Jeep Strokers

I have no clue why it failed. The cam, distributor, and oil pump turn freely. The spots where the teeth got ripped off looks very porous and grainy.

Thats because its sintered metal.

YJason wrote:Is it worth going to a $140 double roller timing chain over a standard $60.00 timing chain? And what brand would you suggest? I've always thought Cloyes was the good stuff?

I also have the JP Performance double roller timing chain set. It's a billet set with 9 crankshaft key ways for adjusting timing. Rollmaster also makes a nice billet timing set. They can be bought on ebay.

When I purchased mine Falcon said something to the effect that JP purchased Rollmaster.. iirc.

I called Cloyes tech line and told them what happened and asked if they had any clue why it happened.

Short version according to Cloyes:

If you use a performance cam and use HD valve springs you must run a double roller timing set. The factory style timing set is not engineered to withstand the added stress of the upgraded spring rate and cam lift.

Tech told me that the chain was trying to climb up the gear teeth and causing the teeth to wear prematurly. Once the wear got far enough into the gear tooth it was able to bite and climb on top of the tooth and once that happened it snapped all the teeth off.

The machine shop now has the engine and is going to completely disassemble, degrease, flush oil passages, install all new brgs, check the valves, get a new double roller timing set, and reassemble.

Hopefully I'll get it back in a couple weeks.

YJason wrote:I called Cloyes tech line and told them what happened and asked if they had any clue why it happened.

Short version according to Cloyes:

If you use a performance cam and use HD valve springs you must run a double roller timing set. The factory style timing set is not engineered to withstand the added stress of the upgraded spring rate and cam lift.

Tech told me that the chain was trying to climb up the gear teeth and causing the teeth to wear prematurly. Once the wear got far enough into the gear tooth it was able to bite and climb on top of the tooth and once that happened it snapped all the teeth off.

The machine shop now has the engine and is going to completely disassemble, degrease, flush oil passages, install all new brgs, check the valves, get a new double roller timing set, and reassemble.

Hopefully I'll get it back in a couple weeks.

did it have a oil slinger on it? I vary thin looking washer that goes on the crank to fling oil up on the chain?

To me that sprocket looked on the dry side, My be just the pic

Yeah it has a oil slinger, I washed the gear before I took the pics.

I thought that the oil slinger's purpose was to get oil away from the front seal so it doesn't leak

SilverXJ wrote:I thought that the oil slinger's purpose was to get oil away from the front seal so it doesn't leak

good point, could vary we be...............now i thing about it, that's got to be right!

SilverXJ wrote:I thought that the oil slinger's purpose was to get oil away from the front seal so it doesn't leak

It serves a dual purpose and that's one of them. The other is to splash oil onto the whole timing set to keep it cool and lubricated. This type of timing gear failure is very rare in the Jeep I6 even with the stock timing set but the Cloyes tech's comment does sound plausible.

was this a double roller or was it a factory style (but still a cloyes) unit? judgin by the picture id say factory style? i was told cloyes was supposed to be good stuff too.

It was a Cloyes factory stlye timing set.