Totally disgusted - flat cam

[GASoline71]

Originally Posted by Jaysonb

I plan on putting in a cam this winter, and this has worried the heck out of me. My buddy just had 2 lobes go flat in about 200 miles, ruined a fresh big block in his trans am. What is the cost difference in going with a roller set up?
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You're going to drop about $250 on the cam, and about $300 on the retro-fit roller lifters. These prices are on the low end of the spectrum.

Gary

[prostreetC-10]

A lot of it does have to do with the core the cam is cut on.

[prostreetC-10]

Originally Posted by GASoline71

You're going to drop about $250 on the cam, and about $300 on the retro-fit roller lifters. These prices are on the low end of the spectrum.

Gary

Very low end and you also have to factor in the correct springs. Hot rodding tends to have a snowball effect on your checking account. Just because one decides to go roller, that doesn't mean all your problems are over. Spring pressure is critical on a roller cam. Go too light and the lifter will bounce on the lobe. When your lifter bounces, so does your valve. Go too heavy and you'll ruin your lifter. You might have to address your dist gear. You might have to upgrade your timing cover so you can correctly set end play because that cam will want to walk. These are just some of the reasons why not every guy on this board is not running a roller.

[GASoline71]

It sure does snowball... when I first got my '72, I was gonna be an intake and carb swap only... That turned into a $5,000 Small block!

Gary

[BigRed76]

Originally Posted by prostreetC-10

Very low end and you also have to factor in the correct springs. Hot rodding tends to have a snowball effect on your checking account. Just because one decides to go roller, that doesn't mean all your problems are over. Spring pressure is critical on a roller cam. Go too light and the lifter will bounce on the lobe. When your lifter bounces, so does your valve. Go too heavy and you'll ruin your lifter. You might have to address your dist gear. You might have to upgrade your timing cover so you can correctly set end play because that cam will want to walk. These are just some of the reasons why not every guy on this board is not running a roller.

Any references for correct spring pressures for roller setups?

Or should this be left to a machine shop?

[prostreetC-10]

I certainly wouldn't leave it up to the machine shop. I'd leave it to the cam people. It can get a little tricky. A SADI core can take a lot of pressure but not as much as a steel billet. Then you have the lifter. Is it the enclosed .700 wheel or an open .750 wheel. My lifters are Morels that run about $600 by themselves. Solid rollers take a way more pressure than a hydro. My hydro roller has 170 seat and 485 open pressure. You try to run that on an enclosed lifter and you will probably kill it over time. It's a decent size cam at 248/262 @ .050 and .665/.612 lift. A lot of these shelf cams will see 140 seat and 350-400 open pressure. Other things come into play as well like installed height. The same spring can vary depending on what height the valve is.

To clarify: To me you have machine shops and then you have engine builders that also run a machine shop. The guy that's doing my 496 machine work is Gray's Racing Engines in Tigard, Or. I am driving 3.5 hrs away for him to do my work and there is a NAPA machine shop about 1 mile from my home. Make sense??

[LEEVON]

I read a very convincing somewhere from a guy who had direct dealings with cam suppliers and the manufacturing side pointed the finger at poor quality and in particular a very large and very bad supply of lifters from a major source. These things could have been made years ago and are still being sold. I've heard the ZDDP story again and again, which makes sense when your talking thousands of miles or the total life of an engine. But it seems like in the last few years you can do everything right and destroy a cam on break-in, even with break-in lube and oil. That can't be the result of simply a missing additive, but poor quality parts. Metals aren't what they used to be across the board, cam and lifter manufacturers are not immune. My money is that Comp and others know this all too well.

[prostreetC-10]

You certainly need to at least hit up who you got the cam from and try to get your money back. Even if it's $150....that's a start.

[Eddie H.]

Originally Posted by LEEVON

I read a very convincing somewhere from a guy who had direct dealings with cam suppliers and the manufacturing side pointed the finger at poor quality and in particular a very large and very bad supply of lifters from a major source. These things could have been made years ago and are still being sold. I've heard the ZDDP story again and again, which makes sense when your talking thousands of miles or the total life of an engine. But it seems like in the last few years you can do everything right and destroy a cam on break-in, even with break-in lube and oil. That can't be the result of simply a missing additive, but poor quality parts. Metals aren't what they used to be across the board, cam and lifter manufacturers are not immune. My money is that Comp and others know this all too well.

I agree completely. It is more of a quality control issue than an oil additive, or break in issue. If a cam manufacturer uses high quality cores, grinds and hardens them correctly, the chances of lobe failure are minimal. I remember in the old days, everybody ran flat tappets, and nobody seemed to worry about proper break in procedures or special additives. We would throw in a new cam and lifters, fire it up and go, but that was when steel was made in the USA instead of imported from China.

[Horsman]

Originally Posted by Eddie H.

I agree completely. It is more of a quality control issue than an oil additive, or break in issue. If a cam manufacturer uses high quality cores, grinds and hardens them correctly, the chances of lobe failure are minimal. I remember in the old days, everybody ran flat tappets, and nobody seemed to worry about proper break in procedures or special additives. We would throw in a new cam and lifters, fire it up and go, but that was when steel was made in the USA instead of imported from China.

You hit the nail on the head...CHINA.

[tipshep]

I had similar probs with my 327. Big Blocks are more prone to cam lobe problems. I use Brad Penn, works. I know there is a coating company out there that will apply a coating, they say you don't even have to do a break in (additve, nothing under 1500 rpm for 20-30 min) and will warranty your cam and lifters.Saw a blurb in Hot Rod, or Pop. Hot Rodding, should be able to google cam coatings, anyway, much cheaper than a roller.

[GASoline71]

I think it's across he board... not more prone to Big Blocks. It's not just Chevy's that are having the flat cams either. All engines... running flat tappets.

Gary

[SSC's76]

I wont buy another comp product. I've only had one cam ever go flat and it was a comp 268 xe in a sb. broken in per directions and lash was checked after break in. the engine made it 700 miles and 3 lobes were trashed. I've never had a problem with a cam before or after that of course I never used a comp cam after that either


Posted from 67-72chevytrucks.com App for Android

[SSC's76]

Originally Posted by SSC's76

I wont buy another comp product. I've only had one cam ever go flat and it was a comp 268 xe in a sb. broken in per directions and lash was checked after break in. the engine made it 700 miles and 3 lobes were trashed. I've never had a problem with a cam before or after that of course I never used a comp cam after that either


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forgot to mention comp ate that one


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[prostreetC-10]

Originally Posted by SSC's76

I wont buy another comp product.
Posted from 67-72chevytrucks.com App for Android

It's interesting that the general public loves them and yet real race engine builders won't touch their stuff. Hmmm.....master marketers??

My comment is from actual builders telling me this....not hearsay.

[GASoline71]

All the good race engine guys I know won't use any Comp products.

Gary

[Eddie H.]

"Good marketing". That pretty much explains it. Unfortunately, it is very easy to sell an inferior product in mass quanity to an unsuspecting public, as long as you have good marketing.
Some other names readily come to mind such as "split fire sparkplug "TheTornado" various bogus "fuel mileage boosters", a multitude of "snake oil" additives, and the list goes on.

[prostreetC-10]

Just look at all they have to offer VS the other guys!

http://www.jegs.com/c/Cams-Valvetrai...10707/10002/-1

I heard they are working on some other really innovative cam products such as:

The XR "lawn shredder" for Briggs and Stratton

The Magnum "massive driver" for golf carts

Also the "compress this beotch thumpr" for upright air compressors.

[GASoline71]

LMAO!

Gary

[SSC's76]

Originally Posted by prostreetC-10

It's interesting that the general public loves them and yet real race engine builders won't touch their stuff. Hmmm.....master marketers??

My comment is from actual builders telling me this....not hearsay.

I'm not sure if it makes a difference but that issue happend when I had the shop. Comp tends to take things a little different when you say you are calling from a shop and they are dealing with an actual mechanic. Im not sure if they think your going to go after them for a new engine or just a cam and labor. I was so unhappy with this product but all i wanted the customers money back for the cam and lifters. I can say the pushrods were ok I did re use those and they were comp. All I know for sure is I have never had an issue with a crower, isky or a melling cam.

[prostreetC-10]

My cam is a Bullet Cam.

[Horsman]

Well, I was wrong...cam is not flat and the lifter appears fine.

See the pics...the pushrod end at the top is mushrooming, the opposite end at the lifter side is normal, ball shaped. This is why I kept having to adjust the #4 intake valve twice in 560 miles.

Now here's the dilemma...do I replace all the pushrods with some new hardened heavy duty ones and move on down the road or completely disassemble and start from scratch again? (See the chunks I found in the head, also some smaller ones found in lifter valley, see pic)

The pushrod just forward of this one looks suspect also, like it is starting to do the same. Part failure or something else going on?

[LONGHAIR]

Wow, I haven't seen that in a while...and never in 500 miles. What kind of rockers?
BTW, I would always up-grade the pushrods on a BBC, the geometry/angularity is a bit quirky

[Horsman]

Comp Magnum rockers with the roller tip.

The pushrods cam from Comp also.

Any ideas?

[Eddie H.]

It looks like their pushrods are no better than their cams. (Probably made in the same Chinese factory).
I would suggest cutting open your oil filter and inspecting for metal before going any further. If it is clean, change the oil, install a magnetic drain plug to catch whatever chunks might find still their way into the pan, new push rods, and drive it.