motor part - high heat & wear but low friction ?

[betauser]

Searching for recommendations for a plastic replacement specifically for a cam chain tensioner in a motorcycle race motor. @ 400cc motor

- it would be in constant contact with oil.
- needs to withstand at LEAST 350 degrees
(measured temp 'hot' off track)
- low friction like PTFE
- 'machinable'
- hard wear resistant - how hard I dont know.

I have perused and searched these forums and have found many possibilities?

Halar ECTFE
ASA Polymer
PTFE Lubricated PEEK
(Ketron® PEEK)
Techtron®
UHMWPE


UHMWPE I presume is the cheapest and all around best, though I am unsure of it applying to all the specs.

If any other information is needed please ask or email me if I have left something off or need to provide more in depth info...

Many thanks!

 

[patprimmer]

ASA and UHMWPE will be melted or very close to their melting point at 350 deg F.

PTFE will be to soft.

PEEK will be OK but it is VERY expensive.

My advice would be nylon 4.6 The only brand is Stanyl

Second choice would be molly and graphite filled nylon 6.6 A popular brand is Nylotron.

I know virtually all OEM plastic timing chain tensioners are nylon. Many are molly nd graphite filed nylon 6.6 but a few used on high end or very high performance cars are nylon 4.6 The 4.6 typically gives 3 times the life of 6.6 but in an air ooled Porsche it gave 9 times in some tests.

I put the extra margin in the Porsche down to oil emperatures approaching the melting point of 6.6 but still well short of 4.6



Regards
Pat
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[Pud]

I guess it's a one-off. If so, PEEK, although expensive, is by far the best choice you have listed. Easily available as stock for machining too.

Harry

http://www.tynevalleyplastics.co.uk

 

[betauser]

Thanks Harry & Pat

Your correct Harry this more or less would be a one off test and if proven successful could be duplicated on a limited scale.

These are to go on some of the highest performance Honda CB350 & CB450 track engines out there..

I agree PEEK sounds like a nice item but yep.. its very pricey
Ketron® PEEK HPV sounds most alluring for its properties..

Stanyl Diablo is amazing for its heat properties far exceeding our needs

I appreciate the advice and we'll be looking over the information on them...


LAST QUESTION...

Are there any good places online where one could order a block or extrusion of any of these or contact manufacturer directly? (ie) DSM & Quadrant

 

[patprimmer]

http://www.davis-plastics.co.uk/

Second hit on google for stanyl bar sock

Regards
Pat
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