351c water pump/timing cover question

[cjkcue]

So I am working on a newly purchased 73 Mach 1 with a 351c. I had a coolant leak at the bottom of the water pump and come to find out that one of the holes is stripped out and leaking though the bolt hole. The one that is stripped is the bolt directly below where the lower radiator hose attaches. Am I correct in thinking that this is one of the bolts that attaches to the timing cover only and not directly into the block? Would love to just replace the timing cover and avoid attempting a helicoil into the block.

Thanks everyone.

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[Don C]

The timing cover on a 351C is just a flat steel plate, with no threaded holes in it that go into the water jacket. The rest of the timing cover is integral with the block and the water pump bolts that go into a water jacket are threaded into the block.

 

[cjkcue]

Thank you. I was looking at this online. Thought I might have stripped the circled.

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[Don C]

Those just hold the bottom of the water pump against the plate. The backside of the plate faces the cavity where the timing chain and sprockets are, and there is only splashed oil there.

 

[cjkcue]

Thank you Don. That makes sense. However, if that bolt is not fully tight and I get separation from the plate and the bottom of the water pump, I could see an antifreeze leak?

Also If this is the case, would the smart play to be to replace the timing cover or try and tap/helicoil that hole?

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[Don C]

Yes, if that is one of the bolt holes that is stripped the gasket would leak. Whether or not you replace the plate depends on the condition of the plate behind the water pump, if staight water was ever used for the coolant the plate is likely to be rusted/pitted. A Helicoil will be fine, just make sure you use sealant on it.

 

[Hemikiller]

If everything else looks in good shape, I'd simply heli-coil the plate and be on my way. If the plate is crusty and the engine of unknown history, I'd pull the plate to ensure the timing set has been replaced with a steel cam gear style and the condition of the chain. You will have to loosen and gently pry down the front of the pan to get the plate out.

 

[cjkcue]

Thank you both. Unfortunately the engine is of unknown origin and would probably be best if I check the timing chain and other components. I will just change the cover at this point.

Now to get another timing cover.

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[Canted 393]

Here is 1, pretty good quality but not cheap.

https://www.summitracing.com/search/part-type/timing-covers/make/ford/engine-size/5-8l-351/engine-family/ford-cleveland?SortBy=Default&

 

[Hemikiller]

Thank you both. Unfortunately the engine is of unknown origin and would probably be best if I check the timing chain and other components. I will just change the cover at this point.

Now to get another timing cover.

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If the cover is otherwise in good shape, you can simply weld a nut to the back side. Probably just do both while you're there. IIRC, the originals were simply punched and the extruded sheetmetal threaded.

 

[davetorry]

Regarding the stripped hole for securing the water pump to the block (5/16 bolt), can a person drill and tap a 3/8 threaded hole? Have the same issue on my 73 351C engine block.

 

[davetorry]

The timing cover on a 351C is just a flat steel plate, with no threaded holes in it that go into the water jacket. The rest of the timing cover is integral with the block and the water pump bolts that go into a water jacket are threaded into the block.



Same problem on my 73 351C (5/16 bolt) Can a person drill and tap for a 3/8 bo;t?

 

[Sheriff41]

Regarding the stripped hole for securing the water pump to the block (5/16 bolt), can a person drill and tap a 3/8 threaded hole? Have the same issue on my 73 351C engine block.

The preferred method is to install a heli-coil and use the original size bolt.