The Stovebolt Site Forums The Shop Area Engine Shop How to Mount an Alternator to the Engine

1956 Chevy 3100 pickup, 235 engine:

I've taken the advice of several of you to switch over to an alternator. I pretty well had to since the generator was kaput. I spent the morning fashioning a new mount for the alternator. How do you tell which front mount goes to which side? One mount has a 6 stamped on it and the other mount has what looks like a q stamped on it. Not sure if this would tell anything.

As the moderator, I’ve taken the liberty of changing the title to reflect that you are talking about the mount for the alternator.

Which alternator do you have? A three wire or a one wire. A photo of your alternator and mount would be helpful.

Here's a link to a previous similar discussion. Hopefully it might help....


https://www.stovebolt.com/ubbthread...-bracket-for-alternator-1962#Post1501882

Cmayna, thanks so much for the link as it will come in very handy as soon as I find the top adjusting bracket to mount to. I know I have it somewhere, lol.

Phak1, close but no cigar. The mounts I am talking about attach to the engine close to the pan. One mount on the right side just simply bolts on. The mount on the left side bolts over the generator bracket of which I have fabricated a new plate to hold the alternator I'm switching to (single wire). It's those two mounts I am having trouble identifying which goes to which side.

As long as the belt is in proper fore/aft alignment with the crankshaft and water pump pulleys, how it gets there is completely irrelevant. Just be sure there's enough contact around the circumference of the pulley to get enough belt traction to avoid slippage. It might be necessary to move the alternator a little further away from the engine than the generator was mounted to get enough belt contact with the pulley.
Jerry

My apologies, but your issue is confusing to me. A photo would really help to clear the confusion.

In case you don’t know, here’s a link to instructions on how to add pictures to a post.

Yes for a photo

Hey, no apology necessary. I'm sorry for the confusion. I copied the mounts (4 in the box) from LMC website to show you what I am talking about. See the attached, ignore 3. I have everything ready to start assembling on the engine, but want to make sure I am getting these mounts on the correct sides of the engine where they belong. When attaching from side to side trying to see which is best, they appear to either slant to the back just slightly or to the front, just slightly, not just flat horizontal.

generator/alt bracket fits behind the motor mount. There is an angle to the mount bracket that avoids the
bolt there for the GEN/Alt bracket to sit flat. I saw 2 mounts on mine. Both were angled so it will not matter which side.
I used this bracket cut shorter. Spectre Performance 42263 Alternator Bracket.

The alternator has a separate mount on the drivers side of the engine. The motor mount should have nothing to do with mounting the alternator. Here is where you can buy it. The photo is what It looks like. There are other styles available but they all mount where the old generator was mounted. The second photo shows where it mounted to the block.

Thank you Phak1, Guitplayer, Cmayna and Hotrod Lincoln for all of your valued advice. This posting has taken some different twists from what I was originally seeking, but at the same time has turned out to be a big help in any case.

For clarification, (1) I cut the old bracket down and welded the shortened pieces together for a brace for the new alternator to set in and then (2) cut a plate the same thickness as the old generator mount brace, (3) slotted the holes for adjustment for mounting on the engine block and then (4) welded the brace in operation #1 to the new plate in operation #2. It all fits and aligns. It's just a matter of getting the engine mounts bolted on the right side and over the aforementioned plate on the driver's side. The original adjusting bracket for the top of the generator isn't long enough for the new alternator so I'm going to have to weld on a extension for it to attach to the bolt on the water pump. I hope all this is doesn't fuel more confusion.

I'll send a pic of it first of next week when I get back out to work on it. Again, thanks. See you next week. Have a great weekend and try to stay cool.

the second hole in the ALT bracket pic accepts the top motor mount bolt. ALT bracket and motor mount sit together.
Oily mount is a 1955 generator bracket and motor mount and the painted is a 1957 with an ALT bracket +MM.
Motor mount needs to angle to clear the 1st ALT mount bolt. But even using the ALT bracket pictured by Phak, I still had to shim the
upper adjusting arm out to line it up with the pulley(s).

I didn't have to do any welding or buy any new parts (other than the alternator and the DA connector)

I simply flipped the generator mount end for end and drilled a new hole for the middle bolt to go into the block. That completed the lower mount.

A simple spacer was used to keep the new alternator in line with the water pump.

The threaded hole on the alternator's adjustment tab is too close to the case; you can't use a straight bar from the alternator to the water pump bolt. That's why many people buy a curved adjustment plate. I made a triangular plate for the alternator to move the adjustment hole further out and reused the old generator's adjustment bar.

Here's the finished product. Since the top adjusting bracket was short by nearly 5.5" I added the needed length plus a little angle to make sure the alternator could be adjusted properly for belt tensioning. From these pics you can see the newly extended bracket plate, newly fabricated brackets welded onto the plate and then the engine mounts bolted over the plate. All is well when a plan comes together (thanks Hotrod Lincoln).

Hawkman - Did adding pics in your last post not work???

I sure thought I had a handle on it, but guess not. I used the Full Editor. Will try again right now since I have actually dropped the engine into the completed frame.
However, I came across another problem. I received front engine mounts for what I believe is a V8 instead of a six cylinder 235 engine. Would any of you know where to obtain the correct front engine mounts? The ones I received are only about 5" tall from the frame top to the top of the special bolt that goes through the rubber portions. With the ones I purchased the engine is sitting on the frame up front. The back bell housing mounts bolted right in correctly.

I show three files attached. I hope it works this time.

I may have the front engine mounts, I will check and post pictures of what I have.

After checking I was wrong, sorry for the mis information.

I have the correct mounts on my engine, I'll check the length later today. I bought mine from LMC .

Here's what you need for the 235 install: GM# 3714387 Stud, front mount 7-1/2" Overall Length w/3/8-24 threads both ends. The rest of the bushings, washers and nuts are all the same as what you already have.

These stands are taller than the V-8 birds leg stands that you have and will put thing back to the right place for you.

Here's a set being offered on ebay GM# 3714387 Pair for a decent price. If you search the GM#, there are a few others being offered by other ebay sellers too.

Classic Parts says they carry Original GM# 3714387 - Works on both 6cyl and V-8 trucks and the pictured part does look like the tall stand legs. Might have to be quick ordering from them as they say only 2 left in stock, but I would also confirm if they are the correct langth.

Gdads51, I will get busy and order from one or the other. Will let you know how it goes. Thanks a bunch!