New valve guides
 

Hi all, Still rounding up the valve train parts for my 255 mercury motor. I'm looking at valve guides and see some are heat treated and prices vary quite a bit. Any thoughts on who's or what is the best for street use?
Thanks as always, Tim

Re: New valve guides
 

SBI or Qualcast will work fine. What does your local machine shop sell?


R

Re: New valve guides
 

Get anything that is on the high side of the tolerance on the OD. Put them in with high temp loctite and then put bronze sleeves in them. They will last longer than you then.

Re: New valve guides
 

Totally agree with Pete.
Cheers
KiWinUS

Re: New valve guides
 

You can also use green retaining compound an lock them in. Install bronze guides before you install them. That requires some bronze tooling but works good.


R

Re: New valve guides
 

Be sure to check your "new" guides and "new" valves for clearance if going that route. My "new" guides and "new" valves measured almost triple Fords allowable clearance between them. So we knurled the old guides and installed bronze sleeves in them, reamed them to fit new valves. When done this way the valves close rather than rattling in place.

Re: New valve guides
 

Knurling the OD of guides is a poor choice. It will cut the heat transfer by as much as 30% due to the reduced contact area.

Re: New valve guides
 

I knurl the valve guide for hne valve stem. This tightens the clearance ti the stem but keeps then well lubricated. I also don't use the guide seal I coat the guide with RTv and install it, By the time you run the engine it will set up. Usingn Never seal on the exhaust will make the next person to dis assemble the engine very happy.
Gramps

Re: New valve guides
 

Ron, I love how you are always thinking of the next guy. That is admirable in theses days of troubled times.

Re: New valve guides
 

I'll second that.