"Fan" Belt Upgrade

The Cobra has been driving great for 18 years. It's often had a bit of a belt squeal when first starting, especially if it's been humid outside. The 1/2" V belt needed regular tightening, and after having successfully converted my '56 F100 to a serpentine system to solve a similar problem, I decided to do the same to the Cobra. "Serpentine" belt is a bit of a misnomer in this application as this is a simple three-pulley system - no AC, no power steering - just crank, water pump and alternator.

Unfortunately, unlike the Ford 302 in my '56, Ford never put a serpentine belt on an FE. Hence, no junkyard searches for this solution. After looking around a bit, I ordered a kit from CVF Racing. Specifically, I picked up their 390-SERPENTINE-ALT kit. This is essentially three pulleys, an alternator mounting bracket, an 8" tension adjustment rod, a Gates 8-rib belt, and miscellaneous nuts and bolts.

This page documents the conversion from a V-belt to a "Serpentine" belt system.
Here's what the CVF Racing kit looks like for an alternator-only conversion. In particular, note where the alternator is placed in this kit - outside the passenger side cylinder head. This does not work in my Cobra - there simply isn't room for this. Also note the use of an 8" tension adjustment rod with this alternator placement.

One option I went for is their high volume pulley - a larger diameter crank pulley. However, this larger diameter pulley only comes in a two-belt format, so it is very deep.

The primary challenge in this install is mounting the alternator and fitting it with a tension adjustment. This shows the original arrangement. I had built a Rube-Goldberg alternator mount for my Powermaster 140A alternator. The alternator sat low, along side the engine block and had a "crowbar" slide adjustment.
Here's another shot of the previous alternator mount. Note, it did not make use of the hole in the passenger side head that is intended for the alternator mounting bolt as the alternator was positioned lower than in the factory position. Hence the home-built bracket sandwiched the alternator mounting "tab" and provided the torque necessary to keep the alternator normal (in the geometric sense) to the plane of the V-belt.

Also shown here is the original crank pulley - this is an overdrive pulley as well. Way back when, the original pulley was a actually an under-drive unit (probably intended for racing). The Cobra would overheat, so a change was made to this size.

Getting started - all previous pulleys and brackets removed and the remote oil filter hoses positioned out of the way.
"The easy part" - put on the new crank pulley. Here one can see the new overdrive pulley is intended for a two-belt system. While it does fit, I have the plumbing for the remote oil filter routed along the front crossmember in this area. So it is either reroute the oil lines, or modify the pulley.
In looking at the clearance and the way the oil plumbing would need to be re-routed, it became clear that cutting the pulley down was much simpler than re-routing the plumbing.
So, time to cut the extra belt grooves off. I don't have a lathe, which would have been the right way to do this, so instead I used my metal bandsaw. This took quite a while because a) the pulley was pretty thick, and b) I didn't have a bandsaw blade intended for aluminum.
But, after an hour or so of patient cutting on the bandsaw, the pulley was reduced to a single belt drive.
The crank pulley in place, with the alternator bracket in position. Also note the spacer bolt in place on the block. More on this later, but when I changed to a GM alternator, it uses 3/8" bolts, whereas the Ford uses 7/16". The spacer bolt came in an an adapter kit from CVF racing made to allow the GM alternator to fit into a Ford application. This spacer bolt has 7/16" male threads to go into the block, and 3/8" female threads to accept the mounting bolt for the alternator. However, I didn't like this as it seemed "flimsy". Instead I drilled out the 3/8" mounting hole on the alternator to 7/16" and used the long 7/16" bolt that came with the original CFV (Ford) kit.
Speaking of alternators - this is the original Powermaster alternator I was using. Long story short, the bearing on the rear of the alternator makes it too long to sit in front of the engine block. As mentioned previously, the CVF Racing kit places the alternator outside the block, so the length of the alternator is not an issue if you follow their installation. I had this alternator sitting below the "Y" of the block, so, again, length was not an issue. However, with this kit, and with no room in the engine bay, I need to place the alternator in front of the block - this alternator is too long. Small Ford alternators are available, but only to around 60Amps. I wanted something in the 140A range. The solution was to change to a GM alternator.
Some pictures along the way (this is with the orignal Powermaster alternator before I figured out it was too long). This alternator fan came along with the CVF Racing kit.
Here's the 8-rib alternator pulley from the CVF Racing kit.
The kit also comes with a dress cover for the alternator pulley. Note, too, where I tried to file down the mounting hole on the Powermaster alternator in an attempt to get it to fit (didn't work - still didn't fit and put the pulley in a mis-aligned postion).
After trial fitting the Powermaster alternator and finally determining it was too long, I spoke with CVF Racing and they recommended going to a GM alternator along with a GM-to-Ford adapter kit. Here's a comparison of the two alternators - GM on left, Powermaster on right (both with built-in regulators).
The CVF Racing alternator fan and pulley mounted on the GM alternator.
Trial fitting the GM alternator showed that the CVF Racing alternator fan would not work - the blades hit the alternator mounting bracket. Again, this is due to the need to place the alternator "inboard" which folded the alternator too close to the mounting bracket. Had it remained "outboard", as intended with the kit, this would not be an issue.
Another view of the trial fit. Note, however, the depth is now fine with this alternator - positioning the alternator in front of the block clears the head with ample free space.
But, the CVF Racing alternator fan needed to come off, so, back to the stock GM fan that came with the alternator - with the 8-rib pulley.
The next step is attaching the tension adjustment. This bracket is part of the CVF Racing kit. The alternator end of the bracket (left side in this picture) is threaded. However, so is the corresponding hole on the alternator. One or the other needed to be drilled out to accommodate a shoulder bolt.
I chose to drill out the tensioning adapter.
Showing the tensioning adapter with said shoulder bolt (that screws into the alternator).
The tensioning adapter fits behind the alternator tab, so screws on from the rear. This shows the tensioning adapter attached to the alternator with the shoulder bolt going in from the back.
Alternator (with tensioning bracket) installed. As mentioned above, the pivot mount for the GM alternator is a 3/8" bolt and fits into an extension threaded into block. This two-piece arrangement didn't seem robust enough, so I drilled out the pivot mount on the alternator itself to 7/16" and used the mounting bolt that came with the original kit. I did, however need to make my own slip-spacer, as the one that came with the kit was too short - the Ford mounting "tab" is longer than the GM mounting "tab", meaning a longer spacer is needed with the GM alternator. This is also what the 7/16" to 3/8" adapter/spacer is intended to accomplish, but I didn't use that, so had to make my own spacer.
Again, since the CVF Racing kit placed the alternator outside the block, the Gates belt that came with the kit was too long (#K080458). I roughly positioned the alternator and measured the actual length I need with this positioning - a Gates 43.5" belt (#K080435) fit the bill.
With the remote oil filter and associated plumbing back in place, here's the clearance with the "sectioned" crank pulley - close, but plenty of clearance.
The tensioning rod that came with the CVF Racing kit is an 8" unit (8" for the main body, close to 9.5" heim-center to heim-center (minimum). Way to long with the alternator positioned inboard. I needed the shortest tensioning rod available, which is a 2" unit generally intended for Chevy products (a 2" unit ia actually close to 4.5" center to center). I ordered one and, as is shown here, it was still about 1" too long for my application, even in the shortest configuration.
So a little surgery with the hacksaw and 1/2" was removed from each end.
The result was a turnbuckle that measured about 3.5" center-to-center.
Even better.... it fits! It's tight getting the belt on when the tension adjustment is at its minimum, which allows for plenty of adjustment for proper belt tension.
A look at the final install. Works great. No squeal. Back in business. By the way, the CVF Racing kit results in perfect belt alignment - absolutely no shims or tweaks were needed - the pulleys are perfectly co-planar - thank you CVF Racing!