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Thanks for your help.

So as to have the car ready for next meeting in 3 weeks time I am assembling with another 86mm crank |I have (with taper end).

I'm waiting for delivery of a piece of 300M bar so that I can rebuild the nose of the damaged 86mm billet crank. Whilst the problem was nothing to do with the splines, but all to do with the reduced diameter of material, I will be putting a taper end on this one too, since this gives me a further 8mm diameter of material for the flywheel to seat on.

Thanks all again.

Joe, what is it you don't like or have trouble with re: the standard set up on the taper?

Spider wrote:Joe, what is it you don't like or have trouble with re: the standard set up on the taper?

50 years of hassle every time I have to remove a flywheel. I have a 20 ton hydraulic puller and still it's never an easy job.

I suppose I'll just have to get used to it.

Fair enough Joe, I only have a 12 tonner, and it is a little bulky and awkward to get in there, but it does beat a screw type remover hands down. Once it's in place though, I do usually find they come easy, it's only with the steel ones that haven't been fitted as well as they could and then have fretted that tend to be painful.

Spider wrote:Fair enough Joe, I only have a 12 tonner, and it is a little bulky and awkward to get in there, but it does beat a screw type remover hands down. Once it's in place though, I do usually find they come easy, it's only with the steel ones that haven't been fitted as well as they could and then have fretted that tend to be painful.

I've heard that with steel ones too, and in my case they have virtually always been steel flywheels on steel cranks, which I am told are a NO NO. I have now fitted one of the old type bolt on centres onto a light steel flywheel. Fingers crossed.

Smiffy wrote:

John Bull wrote:Sick to death of 50 years of cursing every time I have to remove a Mini flywheel

http://www.minifreunde.at/harry/links/flywheel.htm

Anybody else tried this? Looks quite a simple job compared to alternatives. I'm currently toying with the idea of using the pretty unique LynxAE flywheel design on my high revving 970s motor to avoid problems. This could be much more cost effective.

Oldskoolbaby wrote:Anybody else tried this? Looks quite a simple job compared to alternatives.

Look on Turbominis and search for TurboHarry.

John Bull wrote: I've heard that with steel ones too, and in my case they have virtually always been steel flywheels on steel cranks, which I am told are a NO NO. I have now fitted one of the old type bolt on centres onto a light steel flywheel. Fingers crossed.

Joe, I found the same and also heard the same. Then one day, a number of years back, a young whipper snapper who was in the workshop looked at what we where doing. He suggested after lapping them together, we try a smear of light oil on the tapper. OIL - you've got to be kidding!! Well, since doing that one that day that way, just with sewing machine oil, suddenly, the flywheels fit considerably tighter, fretting is a thing of the past and while still requiring considerable force to get them apart, since they have no longer fretted, they do come apart easier and no damage. So now, this is what we do and no looking back.

I too have always put a drop of light oil on the crank tail before fitting. I though everyone did. M

Rather than mucking about with a bronze bush, you could attempt to "lubricate" it with "atomic" copper.

To make this, you need a vacuum filter rig, or a load of time. Get some copper chloride and dissolve it in hot water. Add a load of zinc powder until it stops dissolving, then add a bit more copper chloride to dissolve the residual zinc. Filter everything and wash with water. The stuff on your paper is atomic copper. It is not metallic, it is the finest powder you can imagine. You can cut it up with lard to make a good copper grease or you can cut it up with the smallest amount of thin oil to make it paste-able.

On a much more highly zoomed in mental picture, if you have 2 steel items, on a microscopic level, they are pretty damn jagged and lock together a treat. They work together even more until the surfaces are for all intents and purposes bonded together. So, you have a choice, you can either polish the surfaces so much that there isn't the movement and the "working" to cause the items to bond together, you use an intermediate which does not adhere to the degree (dissimilar metal) or you choose a softer metal, so when you whack it, it deforms to the degree (on a micro level) that it comes "unstuck" or you coat it with some sort of lubricant. Quite clearly, when you put a taper on with a lubricant, there comes a point when it is utterly locked solidly as if you used too much lubricant, it would "squeeze out". So, you whack in your oil and tighten the flywheel up to 2000lb/ft and what happens is that the surfaces are lubricated, but the "working" happens to a degree that the two gradually seat together, oil fills in the voids and prevents bonding happening to a certain degree. This means you can "get it off".

If you used the smallest amount of colloidal "atomic" copper, it would form an interface which would facilitate the degree of friction required, but also back off, when you undid the nut and gave it a tap.

I would probably choose copper over any other oil, purely because over time and with heat, the oil film would degenerate. Copper will sit there.

Feel free to pick apart my reasoning.

In the shed wrote: purely because over time and with heat, the oil film would degenerate.

I'll go back over your post in a short while, however, while another approach and one to consider, it does seem sound to me.

I use a only sewing machine oil so that it will 'degenerate' or actually, shear as the flywheel is pulled on to the taper. The theory being it allows it to slide on considerably further than if dry, then lock, metal to metal.

MKI, probably 99.99% of the guys in this part of the world assemble them dry, in the belief that any sort of lubricant will only allow them to slip.

A variation of the atomic copper suggestion, could be a wipe of copper metal.

Saturated coper sulphate solution, wiped onto steel will deposit a microscopic (but visible layer of copper metal. I use this for lapping in as it makes a great tell tail.

I haven't tried this but some brave soul may fancy it.

TBW. My theory as to why you should lubricate the tail slightly is exactly as stated, it allows the flywheel to slide on that bit further & ensures a tighter fit.

Just a thought....


Would an analogy here be why ARP quote two different
torque settings for their fasteners? One with their own
special "lube" and the other with "normal" oil...

With the recommended lube, less torque is required to
acquire the correct pre-load for the fixing.

Ian

Same principal I would have thought Ian.

I must be lucky . I've been putting a smear of copper ease on the crank tail for years and never had a problem . Hope I never do . ... Ken

Total genius and very obvious solution, Mr Foster.

Go to the top of the class!

Some of the lads over on Turbomini's have had there taper machined out and a phosa Bronze bush put in its place seems to work but ill do a bit more research on it first going from memory at the moment

Chalkie wrote:Some of the lads over on Turbomini's have had there taper machined out and a phosa Bronze bush put in its place seems to work but ill do a bit more research on it first going from memory at the moment

There was a firm also offering Cast Iron inserts as well, they would also be quite OK.

Thank you friends. I feel much more confident now. I shall put a smear of copper grease on before fitting the flywheel, and see what happens.

In the meantime engine rebuild on the way. Block ready with camshaft timed. Drop it on the box Monday and hopefully drop engine into car on Tuesday.

I am having great difficulty getting new 8 port exhaust valves. John Drury (JDM on here) ordered a set from Minispares ages ago. Although they are always shown as being "in stock" on their website, they keep telling him they can't supply, so it looks as though I shall have to assemble with the same head - with worn valves and guides - for the time being, unless anyone else can reccomend someone that might have them. The 8 port exhaust valves are slightly longer than the 5 port items.

Have a great weekend.

Chalkie wrote:Some of the lads over on Turbomini's have had there taper machined
out and a phosa Bronze bush put in its place seems to work

... Most engine tuners don't put the locking tabs on the main bearing caps
of the small-bore engines because these are soft and compress, leading
to a reduction in the clamping ability of the bolts.

Discuss - As regards fitting a nice soft bronze bush to the taper...


Ian