...and the 408 is dead...
12-22-2012, 06:40 PM
#1
...and the 408 is dead... Driving home from work, snapped a timing chain (I think). Reduced engine power mode, I figured it was my throttle body acting up... cleared my codes, tried starting it, it turned over but didn't "crank", just turned the belts and made some noise. Checked all my wiring etc... then I realized, it doesn't sound like it has compression. My dad showed up and agreed. Dave (Bowtie70SS) told us to watch the rocker arm through the oil cap when we crank it, and sure enough, the rocker arm didn't move. I'm HOPING that I didn't destroy any valves. I know it's unlikely, but I can pray.
That's a picture of my pistons that are in my block - I'm hoping the reliefs in the pistons may have saved me some headaches in terms of bent valves, but wish in one hand and **** in the other.
Plan on throwing a double roller timing set in it, and compression testing it, and hopefully she lives again.
the lift on the cam .615/.622... one can only pray.
That's a picture of my pistons that are in my block - I'm hoping the reliefs in the pistons may have saved me some headaches in terms of bent valves, but wish in one hand and **** in the other.
Plan on throwing a double roller timing set in it, and compression testing it, and hopefully she lives again.
the lift on the cam .615/.622... one can only pray.
12-22-2012, 07:12 PM
#4
I'm not so sure what I'll do. If I have bent valves, I might get the heads reworked to flow better, and maybe actually sell them and my FAST102 intake and get LS3 heads and a FAST102 for that, or maybe sell the car.
Thank you for the prayers and wishes.
Thank you for the prayers and wishes.
12-22-2012, 07:23 PM
#6
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Why don't people like to run double roller chains? I run a double roller on everything, always have. There is a enormous amount of strain that the valve train puts on the chain. But, I wonder if your chain broke or if maybe a bolt came out or sheared. On the older SBCs and BBCs the chain ran the oil pump as well so at least on the GEN III engines it runs off the crank and you didn't lose oil pressure. I have my fingers crossed for you. I have a digital video bore scope that I bought from Harbor freight it was relatively cheap and it has already paid for itself with the reluctor wheel issue I had on a 03 Z06. If you use that you can get some what of a idea of what is going on.
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12-22-2012, 08:10 PM
#8
never good news...
Lets hope no damage, but if the chain did in fact break, usually there is more carnage involved.
but rather than jumping to conclusions, lets find out if the chain actually broke.
There are many people running 800+ rwhp with single LS2 chains with zero issues.
Even people like MM have always run single chains.
https://ls1tech.com/forums/forced-in...d-high-hp.html
Lets hope no damage, but if the chain did in fact break, usually there is more carnage involved.
but rather than jumping to conclusions, lets find out if the chain actually broke.
There are many people running 800+ rwhp with single LS2 chains with zero issues.
Even people like MM have always run single chains.
https://ls1tech.com/forums/forced-in...d-high-hp.html
12-23-2012, 09:42 AM
#13
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I've seen chains break an get bound up and break the block. On something like this, I would just pull it. Pull the pan, front cover, heads (have then checked by a machine shop). Better to spend a little money now and make sure it's right than to cheap out and something still be wrong and tear up more stuff.
12-23-2012, 10:23 AM
#14
id be willing to bet you wiped a cam lobe and/or a lifter before a timing chain. I dont know how much power you are pushing but ive been at 500 rwhp for well over a year now on stock ls2 chain
12-23-2012, 01:13 PM
#17
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Sucks man, really sucks. What timing chain and balancer do you have? Easy way to check for bent valves is to just pull the valve covers and remove all of the rockers...a bent valve will be sunken in the head in relation to one that is not...pretty quick and easy to verify.
I can almost guarantee that you will have bent valves...not all of them, but a few. Reliefs in the piston do no change the fact that this is an interference engine, esp with a cam as large as yours. Pistons won't be an issue..just smooth out the gouges. I hope if the chain broke it didn't crack the block as Raven has stated.
I can almost guarantee that you will have bent valves...not all of them, but a few. Reliefs in the piston do no change the fact that this is an interference engine, esp with a cam as large as yours. Pistons won't be an issue..just smooth out the gouges. I hope if the chain broke it didn't crack the block as Raven has stated.
12-23-2012, 03:23 PM
#18
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Why don't people like to run double roller chains? I run a double roller on everything, always have. There is a enormous amount of strain that the valve train puts on the chain. But, I wonder if your chain broke or if maybe a bolt came out or sheared. On the older SBCs and BBCs the chain ran the oil pump as well so at least on the GEN III engines it runs off the crank and you didn't lose oil pressure. I have my fingers crossed for you. I have a digital video bore scope that I bought from Harbor freight it was relatively cheap and it has already paid for itself with the reluctor wheel issue I had on a 03 Z06. If you use that you can get some what of a idea of what is going on.
...that being said, you cant really go wrong with a double roller either
12-23-2012, 06:20 PM
#20
I've never seen anyone have a problem with an LS2 chain that soon. Its a big upgrade over the LS6 chain and even most speed shops recommend just getting an LS2 chain. Hell I put 20k miles on my LS2 chain with a 236/242 .615 lift cam. Its just crappy luck IMO and part of the hobby.
...that being said, you cant really go wrong with a double roller either
...that being said, you cant really go wrong with a double roller either