More Slow Speed Changfa Mods

[vdubnut62]

Thanks playdiesel!   And that's why I love this forum.
I have seen the angular contact bearings before, but I had forgotten. I sure didn't know the correct name or that they were even still available, not to mention in commonly used sizes. The application I saw them in was front wheel bearings on my old 57 Chevy!  And that was probably 35 years ago. I sure am glad you dredged that old memory up.
Ron.

[mobile_bob]

yes the annular contact brgs only work in one direction, the problem is
we need the brg to take thrust going both ways.

when the power pulse comes on we get thrust one way, and when we go to compression stroke
we get thrust the other way.

the more i think about it, i am beginning to come around to the idea (i think it was Vdubs) that the helical gears might present more serious issues than the one we are trying to correct?

however i would still probably order a set of helical gears just for the heck of it.

and i think i want to explore the addition of oil thing a bit more when i get time, which might be quite a while from now.

so maybe i just shut up and live vicariously through you fella's!

bob g

[vdubnut62]

 Yes, there is thrust in both directions, but I feel confident that if an angular contact bearing can stand the cornering forces in an old Chevy for 20+ years,
they can stand thrust from a 16hp firing and compression stroke. I would orient the thrust faces both inward, making sure to leave proper bearing clearance for expansion.
Ok, I am officially out of my element.

Evidently this is a job for my friend the Mechanical Engineer!
Ron.


P.S.
If I were to do the angular bearing thing that I described above, somebody tell me why a regular tapered roller bearing wouldn't work?

[mobile_bob]

tapered roller brgs would work and in my opinion would be preferable to annular contact

reason being the pulsing thrust going back and forth would over time pound those balls
to hell, where the tapered brg would have a larger contact patch.

both brgs would require some means of retainer caps, so that the outer races could be secured to control preload of the brgs, this likely is going to be the biggest hurdle to overcome, because it requires two things

1. machining of the block and manufacture of the retainer caps, and

2. there probably is insufficient room behind the gears to fit a retainer cap

so?  the more i think about it, the more i am leaning toward doing one of two things

1. live with the noise associated with the geartrain, or

2. investigate further the admission of oil into the gear train.

seems prudent to me to start with the easiest to do thing first, most especially if it is easily done
and completely reversible, and see what the outcome might be.

it might well be that the noise is not completely removed, and it might be it has no effect, however it is also possible there is a reduction of gear train noise to that which is acceptable?

thanks for allowing me to tag along in this discussion, at this point i think i will avoid ordering helical cut gears until such time that the oil modification is proven to not correct the issue to an acceptable level.

bob g

[vdubnut62]

Well said Bob. After stretching my brain 'way farther than I should have ( I think I may  have pulled a muscle ) I think I would invest more time into solving all the problems of an engine that was designed to rattle and clatter than I could ever justify.
The phrase make a silk purse out of a sow's ear does come to mind.
Thanks to all for putting up with my wanderings!
Ron.

[mobile_bob]

far easier to strain the brain that have to go out into the shop, clean it up, get frustrated, clean some more,  find my cherrypicker, set it up, take down my trigen, remove the engine, tear it down
and do all the other stuff needed to put in something that might not solve a problem and might well cause me more grief... then have to put everything away, mess the shop back up again ...

yup, it is far easier thing i do when i set out to converse with you.

hahaha, that sorta rhymes!

bob g

nice to have friends like you guys