alternator on a Mercury 4-bolt manifold
 

I have a 10SI alternator on a Speedway adaptor with their pulley mounted on a 4-bolt Mercury manifold. It sets about 3/4" too far forward. Is it common to have to shorten the mount on the alternator to bring it in line? I need all the room I can get to put a fan behind it on the slanted radiator in a '38.

Re: alternator on a Mercury 4-bolt manifold
 

I have the same manifold on an 8BA (I assume that's what you have?) with a 10SI, no problems. Are you running the fat belts or the two narrow belts?

3/4" is a lot, could you have the alternator on the wrong side of the slingshot mount? I know there is a difference in the slingshot mounts used on Trucks with the 8BA vs the Cars. I don't think it's quite that much difference tho.

Re: alternator on a Mercury 4-bolt manifold
 

I have truck pumps, wide belt. I really don't see a way to have it on the wrong side of the adaptor.

Re: alternator on a Mercury 4-bolt manifold
 

It has been a while since I bought this bracket. I just went back to Speedway site and found this "note":
To use this bracket on a wide belt car or truck you would need to cut approximately 1/2" to 5/8" from the wide boss on the base of the alternator. You would also need to cut a similar amount from the spacer supplied with the bracket. This must be done to get the alternator pulley to line up with the drive belt.

Re: alternator on a Mercury 4-bolt manifold
 

You knew that! As you're now remembering, a good hot rodder has to be apt at carving pieces to fit where they once wouldn't fit. Get that hacksaw blade warmed-up. DD

Re: alternator on a Mercury 4-bolt manifold
 

I need the 5/8". I measured back on the wide boss and it only sticks out 1/2" from the main case, so to not dig into the case I think the 1/8" runout will be OK. I wonder if anyone makes a slingshot that fits?

Re: alternator on a Mercury 4-bolt manifold
 

we tried one of the new fabricated (welded) brackets and it fit but had to mill the slot to be able to bolt it on---so we again had to adapt-overcome-the sorry design

Re: alternator on a Mercury 4-bolt manifold
 

Sawzall, its a good thing.

Re: alternator on a Mercury 4-bolt manifold
 

I have never been able to cut square with a hacksaw or sawzall.

Re: alternator on a Mercury 4-bolt manifold
 

Can you cut down the length of the round offset spacers used with the alternator bracket?
That would move the alternator back. Another option is to reconfigure the alum alternator bracket by cutting and rewelding it to fit your alternator in the desired position.
Here's an 8BA engine with the 8BA intake, 8RT pumps and some modification photos that may help with some ideas. Your 10SI one wire alternator is a bit different from mine. I also installed a fusible link on the hot wire between the alternator and the battery...just in case.

Re: alternator on a Mercury 4-bolt manifold
 

I don't know of too many folks that didn't have to modify for the sling shot mounts. If they just made the mount to fit a Delco or whatever GM 1 wire alternator then it would be a usable product BUT NO! Once you modify the alternator case, you own it.

Re: alternator on a Mercury 4-bolt manifold
 

The alternator can be easily moved back without modificatioon. First remove it from the adapter. Then bolt 2 short pieces of angle iron or 1/4" thick steel strip to each *backside* of the adapter so they will butt up against the sides of the alternator case. Then raise the alternator up over the Y and bolt it to strips. Use washers or spacers to adjust the alternator forward or backward to suit if needed.

Jack E/NJ

Re: alternator on a Mercury 4-bolt manifold
 

If you look around, I'm certain there are people selling the mount for Trucks that are made to account for the difference.

Look at the difference between these two:

http://www.speedwaymotors.com/Plain-...cket,4242.html

http://www.ebay.com/itm/1948-53-Ford...-/310813714708

Re: alternator on a Mercury 4-bolt manifold
 

If you look at the one for the 8BA era pickups on flea-pay, you will notice that it is mounted to a 59A era engine so the fit on an 8BA is as clear as mud from that photo.

I still use 6-volt generators but if I ever mount up an alternator, I'll be fabricating my own mount for it.

Re: alternator on a Mercury 4-bolt manifold
 

To save waiting on another bracket I just whacked on the alternator. A few trial fits and minor adjustments to slip up on the right spot and it is OK. Thanks for the commebnts.

Re: alternator on a Mercury 4-bolt manifold
 

Congrats! So can we see a pix of what ya' done. Thanks. Jack E/NJ

Re: alternator on a Mercury 4-bolt manifold
 

Here you go...

Re: alternator on a Mercury 4-bolt manifold
 

Re: alternator on a Mercury 4-bolt manifold
 

The alternator cooling fan doesn't look quite right either.

Re: alternator on a Mercury 4-bolt manifold
 

Nice hacksaw work! But you've mutilated it and can't return it now.

I'd guess to keep crankcase fumes & mists where they belong. I thought everybody would know that.


You mean backward in one pix. And forward in the other. Maybe it's just an optical illusion. 8^)

Jack E/NJ