New small end bronze bushing installation, swaged/burnished or not ?

[Eagle1903]

Dear Friends,

Although, I have read almost all the related topics here, I couldn’t have clear idea on the subject regarding new pressed in bushings have to be definitely swaged/burnished or not.

I would like replace the bronze bushing of the aftermarket steel conrods.
Although not directly related to the topic I may be able to get spare bushings but if I can’t, I am planning to get them custom made.

Can the bushings be made on a manual lathe ?

If swaging is not absolutely necessary then if I understand correct from my readings I will have to install/press the new bushings with some custom made mandrels + heating the rod moderately + freezing the bushing + red Loctite. ( these are my notes from my readings)

But, again in my notes, it has been said that swaging is necessary.

I am aware of the fact after the swaging, bushings has to be finish honed to final size in a rod hone.

The problem is no-one ( including me ) has the swaging tools. And replacing the bushings is something I’d like to perform in house.

And no one literally no one has a rod honing machine over here. But I have a manual stroke Sunnen rod hone. I am planning to post another topic for asking your help regarding some of the user ( me ) in-experience related problems.

Regards,

Kerem

[modok]

Expanding the bushings in place was done with soft bronze bushings going into a rough bore. Many old ford engines were done this way.

If the bearing bore is smooth and accurately sized, and bushings are steel backed or made of a hard bronze then there is no need for it.
1mm wide 25 degree chamfer on leading edges, use a press fit of .003-.004 per 1 diameter, lube with loctite and press into place quickly.

[Eagle1903]

Expanding the bushings in place was done with soft bronze bushings going into a rough bore. Many old ford engines were done this way.

If the bearing bore is smooth and accurately sized, and bushings are steel backed or made of a hard bronze then there is no need for it.
1mm wide 25 degree chamfer on leading edges, use a press fit of .003-.004 per 1 diameter, lube with loctite and press into place quickly.

Hi Modok,

Thank you very much. I fully understood your explanations.

Just couple of more questions if I may please.

Is it an acceptable approach to freeze the bushings in dry ice or due to the wetness etc. freezing the bushings should be avoided ? ( may heating the rod help ? )

If I am designing the bushing ( custom order) what would be the maximum wall thickness of the bushing ?

[BillK]

e,
You should be able to find the bushings pretty easily. All of the rods I have seen use pretty standard sizes. Press one of the old ones out and see what the bore size is. I have never heated the rod or cooled the bushing when doing this on aftermarket rods. The only time I ever burnish the bushings are on the real thin ones like the FE Fords.

[modok]

I don't know,
I have never tried freezing the bushings, but it might be fun to try it.


It might be a good idea to refrigerate the rods If the loctite curing too fast, or use a slower curing loctite formula rather than the usual 640 if this seems to be a problem. I am sure you will find varied opinions about if loctite is a good idea or what is the best lube to use, if any.

Bushings designed to be bored to size usually have .010" (.25mm) greater wall thickness than finished size. This allows the rods to be made all to the same length again.
And sometimes replacement bushings are perhaps .004" larger OD than original, this allows you to hone the rod bore true again before installing the bushing.

making the bushing very heavy wall thickness, 1 or even 1.5mm could work, i'm not sure why you would do that..... just thinking.... heaver wall thickness will take more force to squeeze into the rod, but probably not a big concern. If you are adapting smaller pins than before, you might be able to find a steel backed bushing of the right size.

[Eagle1903]

e,
You should be able to find the bushings pretty easily. All of the rods I have seen use pretty standard sizes. Press one of the old ones out and see what the bore size is. I have never heated the rod or cooled the bushing when doing this on aftermarket rods. The only time I ever burnish the bushings are on the real thin ones like the FE Fords.

Bill,
Thank you very much.

[Eagle1903]

I don't know,
I have never tried freezing the bushings, but it might be fun to try it.


It might be a good idea to refrigerate the rods If the loctite curing too fast, or use a slower curing loctite formula rather than the usual 640 if this seems to be a problem. I am sure you will find varied opinions about if loctite is a good idea or what is the best lube to use, if any.

Bushings designed to be bored to size usually have .010" (.25mm) greater wall thickness than finished size. This allows the rods to be made all to the same length again.
And sometimes replacement bushings are perhaps .004" larger OD than original, this allows you to hone the rod bore true again before installing the bushing.

making the bushing very heavy wall thickness, 1 or even 1.5mm could work, i'm not sure why you would do that..... just thinking.... heaver wall thickness will take more force to squeeze into the rod, but probably not a big concern. If you are adapting smaller pins than before, you might be able to find a steel backed bushing of the right size.

Modok,

Thank you very much.

But if I understand correct, whether it is the red or green Loctite, a small amount of a locking compound should be used.

[BillK]

What exactly are you working on ? Who's rods ? I have never used any type of Loctite etc.

[FloydODB]

im with bill, no on loctite,always thought it was a heat barrier. yes on the right press fit. i'd try heating the rod. doesnt need much and we do it all the time with stock stuff. tried liquid nitrogen on cyl sleeves for a time but they moved around under operation.

[Eagle1903]

What exactly are you working on ? Who's rods ? I have never used any type of Loctite etc.

Hi Bill,
I usually use Farndon ( UK ), Maxspeeding ( Chinese ) rods and other custom made rods from a Greek rod and piston manufacturer. ( also used Eagle, PEC etc kind of rods in my engine builds in the past ) %95 of the engines I work with is European I4 engines, some old school fast road and rally engines, some rather modern Mitsu 4G63 type of engines. Never had a chance to build a V8 yet.
I never had to replace any of their bushings but I would like to learn the bush replacing operation.
I have a Sunnen manual rod hone ( not the power stroke one ) but I have to build experience with this machine which I am planning to open a new topic about that soon ( to ask help ) since I am having some difficulties obtaining straight inner diameter.

[Eagle1903]

im with bill, no on loctite,always thought it was a heat barrier. yes on the right press fit. i'd try heating the rod. doesnt need much and we do it all the time with stock stuff. tried liquid nitrogen on cyl sleeves for a time but they moved around under operation.

Hi Daniel,
I understand your point regarding the heat barrier. I had zero experience with bushing replacement so I asked help. And many thanks for all your help.
I am planning to oven heat the rods but we will first machine the required mandrels for the necessary diameters.
If I understand correct, once the rod ID is known and the bushing is ready it is possible to start installing the new bushing while pushing out the old one. However, old bushings pressed out first and new ones pressed in. Once the old bushings are removed, it may be a good idea lightly Flexhone the bore with some fine grit, probably finer than 320grit.

[BillK]

I never had to replace any of their bushings but I would like to learn the bush replacing operation.
I have a Sunnen manual rod hone ( not the power stroke one ) but I have to build experience with this machine which I am planning to open a new topic about that soon ( to ask help ) since I am having some difficulties obtaining straight inner diameter.

Same machine I have. Lots of flipping the rod back and forth. Every couple of strokes flip the rods. Always do 2 rods at a time. Use the coarse stones as far as possible until almost to finish size. Then switch to the fine ones. Lots of tricks but mostly just experience after doing it for 30 years. Seems like each rod is different. Some you need to overstroke a lot, some none at all. Sort of like hining cylinders. They all act differently.

[Eagle1903]

I never had to replace any of their bushings but I would like to learn the bush replacing operation.
I have a Sunnen manual rod hone ( not the power stroke one ) but I have to build experience with this machine which I am planning to open a new topic about that soon ( to ask help ) since I am having some difficulties obtaining straight inner diameter.

Same machine I have. Lots of flipping the rod back and forth. Every couple of strokes flip the rods. Always do 2 rods at a time. Use the coarse stones as far as possible until almost to finish size. Then switch to the fine ones. Lots of tricks but mostly just experience after doing it for 30 years. Seems like each rod is different. Some you need to overstroke a lot, some none at all. Sort of like hining cylinders. They all act differently.

Bill,
Thank you very much.
What do you mean by overstroke ?
Is it like not pushing/sliding the rod half way ( width wise ) into the mandrel/stone or stroking without the flip ?
Seems a simple machine but very tricky. I am not yet able to get the bushing straight, mostly it is coming out in hourglass shape. But I was not flipping it. Just understanding and learning.
I have some Sunnen mandrels but I also bought some Tennessee abrasives mandrels ( kind of retrofit to Sunnen rod hones ). But, as far as I understand that the stone expansion is different than the Sunnen. Tennessee’s stones don’t expand parallel, it expands conical but if I am right, Sunnen’s stones expand rather parallel.
I am planning to learn to use the Sunnen mandrels first and I will buy some coarse stones.

[modok]

Sounds like you need to use a truing sleeve to get your hone back in shape first off.
most taper problems are due to the stones OR shoes wearing unevenly. Stone wear... need to adjust how you are stroking it, so you spend more time on the areas that are not wearing fast enough, and less time on the areas that are worn down too much.
There are also good and bad ratios of length of the hone VS the workpiece. 1.5 times longer is the worst, 2x or 3x is good.
Very short hole is a PITA, always trying to tilt, can't overstroke, hone two at once if possible.
You can also adjust the oil supply as well. where the oil hits the shoes will wear less, farther from where the oil hits the shoes are getting more grit so they will wear faster there. Adjust as needed.

[BillK]

Bill,
Thank you very much.
What do you mean by overstroke ?

By that I mean when you stroke the rod you have to go off the ends of the stone some. Some rods more than others. You just have to get the feel for each rod.

Also like Modok said you absolutely have to use the truing sleeves that come with the mandrels.

As far as mandrels and stones I have learned in the last 35 years that Sunnen is the only one to buy. Same with honing oil. At least that is what has worked the best for me.

I would get some junk rods and practice with them. After you do a few hundred you will be pretty good at it