IWIS racing chains

[crummasel]

Hi there,
sometimes one reads of IWIS racing chains. What is their technical difference to standard chains?
Are they prestreched?
Different inner design?
Or is that just a marketing feature?
Thanks and Greets,
Robert

[HawgRyder]

Perhaps heavier side links...making the chain less prone to stretch.
Bob

[E Sully]

I searched IWIS and from what I've read on other Forums, they are supposedely designed and built to be the best available for timing chains.

[HawgRyder]

When you look at a cross section of a piece of chain...the axles and rollers can be of different design from chain to chain.
The axle joins the two side plates together...and the roller (the part that actually touches the sprocket) can be either a thick section (with smaller pin) or thin wall (with thicker pin).
The side plates can be either slightly "8" shaped or more square looking (amount of material in each plate)...the more the better in most cases.
From my experience...the thicker the pin the better (stronger) and the material used for the roller should be hard enough to stand up to the pressures encountered in running and rubbing over the sprocket.
The sprockets should be changed at the same time as the chain because they will be slightly bigger in the tooth area...so that the new chain will have to stretch to fit and run over them.
This would require splitting the case to replace the two inner sprockets.
Matching the chains to the sprockets is the best idea...so that friction is reduced as much as possible (less friction...longer life).
Bob

[crummasel]

Clear.
So i assume IWIS Racing chains ARE existing for 911s?
If so, where to source them?
Thanks,
Robert

[E Sully]

Right on Pelican, of course.
Porsche 911 Cam Towers & Timing Chains - Page 1

[Jeff Alton]

IWIS makes timing chains for Porsche, Mercedes and many other vehicle companies. They have a wide range of chains available far beyond standard automotive. Their Canadian branch is across the parking lot from us....

Cheers