All "IMS failures" are not IMS failures! Carnage within!

[jaykay]

Well I hope having a 2000 3.2 with a steel rest pad rather than plastic will keep me a bit safer than most!

Nice idea with the rollers! One has to consider the chain shape produced with them especially the speeds we are talking about; I would guess flat would be better. Any bearing dia that small is going to be doing some wicked rpms assuming no skidding/wear; one will need to ensure strength/lubrication at these sites...increasing the bearing dia will weaken the the arm at points; all in a limited space.

From what I can see the LN arm has a greatly increased web area which would give increased strength. I am surprised the Porsche arm fails as it has. It must be a combination of poor castings or choosing to put a casting where one shouldn't and shock loading resulting from the rest pin failling......just a guess without seeing the set up of the engine

[Jake Raby]

When the factory changed the IMS drive chains in the '01 model engines they also changed the metal tensioner contact pins to the plastic type...

Phil's engine had a metal wear pin because it was a 2000 model Boxster S, the only "S" with the metal contact pin and the old style IMS drive arrangement.

I probably won't have time to tear this core down for a while, but when I do the failure report with pics will be posted.

[jaykay]

Thanks much appreciated.........Jake you must have been an aircraft mechanic or turbine engine specialist. Nobody else usually utters the word boroscope....

[Jake Raby]

Originally Posted by jaykay

Thanks much appreciated.........Jake you must have been an aircraft mechanic or turbine engine specialist. Nobody else usually utters the word boroscope....

Yep, worked with T58 and T64 GE Turboshaft engines as a Marine when I wasn't crewing CH 46E Helos..

Phil calls it a bronchoscope :-)
He has been trying to find me an even more bad ass unit than what I have now.. This new one does video and allows for narration as well, its really sweet!