Cooling side cover plate?
 

I opened up the side of the engine to inspect the cooling passages. I am happy that there is very little rust, but the bolts came out with a lot of resistance and 2 of them snapped off. With the cover off I could feel that the 2 broken bolts extended into the water jacket by a small amount and that area of the bolts were badly rusted. All of the removed bolts showed rust on the ends. I drilled out the broken bolts and cleaned up all of the threads. I have a set of new grade 8 bolts to put in. My questions are #1 what should I do (if anything) to the ends of the bolts that will extend a little into the water jacket? #2, what would be a good sealent that might also give a little corrosion protection to the bolts? I can just slop them up with non-hardening Permatex or paint the bolts with Rustolium primer and then Permatex? or any other suggestion? _____Grant.

I use TFE paste on the side plate and gasket.
I use TFE paste on all water threads, barbs, and gaskets. It helps the seal and makes disassembly the next time easier.

TRUE GRIT

I would use SS bolts. No need for grade 8, It is only a cover and it just needs to be tight.

Grade 8 is a good choice as it is a more similar metal than SS. Goop them up with Aviation grade Permatex and it will last many more years than the std bolts did uncoated. The harder grd 8 will resist rusting quite well.

Dave Neptune :cool:

or switch to studs and never worry about it again. :)

STRONGLY recommend that you change to studs and nuts for this connection.
Studs should be non-corrosive: stainless is good. The Moyer kit for this job uses stainless studs. Some have done it with stainless set screws from McMaster. Did mine with brass all-thread from HD. Depends on whether you're raw water cooled (use stainless) or have a heat exchanger and glycol (brass is fine).
Install studs with permanent sealant - I used JB-Weld, on the stud and in the hole. The holes in the block should be chased with a tap and cleaned with solvent before stud installation.
Once the studs are installed, clean up any excess sealant then install the cover plate and gasket - I like to use the blue silicone sealant in this location. Nuts and washer of your choice - stainless looks good. No more leaks.

One of the charms of set screws for this application is you can hold them stationary with an allen wrench while torquing the brass hex nuts on or off. It prevents breaking the seal where the stud is threaded into the block.

I bought the grade 8 bolts since that is what Moyer sells and my hardware store has a good selection. My question about the sealant is so that I dont have water coming out the threads. I dont think the gasket is a problem but water can run up the threads and leak or cause corrosion. Having broken off two of the old bolts because the threads extended into the water passage I wanted to avoid that. This was a Great Lakes engine so it has only had fresh water thru it. I tried the next shorter bolt length and it would not have worked. I am going to convert to a heat exchanger so I assume the antifreeze will go a long ways toward preventing corrosion. Thanks for all of the responses. Grant.