Comp.410 Cam went wrong!

[rockylaurence]

I installed a 410 cam 3 yrs and 50K miles ago. The motor had severe failure last week. I found that all the exhaust rocker pads had worn through!!! I did everything correctly on the install-I talked to Doug, Comp Cams techs, etc to find out the correct valve lash. I had the high performance springs installed by a speed shop and the seats set up, etc. What caused only the exhaust rockers to fail!! Are the cast rockers too soft? This is CRAZY!!! :fire:

 

[Creager]

all i can figure is either the rocker arms weren't seated on the valves correctly or if new cam bearings were installed, they may have been installed improperly. This would have caused them to be unable to provide adaqet oil to the top end (i'd imagin the lifters and everything else would be trash too). Did you replace the rocker arms with the new cam?

 

[rockylaurence]

Creager, thanks for the reply. First, I had the heads P&P, new springs (double) installed at a reputable speed shop. Second, I installed the cam with the correct length rods (5.525" due to none adjustable rockers) and ensured that I had the correct valve lash. However, when I pulled the motor apart this week all the exhaust rocker tips had worn through (several tips had broke off). The intake rockers all look fine.
Referencing to your questions; The motor only had 60K miles when I installed the cam, so, I didnt install new rockers, bearings or lifters. IMO, it has to be related to a wrong camm or improper setup because its a consistant failer amongst all the exhaust rockers. :roll: Is there a different set up procedure for the exhaust valves compared the the intake? Im wondering if anyone else has had this issue with a 410 camm? I searched 12 months back and didnt find any Nightmares listed.

 

[Creager]

You might try posting at www.rangerpowersports.net/ LOTS of people have used this cam over there.

In all my research i have not come accross something as of this. You said you used 5.525" pushrods, im guessing this was with the delta-cams rocker arms? The stock rockers use a length of 5.550" But i dont see how that alone would wear only the exhaust rockers.

The procedure is the pretty basic for both the intake and the exhaust rockers. Did you take the rockers apart? For rocker-spacers or anything? Shimming/Milling of the rocker pads are sometimes needed to make even contact on the valves. It could be possible that the exhaust rockers needed some machining and didnt recieve it. Thats kind of what im thinking was the cause. But i am having a hard time believing that would be the case for ALL the exhaust rockers, but i cant think what else would cause the issue

Good luck.