Well I retreived the dead cam from my motor tonight.(UPDATE 7-25-05)

[Codeman96]

It didn't look good at all. #8 exhaust was completely round and some of the other lobes looked not so good as well. They weren't gone but looked like they are starting to flatten and some are pitted. I din't see anything that indicated lack of oil bearing surfaces looked good. I guess I may have just got a soft cam. Anything else that might cause this that I should look for?

 

[SUBFAN]

Valve springs to stiff????

 

[HELLBENT DESIGNS]

improper break in did you install the cam?

 

[Codeman96]

Well it crossed my mind but there is nothing special about them. They are just Heavy Duty Replacements made by Pioneer that I got form Northern Auto Parts.

 

[Codeman96]

improper break in did you install the cam?

Yeah I put it in and broke it in like I have 10 others with no problems. I just don't know. I am almost scared to stick in another new cam and cross my fingers. Now there was one screw up when I put it in I didn't soak the lifters in oil before in installed them but we realized it before start up and primed the motor by hand (with a drill the bottom end had about 2000 miles on it when I put this cam in) and all seemed well. Although the lifters have always been a bit noise for my tastes not loud but almost mechanical sounding kind of hard to describe.

I am almost glad this happened because it gave me reason to get off my ass and tear back into this motor that has never performed the way I thought it should.

 

[Mad-Dog]

Agreed, ya got check the open seat pressure of the springs.....
HD replacements was the giveaway clue.
Hydraulic flat-tappet cams require less than 300 psi open seat pressure,
275 psi for most of em....call the cam grinder tomorrow, today....sometime.
Find out the specs on those springs.....they should be 1.25" diameter outers with a flat-wire damper......you might have duals which could have as much as 400 psi open seat pressure..wear a hydraulic grind out n no time "FLAT"

 

[Codeman96]

You got me to thinking so I am taking no chances. A new set of stock spec springs are on their way and they will be changed. Besides a "softer" set of springs will cost me less low end horsepower LOL. For a motor that will never see 5000 RPM there is really no point in heavy duty springs. These were just hd singles with stock dampers but who knows they could have done it.. I only used these because I had them and didn't want to use 130K stock springs.

 

[DesertDueler2]

It sounds like you used your old lifters. You cant reuse lifters unless they are roller lifters. Cam and lifters need to break in together, or it will cause the cam to wear like yours.

Dan

 

[R72K5]

hum yeah i was gonna say same thing about old lifters but i assume that he knows all this, but i guess ya never know,

we will find out, hehe



good luck

 

[Codeman96]

No way new lifters every time. This ain't my first rodeo. That is what is so aggrevating about this motor. I did everything by the book and like I have done on several other motors I have built that held up fine and are still running.

 

[diesel4me]

chevy's flat cam lobes...

I've seen a hundred flat lobes on chevy V8's if I've seen one!...I think a chevy V8 is the king of "cameaters"..I hardly ever sold any for most all other makes of cars at the parts store!..and nearly every chevy engine I've had either needed a cam,or was in the process of losing a lobe as I drove them...

Most of the motors ran 100% after the cam was replaced,and though your supposed to "break them in" at 2500 rpm's for 15 minites,by the time I got the engine started,timed,and running good enough to STAY running for 15 minites,I figured SOME damage was already done!--but none of the cams I installed lost any lobes ,which leads me to believe GM did not harden their OEM cams right (or never broke them in!)..

Many cheapie aftermarket cams are not much better...I always use a name brand like Sealed Power,TRW,Competition Cams,Crane,and have had good luck with them...a few friends have used "Wolverine" brand "bargain" cams ,and a few of them ate lobes..others lasted years with no troubles...

Guess chevy motors really needed the roller lifter cams!...it seems to have cured the lobe eating problems for the most part..

One note of caution--ANY motor that had flat cam lobes,also has ALL the metallic particles from them floating thruout the engine!--I'd look very closesly and make sure none is still in the oilpan,etc...we just got done replacing rod bearings in my friends nova 350 motor--he wiped 3 lobes off the cam in the first motor,and installed another rebuilt 350 but forgot to flush out the remote oil filter setups hoses--all the metallic left behind found its way to the rod bearings--it ran for an hour before it was rapping quite a bit!--caught it just in time before the crank was damaged! :

 

[Codeman96]

Well the new performer is in and it sounds really good. No problems during break in never got hotter than 215* (thats pretty good as far as my experience goes) and lit with the touch of the key. Now I need to just adjust the carb, or change back to the performer carb hmmmm. Took it for a little spin and it feels good just get it to idle smooth and I think we have a keeper.