mk1-forum.net

Hi,

Does anyone know where I can get a set of PTFE gudgeon Pin buttons for S size pins?

I am using a set of H beam rods that have fully floating bearings fitted & need to locate the pin securely. I could make my own, but am too lazy, if I can get them off the shelf I'd be very happy.

Any suggestions appreciated.

Thanks,

Mark

I seem to recall that there was an ebay link on here not too long ago.

However, just be aware that Pin IDs vary from brand to brand, so be sure that if buying off the shelf buttons, they fit the Pins you have.

I was in a similar situation as you after buying some Omega non 'S' pistons, then deciding to go for h-beam rods. I looked around for PTFE buttons but couldn't find any, I ended up sending the pistons to Specialist Components to machine them to take circlips.

Thanks for the tip Andy. How much did it cost?

I guess the best bet will be for me to do them myself, as I said in the first post, I'm just being lazy really.

£120 inc postage back to me, two weeks turnaround.
They haven't arrived as yet, I only sent payment yesterday, so I can't comment on the quality of work but I'll let you know when they land.

Cheers Andy,

I guess I'll be standing at my lathe in the very near future

M

We used Teflon buttons..never had an issue with them.
Circlips are very effective however, if one ever comes loose it is a disaster. Had that happen once.

The circlips in the omega pistons are vastly better than the old type used in 998 / 1098 pistons.

We have never had any trouble with them

I use scroll/spirolox in all my pistons now Bugger to get in and out..........But that's the point I suppose

scroll/spirolox

Please tell me more, I have not heard of this product.

http://www.summitracing.com/int/parts/w ... /overview/

You've got to keep up Mark. It's not 1982 anymore

I'd have the pistons modified for modern Omega circlips. They WILL NOT come out.
In addition you'll get a lighter gudgeon pin

1982?

I'm not even in 1972 yet darling!

360gts wrote:
We used Teflon buttons..never had an issue with them.

So these are fitted on each end of the gudgeon pin, in order to stop it from "go walkies" inside the piston.

I was thinking about this when i built my engine, but wasnt sure about it

Being online surely is a good thing.

Having had a pin come out and wreck an engine I'm now more frightened of pressed in pins. My new pistons are slipper type so can't do the Teflon buttons and have no idea how I could get circlips put in them.

wantafaster1 wrote: My new pistons are slipper type so can't do the Teflon buttons

That shouldn't be an issue, I've been fitting Teflon Buttons to these for a while now, never an issue and easy to disassemble.

If you are worried, make then in Aluminium.

An engine were familiar for you Mark and Rich.



Jonny B's old 1417.

But is the distance from the end of the pin to the bore not too far?

One more thing, there must surely be a certain amount of oil getting to the inside of a pin with open ends, would that not help to cool it?

wantafaster1 wrote: But is the distance from the end of the pin to the bore not too far?

I think what you are getting at here is you are concerned that the head of any button needs to fit thickness wise between the ends of the Pin and the bore?

If that's the question, again, not an issue.

I think Air Cooled VW Engines had this set up from the factory, as do some bikes. None the less, I've done lots now and not had issues with any. On the other hand, I have seen issues with Press Fits.

wantafaster1 wrote:One more thing, there must surely be a certain amount of oil getting to the inside of a pin with open ends, would that not help to cool it?

The Piston Crown runs considerably hotter than the pin ever will. None the less, the Crown along with the Pin and Little End are cooled from oil spray from the Big End.

When making the Buttons, be sure to drill an off centre hole in them so they can vent.

If you're not comfortable using buttons, then maybe try another system.

When using PTFE for the buttons, any specific grade/type of PTFE is required or whatevr is sold everywhere ( ebay, etc ) is ok ?

Thanks
LUis