Idler Chainwheels

[Neven911]

Hi,
Can anyone give me the history of the idler chain wheels, I have 2 types (note they are both bushed), The top one came from a 71E and the lower one (which seems closer to the contemporary) from a 914-6, though both engines have been rebuilt at some time so who knows.
Also how do you check these for wear other than a visual inspection?
Cheers Neven

[BURN-BROS]

Interesting, I have never seen an early style have a bushing. I believe the lower sprocket was introduced during the mid year cars and definitely with the SC. I have never seen any problems with the non bushed sprocket.... only the idler arms. As far as wear, I have not seen one with an issue. They are just along for the ride.

[Neven911]

Thanks Aaron,
You confirmed what I suspected that the later style has been replaced in the earler engine, and yes there is little wear on either. Would you recommend bushing the idler arms or upgrading to the later (wider bearing) ones? (Which seem overly expensive)
Cheers Neven

[BURN-BROS]

The best improvement to the timing components was the wide idler. It has 2 bushings and a generous area for oil to accumulate between the bushings. This is the real “update” to the timing design changes

Supertec mods the non bushed to a wide version for a reasonable price if you are inclined to make the change.

[Neven911]

Thanks again Aaron, yes very interested in the supertec version, Does anyone have a picture and a price?

[SBell]

Originally Posted by Neven911

Thanks again Aaron, yes very interested in the supertec version, Does anyone have a picture and a price?

I just picked up a set from Henry. I don't recall the price but it was very reasonable, definitely cheaper than the factory wide arms. Here's a picture of them next to my old ones. They look great even if you won't see them when the engine is built.

Sent from my SM-G991U using Tapatalk

[drgouk]

Bore gauge set at the pin size and check the clearance.

[Henry Schmidt]

Originally Posted by drgouk

Bore gauge set at the pin size and check the clearance.

Pin fit is not a critical measurement. The important numbers are rotational friction and torsional support.

[drgouk]

im talking on the idler wheel bushing