LSx Motorhead Tidbit
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From: Marysville, WA
LSx Motorhead Tidbit I was up at Marysville Speed talking to Mike Friday, and he told me about something interesting he heard. If you've ever torn into an LS based engine, you've probably noticed the cam chain is a little loose. (I know Ellis & I have talked about this more than once) Turns out this is by design.
Evidently the aluminum blocks grow enough when they heat up that the chain needs some slack in it. And the double rollers that are "nice & tight" can actually cause problems. One guy reported wearing out several front cam bearings, and even broke the front hub off of a cam.
Putting 2 & 2 together, I figure this also contributes to our random misfire issue. Thinking they have programmed this slop into the PCM, so we put tighter chains on there, and then install lighter weight converters or flywheels & rev the engines well past the 5600 they are set at, the cam position sensor signal is outside the window.
Anyway, it's something to consider if you build a motor. Sure makes an iron block look good!
Evidently the aluminum blocks grow enough when they heat up that the chain needs some slack in it. And the double rollers that are "nice & tight" can actually cause problems. One guy reported wearing out several front cam bearings, and even broke the front hub off of a cam.
Putting 2 & 2 together, I figure this also contributes to our random misfire issue. Thinking they have programmed this slop into the PCM, so we put tighter chains on there, and then install lighter weight converters or flywheels & rev the engines well past the 5600 they are set at, the cam position sensor signal is outside the window.
Anyway, it's something to consider if you build a motor. Sure makes an iron block look good!
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From: Seattle, WA
That is really intersting and makes a lot of sense. I have been thinking about going with a double roller for a while but think I might take Rick's suggestion a bit more seriously and look at the LS2 chain.
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I ran a dbl roller on my hot cam & didn't have an issue, but it was only running for 10,000 miles. Which should be enough you'd think. I think as long as the chain isn't VERY tight, it should be ok. Mine was pretty tight, the chain had movement, but not enough to measure. And one car I worked on was pretty loose, like 1/2" of play.
I wasn't trying to make anyone paranoid, just passing info along. But maybe an LS2 chain is the answer. You'd think GM has figured out the solution by now.
I wasn't trying to make anyone paranoid, just passing info along. But maybe an LS2 chain is the answer. You'd think GM has figured out the solution by now.
Funny, I just had an LS2 chain apart this weekend and commented about how loose it was before removal. I just figured it was junk after <20k miles. It seemed to have about 3/8" play on both sides.
Mike
Mike
