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

Ok thanks. I guess removing reintalling the cam and crank gears are not a big deal? I still think I may let Dave do it, but am curious.

you can get the front cover out without removing the oil filter housing, ive done it myself. a number of times actually. and dont say you dont need any special tools, you need the right puller to get the crank pulley off. otherwise everything else is pretty much just a socket set.

i hate taking my car apart, so if my timing chain ever fails in any case then im going to be pissed.

I don't like messing with our cars either. Right now I'm in the middle of a LIM gasket replacement and new rockers install along with other gaskets and orings. I don't mind too much when I have plenty of time, but that really isn't the case right now.

ive pulled the motor, swapped blocks..not that hard. but pulling the heads with the motor in the engine bay the 4+ times ive done it is rediculous. its way too much work.

Brain, again sucks this happened, but I'm glad and thankful it didn't do more.

The oil pump cover I had 0.020" milled off the inside of it for B, just as I had done for mine on my car, and others who wanted it done by me here locally.

For me, I have the same double roller, and run 130# springs. As Brian said we think the main problem lies with
the bevel of the crank sprocket...or lack of it on the Rollmaster.

Here is a picture of the back side of a stock L67 crank sprocket.


See how the inside has a radius machined on it, that mates up with the radius/bevel on the crank.

Brian, can you flip that Rollmaster crank sprocket over and snap a picture of the back side of it for us?

Rollmaster does not machine this radius on their sprockets, cause they are not made for our cars. So you have a flat edge trying to ramp up a bevel or a ramp in general so to say, thats on our cranks. Think of it like an wedge or an ax splitting fire wood. Same thing here. The balancer will push or try to push this crank sprocket on all the way till it stops, but because there is a wedge on the back side mating up against a flat side, its going to wedge the ID of the cranks sprocket on that wedge and its going to start trying to split the crank sprocket like fire wood.

I just dropped $300.00 odd some dollars for a new Rollmaster double roller timing chain set, new 130# Comp. springs and a new front cover gasket. (yes just one gasket) When the timing chain arrives, the crank sprocket will hit the machine shop and be set up on a rotary table to have that radius put on it. Just like the stock one. Thats what I'm going to do anyway.

But I agree 100% that R@D needs to be done NOW on this from the sellers in the US for this item. If vendors sell it as fitting, then it should with no ill effects.

They only know of the rubbing issue with the chain making contact with the front cover, and tell everyone to run two front cover gaskets cause they are against machining the oil pump cover. Well, if this radius was machined on the back side of the crank gear, then there is our lost clearance we need back...cause pretty much...with no radius there, the crank sprocket is not going on the crank all the way.

In your case it finally did...and it broke from the pressure.

My $0.02 on it anyway, and my solution to the problem for good I hope.

~F~

There was a huge multi-page thread by Janice over on the other forums quite some time ago, and the discovery of the of the design flaw when used on an L67.

very good information!

making a block off cylinder?

I had my engine 50% balanced internally, and I removed the balance shaft all together on my build.

But thats one Idea I had was to make a knock in plug where when one was doing a cam install that they could remove the balance shaft, and knock in this plug which would block that oil feed hold from the inside of the motor vs. pulling the motor, removing the rear engine cover and drilling, and tapping that hole from the out side. But now that Its posted out there...I'm sure some vendor will make it.

I would do it now...but I would prefer to do some real life testing to insure it will work flawless for anyone who wanted to run it. I dont want and failures due to something I made or engineered.

~F~

i just left my balance shaft in and removed the gear. that little extra weight isnt going to hurt anything.

Originally Posted by turbocharged406sbc

are you going to be running the fatman rails parallel flow or series flow?

I will have them parallel.

Picture of the back side of a stock L67 crank gear, vs. a brand new Roll Master Double roller crank gear...notice the bevel on the ID of each of them?



~F~

^^^^^wow that is nuts, If you get yours milled Farnsworth post up a thread with some details please.

Am I to understand, then, that if the double roller were chamfered properly, that it would work as intended?

Originally Posted by SyntheticShield

Am I to understand, then, that if the double roller were chamfered properly, that it would work as intended?

correct

^that would be nice...since we know I suck at picture taking and making videos.

Get on it B.

~F~