Hi all! New Guy here. Wonder why no one has ever come up with a chain drive retrofit to replace the belt drives in these motors. It just seems to make sense with all the fuss and expense in replacing them.
What and deny Us the ability to spend 100's of posts asking "when to do a belt change?" ...You My good sir are mad!
This had been discussed in the past. I belive the major issues are how to seal the chain assembly and how to lubricate it.
From the other threads that have asked this question, in summary, "Cost of development and production out weighs the the small size of the market thus making purchase price so high it is actually cheaper to just change the belts every 5 years." Only 12,000+ 308's were built and probably only 8k are still on the road.
It's has been done. Not my car nor engine but here are some pics. You can read on about the project here:http://www.ferrarichat.com/forum/showthread.php?t=185300&highlight=timing+chain+308&page=5 Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
My thoughts: Recommended cam belt change: Every 30K miles. Reality: You can usually go 50K miles w/o worry, as just about every other car has 60K mile cam belt changes, though I will not suggest you do this. Timing chains: should be replaced at 50K miles on any high performance motor as slop in chain starts to degrade cam timing on finely tuned motors. Does not apply to grocery getter cars where no one would notice the slight performance drop off from chain stretch, but chains should be replaced at 100K miles even on low perf cars, or when ever the chain gets so loose it slips a tooth. Only real advantage to chains: You don't have to change them from just age related sitting. Net result, not worth the hassle, IMO. Edit: Leave the AC compressor off and timing belt changes are a snap. Doug
Another thought: If I was going to engineer something like this, I would be temped to go to a gear drive rather than chain drive. It would be noisier, but it would sound cool, and would not suffer from chain stretch. The lubrication would be possibly more critical. If you want to see timing gears, look at the cams drive arrangement on a Hawker Sea Fury radial engine. Doug