Cam and valvetrain longevity....??? low duration high lift...
#1032
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Abones , i wonder if it has something to do with bob selling the 8.1L cam cores for every application. I wonder if something is different with them, ever so slightly, in how the nose is machined
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#1033
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At this point in the investigation it seems likely that indeed is the case!! I think if there are more incidents like Tim and Budman show up that might seal that deal!!
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#1034
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Unjust worry how many guys install and don't check runout to know? It can spin but it's right so if you don't check runout and you don't spin can hear only when installed you would never catch it, I was more thorough on my builds then people know
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#1035
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Hey Tim, I just had a thought this morning and it might be worth looking into. B4 you purchase new cams. It would be nice to see if anyone has done any testing with LS vs non LS firing order with a center rise manifold such as yours... If you think about how the double swap firing order would pull on the runner with the manifold such as yours I would think the exhaust scavenging would totally suck. Did you happen to notice any carbon tracking in the intake runners of the heads or into the intake itself. I was burning some brain cells this morning and have to say with the first cam I got from Bob I had Carbon tracking 2-3"s up into the intake with that combo... This was with Geniii manifolds. Next go round with that setup I added 20*+ duration normal firing order bigger intake bigger carb and had no carbon tracking anywhere in the intake track whatsoever. And that motor idled much better. 500rpms in and out of gear...
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The good Cloyes timing sets come with the iwis chain too.
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#1037
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What i find interesting is, in the thread I linked, budman clearly stated he called bob about the cam nose/retainer fitment issue . Explained it, and said that bob didnt think it was a problem. That was 2013.
Then you guys had the issue. Let me guess, bob acted like he had never heard of that before ?
Just like when orlandi found the issues with his valve seats and other various valvetrain issues. Him and bob were friends . When the topic came up, bob acted like he had never heard of such a thing. After brian had talked to a few other builders, who also presented these issues to bob, he pieced the puzzle together. Bob very well knew about the issues these builders were having, and never shared it with brian, his good customer and friend. Cost brian tens of thousands of dollars.
Engine development at its finest.
Then you guys had the issue. Let me guess, bob acted like he had never heard of that before ?
Just like when orlandi found the issues with his valve seats and other various valvetrain issues. Him and bob were friends . When the topic came up, bob acted like he had never heard of such a thing. After brian had talked to a few other builders, who also presented these issues to bob, he pieced the puzzle together. Bob very well knew about the issues these builders were having, and never shared it with brian, his good customer and friend. Cost brian tens of thousands of dollars.
Engine development at its finest.
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#1038
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One thing I've noticed with the ls firing order is it seems to be considerably more prone to reversion then the conventional firing order even with mild duration. I always assumed that the intake reversion from the Bob cams was probably a combination of the stupid exhaust timing events and possibly instability in the intake valve causing it to bounce on the seat. On engines with a bit of time on them you would start to see the heat and even more carbon tracking on the intake seat. I saw a couple that ended up loosing intake seal completely and looked like they werent far away from getting torched.
So, it sounds like you have moved to tried and true Lunati Cams. Are you going with standard or LS firing order?
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