Full Force

Has any of you guys encountered the mind boggling Rollmaster/Bob cam timing chain issue? I hope you guys checked runout and how the cam spins by installing chain gear on CAM ONLY and spin by hand, not using chain and spin with crankshaft you may not notice it, I had to chamfer the inside edge of both retainers to clear the Torrington bearing.... if you did not check it you better... I told Bob about it and he never really responded... Mike T had the issue also and he and I talked at the time at 12AM to get the fix fr me to move forward....

Wonder who Bob informed of that issue???

MILD THUNDER

I believe that was more of a cam nose machining issue wasn't it? Where the cam was machined for the retaining plate?

I used Rollmaster timing set, but the Mark IV ones, that do not use the retaining plate. From my independent research, they seem like a great timing set. The iwis chain is a quality piece they come with

Full Force

No it was because of the cam retainer in a gen6, the bearing hits. The retainer, won't have the issue on a markIV block, I loved the quality of the timing set and tension on the chain was great. I bet if look back 2 years on our FB messenger I can find pics, I'm sure I sent them to you,

MILD THUNDER

Looks like you, Mike tkach, budman, amd others had the issue,
. They also had bobs cams. I have not heard of this using a regular gen 6 cam from anyone else.

Budman, in this thread, tried a different gen 6 cam, and found more clearance. Wonder if the issue is because bob used all these 8.1L cam cores on reg bbc gen 6 setups? Was there a slight difference in the machining of the nose between those series of engines? Of he stated how he called bob, and bob didnt think he had an issue. Im pretty sure bob prob had recieved many calls on that topic , and dam well knew about the issue and why there was one.

http://www.offshoreonly.com/forums/g...o-you-set.html

Full Force

Well, after half hour of going back on our messages I found it.... Uploaded video we sent mike T on the roll master... Bob had zero answer of course..

https://m.youtube.com/watch?v=VlFJxR2c-Yc

Black Baja

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...

Full Force

I will have to look my buddy has that set of heads now...

Hers a pic of where the timing chain gear rubs on retainer, if not clearances your gonna have issues..

[ATTACH=CONFIG]559971[/ATTACH]

MILD THUNDER

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.

Full Force

Exactly and I searched emails... With the heading "timing chain fix" and I don't see anything about him saying anything at all, trying to dig, seems at least with me... Anything questionable was never put in writing... Hmmmm

abones

I installed a Rollmaster set on one of my engines this spring. (Not purchased from MK) with the retainer in place i measured the amount of the cam nose exposed in relation to the depth of the roller brg and gear to seat properly on the gear without crushng into the retainer, and it worked out just fine, could be the nose on MK cams are not quite to spec?? IDK. I left the other engine the way it was on purpose do a visual inspection this coming spring when I make some other upgades to the engines! I will report back then.