View Full Version : Timing Chain Issues

10-09-2003, 12:37 PM
FOr some reason, I have the worst luck somedays. I spent a 7 & an 8 hour run putting the engine, tranny, new fuel pump, and differential in, all hoping to have my car running last night. But of course, that wasn't going to happen. I had just finished putting the balancer on, and we started to go through the sequence of torquing down the rocker arms. As I'm turning the crank over, I notice the rockers not moving anymore. I pull off the balancer and front cover, and wollah, a broken timing chain. ~~~ caused this ~~~ chain to break. My only guess was maybe because I got bigger stronger valvesprings, the chain was under more stress to move the cam. Anyways, the rockers were torqued at 10ft.lbs , and we had started to adjust them to 20, and were going to use 25ft.lbs. as final. It was a stock chain, but had less than 30k on it. Anyone ever have this sort of problem before? I figure that its better it happened now, than later when blower and all were back on. Any thoughts on this are appreciated. I guess I will be ordering a double roller from morana. Another day, another dollar, and in my case, about another 160 worth of them.

MIKE 38sc
10-09-2003, 01:10 PM
I have no idea why your chain broke other than it was worn out to begin with. Timing chains and such are high wear items that should be replaced anytime you have the engine torn down that far and have high mileage on it. That is just cheap insurance.

I hope you have better luck with Morran's timing chain setup than Kurt K had. He posted pics that showed the timing set upon tear down of his engine. The cam sprocket was rubbing against the block chewing up the cam gear and sending metal shavings all through his motor which caused several other problems.
I would have only used a stock setup myself, thats whats in my new engine. But thats just me.
I'm only gonna use proven parts in my engine and I'm not about to be a R&D dept. for some aftermarket co.;)

10-09-2003, 01:27 PM
The chain did seem quite cheap anyway, when I yanked it off and threw it down the driveway, it looked like a sparkler. just as well it broke in two spots. It was oiled up, so I knew it didn't get stiff and stuck. It's puzzling.

MIKE 38sc
10-09-2003, 01:40 PM
There are 2 points on the chain that are the highest wear area's.
1. Chain teeth, where they contact the gear teeth. That is an area that is easily visible to the eye.
2. The pins that hold the links together. This is the highest wear area and one that you cannot see with the eye, so youre flirting with disaster anytime you reuse the chain.

I have no idea how much milage or abuse your chain has on it because you did not mention how long the chain has been in service.
I know that when I tore my engine down with 128,000 miles on it the chain and gears look almost identicale to the brand new pieces I bought to replace it with. Do you think that for 1 minute I thought about reusing that chain just because visually to the eye it looked just as good as the new one? NO I didnt.
The stock unit is not a cheap or infereror part, its more than up to the job at hand.:)

David Neibert
10-09-2003, 01:47 PM
I believe your the first person I've ever heard of with a broken timing chain. I've got the stock chain and tensioner in mine, and wouldn't install the Morana chain if he gave it to me.

Morana has redesigned the cam sprocket to the same thickness as a stock unit, so rubbing will no longer be an issue. I just don't like the fact that there is no chain tensioner. Kurt's engine has about 5000 miles on it (3000 Highway) and the chain had already stretched enough that it could be moved 1/4" in either direction.

Why did you have the engine out ? There must have been something more that caused the chain to fail.


10-09-2003, 01:49 PM
did you turn the engine by hand first.................it should 0nly take about 25-30 lbs of torque...........FAST FREDDIE:rolleyes: :cool: :D ALSO THAT WILL SHOW IF ANY THING IS BINDING OR HITTING ................

XR7 Dave
10-09-2003, 07:51 PM
I agree with the above posters. I would use a new stock chain. I've never heard of one breaking either.

10-09-2003, 11:50 PM
Will the stock chain be good enough? I figured the morana peice would be a good improvement, but if stock is good, then ~~~. The engine had less than 30K at best. It was torn down to have the heads done up, as well as many other upgrades. I did everything during the course of winter/spring, and summer(unfortunately). I thought it would be best to replace everything at once, instead of peice by peice. Upon teardown, I found a busted motor mount, I had 2 bowed vavlesprings, and I found a reman tag on the engine. Said 1.1.01 as mfg. date. bought the car in 9.13.01 with 62,963 on the clock. When I was at the nationals, others who had looked into my car before I bought it even said the car had a new engine in it. I used to drive the car agressively, but I didn't beat the hell outta it. When I stopped driving it, it had 82k on it, and that's when the mods started. The bottom end was left untouched. All looked good when the engine was on the stand. The engine was turned by hand, and the rockers weren't even torqued to full yet. It really is puzzling. I haven't yet ordered a new chain, so thoughts and suggestions are welcomed, as well as where to get the best price on one at. My only other thoughts were to do gears, or the new belt system.