what's wrong with this cam?

[DBraunig]

Just like the title says.......

Cam has been in since 5-07 has about 5000 miles on it. The wear is only on the intake lobes, no damage to any of the exhaust lobes. All the tappets appear in good condition also.

what say you?

Dave

[VMacKenzie]

Coil bind? Inadequately or improperly hardened cam material?

[zstroken]

Not enough duration would be my guess! Sorry, so what were the symptoms?
Regrind? new lifters used?

[WICKEDDIESELS]

Looks like a regrind, with pretty good lift, based upon the base circle. Could be inadequate lubrication (insufficient tin content), excessive spring pressures, coil bind. Wouldn't blame material hardness as not much material was removed at the nose, can still see some of original lobe edge radius present. Was the camshaft properly broken in, with a good assembly lube?

[Hammer]

Valve train harmonics,or valve float if you prefer could also be a cause.

[RacinDuallie]

Damn Regrinds !!!!

[DBraunig]

It's a regrind obviously. The exhaust looks much better than the intake. i'll get some pictures of the exhaust lobes up later today. This is out of a 12 valve motor with 60lb springs intake and exhaust.

Dave

[jkretzer]

wow looks like the regrind that came out of my truck after only 2k miles, and that time i didnt have 60lb springs. i wouldnt put another regrind in my truck recommend it if i was paid to!

[WICKEDDIESELS]

If they aren't set up correctly, none will last. Some stick a cam with an additional 0.100 lift and more duration in, and never check the springs or look for coil bind. Most of the material removed in the grinding process comes off of the base circle of the cam. Sufficient hardness remains. It is easy to check for coil bind, all you need to do is look for a shiny stripe, where the coils contact each other. Due to the fact that the exhaust is fine, I would say it was an interference issue. Regrinds can fail, if not correctly ground. Normally it is an installation issue, where things were not correctly checked or used tappets were used.

[DBraunig]

Hey guys,

I have gotten several PM's wanting to know whose cam this is. I did not start this thread to Bash a person/company or hurt anyone's reputation or business, that was not the point. Maybe it's my fault. I just wanted some honest opinions on what everyone thinks happened to the cam. I have no intentions of naming names, not really my style.

The parties involved are waiting for the cam to get shipped back to them for inspection so they can see what happened.

Here are some pics of the exhaust lobes

Dave

[joefarmer]

Were the tappets new when you put the cam in?

[Muddin_dude06]

Why did you pull the cam if you don't mind me asking?

[DBraunig]

Originally Posted by joefarmer

Were the tappets new when you put the cam in?

No, i reused the original tappets, and there appear to be fine still. I haven't removed them yet , but i can see/feel #1 cylinder easy and get a good look at #2 and #3 with a boroscope.

I checked last night as best i could for coil bind. The 60lb springs have that white paint mark on them, still intact and i cannot see any shiny areas where the coils would have touched. I never got a cam card, but i degreed it in, so i know what the specs are for the OE and on this cam. I may "simulate" the lift and then check for coil bind that way. This isn't a really big cam, intake lift is right at .450

Dave

[Muddin_dude06]

Random question, did you cut valve reliefs in the pistons for .450" lift?

[DBraunig]

Originally Posted by Muddin_dude06

Random question, did you cut valve reliefs in the pistons for .450" lift?

No, I degreed the cam in at install and i was .055+ ptv intake from 15btc through 15atc, and more on exhaust, this should have been plenty of clearance according to the people i checked with.

Dave

[joefarmer]

I'm kinda curious if the used tappets could cause this? If they were used to one cam and then had to adapt to another, could that cause the wear? Also, I'm thinking you'd want a minimum of .100" p-t-v clearance.

[Jim Fulmer]

Dave your clearence was fine, I ran my big cam with .042 clearence on the intake and more on the exhaust.

When I tear my 98' down I'll tell you what it looks like as I used the same lifters(except the broken ones) when I swapped back to a stock cam.

Sorry but I have a tough time sweating the small stuff like this, seems some vendors are just out to sell more stuff to put more money in there pockets.....yes I can be wrong too.

Jim

[RacinDuallie]

Originally Posted by Jim Fulmer

Sorry but I have a tough time sweating the small stuff like this, seems some vendors are just out to sell more stuff to put more money in there pockets.....yes I can be wrong too.

Jim

Times 2 Jim- you are not alone with that notion.....

[klincoln]

Originally Posted by DBraunig

Just like the title says.......

Cam has been in since 5-07 has about 5000 miles on it. The wear is only on the intake lobes, no damage to any of the exhaust lobes. All the tappets appear in good condition also.

what say you?

Dave

Lifter rotation: flat tappet cams have the lobes ground on a slight taper and the lifter appears to sit offset from the lobe centerline.this will induce a rotation of the lifter on the lobe. this rotation draws oil to the mating surface between the lifter and the lobe.WAS YOUR LIFTER/TAPPET ROTATING?

[klincoln]

In the new A.E.R.A mag it's all on cams it comes out 4 times a year just got the new one it good reading!! it's called engine professional.