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Thu Dec 04, 2014 7:40 pm

Rebuilding some Brosol H30/31 carbs that need throttle shaft bushings.

I'm looking for an Oilite split-style sleeve bushing 10x8x10 (OD, ID, OAL) and am having a hard time finding anywhere that looks like they would deal with me on a small-order level. Only needing a handful, no more than maybe 5.

Any help or links would really be appreciated.

Thu Dec 04, 2014 7:44 pm

Buy a valve guide, a few minutes with a lathe and you'll have them.

Fri Dec 05, 2014 5:03 am

Are valve guides one solid piece of metal? I thought about turning or reaming a plain bushing to fit but everything I've found is a two-layer bearing. I'm not very good at this level of machining - still learning a lot.

Fri Dec 05, 2014 6:30 am

I can make them for you, how many you want? :lol:

You have a way to ream the ID of the carb body for the new bearings?

Fri Dec 05, 2014 6:43 am

Nsracing, I'm game, pm me with price and details!
My carb throttle shaft bore ID is exactly 10mm, give or take .01mm, but I'm fine to buy the reamers I need. The shaft itself has got a little wear undersize so I would need a slightly smaller ID, and just ream it to fit, if possible.

I just couldn't bring myself to buy Chinese bushings and that's all I can find

Fri Dec 05, 2014 7:34 am

If you never want to replace them again...why not use bearing grade Torlon? It machines like butter.....has a hardness that is about 1.5 times harder than delrin, does not deflect or dent like oilite bronze....is good to constant temps over 600F...and has a coefficient of friction just a bit higher than teflon.

I have used it in place of needle bearings in transmissions and in place of cartridge type cam follower roller bearings in all types of machines.
if someonr is going to machine a few bronze pieces for you....have then do them from 4301 Torlon. They would be perfect. ..require no lube at all....and last forever. Ray

Fri Dec 05, 2014 10:41 am

Kline has the kit for about $30. to install a bush.reamer swedge everything.

Fri Dec 05, 2014 12:34 pm

raygreenwood wrote: If you never want to replace them again...why not use bearing grade Torlon?

Dang, at $50/ft for 1/2" rod, I would certainly hope they wouldn't ever need to be replaced again! :shock:

Mark, I emailed them about it.. Didn't see any info about it on their website. I'd rather have Nick make a pair for me though.. I've seen how anal he is about details!

Fri Dec 05, 2014 1:58 pm

scrivyscriv wrote: raygreenwood wrote: If you never want to replace them again...why not use bearing grade Torlon?

Dang, at $50/ft for 1/2" rod, I would certainly hope they wouldn't ever need to be replaced again! :shock:

Mark, I emailed them about it.. Didn't see any info about it on their website. I'd rather have Nick make a pair for me though.. I've seen how anal he is about details!

Yes....its not cheap.....but at maybe 12-15 bushings per foot thats $2-2.50 per bushing. Not bad for something that will outperform any oillite hands down.

Also...just use what you need and save the rest. I have used it for a wide range of things of which it outperforms virtually any other plastic.
Bushings, glides...even rubbing blocks for D-jet fuel injection trigger points...which means you do not even lube them...just polish the cam they ride on.... and they will never wear out. Ray

Fri Dec 05, 2014 6:20 pm

yep, valve guides, pushrods also make good material.

Fri Dec 05, 2014 7:03 pm

Doesn't gas wash out the lubricating properties of the oilite?

Fri Dec 05, 2014 7:07 pm

Dougy Dee wrote: Doesn't gas wash out the lubricating properties of the oilite?

Yes it can....which is exactly why I suggested something like torlon. Chemically inert all the way up to nitric acid....requires no lube except under the hardest sliding pressures. Ray

Fri Dec 05, 2014 8:31 pm

kline on ebay. glass matrix bushings also would work as would moly impregnated bush.or....send the carb to somebody that does them on a regular basis like kadie shack.

Sat Dec 06, 2014 9:20 am

mark tucker wrote: kline on ebay. glass matrix bushings also would work as would moly impregnated bush.or....send the carb to somebody that does them on a regular basis like kadie shack.

True....any will work for this application . My minor issue with oil-lite (oil impregnated bronze) glass matrix (moly impregnated usually nylon or delrin for the base plastic).....is that any material that is "impregnated" with the lubricating additive loke moly or oil or graphite......means that as the lubricating additive is depleted at the surface where itccontacts the part it is acting as a bearing for.....it must either get hot to release new lubricant ( the case with oil-lite)......or it must wear a small amount to uncover new lubricant as it the case with glass or metal matrix plastics.

Really none of them are a problem with a very lightly loaded part like the carb.....but over the years as good available, rebuildable, original parts start to get harder to find..... I have been looking for rebuild materials that dont readily wear out even over several normal part life spans.
Youu can only rebuild some things oversized so many times before its no longer rebuildable with normal methods anymore....if at all. Thats the only reason I suggested this bearing material. Functionally.....you will never go wrong with oil-lite bronze for this application.....but someday it will need to be rebuilt again. With Torlon....likely not in your lifespan or the next owners lifespan. Ray

Sat Dec 06, 2014 9:29 am

crane cams was starting to use the matrix bushings in thier rockers when they went tits up from a bad partnership they got into who had larger debts than crane cams was worth :shock: what a shame. I used the glass matrix back in the mid 90's when I was doing a lot of cnc machining/programing/fabrication. a extreamly large barge needed a new cable spool&axle for the 1 1/2" cable.I had never heard of those bushings.but the boss had used them before and said they get sliperyer with more load,no lube required.they dont wear the shaft like a bronze does.I think crane was on to something , there also a good bit lighter.and take shock very well. I was thinken on using some for my rockers.

Sat Dec 06, 2014 11:42 am

mark tucker wrote: crane cams was starting to use the matrix bushings in thier rockers when they went tits up from a bad partnership they got into who had larger debts than crane cams was worth :shock: what a shame. I used the glass matrix back in the mid 90's when I was doing a lot of cnc machining/programing/fabrication. a extreamly large barge needed a new cable spool&axle for the 1 1/2" cable.I had never heard of those bushings.but the boss had used them before and said they get sliperyer with more load,no lube required.they dont wear the shaft like a bronze does.I think crane was on to something , there also a good bit lighter.and take shock very well. I was thinken on using some for my rockers.

Yes...and the composite bearings like the glass matrix, torlon, nylatron, glass filled nylatron etc.....are really high load. In many cases the only limits for some of these bearing materials is the fear of trying something new in place of a classic material for a plane bearing. Ray

Sat Dec 06, 2014 1:09 pm

You sure you have enough meat in the throttle shaft body to accept a bushing?

You can try to look thru MSC Direct...they have any size bushings you desire in any material.

I will stay away from plastic bushing materials. Sure they can survive acids but fuel hydrocarbons are another.

Bronze material will withstand anything and it is the proper material for this.

Pushrod materials are good too.... like the stock Bush pushrods..that is fat enough already cored out. :lol:

Sat Dec 06, 2014 4:57 pm

nsracing wrote: You sure you have enough meat in the throttle shaft body to accept a bushing?

You can try to look thru MSC Direct...they have any size bushings you desire in any material.

I will stay away from plastic bushing materials. Sure they can survive acids but fuel hydrocarbons are another.

Bronze material will withstand anything and it is the proper material for this.

Pushrod materials are good too.... like the stock Bush pushrods..that is fat enough already cored out. :lol:

Torlon has been proven to be inert to virtually all hydrocarbons and fuels. It beats bronze hands down in almost all environments. You should take a look at the spec sheets. I have replaced bronze incmany industrial applications using aolvents far more harsh than gasoline...and in auto use with gasoline. There are some really good reasons why its so hard to make and so expensive per foot. Ray

Sat Dec 06, 2014 5:32 pm

If you can use this plastic as valve guide , then I'm impressed. Any of the bronze family can be used for valve guides and have tensile strength of 60,000 psi up. For $50 /ft I will rather use the bronze.

I even use Alum Bronze for valve seats in just race heads. I do not think the plastic can survive that.

Sat Dec 06, 2014 10:43 pm

these work, http://www.ebay.com.au/itm/370892726717?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649