OP
Jezza's Turbo LJ
- Thread starter Jezza
- Start date
OP
Sorry I missed it somehow. I am undecided on the springs. They work fine no issues, but I am still getting the same amounts of bearing material in the oil. Last oil change I cut open the filter and found a few nice size chunks. I almost wonder if my cam is bent. I remember the machine shop saying they had to straiten it after the first rebuild. It's a nitrided comp. I spoke with another cam company that told me nitriding is hit and miss with cams. I guess it can cause internal tension that bends the cam over time. Right now it's running fine so I'm not overly worried.
Thanks. And those were drop in, right? I remember you said it quieted down the valve train some, right? Did you ever see any valve float? I shift around 5.5k rpm so that's a bit of a concern for me.
And please excuse my ignorance, but the lift listed on a cam card is seen at the valve with stock ratio rockers, right? Or is it at the cam lobe and math is required? Your springs are listed at 550 max lift IIRC. Also I have 1.65 ratio rockers.
I have metallic sheen in my oil and a nitrided cam as well fwiw.
And please excuse my ignorance, but the lift listed on a cam card is seen at the valve with stock ratio rockers, right? Or is it at the cam lobe and math is required? Your springs are listed at 550 max lift IIRC. Also I have 1.65 ratio rockers.
I have metallic sheen in my oil and a nitrided cam as well fwiw.
i wonder if Cryogenic treatment could help resolve this ?
Cryo treatment seems to relax and release any tension from within the metal from what ive read ! So i may be doing that on my cam&crank once i'm ready build my next motor!
I as well have seen a glazy metallic sheen on my cam from Comp too ! My 1st cam bearing was kinda chewed and i suspect it was the very stiff springs that clearwater put on the head (That I ruined head while porting) So i just put back my stock head that i cleaned up and ported and ill see how my next oil changes are like with the stock head with the stock springs of course that'll handle .450 lift and so far no problems !
My next cam might be a howards cam, i like the specs on them and my intake closing angles are where id like them to be and i like their lifters they're heavy duty looking (if that makes sense) They use an actual Retaining ring (C-clip that has the 2 holes) over the paper clip like retainer that many lifters use! Just not too happy with the lift so i may run some 1.7 ratio rockers
Heres the part number to the cam MC320111-10, still am looking at some more options since id like to keep my retaining plate since "S.A Gear" makes a billet dual roller setup for the thrust plate style cams !
Billet dual roller? As in a true roller cam (as opposed to flat tappet)?
Nevermind. I googled it. Had me excited there for a minute. I would pay way more money than I should for a roller cam option for our motors. I think maybe it's not possible due to engine architecture?
You'd need a way to keep the lifters from rotating. IDK if there's room for a SBC style link-bar setup. I'm sure someone could come up with something, maybe even by cutting a window into the block, but I doubt it'd be worth it.
I do believe that is exactly the reason and as for worth it, after replacing several cams which seems to be the predominant issue for most any performance built AMC I6, it would have paid for itself long ago in my case.
Yeah, warping hasn't been my issue so far. It's eating lobes off the cam.
Has anyone asked Russ about this? If I remember correctly, all 3 of you (Jezza, Skyline & RickyD) are running, or have run, a cam from him.
The nitrided cams are eating lobes?
One reason i went with a milder cam and nitriding was in hopes of avoiding flat tappet woes
If this is an ongoing, repeating issue, have you checked for other causes, like stuck lifters and out-of-round lifter bores?
I may be wrong, but I believe any warping occurs during the nitriding process, and the cams are straightened to a spec afterward. Since the cams shouldn't be reaching anything near that temp inside an engine, any warping issues should be present out of the box.
That is how i understood it when l researched before buying.I did check my cam against a machinists straight edge in a few places. so
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No,"Billet dual roller" as In dual roller Timing chain
My bad,I should've elaborated! I wish that was a thing though. However I bet it's possible with a good machinist by grooving the lifter bores. I've seen it done to other engines so it's probably just a matter of money to get it done on a 4.0/Amc application.....
Edit just read the rest of the replies,Ya know what i mean now
Unfortunately cam manufacturers are drying up and dying as their old(but still the best) equipment breaks or needs 100k$ in repairs. Lifter manufacturers are the same story.
Anyone in industry can tell you that whenever they went to auction in the last 30 years to buy mills and lathes the chinese were there taking everything. Now we have the results. For them its business as usual with coal power. Here in CA i can't even buy a gas powered lawn mower legally. Mods feel free to move this to the piss and moan table thread
