Mid- Engine Modified Sports

[tauruck]

I'm ready brother.
How cool would that be???.

[manta22]

I've exhausted all my ideas about getting the water pump pulley off; I tried unbolting it from the WP flange, unbolting the WP itself and moving everything around but it just won't come off.    I managed to install the crank pulley on the damper but the WP pulley is an underdrive so it is a larger than stock diameter and the two pulley flanges interfere by about 1/8".

I've now thrown in the towel and am getting ready to pull the engine & transaxle out. At least then I'll have easy access to the front of the engine and I can install two V-belts on the pulleys.

As Miss Emily Latella used to say on SNL, "It's always something"

Regards, Neil  Tucson, AZ

[Milwaukee Midget]

Neil, all I can say is that sucks.

Yes - 2 V belts.  Redundancy is this situation is to be encouraged.

Know that if this is the biggest misstep, you're still way ahead of the rest of us. 

[hotrod]

Any chance you can get in there with a grinder and put a couple strategically located notches in the pulley flanges so you can get them to clear each other if you put them in just the right position?

By your discription an 1/8 inch over lap means two 1/16 inch notches in the flanges matched up will get you the clearance you need.

One of those align slot A with notch B while standing on your left foot sort of solutions but could be a lot easier than pulling the car apart.

[tauruck]

Lousy one Neil.
Not a fun job just to get some belts on.

[manta22]

Unfortunately, Hotrod, I'd have to grind off at least 1/8" off one pulley flange-- but for 360 degrees; completely around the circumference.

Today I removed the starter, headers, and all the mounting bolts but 4 and those are ready to be slid out when I pick up the weight of the engine & transaxle. Fortunately my approach to the rear chassis was to make a removable top framework that allows the engine and transaxle to be lifted as one unit straight up to clear the chassis and then swung over onto the floor or whatever. The ignition box, etc. has connectors that unplug from a wire harness so that makes it easier, too.

After both pulleys are bolted on I can measure the length of V-belts that I'll need. I'll try to find appropriate size Gates, Dayco, or Goodyear belts. Those brands should not stretch out like a rubber band- unlike some el cheapo belts.

Regards, Neil  Tucson, AZ

[DND]

Hi Neil

When building the SBC for the Can-Am stuff we used two steel factory pulleys for two belts

Had to lower the alum pump body by about 1/16 of a inch so the belts would not be too tight

Clamp the body down flat on its back and use an end mill and elongate the 4 mounting holes

Those two pulleys cleared each other by about 1/16 " when bolted up tight, belt's never slipped on came off and worked like a charm

Why not just use a toothed belt set up as it is so much easer to get the right belts and pulleys, not enough room maybe?

Don

[fordboy628]

Why not just use a toothed belt set up as it is so much easer to get the right belts and pulleys, not enough room maybe?

Don

Neil,

Weaver Bros has off the shelf gilmer belt drive sets for Chevy water pumps in various under/over drive ratios.   They may have V-belt pulleys in alternate ratios as well.

No idea on cost.   Give them a call.

 
Fordboy

[manta22]

Don & Fordboy;

Thanks for those suggestions but, since I'm already pulling the engine & transaxle up about a foot out of the chassis to get to the water pump, I'll continue with the v-belt pulleys. If I run into problems I'll give Weaver a call.

Regards, Neil  Tucson, AZ

[manta22]

Pulling an engine & transaxle by yourself is no fun but it's now out far enough to remove the water pump and pulley.

I'll attach a picture of the pulley that was causing problems- it's huge, 7 3/4" diameter. I'm replacing it with an aluminum 2-groove v-belt pulley that is stock diameter, 6 1/2". The water pump is an Edelbrock 8819 with a 3/4" snout so I had to ream the new pulley to fit since it was originally 1/2". A 1/8" shim on the crank pulley lined up both nicely. I measured around the outside of both pulleys to find out the length of fan belt needed. I measured 35"- does this sound right?

I fabricated the cradle in this photo to support the top rear of the Porsche G50 transaxle (left) and the rear of the engine (right). It makes it possible to remove both without separating the two. There are other engine mounts as well directly on the chassis tubes.

Regards, Neil  Tucson, AZ

[DND]

Neil you cant go by the O.D. of the pulleys as the groves are not the same far a how deep the belts set into them

Like I was saying I used to lower the pump so the belts would not be too tight

You will have to buy a set that you think is right and swap different sizes till you get the right combo

Try to find a local parts guy that will let try different ones and pay him for the two that fight while returning the other ones

You will have to use the 4 bolts to suck the pump up to the block for the final size check, as this will take a bit of time to get it right

Make a cardboard template from your front motor plate to the back panel of the engine bay, then you will know how much room you have and give Weaver's a call for a toothed set up

Don

[manta22]

Don;

V-belt sizing is one of the most confusing things I've encountered in some time.

I did find a listing for a Dayco Top Cog #15345 which is spec'ed at 35.07" outside length, effective length 34.5" and 0.44" wide. We'll see if this works.

Regards, Neil  Tucson, AZ

[Dynoroom]

Neil, it's the pest again...

The reason the pulley is so large on the water pump is to SLOW it down. I know this seems obvious but the water pump can cavitate at 4000+ PUMP rpm. So the large pulley will allow the water pump to operate in it's correct speed range with the engine running at say 7500 rpm for 5 miles.
As to Don's point about slotting the bolt holes allowing the pump to be shifted to keep the belts from being too tight is a smart idea. You should consider this as you already have the engine out of the car.
We had a access panel behind the drivers seat on one car to allow us to get to the belts or what ever if needed. Again the engine is out of the car, might be a good time to look at it.
Here is a picture of the water pump on my modified roadster. You car see the jack screws that let me adjust the belt tension as needed.

Good Luck on your project. 

[manta22]

Mike;

That is a very nice looking powerplant! 

Yes, my original one was an underdrive pulley (12% with a stock crank pulley) but I may not need to go to an underdrive. My water pump is an Edelbrock 8819 which is a pump designed for sprint cars, not for street applications. It has an impeller that is designed for high RPM.

http://www.edelbrock.com/automotive/mc/water-pumps/competition.shtml

Slotting the pump mounting holes is a good idea. I'll open up the holes into short slots.

Regards, Neil  Tucson, AZ

[DND]

Neil I forgot to say that when you get the two belts on tight, push in at the center where the belts are not touching the pulleys one at a time and see how stiff they are

That will let you know if they both have the same tension, if one is stiffer make a change so they are both equal

If not one is doing all the work , the other one is just going along for the ride

Don