Hang Time 27

Ok what's the issue here? Shouldn't be anything wrong with roll master setups. Was it the nose of the cam wasn't right? Thought maybe I heard that mentioned earlier.

Full Force

The issue was the cam gear was hitting the retainer, I had to chamfer the retainer to make if fit right..


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

Full Force

Some of last winters heat has carried over and is slowly easing off and it's getting better ...I am not innocent of being defensive but trying to keep it factual.. hard at times lol

bck

I'm sorry I don't know why. The builder noticed the issue. He used a different timing set with no issues. No machining was necessary with the part number he ended up using. Seems to be a problem specific to that particular cam and timing set. I'm using a GM gen 6 block, I think Tim has an aftermarket block.

Full Force

I have gen6 Dart blocks, uses same retainer as stock Gen6, I posted the video of the issues a couple times for people to see what the issue is.

bck

Seems funny that one part number fits and one doesn't. The builder said it could be machined like you did, but it was cheaper and easier to just use a different one. I can get the two part numbers and maybe someone can figure it out. I'm pretty sure we did end up using still using a rollmaster just not that one.[ATTACH=CONFIG]560422[/ATTACH]
This one didn't fit.


+++Edit+++ we ended up using a rollmaster CS 2095 without issue

Full Force

Odd, I was not aware there was 2 different ones... most guys do what I did that I talked to about it... it came out ok in the end, just annoying at 12 midnight when assembling to find that out...

Hang Time 27

Ok, back to the cam - I'm no expert, so just some thoughts - as far as the finely cracked surface on the cam - that looks like the same type of heat glaze cracking you see on flywheels (clutch disc sliding directly against them, with no lube) and brake rotors (pads sliding against them, no lube) - both when they have been used extremely hard (I don't like the word abuse ��). I would not expect to see that on a cam lobe that is meeting a lubricated rolling wheel - a flat tappet where the pressure was too great, or lube insuficient maybe. So I am really interested to hear an experts opinion on that, but I'm not sure I would trust the maker of the cam to assess it though, unless they accepted culpability of course, then I'd take take them at their word.

If it ends up the ramps are too steep on the lobes, and put more pressure on the lifter wheel than it could handle, I would think there would be lifter bore damage in the block, and damage on the side of the lifters as well? If they can't go up fast enough, I would think they would be pushed to the side some, thus the wear in those areas? Not an expert opinion, just my common sense curiosity. I also think that if the lobes look like that at 65 hours, that eventually the wheels would have started to cut into to the lobes.

My last question is, was that cracked glazing only on the "lift" side of the lobe? Or was that the "drop" side? I would think that type of damage would be on the "lift" side, and that if the wheel was leaving the lobe surface on the "drop" side and crashing back into the lobe, it would look different? These are questions for who professionally diagnoses the cam, not presented as an example of my knowledge (or lack thereof).

I too was concerned with the low duration high lift numbers I was given last spring, but thought it was a proven setup. Thank goodness I delayed things till fall, only have my heads and lifters so far, and now have decisions to make that will be affected by the answers found here. So far I see no real answers, so as an outsider to this conversation, and one who hasn't been on this site much in years (because my rig was running great, and life was pulling me in other directions) I would agree with BCK in that further bashing should wait till the facts of this case are fully known. The red flag has been flown, and duly noted ����. I too wish we could here from someone who has successfully run some hours on this profile.

Full Force

certaintly not oiling issues I know that, lifters look fine at this point and will be sent to Johnson to be checked out...cam will be at some point also, needing to get engine 2 out and see what things look like..

Any bashing I have done is justified as far as I am concerned...

MILD THUNDER

I cant speak for the gen 6 style rollmaster timing sets. I hsve used the mark iv style, and imo, a really nice piece. Billet gears, with the Iwis chains. I replaced my cast gear cloyes with them. One of the cloyes had a iwis chain, the other chain wasnt labeled. Both had same runtime, but the iwis chain was significantly tighter. Either way, i wanted to get away from a cast timing set, and go with billet.

Slightly off topic, but i think they are a really good timing set for the cost.