Kawi2strokes.com Forum

So shot peening increases tensile strength?

No, it creates a region of compressive stress at the surface of the part. It makes the part more resistant to cracking when it is stressed in use. Areas near the surface that would have tensile stress from running forces might have none or at least less, so the chance of a crack forming is reduced.

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If it surges, that's normal, upshift.

I would expect Rod mfgs to have this (peen) as part of their process. I would expect OEMs would include this step also but, can't prove it. Aftermarkets may skip this steps why this post for example.

The other concern to me is machining tolerance on rod. For example, once you install the aftermarket rod how much rocking distance did you measure/see? BE Bearing roller tolerance/grading seem to vary quite a bit as well. I have heard guys throw away aftermarket BE bearing and use OEM or Silver cage for better quality machining. Silver cage bearings are prefered over copper if you can locate piece quantities.

I now test the complete assembly in a vice before I have them installed and check for rocking distance. I have purchase aftermarket set's for other bikes before, and too much rocking distance ...even crank re-builder would not install.

This is one of those items where quality is really going to matter, if you want to keep the bike.

So the reason for this post is to understand such questions for those who have used aftermarket rods on H1. And, have I missed a quality aftermarket supplier as I am new to H1s.

ProX claims they do peen a part of the process
http://blog.pro-x.com/prox-connecting-r ... em-quality.


I am used to acquiring may own parts and sending to rebuilder. Regardless if provided I would like to know what I am using. NOS if you can find with no shelf damage/surface rust on machined surfaces or without some one who sanded the shite out of it to remove signs of rust (easy to tell once in you hand ... no. more nice X cross hatch nobe marks). Or they won't show this area in their pics nor will answer questions when you ask.

You just got to love vintage bikes where parts have been obsolete for decades!

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Bikes I drive/own

Kawasaki
1973 H1-D (New Project)
Suzuki
1974 GT250 (T350 upgrade)
1976 GT250 (T350 upgrade)
1971 T350
1970 T350 (New Project)
1974 GT380
1975 T500
1973 GT550
1975 GT750
Yamaha
1972 DS7 (R5 upgrade)
1977 RD400

Shot peening relieves stress, you might beef up the reliability but I’d be more concerned about the parallelism of the journals afterwards. Ideally the last thing done to any precision part is grinding the journals, not stress relief.

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http://kawatriple.com/wtf/

Our rods are heat treated two different levels at once. The bearing races are harder than the rod beams and other areas, but the treating process occurs in one operation, not two.

The two levels of treat are done by copper claddng the areas that get treated with a softer treat, beams, big and small ends, the harder areas are the rounds for the crank and piston pin areas.

Shot peening relieves most of the stresses in the metal that remain after the heat treating, and is a great process to do, but, for the rod and pin inner area surfaces, they should be masked off, or, inserts put into those areas to mot allow the peeing to alter the bearing surfaces.

Shot peening should be done before the big and small end bearing surfaces are finished so the stress relief is done before the final bearing surface sizing honing.

There are some people, like me, that polish the rods I use, especially in auto engines, then have them shot peened, best scenario, but, because of the copper cladding, we can;t do much but peen the copper facing, still works well to help the strength of our rods and other pieces, like crankshaft wheels, etc.

I saw a factory Honda road race rod for a 500 triple in Steve Whitelock's office being used as a paperweight, it was polished, shot peened, and nice, except that the grinding tool made one tiny dimple in the rod beam. That dimple would cause a stress fracture and rod failure, I was told, and is why that rod is that paper weight.

What do you mean "Our rods..." H2RTuner.? Is this something you sell or you mean our bikes ... Kawasaki OEM rods.

Thanks.

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Bikes I drive/own

Kawasaki
1973 H1-D (New Project)
Suzuki
1974 GT250 (T350 upgrade)
1976 GT250 (T350 upgrade)
1971 T350
1970 T350 (New Project)
1974 GT380
1975 T500
1973 GT550
1975 GT750
Yamaha
1972 DS7 (R5 upgrade)
1977 RD400

Full circle bearing end connecting rods for our motorcycles, and every other Japanese 2 stroke motorcycle that has closed end bearing races, in every Japanese motorcycle that has been made. If it has a copper coating, it has been dual heat treated. It is also done that way for the 4 stroke, full circle rods in Z1 thru KZ1100GPZ, and most single cylinder, twin cylinder 2 and 4 stroke motorcycle engines with built up, pressed together cranks.

These rods are all peened and plated.
The peening imparts MORE stress on the skin of the steel(compressive), thus strengthening thru work hardening.

Copper plate is a mask for the rod to nitro carbide, salt or atmosphere bearing races only(super hard), the copper keeps the carbon/nitrogen away from the beams or all other features to avoid embrittlement.

cliff

Allowing for two different heat treat levels from one heat level process.

That is the way it has worked all along, and still does. The copper is not used for any other reason, nor process.

Well, it was Hurley Wilvert that turned me onto the rod shot peening. He was breaking rods in his H1R, and started having them shot peened, all was good. He had all his rods done after that. And that is good enough for me. I have Charlie get mine shot peened also.

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Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........