Will a stock 383 really go down the street any faster with an Xtreme cam instead of the vintage pattern? I need to know before I pull mine out.

A friend of mine purchased a complete K kit for a big block chevy. Nothing was left out for info on its intended use or its specifications. Two months and maybe 1500 miles a clatter began inspections revealed their push rods balls were being pushed inside of the PR tubes. The parts boxed and returned pictures taken before being sent back. Some how these push rod tips heated the tubes enough to not gall the balls but fatigue the tube material.BS! They chose to do nothing about the obvious problem of the tubes being over heated upon build only 3. New Lunati push rods installed and all was well for a week. Then the HYD ROLLER lifters on the other bank became noisy. So a call to comp and what is there reply obviously you installed and broke in incorrectly. SOOO new Lunati cam, lifters, springs and push rods went in and its going on 9 months no issues. COMP ADVERTISERS ARE GREAT but they don't live up to the hype it seems.

I would tend to agree with the bad Comp lifter theory.

I know I'll get boo'd, but I like Summit house cam and
lifters. I've had two in my 360 with NO problem what
so ever.

If I ever put another cam in, I will go with a solid lifter
that has the laser drill hole in the bottom. Not sure
of the brand.

Life used to be so simple.
You called Iskendarian and talked to Ed...

I've heard from a couple local motorheads that Isky cams are good. I'm wondering why I have not heard much replies on this forum about the Mopar Purpleshaft cams??? I'm hoping for more feedback today!

How do you break in a cam anyways? Doesn't it break in with the motor automatically. I am gonna need to know this when I start my motor for the first time very soon. I am running a comp cam also.

Have it setup so it fires right away and vary the revs a bit but keep them above 2000RPM for the first 30 minutes of run time. Lots of breakin lube on the lobes and lifter faces, oil on the sides of the lifters and make sure the lifters are free to spin in their bores before starting. If you have dual valve springs, take the inners out for cam breakin.

Sheldon

Plus you need an oil with the proper chemistry for flat tappet
protection, normal car oil for modern cars cannot protect a flat tappet cam.

You'll need to add ZDDP or other additive for this.

Also you can choose to use one of the many oils advertised for that specific purpose, I use Valvoline VR-1, but there are others.

VERY IMPORTANT!!!

Joe

I don't know if they're junk, I've always heard pretty good things about them on here. I did just read an interesting article in the July issue of MM. They used a short duration, fast lobe/high lift hydraulic roller and were able to get the best of both worlds when it comes to cam qualities. It gave them the smooth (sleeper) idle with high vacuum and still provided the same power as a long duration, choppy idle, low vacuum flat tappet. It was a really informative read for me seeing as I don't know jack diddly about cams so I feel like I learned something.

roe

I could really use some reports how the Purpleshaft cams (268/284 duration .450"/.458"lift) have worked out in stock intake/exhaust/rockers on 383HP rebuilds with 4 speed 3.23 gears. But reports on any cam also welcome!

About 7-8 yrs back when I bought my XR-280 Comp...my speed shop guy warned me against Hydraulic cams because the factory was using less nickel in the foundry process. Premature wear and failure. He said the only cams (at the time) still worth purchasing were Roller cams. I had bought it for my 505 but I am not anywhere close to building it. I bought the X-treme Energy Roller and matching lifters. I imagine with the EPA being the way it is, my model bumpstick is better than the same model on the shelf today

Hearing people complain about noise from their cam cracks me up. These are classic cars that we build to be faster and quicker than they were new. Some compromises are to be expected. Old cars have more vibrations, noise from roof rain gutters, less sound deadening in the floors, etc.
I don't mind a bit of all that. It makes me feel more involved in the experience. A car with no sound or vibration is akin to watching an "in-car" video on a muted TV.
No thanks, I like my cars to be real.

a note on break-in. As said, you want everything set up so it fires and runs ASAP, and can keep running for 30 minutes at ~2000 RPM. This means more timing usually, and have a BIG FAN and a hose nearby to keep it cool.
Fresh engines tend to run warm (more friction) and sitting there working the throttle, setting the timing, checking for leaks, having the headers or manifolds cook off, you really don't want the cooling system overheating too.

I just got a Comp cam for my car. Hope it holds up!

The Mr. Sixpak cam didn't.

I run a Muscle Motors "custom" cam ground by Comp. Break-in as mentioned above and high zinc oil. No problems with ~14k miles.

I don't have #s, but would bet everything that Comp sells the most cams by a huge margin. Given a somewhat similar rate of failure across cam companies (for reasons including bad lifters or improper break in-- neither being CAM related), there are going to be more individuals who have had failures with comp cams. Just numbers. Maybe some people get unlucky.

I have had 100% success with 3 cams of theirs and I'm getting ready to use another. I've also run two XE284 hydraulic flat cams, and frankly I didn't notice any funny noises using an otherwise stock valvetrain.

The cam you have chosen sounds fine, don't sweat it and run it.

I need to quit reading these "cam horror story" posts until I break mine in I have the XE256H-10 for my 318 build. I bought it too long ago and due to life getting in the way still haven't fired it up. Is there any recourse for a failed cam after the warranty period has passed even if it hasn't been run? I understand that most of the cam failures are the more radical grinds than mine. True?(Its supposed to be what would be like stock for a 340 or 360(?))

Scott