Quote:
Originally Posted by Karl Wolf
The (one that I know of) tool that does this job is a Sunnen hone... The mandrell that this is for has a relatively small rounded button that is pressurerized by the machine. As this is rotated inside the installed bushing, pressure can be increased... The point loading is relatively high, stretching the bushing outwards into the rough rod bore... Not anything that I could do at home...
Karl
|
Correct, Karl has it exactly right, and this is the ONLY recommended way to do the Flathead bushings. I had mentioned this in another post here earlier!
This part of the procedure is done on the Sunnen rod reconditioner!
You could hone the bores smoother also (just changing the finish) then press the bushing in, this becomes an alternative method, but if you have the "burnisher", it really isn't necessary! And you do not want to compromise the press fit with this method! It can all be measured beforehand.
Also, it helps to pre-heat the pin ends in the rod heater to help ease the bushing into place! We use this method in conjunction with the "burnisher"!
One VERY important step BEFORE pressing the bushings in is to "chamfer" the pin holes, at least on the one starting side where the bushing will go in! It helps to do bushing also, at least on the starting side!
(Add) This "burnishing" procedure is the very same method we use today to finish the valve guides (on the Flatheads also) when "lining" them with the .030" bronze inserts. The only difference being when you run the "burnisher" through it leaves the desired finished size without any add'l honing! They come in increments of .0005" (half-thou) for sizing!
Thanks, Gary in N.Y.
P.S. There was some mention also earlier about "shortening" the rods (C/C) slightly by the resizing procedure. It really isn't an issue BUT, this can be corrected also, by resizing the rod first, then do the bushings, but before finish-honing to the desired pin clearance you would "bore" the bushing in another fixture correcting the C/C by slightly off-setting the hole in the bushing! You only have minimal material to make the correction! Normally you only need about .002"/.004" offset to correct the distance. It will make the bushing slightly thinner on one side, but again, this a non-issue!