Need Help with taper identification, bushing identification

Hi Everyone,

I’m looking to find a tapered bore bushing for a project I’m working on and can’t seem to find any information. I figured maybe someone here can help me get it figured out.

Long story short I have a small engine crankshaft with a tapered end on it. i need a bushing with the same taper to sit on the end to adapt a different flywheel by means of bolting on.

My measurements are:

Large dia: (closer to engine block) ~.892”
Smaller dia: (end of crankshaft) ~.708
Length of taper: ~1.125”


I’m looking for a bushing similar to this: Tapered and QD Bushings - Bushings - Grainger Industrial Supply


Basically what I want to do is bore the new flywheel and bolt the bushing onto said flywheel that will fit my crankshafts taper properly.

I believe this makes sense but maybe I’m looking in the wrong place for a “mount” or bushing.

Thanks!

Bushings you are looking at are tapered OUTSIDE. Made to fit in sheaves/pulleys with a tapered bore.

All the bores are straight. The taper design allows the bush to grip a straight shaft as it is forced into sheave/pulley by the bolts

You will need one tapered inside, which will very likely need to be MADE and not bought

Your numbers result in a bit under 2" taper per foot on diameter on the crank nose (or 4.675 degrees off centerline)

johnoder said:

Bushings you are looking at are tapered OUTSIDE. Made to fit in sheaves/pulleys with a tapered bore.

All the bores are straight. The taper design allows the bush to grip a straight shaft as it is forced into sheave/pulley by the bolts

You will need one tapered inside, which will very likely need to be MADE and not bought

Your numbers result in a bit under 2" taper per foot on diameter on the crank nose

Click to expand...

Ahh this is unfortunate, might be easier to have the flywheel retapered instead then if I have to make something.

I am looking at exactly the same thing......fit a Harley crankpin to a JAP flywheel pair..........aftermarket HD crankpin is maybe $10......custom JAP crankpin by Alpha Bearings around 200 quid......solution make a bushing tapered inside and outside ,and hope its accurate enough to line up the flywheels.(JAP= J.A.Prestwich)

71Rupp said:

i need a bushing with the same taper to sit on the end to adapt a different flywheel by means of bolting on.

Click to expand...

No. You do not. IC engine, not electric. "Few", not "many" firing cylinders per the one crankshaft.
A slow-turning Series-90 V-16 or a 28-cylinder "corn-cob" radial, you haveth neither of.

Shaft and flywheel have mating taper because there is more impulse stress, every second of operation, and over a hopefully long life, than you have yet realized. Hint: Even properly fitted OEM ones can become damaged!

IC recip engines were "smooth", they would not NEED flywheels. Bushings were a good idea, they'd have been stock parts for about 150 years, but are not. Just because a "shape" can be machined does not make all possible uses of it equally sound in practice.

Introducing another set of mating surfaces in the form of a bushing can reliably be expected to degrade any reserve, almost certainly fail, and sooner, rather than later.

Make them match - directly, no middleman - ELSE go do something with a better chance of a durable outcome and a lower risk of serious injury.

71Rupp said:

Hi Everyone,

I’m looking to find a tapered bore bushing for a project I’m working on and can’t seem to find any information. I figured maybe someone here can help me get it figured out.

Long story short I have a small engine crankshaft with a tapered end on it. i need a bushing with the same taper to sit on the end to adapt a different flywheel by means of bolting on.

My measurements are:

Large dia: (closer to engine block) ~.892”
Smaller dia: (end of crankshaft) ~.708
Length of taper: ~1.125”


I’m looking for a bushing similar to this: Tapered and QD Bushings - Bushings - Grainger Industrial Supply


Basically what I want to do is bore the new flywheel and bolt the bushing onto said flywheel that will fit my crankshafts taper properly.

I believe this makes sense but maybe I’m looking in the wrong place for a “mount” or bushing.

Thanks!

Click to expand...

Y'know, it's a lot easier to get information, when you give up a little along the way. Information, that is.

WHAT MAKE small engine crank?

To me, it does not sound at all like what you want is a bushing, so much as a flange that you can fit to the crank and bolt the remainder of a wheel to.

In which case, some quality time spent test fitting various tapers with some blue, until you work out the near enough exact settings for either a taper attachment or the compound angle, would be time well spent.

Of course, that completely ignores the idea of haking the living hell out of an original fitment flywheel to make said flange.

You will find the bushing you seek trapped inside a piece of 1"steel bar.You may need to find a handsome prince like Thermite with a Monarch 10ee to do the rest of the deed.

trevj said:

To me, it does not sound at all like what you want is a bushing, so much as a flange that you can fit to the crank and bolt the remainder of a wheel to.

Click to expand...

"Been a while.." but if memory serves... GMC, Ford, MOPAR - many other auto/truck mills all had those bolt and or bolt and dowel flange & boss mountups so they could accept EITHER of a flywheel and clutch/pressure plate - or a flex spider to mount a slushbox torque converter.

Work well. Stand serious abuse. Last a long time. etc.

Also cast or forged integral with the crank, though were they not?

john.k said:

You will find the bushing you seek trapped inside a piece of 1"steel bar.You may need to find a handsome prince like Thermite with a Monarch 10ee to do the rest of the deed.

Click to expand...

Phhht..."trapped"? I'm "try-lingual".

Just "Araldite" the bugger, motor on down the road, trade it for a pair of used Welly's as don't hurt the old feet, leak overmuch, nor have the innards all wore out from trapped Ewe's aftermost hooves trashing about in passion..... fear ... wooly-laughter...ridicule ... declined charge-card transaction ..wotever