351w water pump gasket keeps blowing

drchip

Member
I'm having trouble with this dang pump blowing gaskets on the back plate.The first time it blew shortly after motor install before it left the garage. I attributed it to the bolts on the back plate (there are 2) possibly being too loose from the manufacturer. Replaced the gasket and reinstalled and got it on the road this week. I have drove it less than 200 miles and last night it blew again.I'm afraid I'm gonna blow this engine if I don't get this cured. I noticed over the winter after the first reinstall a few drops of antifreeze on the garage floor. I couldnt tell for sure where it was coming from but I resnugged the mounting bolts a couple times and it continued. I obviously couldnt get to the back plate bolts and I was cautious of overtightening on the aluminum cover. It is a ford racing short nose pump which is based on a mustang pump only with a v belt. I have an 18 lb. cap on it - is that too high or is there likley another problem. Hopefully someone will offer some thoughts on this thread - thank you
 
I run a 16lb cap on my '41 with a 351W and no problems. I'm running a cast pump with a back plate on the impeller for higher flow. My 2¢
 
There are 4 bolts on water pump plate and maybe the bottom bolts stick out to far and hitting case,make sure there is enought clearance grind or file bolt heads.
 
Well guys I assumed it was a gasket - wrong! I pulled the pump off and took the cover off and theres a plate thats spotwelded to the impeller that came off. It bounced around and spun in there and wore a groove all the way through the housing. Obviously defective workmanship but I've had it nearly a year even though it hadn't been run so I doubt Summit or Ford racing will back it but I'll try calling. I probably will end up finding someone that can weld aluminum and run it without that stupid plate.
 
Got it welded, ordered gaskets and got a 13lb cap. Someone suggested I may have the wrong pulleys and may be over spinning it. I need to look into that .
 
Yep, wrong pulleys. Ford racing doesnt make the correct set anymore but they are available from Runne-rite. More money wasted.
 
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