Technical Distributor Bushing Reamer - what size?

Installed new bushing in housing. Old one loose as a goose. New distributor shaft & gear & point cam &c.

Bushing is listed as max ID 0.4690" ; distributor shaft min dia 0.4675" ; I'd maybe take it to a shop, unless they know what they are doing they'd probably hog it out so there would be more clearance than the old setup. Depending on what they charge, too, I can pick up a reamer and who doesn't like more tools, right? Maybe a .4680" fluted reamer? The Ford shop manual calls it "burnishing" after installatiin' with tool #12132

 

Uncanny. I was only reading this in the Ford factory manual two nights ago and wondered whether anyone still does this!

Sorry, no answer, but my old distributors are OK in the bush dept.

 

Fluted reamer ???

Doesnt that imply that it has a taper ?

Just asking.

Oldmics

 

I'm gonna have to do this. The bushing fit on a used distributor shaft before installation, once installed though, no way no how. Tight as bark on a tree. A new shaft will not improve. Maybe a nominal size 0.4675" reamer would actually skim off juuuust enough material? Kinda sneak up on it at least. Except I don't want to keep buying reamers. Adjustable reamers?

Most of the tools I see online when searching are called chuck reamers, for use in a lathe. I probably don't want those.

Edit : Doh! .4685 - is 15/32nds, hand reamers are pretty inexpensive from Grainger. That would make a nominal clearance of .0012" between the shaft and bushing.

 

Beats me, that's why I asked the H.A.M.B.! Good question. Think it just means there are channels.

 

"Fluted" simply equates to the number of reliefs that are in front of each cutting edge. A 4-flute reamer or end mill has 4 flutes that correspond to 4 cutting edges. There are also straight and helical flutes. All of this applies to any reamer regardless of straight (no taper) or with a taper.

- EM

 

Early mopar has it correct. The number of flutes just tells you the number of cutting edges around the cir***ference of the cutting tool.

 

I see there are adjustable reamers available, but they seem to start at 15/32", maybe that's too much to take off from the git go. I dunno.

The original was (I think) steel oilite. Tapped it for removal and it cut easy as pie. The replacement is copper colored with an oil hole, might be a CNC aftermarket deal. The dimensions are correct, but even an old shaft won't go. New shaft is .4675", would a reamer that size be the one to use?

 

15/16" aka 30/32nds"....almost 1 inch....not what you need . That Grainger supplied 15/32 (.4685") sounds like it may be okay..just a tad big for a new bore....but apparently within spec range

Ray

 

Thanks. Er, yeah, the dwell would be a little off after that operation! LOL, I'll edit that.

So a spiral cut hand type reamer would be what I want? I guess the question would be what is the accepted practice for clearance in a distributor shaft. .4675" is the shaft diameter, how close to that is optimum.

 

I would get a adjustable reamer so you can sneak up on your clearance.

 

How about a few p***es with a flex-hone?

https://www.amazon.com/Valve-Guide-Flex-Hone-Hone-Size/dp/B00XLWI7DQ

 

That was my thought too, but it seems like size wise they start and end at 15/32", have to buy two I guess. They make a gazillion different kinds, straight cut, right hand, left hand, &c

I'm just a simple guy trying to do a simple job. LOL

 

Would that... would that work!? I don't know.

 

I had some kingpins that were a little tight and used a brake cylinder hone to free them up. Worked OK.

 

Thanks for the education. Appreciate it !

Oldmics

 

Are you replacing bushings at both ends of the housing? If so, they need to be reamed(or honed) in line with each other.
Also, if the bushing has a parting line a straight fluted reamer won't work.

 

This is an older Ford/Autolite distributor. Only one bushing on those.

I think maybe sneak up on it with a dingle ball hone will actually work. That's why you guys make the big bucks.

 

Find a manual and see what your clearance wants too be. Measure your shaft (actually measure it don't take the shaft size as advertised for granted) and buy a reamer the proper size according to shaft size and clearance.

Yes a fluted reamer is a good idea. I like mine to be align bored so a reamer that has a snout to reach the top bushing is my personal preference.

 

The shaft actually measures .4675" with a mic on an unused portion, and that is the minimum accepted size in the book, but finding it difficult to determine accepted running clearance between the two. I can see daylight in the mic on the worn part of the shaft, probably .001" or .002" wear, not much but enough to ****** the dwell when bush wear is added in too. The new distributor shaft will be here Friday maybe. It will measure exactly .4675" or near enough I expect.

The manual pretty much only talks about endplay. I have written down max ID allowed for the bush is .4690" but I can't remember where I found it. It's not in the shop manual as such.

 

I have one you could barrow.

 

I don't see why not for no more material than you'll probably need to remove. Just sneak up on it a little at a time and make sure to flush out any abrasive residue before you put it all back together.

 

Do it.

 

Spiral cut is for those cases of a keyway or split in the hole to be reamed where as the straight cut would get hung up in the slot

 

I'm not a machinist , but could you chuck your distributor up in a lathe and bore it to fit?

 

Just for the record, a reamer will flex enough to follow the location an existing hole, meaning it will not ream inline two holes that are not inline to begin with. Usually .001-.002 max removal. To straighten or accuratly locate a hole it must be single point bored first, then ream if wanted. (21 years machine shop, including lots of space shuttle work)

 

Absolutely true, contrary to what many believe.

- EM

 

Take a 1/4'' rod slot the end of it with a saw stick co**** emery cloth in it and wrap it until it's close to shaft size and use a drill

 

Guys, talking about using homes in this bushing......bear in mind it’s inner diameter is less than half of an inch.......there may be hones that small, but none of the brake cylinder hones I have, or have had, have ever been that small in diameter.

I do like the idea of the slotted metal rod (or maybe a wood dowel) with sand paper ....

Ray

 

I thought that's what the Dishwasher is for.