it is eccentric by 0.052 from the bore.

Lesson learned on my part.

I have a well used, original distributor cam in it now, and running good. I am going to leave well enough alone, for now anyway.

[Tom Wesenberg]

I think you have a couple of the best Parts houses closer to home.

[CarlG]

IMHO, Bill Stipe's dissy cam is the best way to go. And they aren't all that expensive, but they are precision.

[George Miller]

If the cam is running out .005 it will change the point gap by at least .010.
so if you have on .020 on the close lobe it will be .030 on the lobe 180 degrees apart. Other wise your point gap will go from .020 to .030. This also affects the timing on each cylinder. Not a good thing

Just another poor part that us A guys accept.

[Charlie Stephens]

I hope that you will return it with an explanation. This is the feedback that the vendors need to improve their product. If they won't take it back please let us know who sold it to you.

Charlie Stephens

[Brianfrench65]

George; yes you are correct. The TIR (total indicator reading) is 0.0104, Disgusting...

I am ordering one of these: " 17480 DISTRIBUTOR CAM
New aircraft strength 1144 steel, with a rockwell hardness of 23, and precision ground to within .0005 to meet Fords original specifications; polished for smooth surface. the best on the market. This is the Model ‘B’ cam. The ‘B’ cam creates twice as hot a spark as the ‘A’ cam, resulting in longer spark plug life.", From Bratton's. And, by the way, I will check it, as soon as I get it.

I threw away my catalog from Lockport NY. No more junk, at least not from them. No returns after 30 days.

[Patrick L.]

I thought the new owners of the Lockport facility was trying to correct the problems of the old owners, but, maybe not.

[hardtimes]

Originally Posted by Brianfrench65

George; yes you are correct. The TIR (total indicator reading) is 0.0104, Disgusting...

I am ordering one of these: " 17480 DISTRIBUTOR CAM
New aircraft strength 1144 steel, with a rockwell hardness of 23, and precision ground to within .0005 to meet Fords original specifications; polished for smooth surface. the best on the market. This is the Model ‘B’ cam. The ‘B’ cam creates twice as hot a spark as the ‘A’ cam, resulting in longer spark plug life.", From Bratton's. And, by the way, I will check it, as soon as I get it.

I threw away my catalog from Lockport NY. No more junk, at least not from them. No returns after 30 days.

Hey Brian,
THANKS, for sharing your efforts and information ! We are not all engineers and/or have the equipment/knowledge that you've shared.
Sounds like the B cam that you've settled on getting....is a STIPE cam , at least in quality. Hm, wonder is Bill sells bulk to suppliers ?

[CarlG]

Sometimes I wish the vendors would identify who their supplier is in their catalogs. When I bought my Stipe IB330 camshaft, I actually bought it from Snyder's because I was buying a bunch of other stuff at the same time. BUT, I had to ask: 1) if that was a Stipe cam, and 2) if it was an IB330 (since Bill Stipe makes several models of his camshaft.) They did confirm that it was. And here again, I only bought it from Snyder's because I was trying to be willing to support the vendors and not so much the freight companies by splitting up the orders.

[SteveB31]

Brian,

What a couple of these guys are saying, is it is likely you bought the worst cam currently made.

Their are currently 5 different manufacturers , that I know of, making distributor cams. You got one of the not so good ones.

This is why I often get upset when someone says the repro part is no good. Often it depends on WHICH repro part you purchase, and in this case that is the case.

Now, that being said, I am VERY aware that most repro parts are not as good as most original parts. However, it needs to be remembered that often their is a better repro part, and a worse reprop part made of the same part.

Some vendors carry the worse one, Some vendors carry the best one. Some vendors don't know which one they carry.

Steve Becker
Berts Model A Center

[Big hammer]

Originally Posted by Brianfrench65

George; yes you are correct. The TIR (total indicator reading) is 0.0104, Disgusting...

I am ordering one of these: " 17480 DISTRIBUTOR CAM
New aircraft strength 1144 steel, with a rockwell hardness of 23, and precision ground to within .0005 to meet Fords original specifications; polished for smooth surface. the best on the market. This is the Model ‘B’ cam. The ‘B’ cam creates twice as hot a spark as the ‘A’ cam, resulting in longer spark plug life.", From Bratton's. And, by the way, I will check it, as soon as I get it.

I threw away my catalog from Lockport NY. No more junk, at least not from them. No returns after 30 days.

I paid for new parts received old rusty parts called and ask is this a joke
I did get my $ back in a NOT timely manor never again will look at their catalogs
let alone give them any $

[harleytoprock]

Brianfrench65, Let us know how the Bratton's cam measures up. Thanks

[Ron in Quincy]

Several years ago I rebuilt the Distributor for my 30 Coupe; the engine had just been rebuilt and it was a touring engine with a 5.9 Snyder head.

I used a new B cam and checked the lobes using my dial indicator, they all were within .001 variation; I set the clearance between the rotor and the contacts in the distributor body at .025 and my sparkplugs at .030.

The timing was set so the points were just opening as the rotor made contact. To me it always seemed the engine was running advanced but it got good mileage, idled smooth and started easy. One day I even pulled the front timing cover off to check the marks on the crankshaft gear and cam gear to be sure they were correct, everything was fine.

A year later we drove to the Apple Hill Meet in Placerville, CA. I was talking to Les Andrews about the timing so he got his light and we checked the timing and it showed advanced. We spent over an hour messing with timing, even changed the rotor but could not figure out what was wrong.
I finally suggested to Les that I had a stock rebuilt distributor with me and why do we not try it. I installed the distributor, we checked the timing and it was right on, no more advanced.

The problem was the B cam, the detent for the rotor had been cut in the wrong position on the cam.

It is un-fortunate that I do not know which dealer I had got the B cam from, but there must be others out there !!!!

Ron

[Bill Stipe]

The Distributor cam that I make has almost 9 degrees more dwell then any of the other Mfg that I know of which is a great improvement for the Model A and B engines. It will give you more coil saturation time and should give you a hotter spark. Also they are machined from tool steel I believe all other Mfg are pressed out of powered metal.