Author Topic: Floating bush (Read 8014 times)

ace.cafe · **on:** May 10, 2013, 02:16:04 am

We have just got our new Bronze Floating Bush in.
It's a special run that works specifically with properly matched Carrillo rods.

Eliminates the flaking failures that plague the OEM babbitted floating bush, and replaces it with a monolithic bronze bush that is made with new bearing clearances suitable for its thermal expansion behavior.The use of a floating bush is actually a fine idea for a design, but the propensity of the OEM bush to flake off the babbitting material makes it fail early, and so it just isn't a reliable option in its OEM form. The monolithic bronze makes the entire bush out of suitable bush material, eliminating the surface babbitting, so that there is nothing to flake off. This keeps the basic original design, and eliminates the problems of the babbitted coating.
Cuts the cost of a crank rebuild by 1/3 less than with the Alpha roller big end bearing. It's our latest attempt to try to make things more affordable for the Bullet performance enthusiast on a budget.

Arizoni · **Reply #1 on:** May 10, 2013, 04:25:11 am

Looking good Ace.

High On Octane · **Reply #2 on:** May 10, 2013, 05:51:46 am

Keep up the great work Tom!

Scottie

ace.cafe · **Reply #3 on:** May 10, 2013, 12:17:16 pm

Thanks guys!

We have had a test bike running this bush with its matching Carrillo rod for well over a year in all seasons and conditions, and it tested out great.
So, we decided to go ahead and make some of these with specially made Ace/Carrillo rods that are designed specifically to work with this bush.
They work as a pair. The dimensions are set so that the Ace Carrillo rod can receive a replacement bronze floating bush when rebuild time comes around, but these items are not suitable for use with the OEM con-rod or the OEM bush. They vary enough from the OEM sizes that they will not work with the OEM items. We had to do this because the bronze exhibits different thermal expansion.

mrunderhill1975a · **Reply #4 on:** May 10, 2013, 04:19:17 pm

Tom,
Since we are speaking of budget, where can I find a listing of the possible options for this and other fireball performance enhancements? Any suggestions on how to convince the wife that these improvements are a necessity?

ace.cafe · **Reply #5 on:** May 10, 2013, 04:21:53 pm

Quote from: mrunderhill1975a on May 10, 2013, 04:19:17 pm

Tom,
Since we are speaking of budget, where can I find a listing of the possible options for this and other fireball performance enhancements? Any suggestions on how to convince the wife that these improvements are a necessity?

I'll send you a PM about it.

Thanks,
Tom

Chuck D · **Reply #6 on:** May 10, 2013, 04:32:26 pm

First the rockers and now this in the same week. Tom, you're gonna need a press agent.
Mazel Tov!

ace.cafe · **Reply #7 on:** May 10, 2013, 05:00:48 pm

Quote from: Chuck D on May 10, 2013, 04:32:26 pm

First the rockers and now this in the same week. Tom, you're gonna need a press agent.
Mazel Tov!

Blltrdr · **Reply #8 on:** May 10, 2013, 06:33:51 pm

In the technical article where Alan Baker interviews the RE Technical Manager, R.A. Wilson-Jones, Baker asks Wilson-Jones about his reasoning for using of the floating bush which was commonly seen in radial aircraft engine design. In response, Wilson-Jones replied that it was the best high speed bearing that was comparable only to an Alpha bearing which was not easily obtainable in sufficient quantities at the time.

What I take out of the Wilson-Jones response is that even though both bearing designs are different, both perform on or near the same level. The bush referred to in the article was made of steel with white metal outer plate which was of a superior quality of the bush used in the iron barrel Bullet of today. Why did they not opt for a bronze bush which would have been easily sourced at the time? How does the Ace bronze bush compare to the original British made bush?

RE Bullet's of the 50's never attained or sustained speeds like the Fireball bikes do today. I think Mr. Wilson-Jones if alive today would have been extremely proud of this new Ace bronze bush/Carrillo rod combo and the rest of the Ace products. Another way to look at it is the Alpha bearing is easily sourced today, so for someone like Ace to keep true to the original design and go out of his way to develop a newly designed floating bush is a a testament to Mr. Wilson-Jones engineering legacy. Maybe a fitting name would be the Ace Legacy Bronze Bush (kinda wordy though).

The Garbone · **Reply #9 on:** May 10, 2013, 06:55:11 pm

L0oking good Tom.

I saw the bush special over at the other place a bit to late to get in on it. Love the look of it and I just happen to have a spare motor case and crank in my garage. Maybe I will get myself one of these for my birthday.

geichal · **Reply #10 on:** May 10, 2013, 07:18:40 pm

Are these the Bushes Chumma is going to use in his bottom end jobs? If so, yay for me!!
geichal

ace.cafe · **Reply #11 on:** May 10, 2013, 07:30:39 pm

Quote from: geichal on May 10, 2013, 07:18:40 pm

Are these the Bushes Chumma is going to use in his bottom end jobs? If so, yay for me!!
geichal

Yep!

noisymilk · **Reply #12 on:** May 10, 2013, 08:12:59 pm

Extremely excited about this. I am saving up my pennies now for the work, and already have the fleabay find blown crank cased up in the garage ready to go.

geichal · **Reply #13 on:** May 11, 2013, 03:27:39 pm

End of August, Geichal is going to do his happy dance!!
geichal

Paul W · **Reply #14 on:** November 11, 2021, 05:50:17 pm

Apologies for dragging this thread from the back of beyond!

We've had some discussion on the Midland Bullet Riders forum about an Indian made bronze floating bush that came with a crankpin assembly I bought a few weeks ago.

These bronze bushes seem to be something of an unknown quantity this side of the Atlantic (UK). Bullet Whisperer has his doubts about them and prefers the old metalled steel type.

I'd be grateful for any further information on this subject. The part seems very well made but there's very little information around. I did find a thread on an Indian forum where some contributors thought very highly of them, but some were not sure that bronze would be up to the job. Thanks!

AzCal Retred · **Reply #15 on:** November 11, 2021, 07:25:27 pm

Do you have a link to a source for these bronze bushings?

I found this one:
https://www.sparezo.com/royal-enfield-connecting-rod-floating-bush

and this one:
NEW CONNECTING ROD FLOATING BUSH SUITABLE FOR ROYAL ENFIELD @JUSTROYAL
https://www.ebay.com/itm/324666485268

and this brass one:
https://www.royalenfieldzone.com/engine_components.asp

Paul W · **Reply #16 on:** November 11, 2021, 09:13:21 pm

The bushing came as part of the crank pin assembly. I don’t have a source for the bush by itself.

richard211 · **Reply #17 on:** November 12, 2021, 05:44:59 pm

If the bush is not easily available, my suggestion would be to approach a local machine shop and ask them to machine a bush out of phosphor bronze stock. Even though the bush is available as a replacement part in India, people prefer using their existing connecting rod and crank pin, rather than fork out for all new parts. The big end crank pin and the connecting rod big end is cleaned up and the new bush is machined to work the increased clearances, much like a slightly oversized bush. It's amazing to see how much abuse the floating bush can take compared to the big end roller bearings on the AVL and UCE engines.

Paul W · **Reply #18 on:** November 12, 2021, 05:51:48 pm

They are easily available! I already have a bronze bush; it was included in the assembly...

My question is, how good are they, compared to an old type steel/Babbit metalled one.

AzCal Retred · **Reply #19 on:** November 12, 2021, 06:29:40 pm

" They are easily available! I already have a bronze bush; it was included in the assembly..."
OK, where did the assembly you are using come from? Any links to where YOUR bush was sourced? If yours is working, it'd work for me also. The Sparezo link I found doesn't mention what their bush is made of. Richard211 may have a good idea, a custom built bush. At least the fitment would be solid.
Chumma used to do complete bushed/welded/balanced cranks also, I dunno if he still does.
The bronze is mechanically tough and monolithic, so it can't spall off pieces of the outer coating as can the coated steel bushes. Ace & Chumma swear by them. I'm certain that careful fitment is another reason for their success. I forget exactly who, but one of our builders said that many new crankpins aren't actually very round. Again, proper fitment is essential to any bushing installation.

richard211 · **Reply #20 on:** November 12, 2021, 06:36:21 pm

Quote from: Paul W on November 12, 2021, 05:51:48 pm

They are easily available! I already have a bronze bush; it was included in the assembly...

My question is, how good are they, compared to an old type steel/Babbit metalled one.

I have not worked on any bullet engine with the steel / babbit bearing. So I am not able to give a direct comparison, however the bronze bush is very durable as long as it has sufficient clean lubrication. It common here to see the cast iron bullets with the floating bush exceed over 60,000 km before engines are partially rebuilt and there are also a few bullets that cross 100,000km before a complete engine rebuild. That being said the cast iron engines here are generally run at lower engine rpms and not at full throttle at highway speeds. Also the type of engine oil used plays a big role in the wear and tear of components, drastic reduction / elimination of zinc and phosphorus in modern engine oils to preserve the catalytic converters have not helped either.

Paul W · **Reply #21 on:** November 12, 2021, 07:06:36 pm

Richard 211,

Thanks. You say you have no experience of the original Babbit metal type - so have you built cranks with the bronze one?

AzCal,

I'm not fitting the bush at the moment; I'm buying spares that I might need in future while the price is reasonable. Here's what I originally posted in the UK forum in reply to a question from another person; it has the seller's detail in it:

Quote

I bought the entire crankpin, thrust washers, nuts, outer race and floating bush assembly from eBay, an Indian based seller. Despite its very low cost, it seems very good quality. I think it came by surface transport so it took quite a while to get here.

This is a link to the same trader. I note the price has gone up by a fiver since I bought mine but at less than £30 it's still very reasonable! https://www.ebay.co.uk/itm/392877318492

I already had an unused (and partly polished up ) ally con-rod from a UK private seller. I took time to confirm it all fitted together nicely because the con-rod came with a steel outer race already pressed into the bottom so it was obviously from a completely different manufacturer. Thankfully the floating bush (which is phosphor bronze) was an excellent fit with no play but on rotating it there were a couple of places where I could feel a little drag. These turned out to be where the inner circle of oil holes had been slightly countersunk; the surface had just pulled up very slightly. I lapped it in to the crank pin and the con-rod using Solvol Autosol and it's now as smooth as silk. I then greased it all up and stashed it in a plastic bag. I also have a new standard piston and the gudgeon pin is also a really good fit in the rod.

Hopefully I'll never need any of these but I want to future proof the bike as much as I can. I've also bought a magneto rotor, a stator and a wiring harness; these all appear to be unique to the Indian home market 350 Bullet Electra so I like to grab them while they are there for not much money

AzCal Retred · **Reply #22 on:** November 12, 2021, 07:09:22 pm

Thanks! - ACR -

richard211 · **Reply #23 on:** November 12, 2021, 07:44:44 pm

Quote from: Paul W on November 12, 2021, 07:06:36 pm

Richard 211,

Thanks. You say you have no experience of the original Babbit metal type - so have you built cranks with the bronze one?

AzCal,

I'm not fitting the bush at the moment; I'm buying spares that I might need in future while the price is reasonable. Here's what I originally posted in the UK forum in reply to a question from another person; it has the seller's detail in it:

Yes, the cranks I have worked on are all having the bronze bushes. The photo I am attaching is a mock up crank that I had put together. The crank was originally a 350cc G2 model crank and adapted to work with my AVL engine. It has been converted to have the 3 phase charging along with the TCI ignition and electric start. The timing side shaft is also from the AVL which means it has the higher flowing gear type oil pumps. The connecting rod big end bearing is a bronze bush with additional oil drain grooves machined into it so that it has more oil flow to try and replicate the oil flow of the big end roller bearings that was present on the AVL crank, that way it would not rapidly wear out the oil pump spindle and worm gear due to addition forces caused by the higher oil pressure.

Adrian II · **Reply #24 on:** November 12, 2021, 07:55:44 pm

Here is one source of the bronze Indian bushes. £33.59 GBP ($45.05) for a set of FIVE is either a bargain, a misprint or a tacit admission concerning the quality of the metal!

https://www.ebay.co.uk/itm/324880443070?hash=item4ba46226be:g:fCoAAOSwIxVZebi4

A.

Paul W · **Reply #25 on:** November 12, 2021, 08:45:08 pm

Richard211,

Thanks, very helpful and reassuring to know that the bronze type bush seems to be more common than I had thought.

In which part of the world are you living, by the way?

My own iron engine bike is an Indian home market 350 Bullet Electra with TCI ignition, but kickstart only. It has the older type plunger oil pumps so the flow rate should be well suited, in any case I’ve fitted a Hitchcock’s return pressure relief valve to ease the strain on the drive mechanism.

richard211 · **Reply #26 on:** November 12, 2021, 09:47:01 pm

Quote from: Paul W on November 12, 2021, 08:45:08 pm

Richard211,

Thanks, very helpful and reassuring to know that the bronze type bush seems to be more common than I had thought.

In which part of the world are you living, by the way?

My own iron engine bike is an Indian home market 350 Bullet Electra with TCI ignition, but kickstart only. It has the older type plunger oil pumps so the flow rate should be well suited, in any case I’ve fitted a Hitchcock’s return pressure relief valve to ease the strain on the drive mechanism.

I am currently living in india. With regards to the bronze bush, pretty much all the iron barrel bullets in India is using them.

Paul W · **Reply #27 on:** November 12, 2021, 10:44:27 pm

Perfect! I’ll be happy to use the one I bought….if the present bottom end ever needs replacing. So far, after 16,000 miles of hard use (and relatively high revs) in my ownership, it appeared to have absolutely no play when I fitted the new high compression piston a few weeks back.

AzCal Retred · **Reply #28 on:** November 12, 2021, 11:15:53 pm

@ #24: ...maybe they are 5X better?...

5 X ROYAL ENFIELD CONNECTING ROD FLOATING BUSH
Condition:New
Multi-buy:
Buy 1 £27.99 each

AzCal Retred · **Reply #29 on:** November 12, 2021, 11:22:32 pm

@ #27: That's what you get for keeping clean oil & filters in the wee beastie - boring reliability!
No random Golden Opportunity to disassemble & poke about the crank...what an entertainment loss.

Tongue in cheek aside, well done on the reliability! 16K miles and the bottom end still solid, no small feat. - ACR -

Paul W · **Reply #30 on:** November 13, 2021, 12:03:47 am

Hopefully, the Meteor Minor piston I’ve now fitted will give the bottom end even less strain and keep it going for many miles yet. I weighed it against a standard one and it was surprisingly lighter! It does seem to be a bit smoother (not that a single can ever really be described as smooth…), despite it now having a significantly higher compression ratio.