Cam failures in the 4.0L

Who has had a cam failure in the 4.0L motor? Strokers count as well since its a 4.0L block.

I figured I would post this here since it gets seen more than the street and performance forum. I have just had my second cam failure. Both cams that died where from Crane. The first one died due to them sending me the wrong spring retainers which created excessive spring pressure that intern bent a few pushrods and ruined a couple lifters and cam lobes. That happened at 5k miles. The second failure just happened at 11k. The distributer gear on the cam wore out. Again I think its a bad cam from Crane.

I know of several others who have had issues with Crane cams going bad. Has anybody else had a problem with Crane or any other brand of cam going bad? Anything about Hesco and their cams or Comp or Lunati? I would like to see if this is just a problem with Crane or if its something wrong with the 4.0L block and cams in general for the motor. I plan on getting a cam from Hesco and paying the extra cash to do it right...hopefully.

Thanks,

AARON

MrShoeBoy said:

or if its something wrong with the 4.0L block and cams in general for the motor.

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There's certainly nothing wrong with a stock 4.0 mechanically.

I think aftermarket cams are having trouble because they are far too radical in terms of lift for the given amount of duration. In other words, the valve doesn't have as much time to open and close as it would with a longer duration cam.

I don't see the point of cam upgrades in anything but serious race engines that get rebuilt often anyway.

I think the factory designed the 4.0 cam very well, both the HO/renix and the 96+ cams.


Hey did you ever find your dyno sheet for the 99+ intake? I've been itching to see it.

I've seen that one. But Dr. Dyno educated me into the possibility that something else that was replaced might have skewed the results. Like clogged fuel injectors or whatnot.

He came up with that conclusion because the numbers for his baseline run were far too low to begin with. I believe him.

120 rear wheel horsepower for the baseline? Come on, thats weak. A dodge minivan could put more than that to the wheels.

I have not been able to find the digital copy of the dyno results. I have them printed out and stuck to my cork board. The gain was 3hp and 5ftlbs torque at the wheels. I plan on going back to the shop and getting a digital copy of it this week if I have time. Between working and dealing with another cam failure in my motor has left time flying out the window.

AARON

MrShoeBoy said:

The gain was 3hp and 5ftlbs torque at the wheels.

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Ha ha, when I was telling everybody that the newer intake manifold would yield only a 3hp/6lbft gain, not many people believed me. Many thought that they'd gain at least 15hp. I'm glad you've proved me right Aaron so we can lay this subject to bed.
j99xj, that 27hp/26lbft gain on DJJordache's dyno sheet was the result of the newer intake AND injectors, not the manifold alone. I think the low baseline numbers were due to the old injectors being clogged.

On my 2.5 in the Heep (the valvetrain architecture is identical) running high seat pressures and regularly twisting the motor to the 7k+ rpm range, I have not had any cam lobe/lifter problems...maybe there is a quality control issue with Crane....I have no idea who built the "Clifford" cam I run.

Dr. Dyno said:

Ha ha, when I was telling everybody that the newer intake manifold would yield only a 3hp/6lbft gain, not many people believed me.

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They don't call you Dr. Dyno for nothing. :rof:

20K on mine and all is good sofar. Been running Rotella 15W40 since the first oil change on the motor. Broke it in on valvoline 10/30 before I new the benefits of the Rotella and the better Zinc content.