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Those of you with double roller timing chains....

Reptile

Reptile

Bastard
Take it out......trust me on this one boys.
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Now, keep in mind also...I had the front cover milled by Farnsworth, and I used the double gasket method. I was trying to make double-dog sure that this wouldn't happen. The chain didn't fail, obviously....but it was still rubbing.

I'm going out on a limb here, and saying that vendors should really put up hard stats that they actually do R&D on things. Not pointing fingers or anything....they know who they are.
 
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I was looking to see what was your reasoning........took me a minute before I saw the crack in your crank sprocket. Wow!

Is that a Rollmaster or a JP?
 
That would be the infamous rollmaster that I purchased from ZZP about 2 1/2 years ago. 12,000 hard, beat on miles.

It started making noise on sunday, kinda like the IAC does when you start up first thing in the morning. I've constatnly worried about this since I've read the horror stories, and it finally came true...although it doesn't seem to have done any other damage.
 
LOVE MY JP! you cant make me get rid of it. its the only thing that guarantees i will not ever have to crack open the front cover again for a timing chain and tensioner.

but then again, i run a low 13s rockered car. ;)
 
wow! look at those wear marks! did you mill down your oil pump cover? mine is milled and ive had no problems at all so far.
 


Yup, milled down, and I ran the double gasket.

Stock timing chain for me. I don't need that big old thing anyway.
 
holy crap! im still not taking mine apart until something breaks though. it runs great right now. but still, holy crap!
 
Damn Brian! That sux to find for sure! I guess I am glad I have always been a strong stock chain user and never had one fail any any of my or my customers builds, but when you reach a point in time when you must use one then it prolly isnt going to get many miles put on it. The JP stuff was advertised after Rollmaster IIRC and I remember reading stuff about the quality being better and maybe that holds true, especially with your findings.
 
stock oem chain here. good thing i take trannyman95 advice. new stock chain $25. double roller chain $200 plus more $$$$ for fixing cost? ouch!:th_lipssealed1:
 


could it have been metal fatigue on the crank sprocket? that might have caused it to have side to side movement at which point would definately have caused it to rub. tolerances are very tight...and you had double gaskets....that pulley must have had a LOT of play.

who put it on? did they use proper tools? I would notify Rollmaster and raise a storm. tat could have cost you your engine!!!!

edit: that sprocket could have also been oblong......not fully round. when the crank expands and contracts fom heat...that could have caused it to fatigue....
 
If Rollmaster is like JP they will tell you their timing chain were designed for the L36 and not the L67. I called Australia to confirm this with JP. btw...that short phone call cost $20... last time I plan on calling outside of the US. :

Oh and Dave, I think we may want to put my stock set back on.
 
Would you suggest running a stock chain with xp and 105 lb springs? I ran it with 90lb springs for a year with no problems, but not sure about now.

I want to pull my timing cover and see if my double I put in 2 years ago is rubbing. Mabey I should and call it a good reason to get the SFI balancer.
 
I thought it was discovered that the problem was the chamfer on the sprocket vs. chamfer on the stock sprocket. The chamfer was done to spec on Australian cars, when we used them on our l67's it was not chamfered enough and made the sprocket stick out. That caused it to have the clearance issues and rubbing. Just milling your timing cover or putting 2 gaskets on will not solve the problem. The other problem is since they aren't aligned properly, this causes uneven tension on the chain, stretching it and ultimately functioning like a single chain.

I'll try to find the thread on clubgp, there was pictures and everything to help explain in detail.
 


with 105's you shouldnt have a problem with stock chain. Vendors required you to have a Double when you exceed 130+.

just make sure its a new chain you put on...and not reuse the old one.
 
Wonder if I could change mine out myself? How hard is the job? Any special tools? How about a how-to?:D
 
I did the work myself when I put the cam in. Farnsworth and I figure that the chamfer is the problem in this case as well. trying to put a round peg in a square hole type of thing, and the pressure of the balancer pushing on it with the stress of my driving pretty much did it in. I know it's hard to tell in the picture, but it fractured at the thinnest area of the sprocket. Needless to say, I'm concerned if I ever go with bigger valve springs.

Lee, the whole deal isn't hard to do really....just time consuming. You can do it with the subframe still in place, but you have to take the oil filter housing off so that you can wiggle the cover out through where the coolant tank sits. I didn't want to tear the whole top end apart, so the supercharger is still sitting where it should be too.
 
Reptile said:
I did the work myself when I put the cam in. Farnsworth and I figure that the chamfer is the problem in this case as well. trying to put a round peg in a square hole type of thing, and the pressure of the balancer pushing on it with the stress of my driving pretty much did it in. I know it's hard to tell in the picture, but it fractured at the thinnest area of the sprocket. Needless to say, I'm concerned if I ever go with bigger valve springs.

Lee, the whole deal isn't hard to do really....just time consuming. You can do it with the subframe still in place, but you have to take the oil filter housing off so that you can wiggle the cover out through where the coolant tank sits. I didn't want to tear the whole top end apart, so the supercharger is still sitting where it should be too.
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No special tools needed? Wonder if the oil filer housing could stay in place by doing the work through the fender well like many do cam installs? Dave is/was going to help me out, but if it's not that difficult, it would have me 12 hours of driving and a lot of high dollar gas to try this myself....not sure I'm brave enough, but just wondering.
 
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