The Ford Barn

quickchange · 09-22-2010, 10:20 PM

New upper shafts , have had from two suppliers & both are 4thou to 5 thou out of round where the cam screws on, Made in USA ??

Shaft runs true but when checking top that has been machined for the cam 5thou wobble so 3 lobes on cam would read correct & one 5thou under, yes will run on it but why make it wrong, Awaiting shippment from another supplier to check. Have checked 20 shafts so far, so not just one,

Even the main shaft varies in dia from shaft to shaft, Derek , waiting for spring to arrive on the mainland, NZ

Ron in Quincy · 09-23-2010, 12:22 AM

Hopefully you are not using a one piece shaft; this is a common problem with the one piece shaft.

Myself I use the two piece shafts; like you I use a dial indicator to check the shaft and cam; I shoot for .001 variation.

Ron

Tom Wesenberg · 09-23-2010, 04:16 AM

I haven't bought any shafts lately, but have purchased the 2 piece shafts and cams from Bratton's and not had a problem. I also used a dial indicator to check them.

Marco Tahtaras · 09-23-2010, 08:27 AM

First, good job on identifying a problem. It's amazing how many folks just replace things assuming they will be fine because they are new.

I first encountered that problem 30 years ago working on my buddy's '28 Phaeton. I was on a pinch for time and fortunately my neighbor had a lathe. I "knurled" (hand punched) the low side to raise the surface and my neighbor turned it to size on center. That shaft is still in the car all these years later!

I assumed that was a fairly isolated problem as it was from a reliable source. However I've been collecting NOS shafts for my personal use ever since so I haven't used a modern replacement to know if they are still prone to issues.

Rowdy · 09-23-2010, 08:48 AM

I ordered one from a supplier with the same problem. I ordered a different one from Bert's and it was good. I beleive there are 4 differnt manufacurers of these. Rod

Tom Wesenberg · 09-23-2010, 02:46 PM

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Quote:

Originally Posted by quickchange

New upper shafts , have had from two suppliers & both are 4thou to 5 thou out of round where the cam screws on, Made in USA ??

Shaft runs true but when checking top that has been machined for the cam 5thou wobble so 3 lobes on cam would read correct & one 5thou under, yes will run on it but why make it wrong, Awaiting shippment from another supplier to check. Have checked 20 shafts so far, so not just one,

Even the main shaft varies in dia from shaft to shaft, Derek , waiting for spring to arrive on the mainland, NZ

You say you checked 20 shafts so far, but didn't mention if they are all bad, and are all from the same supplier?

I'd assume you aren't centering by using a live center in the notched end when making the measurements.

quickchange · 09-24-2010, 01:13 AM

All from one supplier & yes short one, Checked 20, 2 manurfactures , supplier now flying in more from a differant source. so hope 3rd time lucky, Supplier has been very good about it as odd problem with other repo parts, they never hesitate to replace & try to correct the part, problem is supplier only sells & never restored a vehicle, Derek from a warming south island. NZ

Kurt in NJ · 09-25-2010, 08:25 AM

I was curious about this, I checked some of the original shafts (NOS) that my brother has, they are in the old style green boxes, 5 to a box, with the shaft resting in a V block the cam surface was within 0.000 -0.0001, I only tested 3, all the same.

Both areas of the shaft were ground, a small undercut each side of the flange, and the flange is not a seperate washer pressed on.

The repro that my dist had was a piece of cold rolled steel the diameter od the shaft--rough finish, pressed on washer ,lathe turned for the cam, and the point gap changed, after I replaced it with one of the NOS ones my idle was much smoother.

Perhaps if the repro cams are off center too indexing the cam, and shaft, then moving the drive gear to position it for your indexed dist you can get acceptable results.

09-22-2010, 10:20 PM	#1
quickchange Senior Member Join Date: May 2010 Location: Nelson. New Zealand Posts: 2,009	Top dissy shaft, out of round New upper shafts , have had from two suppliers & both are 4thou to 5 thou out of round where the cam screws on, Made in USA ?? Shaft runs true but when checking top that has been machined for the cam 5thou wobble so 3 lobes on cam would read correct & one 5thou under, yes will run on it but why make it wrong, Awaiting shippment from another supplier to check. Have checked 20 shafts so far, so not just one, Even the main shaft varies in dia from shaft to shaft, Derek , waiting for spring to arrive on the mainland, NZ

09-23-2010, 12:22 AM	#2
Ron in Quincy Senior Member Join Date: May 2010 Location: Quincy, CA. Posts: 1,708	Re: Top dissy shaft, out of round Hopefully you are not using a one piece shaft; this is a common problem with the one piece shaft. Myself I use the two piece shafts; like you I use a dial indicator to check the shaft and cam; I shoot for .001 variation. Ron

09-23-2010, 04:16 AM	#3
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Top dissy shaft, out of round I haven't bought any shafts lately, but have purchased the 2 piece shafts and cams from Bratton's and not had a problem. I also used a dial indicator to check them.

09-23-2010, 08:27 AM	#4
Marco Tahtaras Senior Member Join Date: May 2010 Posts: 3,099	Re: Top dissy shaft, out of round First, good job on identifying a problem. It's amazing how many folks just replace things assuming they will be fine because they are new. I first encountered that problem 30 years ago working on my buddy's '28 Phaeton. I was on a pinch for time and fortunately my neighbor had a lathe. I "knurled" (hand punched) the low side to raise the surface and my neighbor turned it to size on center. That shaft is still in the car all these years later! I assumed that was a fairly isolated problem as it was from a reliable source. However I've been collecting NOS shafts for my personal use ever since so I haven't used a modern replacement to know if they are still prone to issues. __________________ http://www.abarnyard.com/

09-23-2010, 08:48 AM	#5
Rowdy BANNED Join Date: May 2010 Location: Gothenburg Nebraska Just off I-80 Posts: 4,893	Re: Top dissy shaft, out of round I ordered one from a supplier with the same problem. I ordered a different one from Bert's and it was good. I beleive there are 4 differnt manufacurers of these. Rod __________________ Do the RIGHT thing - Support the H.A.M.B. Alliance!!!!

09-24-2010, 01:13 AM	#7
quickchange Senior Member Join Date: May 2010 Location: Nelson. New Zealand Posts: 2,009	Re: Top dissy shaft, out of round All from one supplier & yes short one, Checked 20, 2 manurfactures , supplier now flying in more from a differant source. so hope 3rd time lucky, Supplier has been very good about it as odd problem with other repo parts, they never hesitate to replace & try to correct the part, problem is supplier only sells & never restored a vehicle, Derek from a warming south island. NZ

09-25-2010, 08:25 AM	#8
Kurt in NJ Senior Member Join Date: May 2010 Location: on the Littlefield Posts: 6,159	Re: Top dissy shaft, out of round I was curious about this, I checked some of the original shafts (NOS) that my brother has, they are in the old style green boxes, 5 to a box, with the shaft resting in a V block the cam surface was within 0.000 -0.0001, I only tested 3, all the same. Both areas of the shaft were ground, a small undercut each side of the flange, and the flange is not a seperate washer pressed on. The repro that my dist had was a piece of cold rolled steel the diameter od the shaft--rough finish, pressed on washer ,lathe turned for the cam, and the point gap changed, after I replaced it with one of the NOS ones my idle was much smoother. Perhaps if the repro cams are off center too indexing the cam, and shaft, then moving the drive gear to position it for your indexed dist you can get acceptable results.