So you need a reverse rotation Water Pump!

[trotterlg]

Not everyone will need one, but from time to time you will need to change belt routing and drive the pump from the other side of the belt which will require a pump that pumps water when turned backwards. I need this for a swap of a 3.1 aluminum head engine into a Fiero. The late model front timing cover uses a slightly different water pump than the older 2.8 engines did. I needed the new timing cover to fit the cast oil pan the 3.1 has on it. So what I needed is a pump that fits the new timing cover but turns the direction of the pump that fits the old timing cover.

My solution is this, there are probably other ways to get there however.

I got a new pump that fits the timing cover on my engine. I removed the cast impeller from the pump. You cannot pull them off with a puller, the case iron will just break on you. I drilled a small hole through the impeller next to the shaft taking care not to drill into the shaft any. I then used a die grinder to cut a slit in the impeller so I could crack it with a chisel. I supported the other side of the impeller on a concrete block and just a couple of whacks with a hammer split it clean, the impeller just slipped right off. You cannot just drive the impeller off the shaft because you will trash the bearings and seal doing that. Next I will get an older pump with the proper rotation impeller on it, drive out the shaft and machine out the metal shaft from inside the impeller to relieve the pressure before I attempt to pull it off. That part will get pictures later. Then just press the new one on the shaft and off we go. Pictures below of what to expect. The water seal is done with the sleeve you see in the picture so removing the impeller doesn't affect it at all. I would think this would work with other pumps as long as you can find an impeller that turns the right way. Larry

[CNCguy]

You will get some circulation with that setup but nowhere near as much as it should be. You can buy brand new CW rotation front covers on Ebay that will fit the aluminum pan.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=140364272386&viewitem=&sspagename=STRK%3AMEWAX%3AIT

[trotterlg]

I really appreciate the posting! I am wondering what vehicle these were installed on. All other covers with teh round type pan surfaces have pumps that rotate in the opposite direction, the one I have is from an Isuzu. This is a better solution than the one I came up with, just not sure where they come from and what exact pump will fit it. Do you know? Larry

[CNCguy]

The later ('87~'88 I think) V6 Fieros used this style cover as well as the 3.4L crate engine. We were buying these from GM until they ran out of inventory a few years ago. For whatever reason, they showed up on Ebay recently. The only problem with this style cover is if you want to run OBD-II since it doesn't have provisions for the 24X crank trigger. I believe any of the earlier V-belt driven CW rotating pumps will mount to it along with the Fiero pumps.

[trotterlg]

I want to thank the members here for their help. While I think the reverse rotation pump would have worked out OK, I will go with the proper solution, I have purchased a proper front cover for the proper water pump. Thanks again to CNCGuy for the heads up on Ebay, there are three sellers of these that I can find I think. Got a new one for $60.00 shipped which is well worth the money to not put a science experment on a $1,000 engine. Larry

[geoffinbc]

An 86 S-10 is a Crate Motor cover is disguise. New style pan seal with standard rotation pump.

Anything before was old pan seal with standard rotation pump. Anything after 86 is new pan seal reverse rotation.

[trotterlg]

I got a proper one in the mail now, I will take some pictures when I get it installed. Today I also learned the rear cam plug (drive in freeze plug) will swap out to a Dorman # 555-080 if any one needs a sub for the factory plug. Larry