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What's up with the timing chain issues

joesforspeed

joesforspeed

New member
Ok I'm literally almost done with my Turbo build and my shop calls me and says someone told him the JP double roller is no good. I mean my car is started and all were doing now is tuning and installing some extra gauges. WTF Now were back pedaling and trying to figure out which chain to use.
So my fellow turbo GP's can you guys give me some feedback on what I should do. Joe:th_sign-pontiacs:
 


the JP chains are breaking, but JP also owns Rollmaster, so i dunno what youre going to do. what cam is in there now?
 
My shop specs out his own grind. I know its has a lower lift than 592 because I told him that Todd at Intense is running a 592 lift and he said mine is not that high. Plus Todd is running 130 pound springs and has a single chain. So I might just go with the single since my lift is not that high.
 
Lift is only one part of a cam shaft... you have to take into account LSA, as well as duration. these all play a part in which spring is used, and how much stress goes on that chain.

I have a Rollmaster in my track car.... honed out the crank gear a bit for a better fit..other than that. I like it.
 
I just bought a rollmaster double. They are not making the ones with the single crank gear anymore and are only selling the 2 peice crank gear type.


So i'm stuck with that.


I'd rather try something new and untested than to try something that has been proven to be a failure.
 
depending on cam and springs you may be able to go back to stock chain and tensioner.. so gets some specs on cam and valvetrain..dont do a single ive read there wrose then stock.. its stock or double is the way to go....
 


LOL



Well at least i'm not the first to use one. They made it sound like that.
 


I ran a JP with the two-piece crank sprocket/oil pump drive for well over two years with no outward issues while running double gaskets...Not a whole lot of mileage, but there was a good deal of heavy throttle during its time in my engine.

That being said, when I removed the set last week, the crankshaft itself showed evidence of the chain itself having been in contact with the chamfered area. The front cover showed no wear at all, and the chain was still working fine (though stretched significantly). The chain did not appear to be on the verge of failure or anything, but the gouges on the crankshaft were certainly not reassuring in the least.
 
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