Replacing Cylinder Head

I am in the process of replacing the cylinder head on my '56 Evinrude Fastwin and I am concerned about putting the bolts back into the head. Do I need to put anti seize or anything on them to keep the bolts from freezing up in the aluminum head over time. I don't want to worry about twisting them off if I have to take the head off again.

ALSO...does anyone know what spark plug is supposed to be used in these motors. When I got it, it had Autolite 303s, I just want to make sure that is the correct number before I replace them.

Re: Replacing Cylinder Head

I would buy some grade 8 bolts and replace them or go with stainless. Yes anti-sieze is good. Put J6C Champions in it gapped at .030

Re: Replacing Cylinder Head

Well that saves me from having to say "ask Zephyr"........greetings my ole friend.

Re: Replacing Cylinder Head

I personally would use OMC "thread sealant" on the bolts...too many variations of anti-sieze...some of which will chemically/galvanically interact with the bolt & aluminum. ALso, "grade 8" bolts are great...until the heads twist off. I had to scrap a good powerhead because the PO put higher grade bolts in that could not be drilled out after one of the heads twisted off.

Mas

Re: Replacing Cylinder Head

I agree Mas. I also think that some of the anti seize products add too much resistance when torquing not allowing proper torque on the bolt.

It seems like alot of guys go to their "product" shelf in their garage/shop/basement and just fire on anything they have on the front of the shelf cause Bob the Builder down the street said it would be ok. The worst example I have seen of this is someone putting Loctite on the crank taper before installing the flywheel because a neighbour said it would help from his flywheel key shearing issue. Well, torquing the flywheel nut to spec would have worked as well

Disclaimer: That is my 02 cents and wont even buy you a coffee

Re: Replacing Cylinder Head

Sixmark said:

Well that saves me from having to say "ask Zephyr"........greetings my ole friend.

Click to expand...

Greetings, my ole friend too. Long time no see. I hope you have been well.

Well, if your motor is kept care of, snapping off bolts won't be an issue. I just put back together my HD-20, using nothing but stainless in it. Those bolts will never rust. That alone will eliminate at least 50% of the future problems. People will say, "but if they snap off...." Well, the lower unit uses stainless already, but that part lives under water. Stainless above the water line will only add better protection.
If you do use anti-sieze, just make sure you read the application directions carefully and make sure it's okay to use with aluminum. Personally, I would just put a little oil on the threads and call it good.

Yea, like HighTrim says, never use locktite. Not unless you're installing a heli-coil.