Oil Pump Bolts?

[Bodo]

Howdy gang,

Can someone put my mind at ease? Are there special bolts for the oil pump or can I use proper length 5/16 bolts?

Thanks

[5-90]

Proper length screws are fine.

There aren't very many "critical" or "exotic" fasteners in an engine that just can't be replaced with quality aftermarket parts. Cylinder head screws are something I don't like to play with (although most of them have SAE8 markings,) main cap screws can generally be replaced with SAE8, and conrod cap bolts and nuts are typicall an odd size and profile (the head is usually a "D" shape to wedge against the side of the rod, and many are 11/32"!)

For just about everything else, a standard SAE carbon steel replacement is just fine - although using carbon steel isn't always best. I like to use CRES, brass, or bronze for hardware exposed to coolant (if you can only get carbon steel, coat the shank with RTV or PTFE paste,) and I favour bronze or brass for exhaust hardware (eliminates the problem of screw seizure.)

I also tend to replace a number of external screws with socket head capscrews and washers (I like the look,) and large and difficult-to-align bits will often get a few studs installed to help (oil sump and valve cover in particular.) Studs on the manifolds also will help - I'll usually cut those from brass threaded rod and harden to about "half-hard" for greater endurance. Why? Because the useful location for studs on the AMC 242ci happen to be near or between exhaust ports, and that makes things screwy. If you can only get carbon steel for exhaust hardware, I strongly suggest using SAE5 instead of SAE8 - SAE5 is somewhat less sensitive to heat-cycling, and will lose strength less rapidly than SAE8 (there comes a point where SAE5 in service will still have more strength than SAE8, after some number of annealing cycles!) If all you can get for exhaust hardware is carbon steel, then replace it /every/ /time/ /it/ /comes/ /out!/ Cheap insurance.

[Bodo]

Thank you for the thoughtful reply.

Good info there

[5-90]

Thank you for the thoughtful reply.

Good info there

Can ya /tell/ I've been doing this for a couple of whiles?

I gotta get around to writing that fastener primer I've been meaning to do. I know BillAVista has one up, but he could have covered a good deal more (as I recall, he's stuck to SAE- and ISO-classed carbon steel goodies, and there's more to the fastener world than that!)