I posted this a while back and a few people have asked me about it - so, allow me to repeat myself!!!

I just performed this operation on a McCoy redhead and  was very pleased with the results.

Bob Z.

When I was building high performance overhead cam engines, I used valve guides made from silicone/aluminum/bronze. The material was later improved to manganese bronze alloy and is now available as stock valve guides for ALFA Romeo. The alloy is engineered to act as an interface bearing material between aluminum and steel, as in our plain bushing engines. It is compatible with any lubricant and extremely resistant to wear from sliding and rotation. The beauty of the guides is that they are perfect size for making front bushings! 

They are available from International Auto Parts (800 953 0813/434 973 0555). The manganese bronze guides, #37253000 or #37252000 are $4.95 each. If you want standard bronze, which is also a very good material, you can get #10700000 for $1.50.

Installation is simple (Assuming you have a lathe).

1)   Measure the protrusion of the original bushing into the case.
2)   Set the case up very accurately and carefully bore out the old bushing just until all the bronze has been removed.
3)   Machine the OD of the guide for an interference fit of .0005è.001” (any more could split the case). Be sure and leave a shoulder of the dimension in (1)
4)   Heat the case to around 250°F and freeze the new bushing.
5)   Quickly assemble from inside – the bushing should slip right in. A light tap with a plastic hammer is a good idea.
6)   Machine the intake port into the bushing.
7)   Set up for final boring/reaming. This step is critical: Before you bore, indicate to insure that the new bushing bore C/L is PERPENDICULAR to the cylinder bore. If you’re off 1°, you might have problems with connecting rod wear.
   Check/measure the main journal of the crank – if it is out-of-round by more than .001, consider a new one. Also, it would not hurt to polish the wearing surfaces with crocus cloth.
9)   Finally, ream the new bushing to the proper ID such the crank JUST SLIPS IN. Double check dimension (1)

I sent some of these guides to George Aldrich to restore the old sand-cast Foxes. We were considering writing an article but------ well, you know.

As I final note, I would avoid standard “Oilite” bushings. They work well for pure rotation but the impact loads imparted to the crank will prevent long life.

Hope this helps!

Bob Z

  What ya think about melting babbit in to the bushing and reaming
 to fit ?

 Keith

Bob, just remember to do your babbit operation in a well ventilated area.  Lead fumes, of course. 

BOB and BILL.

  Thanks for the ideas and feedback.  I did read an article on Lenard's site to do the 400 Degs. in the oven thing. But I too agree, that chroming the piston is the real cure. Appreciate all the info.

    REGARDS.    DAVE

Good luck trying to get the babbit alloy to metallurgically bond to the original bronze bushing- I'm a welding engineer/ metallurgist- and deal with babbitt for large turbines-
You will need to clean the bronze very well and then preheat and then "pre- tin" the surface of the bronze  bushing before you atempt to pour in any molten babbitt. You can pre- tin using a tin-lead solder with flux - then you need to neutralize and wash out the flux residue. Before you try to static pour the babbitt you will need to preheat the bronze bushing to a point just below where the pre tin will begin to melt.
Good luck on this.
Lyle

Hi, Lyle & Rob - OK, you've shown me the light.

Seems like my original idea might just be the most practical.

With the price of some of the newer imported lathes, more hobbyists can set up to do their own machine work.

If you're on the market, try Harbor Freight. I bought one of my lathes there and for around $800.00 delivered, I got a decent light-duty machine that will cut both metric and English threads.

Bob Z.

I've had three lathes, currently an ENCO (china) 9 x 20. The others were 16x40 Victor, and 4" china model.  All the "china" models come from the same factory.

The Victor was of course the best of the best, but I had to give it up when I moved to smaller digs.  The 9x20 is adequate but not great.  The smaller machines all suffer from stability of the cross slides.  The quality of assembly suffers due to the cost of manufacture.  There's something to be said about the mass of the machine leading to stability of use.

I had so many problems taking other than a couple of 1/1000ths cut with the 4" I would avoid one of those like the plague! 

And I always like to say, you can make a small part on a big machine, but you can't make a big part on a small machine.