Author	[Modern View]
Farmerhr 11-14-2012 23:56:39 108.224.0.124 Report to Moderator	I am working on a 1948 8N front mount distributor converted to 12 volts. In the rebuild kit I purchased for the engine, there is a set of wrist pin bushings. I want to install them. I made a stepped mandel and have pressed the old bushings out. They came out fine. What is the best way to press in the new bushings ? Should I use two flat pieces of metal one on the bushing and the other under the rod and then press them in ? Or should I make a stepped mandel and use it to push the bushings in ? The new bushings are the split type. Also, what is the best way to size the inside diameter. Can they be reamed to size with an expansion reamer or should they be bored to size on a mill ? It appears there is going to be several thousandths of bearing metal to be remove. Thank you in advance for any help you might be. [Reply]   [No Email]
russb wa 11-15-2012 23:38:13 67.185.6.72 Report to Moderator	Re: Pressing in Wrist Pin Bushings in reply to Farmerhr, 11-14-2012 23:56:39   HR, If I were going to make bushing to fit the wrist pins, I would not use the supplied bushings. Here is what I would do. First I would study the rods with a test bar to see if I could find any "unsquareness". You need to be pure of thoughts when pondering "truthiness". If I were satisfied that the holes were parallel I would proceed as follows: Start with a bronze bar about 1/8 diameter larger than your finished od. Chuck with enough metal hanging out for ~3 bushings. Drill to within 1/8, bore to three thou undersized and "almost" finish with a brake cylinder hone. Oh, you have to sneak up on your fits. You'd need to make up a "go, no go" bar with steps, to check yer hole and a sharp cutting tool with a small nose radius for boring. Then turn and polish the outside to fit. Sneak up on the final fit checking with a stepped gage that you bored before starting. Then cut two bushings out of the middle length, discarding the ends, which are going to be bell mouthed from the hone. Have to do the above twice. Cut a five thou releif in the center of each bush about 20% of the length. That way the center can't be high, rocker. You should at this point be about 5 ten thou under. Finish with made to fit soft aluminum or brass lap and fine compound, or a dowel and micron paper. Much of the modern world is working off numbers. Many old time machinists did first class "fitment" without bothering to know exact dimensions. You'd definately want to watch the side clearance on each rod when assembling the engine, well any engine. Check at 90 degree increments, feeler gauges if unsure. You will be money ahead to pay the automotive machine shop to hone the bushing you already have.   [Reply]  [No Email]
Bruce in 100 mile house 11-15-2012 07:30:46 207.194.36.218 Report to Moderator	Re: Pressing in Wrist Pin Bushings in reply to Farmerhr, 11-14-2012 23:56:39   I made up a guide and honed mine with a small 2 stone brake hone. After honing clean out the bore.With the rod laying on it's side put the Wrist pin in the bore,it should slowly slide down the bore under it's own weight dry.   [Reply]  [No Email]
teddy52food 11-15-2012 10:23:37 184.94.175.179 Report to Moderator	Re: Pressing in Wrist Pin Bushings in reply to Bruce in 100 mile house, 11-15-2012 07:30:46   It is guys like you that will be back later asking why your engine is noisy. Those brake hones do nothing to an egg shaped or tapered hole. So you have it fitted to the smallest part & the rest is too loose. Get it done right.   [Reply]  [No Email]
David G 11-15-2012 07:19:18 205.215.206.18 Report to Moderator	Re: Pressing in Wrist Pin Bushings in reply to Farmerhr, 11-14-2012 23:56:39   Take them to a shop, cost is minimal, rod should be heated, bushing pressed in, then cooled and honed straight.   [Reply]  [No Email]
teddy52food 11-15-2012 06:42:17 184.94.175.179 Report to Moderator	Re: Pressing in Wrist Pin Bushings in reply to Farmerhr, 11-14-2012 23:56:39   They are fitted with a one to three ten-thousands clearance. A job for a Sunnen hone at a machine shop. Take 2 pins along to set up the gauge. You can press them in with a smooth jawed vice if you have one.   [Reply]  [No Email]
01BIRDDOG 11-15-2012 05:44:14 50.147.88.242 Report to Moderator	Re: Pressing in Wrist Pin Bushings in reply to Farmerhr, 11-14-2012 23:56:39   They should be done on a hone like a good Sunnen. You can freeze the new bushing then us a arbor press to install before finish hone. Get dead nuts on the size or you will just do it over again. Hard to use a hand reamer and get perfect straight plus the finish is not what you want.   [Reply]  [No Email]
TheOldHokie 11-15-2012 05:28:35 74.110.75.221 Report to Moderator	Re: Pressing in Wrist Pin Bushings in reply to CJ in Michigan, 11-14-2012 23:56:39   Quoting Removed, click Modern View to see Press them in the same way you pressed them out. Ream or hone to size. You want a very light press fit to the new pins - thumb pressure is the usual measure. The bore needs to be square to the big end of the rod and an automotive machine shop uses a honing machine specially designed for that job. If you have a mill you can approximate that machine quite well.... TOH   [Reply]  [No Email]
welding man 11-15-2012 04:25:35 76.9.225.68 Report to Moderator	Re: Pressing in Wrist Pin Bushings in reply to Farmerhr, 11-14-2012 23:56:39   Take them to an automotive machine shop and let a professional do them,unless you have the proper equipment.   [Reply]  [No Email]