35 Fan Belt
 

The green book calls for a 40-8620-A fan belt for the 1935 Ford........

Can anyone identify what the lenght, width and angle was for this original Ford part number?? Would be helpfull to know what I am looking for when trying to get a close match.....

Also, what Napa or Gates part number has worked for you on the 1935 85HP ??

Thank you, Jim

Re: 35 Fan Belt
 

Try A 'B54" IF my memory is correct it worked for me !

Re: 35 Fan Belt
 

jfcrash-

B” belts will work on a flathead but they are not the best choice. “B” belts are not made for automotive use. They are designed for electric motor applications.

When you compare an original Ford belt to a "B" belt the differences can be easily seen. Measurement-wise the Ford belt top width is 0.650", the "B" belt is 0.602" The bottom Ford is 0.461 and the "B" belt is 0.406". These measurements are with new belts one of which is an original Ford belt. Of course belt widths can vary slightly between different manufactures but not to extremities noted.

Without having to delve into micro-measurements the most obvious difference is the slope angle of the belts created by the differing dimensions. This difference make a different belt shoulder. It is this shoulder that significantly alters the efficiency of the two belts. Note the pictures. When the belts are placed in a water pump pulley the Ford belt actually sits up slightly higher than the "B" belt. This is because the slope angle of the "B" belt does not have a full contact with the pulley sheaves whereas the Ford belt does and as a result the "B" belt sits lower in the pulley. The actual "B" belt contact with the pulley is only with the top 1/8" of the belt (note chalk mark) whereas the Ford belt has full contact. Less contact, less efficiency.

Users will find the "B" belt will need more frequent belt adjustments and tend to be somewhat noisier than an original belt. In competitive show judging the "B" belt will be easily noticed which may be a concern for those seeking a high-point restoration.

What should you do if you need a belt and can't find a correct one? The "B" belt will work as a substitute belt for the correct Ford belt on an early flathead. However. there are still lots of correct belts still available but the problem is they are often age-hardened from years of non-use. To complicate things even more, belts at swap meets are often found in large unmarked piles with lost identification marks or labels which can make all belts look the same after a few minutes of searching. So, if you are on a belt-hunting mission you best go with something original that you can use for comparison.

Oh yes, The "B" belts do have a couple of advantages over old automotive belts. They are cheaper and 'fresher."

Hope this helps.

Tom

Re: 35 Fan Belt
 

i just asked the parts guy for a replacement belt for mine and he looked it up on his computer and ordered one for me. worked perfectly.

Re: 35 Fan Belt
 

I have a NAPA B54 on my 35 and it is too long. The generator is adjusted up to the furthest extent as the output wiring will allow. flatheadfan is correct, I have had to adjust the belt too much and the angle of the belt is incorrect. With all that said I will try the next shortest belt, which I believe is 2" shorter.

Re: 35 Fan Belt
 

After checking other forums, there does not seem to be a consistent condenses as to what is the best replacement for the original fan belt would be…many different belts have been mentioned that worked for them.

I borrowed a generic NAPA B54 from a friend, it fits around all 4 pulleys but does not have much sidewall pulley contact as Tom mentions above…It has an OS circumference of 57.5” and an IS Cir of 54.5”, top is 5/8” wide and not sure what it’s angle would be.

Drove to Mac’s and purchased their 40-8260-S, the tech guy said theirs has a cir of 55’ measured half way between the OS and IS circumference, 5/8” wide at the top and an angle of 37 degr…it is to small. I even tried to tilt the generator forward on its mounting stud, and then attempted to tighten the big nut to get the generator back in place, but its to tight and obviously would have no slack on the belt even if I got the generator back in place. I did measure its OC to be 56.5” and its IS Cir to be 53.5”..both less than the B54.

Both NAPA and Car Quest each have their own belt called out for the 35 Ford application, but both are ¾” wide at the top and may sit out of the pulley to high??.

At this point, I plan to go with a new B54 , but still open to comments/info…

Thanks your comments,
Jim

Re: 35 Fan Belt
 

If your engine has, other than the correct intake, you will, probably, have a difficult time in figuring out which belt to use.
The generator risers are of different heights, for different years.
MIKE :)