Thread: SBC Help - Water Pump & Pulleys

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I've always heard that dropping a SBC in a hot rod was the chosen path because it was so much easier, and that clearance was not a problem. Well, the PO of my '32 project bought a 350 SBC ZZ4 engine. I've been looking at how close the water pump pulley snout is to the radiator, but "assumed" that it was going to be close, but OK with a mechanical fan. WRONG!

I'm now finding that Chevy has a short and long water pump for the SBC, and I've got the long one. Of course, the PO went out and bought billet pulleys for pump & crank, chrome alternator bracket for the chrome alternator with the red Chevy bow tie embossed on it..... I swear, if I hadn't already swapped out the TH350 for a 700R4 I'd be cutting motor mounts and fabbing up for a 4.6L Ford!

My question, in the current setup the water pump and alternator align with the forward belt groove on the billet crank pulley. Once I buy a short pump, clockwise rotation, will I be able to use anything that I have, or am I shopping for a new short pump, new water pump pulley, new alternator bracket, and new crank pulley? Does the alternator stay high on the passenger side or will it move? I'd like some help from the bow tie guys that know here. Pictures show what I've got.

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".....will I be able to use anything that I have, or am I shopping for a new short pump, new water pump pulley, new alternator bracket, and new crank pulley? Does the alternator stay high on the passenger side or will it move? ......."

I think I'm going to be the bearer or bad news Roger. Basically you will probably need everything. I've primary played with the stock short water pump stuff (or the cheapy chrome repop stuff) over the years, and that's still out there. The billet stuff will probably need to come from the same manufacturer for everything to line up.

As far as moving the alternator, you can probably leave it on the same side with the right aftermarket brackets/pulleys. The factory stuff will move it to the drivers side, either on the exhaust manifold or with the head mounted bracket used on 70's trucks and Corvettes.


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use the stuff you have but use an electric fan.....

Originally Posted by TooMany2count

use the stuff you have but use an electric fan.....

Yeah.. what he said!

If you go with an electric fan you may have to upgrade your alternator for the fan load. Add the cost of the fan and alternator, it maybe similar to the cost of new pulleys and brackets. However, I would measure first to see if the mechanical fan will fit with the short pump, then make a decision.

Yeah, I thought of going with an electric fan, but I'd really like to keep it simple. Already have a 15" fan, and the 1.375" difference in length will work, but like 36 Sedan says the cost of a bigger alternator, fan, and fan controller will likely be nearly twice the cost of a new short water pump, pulleys and an alternator bracket. A bit ticked right now.....

That stinks Roger. I think the electric fan and an alt may be cheaper than all new brackets, nice aluminum pullies, and a water pump.

Roger, what size is your alternator? I think assuming you need a new one might be in error. I have an electric fan, an electric water pump, an electric fan on my trans cooler and an air conditioner. My 100 amp alternator keeps my voltage steady as a rock. However, it doesn't look like you have room for an electric fan behind the radiator, and I never would put one in front. My 2 cents.

Correct me if I'm wrong, but the long water pump was necessary due to the increased thickness of the harmonic dampener/balancer. The short water pump will bolt up but the pulleys won't align unless you space out the pulley on the water pump which will put you in the same place as a long water pump.

I'm not going electric. I've been flogging Speedway & Summit's listings, along with some evil bay places for pulleys and parts. Mike P's got the scoop (thanks, Mike!) on the alternator. I think I can be back on track for $200 or less, unless Ken is right about the harmonic balancer.

Early sbc's, 265, 283, 327 before 68 I believe, used a short water pump and thin harmonic dampener/balancer and the long water pump came about when the dampener/balancer was thickened. I can't think of a lower pulley arrangement that would line using a thick dampener/balancer with a short water pump. My solution would be to use a short blade non clutch style fan with the set up you have. That is what I used on my 36 coupe after moving the stock radiator forward as far as it would go. I never had a cooling problem but then again I was never in stop and go traffic either. BTW, I drove that car from Dayton, Ohio to Camp Pendleton, Calif. and didn't have a cooling problem even running through the desert in the middle of the afternoon. I added the fan after getting stuck in line at Lions Drag Strip in late 64.

Here's some actual data with no assumptions. My '34 has a Fast Burn 385 crate motor. It's essentially a ZZ4 with Fastburn heads. The harmonic balancer is 1.5" thick x 8" dia. It came with a long water pump, and I changed it to a short water pump. I used pump and crank pulleys for a short water pump and Billet Specialties alternator and A/C brackets. Everything lines up and it works fine.

One other small item . . . I had to replace the composite timing cover with a stamped steel one. Read the following caution from Chevrolet Performance:

If a short water pump is to be used on this engine, there will be clearance problems between the water pump backing plate bolt heads and the composite timing cover used on the Fast Burn 385. Many times this problem can be fixed easily by replacing the bolts on the water pump backing plate with button head Allen bolts. If this approach does not work, the timing cover will need to be replaced with a sheetmetal or any chrome unit. Any small block Chevy timing cover will work on the Fast Burn 385. If the timing cover is replaced, dowel pins are also needed.

Nice looking setup Jack!!!!! It's probably an optical allusion but it sure looks like the WP pulley still sticks out pretty far.

The guys are right about the about the balancer and much as I hate to admit it I had forgotten about that (ain’t old age great). However the stock SWP and pulleys can be used with a fan and the thick balancer. The key is you must use a single groove crankshaft (lower) pulley.

Here is the 283 I currently have on the stand (SWP/thin balancer/2 groove pulley). The fan belt is in the outer groove of the crank pulley.



The thick balancer will space the rear pulley groove out to line up with the water pump pulley (a 2 belt lower pulley on a thick balancer would interfere with the fan however). The single groove lower pulley/thick balancer/head mounted alternator set up was what I used to run back in my V8 Vega days.

The down side is you will be limited to running an alternator only with stock pulleys. A way to add accessories might be playing with a 2 groove water pump pulley and using the second grove off the WP to drive the PS or AC (Cadillac used to run the alternator off the water pump pulley so it’s not like it’s a concept that’s never been used before ).



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Thanks, guys! Looks like I'll probably have to add a timing cover to my parts list, but it's still gonna be a little cheaper than going electric puller, which would be very tight, biased to the top of the radiator for an "in your face, look at me" look that I don't want. Besides, I want the simplicity and reliability of a mechanical fan. Ken, I'm already looking at a 15", no clutch fan and it doesn't clear so there's no choice here. Jack, that's one of the styles of alternator bracket I looked at from Speedway, and it's likely the way I'll go since I'm running a full hood on this one. The single pulley approach is just fine, as I'm only running the water pump and alternator. I truly appreciate the help, and especially the pictures!

Hmmmm...........there are so many options with an SBC that solutions are almost overwhelmingly available.
Here are a couple pics of what we did on the '36 roadster. This is the 330 hp crate engine, short water pump, "big" damper. The pulleys came from Summit IIRC (been quite a few years). I prefer the alternator mounted low just so it's not an ugly, conspicuous lump on top. The fan is a nylon unit from Flex-a-lite that is almost flat to the front so works well in tight confines. The shroud is the typical molded unit from Walker that you cut your own opening to fit. Since we're still in the final throws of finishing the car I don't have any road report, but to test effectiveness of the fan/shroud we let it idle for almost 45 min. in 80+ degree day and it maintained 180. You probably already know this, but there are packs of spacers available to compensate for minor alignment issues (e.g. Universal Water Pump Shim Kit - Speedway Motors, America's Oldest Speed Shop and Aluminum Lower Pulley Spacer - Speedway Motors, America's Oldest Speed Shop)

On an added note re: timing cover. This engine came from Chevrolet with the chrome cover in these pics. We couldn't get the damn thing to stop weeping oil. I don't know if GM is getting these from some hooch in Taiwan or wherever but it acted like the cheap junk ones. A switch to an "old" painted stocker with the "thick" (in other words normal) flange and leak gone.