slick98ta

I just got my car back to together after doing a heads and cam swap.
And just while cranking it over the timing chain broke.I never even heard of this happen to anyone while just tring to start it.
My car never ran,just cranked a few times then broke the chain.
I also did the a ls6 oil pump and inspected the chain then and everthing looked fine.Chain was stock and had only 20,000 miles on it.

Any thoughts as to what caused this?

Thanks
mark

Beast96Z

iTrader: (21)

Hopefully you didn't install it 180 out, or have it in some sorta bind??? Other than that, maybe it was just bad luck.

Ferocity02

iTrader: (60)

Maybe it got damaged while it was off the car. Also, the cam could be too large and the springs to stiff for the stock chain to handle, but that seems unlikely. Or, it was not lined up correctly. Not sure why you would put the stock chain back in anyways, time for double roller.

Also check for damage, broken chain = open valves. Open valves + pistons = not good

wrencher

iTrader: (2)

Wow that sucks!
Is it a big cam?
Was installed dot to dot?

Mike K.

Yeah that does suck, how was it installed?

Ferocity02

iTrader: (60)

When I say lined up correctly, I mean dot to dot AND laterally. Meaning there sprockets are lined up with eachother if looking from the side. You can use a ruler to determine this or just make sure the crank sprocket it as far back as possible.

Chuck@

iTrader: (1)

You didn't by chance forget to install the cam thrust plate? Easy thing to forget, and if it was left off, the cam could've easily walked forward and caused the chain to break.

Chuck

slick98ta

Yeah, I put that plate back on.I didn't leave nothing off.
And yes it was dot to dot meaning i put it where the top gear had the dot on the bottom of the gear and the bottom gear had the dot on the top of the gear.
Cranked it over once by had to make sure it stayed dot to dot.Only thing that did seem kinda odd was that when i first tried to crank it over by hand it seemed really hard to do(sorta like a bind).And that was with the heads off the car.So I took the timing chain and top gear back off and checked everything.It looked ok so I put it back on and it turned over fine(normal)
I have no clue what that was all about.

I know its time for a double roller,but the heads have to come back off now to see if I have bent valves(which i probally do) and whatever else that might be wrong.The heads arn't milled and I'm using the Futral Motorsports F6 on a 112 which isn't big enough I don't think to even worry about clearance issues.
I just don't want to throw another chain on there for it to do the same thing.It just don't seem right that it broke while tring to crank it over.

Hey Beast
How would I know by looking at the gears if it was 180 out?I mean I put the top gear back on the same way it came off without ever turning the motor over.

Nice4thgenZ

iTrader: (10)

i just went over to slicks house today, everything was installed right. it is all the cam. when you tighten the cam pulley down the cam WILL NOT turn! when they ground the cam it looks as if they did a poor job... kinda ashame that alittle thing like that can cause that much damage.




pics soon to come!

Futral

iTrader: (1)

slick98ta - I sent you a pm, we will try to help you get to the bottom of your problem.

Nice4thgenz - FYI there is nothing that you can do when grinding a cam that will cause this problem. But we are going to check it out.

-Joseph-

iTrader: (12)

I've heard of something similiar before but it was another vendors camshaft, the way they checked it was pulled the camshaft out and install the thrust plate and upper timing gear with the cam outta the car. The thrust plate should spin freely from the cam/timing chain when all bolted together.

1999_SS_M6

I don't know that I agree with that... For instance, what if the billet itself was drilled and tapped off center? Maybe that's a stretch, but if the pulley is mounted off center to the cam centerline, I could see all sorts of weirdness occurring. Unless of course you're specifying that the billets are already tapped BEFORE they get ground to their finished profile. I'm not getting into the semantics of the blame game, I'm just spitballing ideas about where the defective component may lie.

slick98ta

I got the PM and sent you one back.
As I said in my PM to you.
I just put the stock cam back in the car and everything spins freely like it should.I also have a C1 hammer cam that was in the car before when it was cam only and it was fine of course.
So that leads me to believe that something is wrong with the cam.I'm glad your looking into this,and I thank you for that.Hope to figure out what's wrong with the cam soon as you get it.

Thanks
Mark

Nice4thgenZ

iTrader: (10)

Well excuse me for using the wrong term, just trying to explain what is going on..



FYI I'm not in the cam manufacturing business so I wouldn't know

BigD

iTrader: (31)

Could it be the front snout of the cam is machined wong? Might be to short and pinching the cam against the cam retainer plate when you tighten the cam sprocket down.

crainholio

iTrader: (2)

If you're not in the cam biz, and wouldn't know, then why are you trying to explain what is going on?

badass 2002 z28

iTrader: (5)

I was there with Slick98ta and Nice4thgen. You don't have to be in the cam business to explain that once bolted in that the cam isn't spinning

It would spin over with the 3 bolts in finger tight, but once tightened it would not move at all. I've done 3 cam swaps on my car and I've never had a problem like this.

As Slick stated he never had a problem with his C1 cam and even put the stock cam back in and it spins over. So it seems to be a problem with the cam itself.

Nice4thgenZ

iTrader: (10)

guess the team doesnt know ****, its not like we havent messed with countless ls1 cars...


we might as well just fly in allan from Futral Motorsports

slick98ta

Well,
Soon as Allen gets the cam back we should know what the problem is or what happen.

Futral Motorsports customer service is top notch thus far,and is doing everything he can to take care of this problem. Thanks Allen

Its just one of those things,it happens

Nice4thgenZ

iTrader: (10)