I have a Chevy water pump that I want to install on my 55 Chevy with a 350. The current water pump is tired and leaking. I have a long version pump that came off a ZZ4, last numbers are cast on it "306". Will this pump work on my standard issue SBC? My fear is that its a reverse follow pump!
This thread from 2003 says it's standard rotation https://www.thirdgen.org/forums/engine-swap/208133-whats-deal-w-zz4.html
Look at the pump impeller. When the vanes of the impeller are turning they should be pushing the water (picture a back handed slap) not scooping. Phil
Are you willing to take the back cover off? If so, here’s a reverse rotation pump impeller pic for you to compare to.
When I moved from my big shop on the farm there were 6-7 GM long water pumps that were off ZZ4 engines. Non of the ZZ series engines I used thru the years were serpentine. I don't know anything about the current ZZ engines.
This is the water pump I took off my car. It was leaking from the front seal. I replaced the pump with a Chevy perfromance part # 12685965, which is a ZZ4 replacement pump. Visually indentical to what I took off the car. The pump I removed has no casting numbers or identification on it. My dilemma is the the CTS in the cylinder head no reads 20-30 hotter than the CTS in the intake manifold. This was not the case with the old water pump. I have replaced both the CTS in the cylinder head with a Holley part, the car has a Holley Sniper, and the intake manifold CTS. Looking at my picture is the impeller an issue, it looks to me that the impeller is mounted in the wrong rotation. Even though I had no overheating problem with this pump! Does anyone know if the ZZ4 impeller is mounted like the picture? The car runs belts and pulleys not a serpentine.
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