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Timleech
08-19-2008, 05:44 PM
I need to make a pair of shims in the morning for a diesel engine big end bearing, about 2 thou thick.
I was struggling earlier on to find my shim assortment, so trying to think what everyday object could be butchered or pressed in to service.
Tin cans are too thick, cooking foil is too thin. Good quality paper is about the right thickness, but would it do the job?
I don't need to find out, as I've found my shim stock, and wouldn't be keen to test it on someone else's engine, but am still wondering. My guess is that if the mating faces of the bearing halves made good flat contact it might last for quite a while.

Views?

Tim

John Stevenson
08-19-2008, 05:53 PM
No problem Tim, been using ordinary paper gaskets as cylinder base gaskets on racing bikes for ages.
Smear a bit of Hylomar on it and it's better than gorilla snot......
.

hardtail
08-19-2008, 06:00 PM
It may have been done before and be done again but you wouldn't ever find me using it on the shock end of an engine, especially a diesel, those higher compression ratios above directly translate to more pressure below........I would think other material more suitable. That and should it come apart on someone elses engine and your not chosen to look at it again......kinda gives the competition something to talk about.........

bollie7
08-19-2008, 06:09 PM
This is a good question and has got me curious.
Using paper for a gasket is one thing but using it for a shim on a big end? I agree with you Tim "wouldn't be keen to test it on someone else's engine" nor my own, unless I was stuck in the middle of nowhere with absolutely no alternative. Paper is basically wood fibre and I think with the constant pounding a big end gets I don't think it would hold up for long. I could be wrong and I'm sure someone on ths forum will correct me if I'm am. How thick is an aluminium can? I have measured in the past but can't remember. I just measured some 80G/Sq metre copy paper (sorry no idera what that is in imp) and its about .004". Some lined writing paper I have here is about .0025". As soon as a can becomes available later today I'll try and measure the aluminium.

regards
bollie7

lwbates
08-19-2008, 06:09 PM
I've used paper shims in some applications, but I wouldn't try it on rod bearing caps, particularly on a diesel. The unit stress john describes is surely much less than the small shims in a big end rod bearing. Imagine comparing the area under load in a M/C cylinder base gasket to the much smaller area of a split big end shim. (I Know, the M/C rod isn't split, but play along). As a conservative estimate the cylinder base gasket would have 5 or 6 times the area to absorb the same firing pressure as the rod end. Then add the fact that it's a diesel engine.
lwbates

John Stevenson
08-19-2008, 06:11 PM
It may have been done before and be done again but you wouldn't ever find me using it on the shock end of an engine, especially a diesel, those higher compression ratios above directly translate to more pressure below........I would think other material more suitable. That and should it come apart on someone elses engine and your not chosen to look at it again......kinda gives the competition something to talk about.........


Ignore, didn't read the big end bit.
No Tim not viable - weld it together.

.

.

Timleech
08-19-2008, 06:29 PM
I've used paper shims in some applications, but I wouldn't try it on rod bearing caps, particularly on a diesel. The unit stress john describes is surely much less than the small shims in a big end rod bearing. Imagine comparing the area under load in a M/C cylinder base gasket to the much smaller area of a split big end shim. (I Know, the M/C rod isn't split, but play along). As a conservative estimate the cylinder base gasket would have 5 or 6 times the area to absorb the same firing pressure as the rod end. Then add the fact that it's a diesel engine.
lwbates

The shim shouldn't be absorbing any of the firing pressure as such. It should always be under compression from the big end bolts, but the amount of compression will be reduced on every induction stroke as the bolts are 'stretched'.

Tim

oldtiffie
08-19-2008, 08:56 PM
It may have been done before and be done again but you wouldn't ever find me using it on the shock end of an engine, especially a diesel, those higher compression ratios above directly translate to more pressure below........I would think other material more suitable. That and should it come apart on someone elses engine and your not chosen to look at it again......kinda gives the competition something to talk about.........


Ignore, didn't read the big end bit.
No Tim not viable - weld it together.

.

.

True John, but surely after peaning the journal with a VERY BFH?

But I agree with you. I've seen all sorts of stuff - paper included - used as shim. Depends on whether it is an "emergency", "temporary", "quick-fix" or "to a be done proper" project.

lazlo
08-19-2008, 09:17 PM
No problem Tim, been using ordinary paper gaskets as cylinder base gaskets on racing bikes for ages.

The head gasket on the Clausing 59xx and 690xx headstocks is paper. When I first got mine, the gasket was likely 40 years old, and was still in fine condition, since the headstock is in an oil bath, and the paper was continually lubricated by the oil.

That's almost zero pressure though...

wierdscience
08-19-2008, 11:22 PM
It's a shim going under a big end,bandaid over a bullet hole anyone?

If it's a diesel and if it's being shimmed then either the crank journal or the rod are toast already.

Many of the old gas engines I have torn down had paper shims under the caps.They were all cast babbit bearings and all gas engines,but like said before the cap sees enough load to pull the piston and rod down nothing more.

Paper would work in a pinch.

Paul Alciatore
08-20-2008, 02:43 AM
Just an ignorant comment here but wouldn't three layers of aluminum foil (3 X 0.0007" = 0.0021" make a better emergency substitute. I would think the aluminum would compress less when torqued and stand up better to the pounding it will get.

Timleech
08-20-2008, 02:50 AM
It's a shim going under a big end,bandaid over a bullet hole anyone?

If it's a diesel and if it's being shimmed then either the crank journal or the rod are toast already.

Many of the old gas engines I have torn down had paper shims under the caps.They were all cast babbit bearings and all gas engines,but like said before the cap sees enough load to pull the piston and rod down nothing more.

Paper would work in a pinch.

No, it's a 1930s engine with 'marine type' big ends (ie like a steam engine, the bearing is two directly metalled halves which are bolted onto the end of the con rod). The bearings have been remetalled and the shim is just a running clearance adjustment, absolutely normal.

Tim

Evan
08-20-2008, 06:00 AM
They were all cast babbit bearings and all gas engines,but like said before the cap sees enough load to pull the piston and rod down nothing more.


That is not a trivial amount at rpm as the cap is not only pulling the piston down but reversing the direction of travel of the piston. On the intake stroke it is also pulling most of a vacuum so that adds the area of the piston times atmospheric pressure on the underside of the piston.

Swarf&Sparks
08-20-2008, 08:31 AM
Try brewer's shim (beercan)
The secret is, strip the plastic coating with acetone (or heat gun, if you're careful)
After torquing down, should get at or under 2 thou.

wierdscience
08-20-2008, 08:49 AM
No, it's a 1930s engine with 'marine type' big ends (ie like a steam engine, the bearing is two directly metalled halves which are bolted onto the end of the con rod). The bearings have been remetalled and the shim is just a running clearance adjustment, absolutely normal.

Tim

So it is ancient:D

I thought it was a modern diesel 1.5hp/cid.

wierdscience
08-20-2008, 08:54 AM
That is not a trivial amount at rpm as the cap is not only pulling the piston down but reversing the direction of travel of the piston. On the intake stroke it is also pulling most of a vacuum so that adds the area of the piston times atmospheric pressure on the underside of the piston.

All of those are factors,but the load is miniscule compared to the power stroke.

My only concern would be setting torque,waiting 10-15 minutes for the paper to compress and re-torquing.

Timleech
08-20-2008, 02:22 PM
So it is ancient:D

I thought it was a modern diesel 1.5hp/cid.

It's one of these, but about 70 years old

http://www.russellnewbery.co.uk/engines.html

18 bhp @ 1000 rpm, weight with its 1930s marine gearbox getting on for a ton.

They've used 'modern' H section con rods with thin wall bearings for at least the last 30 years.

Tim

Oldbrock
08-20-2008, 11:08 PM
I have just finished a Bud, cut open the can and it was .005". My solution would be to surface grind .003 off the cap and use an empty can. Peter

wierdscience
08-20-2008, 11:33 PM
It's one of these, but about 70 years old

http://www.russellnewbery.co.uk/engines.html

18 bhp @ 1000 rpm, weight with its 1930s marine gearbox getting on for a ton.

They've used 'modern' H section con rods with thin wall bearings for at least the last 30 years.

Tim

Nice looking engines,I like their line of thinking-

"Also remember, a well maintained RN engine will last much longer than modern lightweight high-revving engines. We know of RN engines that are over 60 years old, still in use on boats and auxiliary equipment. Just think of how much energy and pollution is saved by manufacturing one engine every 60 years rather than six engines!"

What does one fetch new?

Timleech
08-21-2008, 05:31 AM
Nice looking engines,I like their line of thinking-

"Also remember, a well maintained RN engine will last much longer than modern lightweight high-revving engines. We know of RN engines that are over 60 years old, still in use on boats and auxiliary equipment. Just think of how much energy and pollution is saved by manufacturing one engine every 60 years rather than six engines!"

What does one fetch new?

I believe something like 15K, or $27000 US at current rates, for a complete marine unit. They reckon to need to sell about one per month to keep going. That might be a bit of a struggle in the current economic climate, but they have had a couple of recent orders for stationary engines for running on 'alternative' fuels, they're much better suited to that than most modern diesel designs and well made compared with the Indian so-called 'Listeroid' engines.

Tim

wierdscience
08-21-2008, 08:54 AM
Not bad really,that's close to the $20k figure I had in mind.

The Indian Listeroids,that's a mixed lot,some are really good,some not so.Friend of mine bought a two cylinder,the quality of the machinework was fine,but little things like all the oil and fuel piping had to be redone as everything leaked.Doesn't matter much now though since our wonderful EPA has prohibited them from import along with all the other stationary import engines.Even the R&N would not pass emissions,stupid policy IMHO.

Funny thing about the genuine Lister engines,the older designs are very rare here,but the newer aircooled are all over the place,never figured out why.

Timleech
08-21-2008, 11:40 AM
Not bad really,that's close to the $20k figure I had in mind.

The Indian Listeroids,that's a mixed lot,some are really good,some not so.Friend of mine bought a two cylinder,the quality of the machinework was fine,but little things like all the oil and fuel piping had to be redone as everything leaked.Doesn't matter much now though since our wonderful EPA has prohibited them from import along with all the other stationary import engines.Even the R&N would not pass emissions,stupid policy IMHO.

Funny thing about the genuine Lister engines,the older designs are very rare here,but the newer aircooled are all over the place,never figured out why.


RN have done a bit of tweaking to get their engine through Euro emissions regs, I wonder how they compare with yours?

Tim

pcarpenter
08-21-2008, 12:06 PM
To address the question more generally....didn't we go off topic in describing use of paper for *gasket material*? The question is will it suffice for *shim* material. I generally think of gasket material as having some fixed force applied to it in torquing cover bolts for example. In a shim arrangement, the question becomes: "Will the material compress or displace due to forces on it and stuff it might be exposed to?"

I would think that not all paper is created equally in this regard. Ordinary paper might fall apart under exposure to certain things that paper gasket material would handle quite well....the binder material is (hopefully) different.

Paul

wierdscience
08-21-2008, 11:05 PM
RN have done a bit of tweaking to get their engine through Euro emissions regs, I wonder how they compare with yours?

Tim

Tim,it's very difficult to get a diesel car or light pickup here because of them.All of the small car and truck diesels here are imports and they are few and far between often fairly expensive compared to their gasoline siblings.

IIRC for example Ford sells a diesel version of the Ranger in the UK,but not here as it would not pass emissions.

Small engines and stationary engines must go through emissions testing before they are legal to import.If the RN went through that testing it would likely pass and be sold for stationary applications.Marine use might be different though.

The Listeroids and the Chinese Chang Fa engines I believe were banned mainly because they were imported and didn't go through testing first.

lwbates
08-22-2008, 12:50 AM
I have it on good authority that the thickness of Budwieser cans vary greatly from can to can. Probably your best bet is to MT a goodly number of cans and then go to work with your micrometer to find the one you need.
lwbates

Timleech
08-22-2008, 03:16 AM
I have it on good authority that the thickness of Budwieser cans vary greatly from can to can. Probably your best bet is to MT a goodly number of cans and then go to work with your micrometer to find the one you need.
lwbates

I think I would pick something with more taste than Budweiser for the research :)

Tim

John Stevenson
08-22-2008, 04:02 AM
I think I would pick something with more taste than Budweiser for the research :)

Tim

Can you get picked onions in cans ?

.

Swarf&Sparks
08-22-2008, 07:43 AM
Just in case you missed it, I'll say it again.
Remove the plastic coating before using as shim!
:cool:

Evan
08-22-2008, 09:55 AM
The paper used to insulate electric motor windings should do nicely. It's tough as nails with excellent high temperature and oil resistance properties. It's available in a variety of thicknesses from your local motor rewinder. I just picked up some of the heavier grade yesterday and it measures .008 and should probably compress a thou or two. Thinner grades are also available as this paper is intended for multi hp motors.

steverice
08-22-2008, 11:54 AM
Why wouldnt you want to resize the rod to have the right size of big end I.D.?

No shimming necessary then.

s.r.

Timleech
08-22-2008, 12:49 PM
Why wouldnt you want to resize the rod to have the right size of big end I.D.?

No shimming necessary then.

s.r.


erm...
Have you read the whole of the thread?
;)

Tim

steverice
08-22-2008, 05:29 PM
Yes, just to be sure I re-read it again. So to be sure that I have it correct.

The question is about using a peice of paper under a big end rod bearing to make up for excessive clearance. Correct?

Paper doesnt have any place inside of an egine, excpet in some multi plate clutch applications and in gasket material.

The route to go, to close up the tollerances would be to make the big end of the crank larger, or to make the big end of the rod smaller. It maybe easier to make the crankshaft larger.

Shimming of any kind on a bearing shell like what is being suggested here is not a good idea. (or am I missing the joke?)

If all you want to do is take up some room, but some red loctite on the back side of the bearing, that will tighten it up.

s.r.

Timleech
08-22-2008, 05:37 PM
Yes, just to be sure I re-read it again. So to be sure that I have it correct.

The question is about using a peice of paper under a big end rod bearing to make up for excessive clearance. Correct?

Paper doesnt have any place inside of an egine, excpet in some multi plate clutch applications and in gasket material.

The route to go, to close up the tollerances would be to make the big end of the crank larger, or to make the big end of the rod smaller. It maybe easier to make the crankshaft larger.

Shimming of any kind on a bearing shell like what is being suggested here is not a good idea. (or am I missing the joke?)

If all you want to do is take up some room, but some red loctite on the back side of the bearing, that will tighten it up.

s.r.

No, forget the modern style of conrod. Think steam engine, where the bearing is separate from the conrod, and held onto the rod with the big end bolts.
The bearing is two lumps of steel or bronze, with white metal (Babbitt) cast directly into them. Here is one of the bearings being bored after remetalling:-

http://home.btconnect.com/duttondock/images/Mech/boretable-1.jpg

The shim was required to go between the two bearing halves to adjust the running clearance.

Tim

derekm
08-23-2008, 10:06 AM
It isnt possible to scrape the white metal to running clearance? I remember tales from my father about scraping in white metal bearings for large fans.

Derek

Timleech
08-23-2008, 10:21 AM
It isnt possible to scrape the white metal to running clearance? I remember tales from my father about scraping in white metal bearings for large fans.

Derek

Indeed it is, and the halves had already been scraped to give a good fit onto the rod. I could have scraped more, to give the running clearance, but my preference was to add a shim. Partly it's less work (if you have the right material), partly the shims can be removed at a later date to take up wear, preferable to filing the bearing cap.

Tim

Peter.
08-23-2008, 02:03 PM
No problem Tim, been using ordinary paper gaskets as cylinder base gaskets on racing bikes for ages.
Smear a bit of Hylomar on it and it's better than gorilla snot......
.

I also make paper gaskets when needed, but hylomar to me is stuff of the devil. Seen too many oilways and strainers blocked with squeeze-out from over-applied hylomar. This is what I use to seal both gaskets and case-halves:

http://www.jlindustrial.co.uk/PMX-80697H/product.html

Timleech
08-23-2008, 02:22 PM
I also make paper gaskets when needed, but hylomar to me is stuff of the devil. Seen too many oilways and strainers blocked with squeeze-out from over-applied hylomar. This is what I use to seal both gaskets and case-halves:

http://www.jlindustrial.co.uk/PMX-80697H/product.html

This is what real men use

http://www.burtonbikebits.net/jointing_compound.htm

;)

Tim

derekm
08-23-2008, 03:39 PM
Indeed it is, and the halves had already been scraped to give a good fit onto the rod. I could have scraped more, to give the running clearance, but my preference was to add a shim. Partly it's less work (if you have the right material), partly the shims can be removed at a later date to take up wear, preferable to filing the bearing cap.

Tim
In the time taken for all this gassing you could have gone and got a tin of brass shim from the local tool shop, or gone to to the all night car parts shop and bought 10 sets of feeler gauges and done the deed. :)

Derek

John Stevenson
08-23-2008, 04:52 PM
This is what real men use

http://www.burtonbikebits.net/jointing_compound.htm

;)

Tim

Well unless they have changed the formula a few years ago this stuff used to harden off like varnish and getting two faces apart meant using a chisel or road hammer.

Hylomar doesn't block strainers and oil ways, bad application of it does.
The Rolls Royce Merlins used only this on build up.
It's jointing compound not Aunty Flo's foundation cream that you trowel on...........

.

steverice
08-23-2008, 05:16 PM
Three Bond 1211 is the stuff.

http://threebond.com/Comsumer.html

Timleech
08-24-2008, 03:24 AM
In the time taken for all this gassing you could have gone and got a tin of brass shim from the local tool shop, or gone to to the all night car parts shop and bought 10 sets of feeler gauges and done the deed. :)

Derek

It's all been gassing ;), I did say in my first post that I'd found my shim stock but while trying to find it had been pondering what else could be pressed into service. Our local town used to have three good engineers' supply houses (known locally as 'Mill Furnishers' until recently), now there's only one and they are more interested in selling things like cordless drills and buckets, I wouldn't want to rely on them keeping shim in stock and I needed to get the job wrapped up the next morning.
Also the last shim assortment I bought cost me something like $80 US, I didn't want to have to shell that out again only for mine to turn up when the job was finished.
All night car parts? Not in this neck of the woods, never heard of such a thing. I did think of robbing a feeler set, but they're not wide enough to do the job properly.

Tim

John Stevenson
08-24-2008, 05:37 AM
It's all been gassing ;)

Tim

If you think this is bad there has been a thread running over on CAD_CAM_DRO for a week on how to or where to get a sleeve to bush a sprocket out from 1/2" to 5/8"

Idea's like taper locks, make on, buy one and the guy still hasn't done it.

He ought to make one out the sheet of tin thats currently welding his arse to the armchair..................

.

oldtiffie
08-24-2008, 06:02 AM
Dead right John.

I just can't believe that any sort of a shop would not have and keep up a stock of shim-stock. This and a couple of very good "air-craft" shears/"snips" and a good set or hole/wad punches and a hard-wood and a lead block and I'm set to go.

I just buy it if required as I go into town (pass through or shopping every second day at least).

Local steel and tool supplier and fabricator has it - all the time - in brass. Many auto stores have it in steel "feeler" stock.

I've always liked hard brass.

This is a pic of a pack of hard brass 6" square.

Cost? Don't know - forgot - not much - don't care - I just buy it. It has paid for itself many times over, what-ever it cost.

http://i200.photobucket.com/albums/aa294/oldtiffie/Shim_stock1.jpg

John Stevenson
08-24-2008, 06:25 AM
Tiffie,

Did a search on Tiffiepedia for shim stock and horror of horrors, there isn't one :eek:

Quick get your picture of the packet on there, millions are waiting to see what a packet of shim stock looks like.................

.

Swarf&Sparks
08-24-2008, 06:34 AM
Got me Moore & Wright out, this avo.
Metric.
Was (W)right though.
Strip the plastic, and, voila!
(as opposed to wallah, or viola)
2 thou, before compression.
:rolleyes:

oldtiffie
08-24-2008, 07:03 AM
Down at the bottom of the page John:

http://www.championparts.com.au/cross_index.html

If I think of it I will price it at our supplier tomorrow.

Evan
08-24-2008, 07:16 AM
Look for K&S Engineering metal products. They are sold at hobby shops all over the planet and they have every possible sort of shim stock in brass, aluminum, copper, phosphor bronze and stainless steel. The also have assortments in small quantities and rolls up to 30 ft long depending on what the local retailer carries.

http://www.ksmetals.com/retail.html

Swarf&Sparks
08-24-2008, 07:19 AM
Sorry Mick, but buggered if I can find brass shim on that page.
I'm looking for a bit o' thin brass for some ECM, off me little CNC machine.
Something in the 6-8 thou range would be lovely.

BillB
08-24-2008, 10:48 PM
Swarf&Sparks said:

Try brewer's shim (beercan)
The secret is, strip the plastic coating with acetone (or heat gun, if you're careful)
After torquing down, should get at or under 2 thou.
_______________

I have a pack of shim stock which came with my old SBL, but I usually prefer using the .005" Guiness shim. Much more fun to scrounge, ya know. Hadn't thought about the plastic coating, though. Obviously, more research is called for. 8)

BillB

oldtiffie
08-25-2008, 03:45 AM
Sorry Mick, but buggered if I can find brass shim on that page.
I'm looking for a bit o' thin brass for some ECM, off me little CNC machine.
Something in the 6-8 thou range would be lovely.

Hi Lin.

Its there OK.

This might be better.

http://www.championparts.com.au/products.html

Is available in brass, stainless and carbon steel in various pack and size and cost configurations.

Click on "2. Assortment by Product Type" on this link. Shims are at page 32 of the *.pdf file

Screen-shot - for info:
http://i200.photobucket.com/albums/aa294/oldtiffie/shim_stock_pdf1.jpg

Supplier contact details are at:
http://www.championparts.com.au/contact.php

Cost of pack today of previously pack is about AUD25 which given the cost of brass - and all ferrous and non-ferrous metals is pretty cheap.

See "Contact" for WA site details.

Post will be OK from SA or VIC.

Hope it helps.

Peter.
08-25-2008, 04:51 PM
This is what real men use

http://www.burtonbikebits.net/jointing_compound.htm

;)

Tim

I'm a real man - last time I checked anyhow :D

Not seen this stuff before, what is there about it that is so great? How is it applied?

John: I agree, bad application is what causes the damage and I've not suffered any self-induced failiures, but the stuff is so confounded dificult to apply evenly and get no squeeze-out at all whilst getting complete coverage (even on the assembly-line they can't do it). The threebond is a better product IMO but still leaves squeeze-out though it cures more. The stuff I use can be applied to 100% of the surface with a perfectly even film, and squeeze-out is just a few thou.

John Stevenson
08-25-2008, 05:53 PM
I

John: I agree, bad application is what causes the damage and I've not suffered any self-induced failiures, but the stuff is so confounded dificult to apply evenly and get no squeeze-out at all whilst getting complete coverage (even on the assembly-line they can't do it).

Squeeze some into a small container and paint it on with an artists brush.

.

Timleech
08-25-2008, 06:41 PM
I'm a real man - last time I checked anyhow :D

Not seen this stuff before, what is there about it that is so great? How is it applied?



It's quite liquid, so can be applied from the tube and smeared, or with a little brush from the tin. The instructions used to say to spread it with your finger, now they say for god's sake don't touch the stuff :D
It doesn't block oilways, it sticks like sh*t to the components and is supposed to be non-hardening and easy to break though it will harden if you get it really hot such as on cylinder head joints.
It's good for things like head joints because it doesn't build up & affect the head clearance. Listers recommend it for things like head joints and main bearing housings, their engines often employ multiple shims on these parts to get the right clearances so you need something which will squeeze out almost completely.

I believe both Wellseal and Hylomar were developed by Rolls Royce.

Tim

Timleech
08-26-2008, 04:42 AM
I'm a real man - last time I checked anyhow :D

Not seen this stuff before, what is there about it that is so great? How is it applied?


Forgot to say that Wellseal is also good for sealing things like head nuts, eg on an aircooled engine where oil getting past the thread or under the nut will find its way out of the engine.

Tim

Peter.
08-26-2008, 05:57 PM
Aircooled engine? I remember seeing one of those in the science museum :D

Timleech
08-26-2008, 06:18 PM
Aircooled engine? I remember seeing one of those in the science museum :D

Lots of them in canal boats still, though I don't think anyone is fitting new ones.

Motor cycles?

Tim

Swarf&Sparks
08-26-2008, 07:41 PM
jaysus!
thanks for the tip Mick (ish)
:eek: