I have 454 with about 200 miles on it. I just pulled the Comp Cam 280H out of which 2 lobes was toast and 2 others looking bad. I can't say it's a bad cam because I think I am running too much spring pressure but to get to the question, My engine builder suggested that I pull the motor and clean it out and check the bearings. But I am not really that motivated about pulling it out after I just put it in. I did drain the oil no signs of metal in the oil, I have changed the oil in it twice before. I cut the oil filter open and check the paper no signs of large metal shavings but it did have a light metalic/gray look to the oil trapped on the filter paper. So what do ya'll suggest throw the new solid cam I got in and run it or spent the weekend hiding out in the garage and pull it back out? :confused: thanks David

Bummer. The metal that is not on your cam is in your engine. Yank it. Only way to go back right, clean everything and start over.

i think the "grey"is the metal that has allready worked its way around,ie:bearings and journals,its just real fine now..
pull it and protect your investment!!
shane

I know how you feel. I wipped a lobe at the beginning of the year. My case was a little more server, because I found large metal chunks around the head bolts. I would go through the engine to be on the safe side.

better safe than sorry. and do yourself a favor, get a roller cam so you don't have to go through that again. i had the same problem with my 454 and i did everything per the instructions from Crane, still wiped several lobes, and screwed up a couple of pushrods, and this was just in the first 45 minutes it was running. there are alot of 454's from the mid 70's that are just cam eaters because the lifter bores are not right from the factory. i have personally seen 2 like this and have a friend who has seen at least a half-dozen, he was the one who enlightened me on this problem. he runs truck pulls and that is all he's ever run are 454's, he's built dozens of them.

I lost a cam years ago and it made a mess. Had to have the crank reground and really clean the block and pan. I'd pull it and tear it down unfortunately.

I'd inspect the oil pump for sure, if the filter was doing it's job the bearings should be ok but you can bet the oil pump was scarred after chewing up all those cam shavings.

Also when you're inspecting the oil filter element/paper, remove the paper from the filter and wrap it in some rags then squish it in a vise, the trapped oil will get collected in the rags and when you remove from the vise the paper will read like a book showing everything very well. I do this on every oil change, any problem will show up-good piece of mind.

I hope this isn't off-topic too much.Has anyone ever had success with those flat-tappet lifters that positivley feed oil to the lobes?
These are the lifters that have a small EDM hole on the flat side.
I sure like the idea,& would think that it would really cut-back on wiped lobes. :rolleyes:

Originally posted by headerfire:
I hope this isn't off-topic too much.Has anyone ever had success with those flat-tappet lifters that positivley feed oil to the lobes?
These are the lifters that have a small EDM hole on the flat side.
I sure like the idea,& would think that it would really cut-back on wiped lobes. :rolleyes: We prefer to use the Comp tool that puts a groove in the lifter bore to oil the lifter but it needs to be done when the block is being machined.
The EDM hole lifters seem like they should work well but this is a perfect place for a hi volume pump as you are adding 16 new "oil leaks" to your system :D
They will drop the hot oil pressure.
I have only used them once when a customer brought them in with his cam.
So far so good,,,, but I don't seem to have much cam trouble anyway so I can't really say they are any better or worse except for the oil pressure deal.

Am I gonna have to worry about this when I start up my 350 or is this just common on 454s? :eek: :confused:

Ditto the above - pull it. It sucks, I just did the same thing in August - lost #6 exhaust lobe on my Comp XE-274, with 2,000 miles on it :mad: . I'm glad I tore it down though, good piece of mind. Incidentally, the crank was a little scored - might've gotten away with a polish, but I opted to cut .010 off. Good luck, I know how you feel graemlins/sad.gif .

David, pull it otherwise you'll wish you had. graemlins/sad.gif

Jim

We prefer to use the Comp tool that puts a groove in the lifter bore to oil the lifter but it needs to be done when the block is being machined.Is using this tool something recommended by Comp Cams ? If so, could this be one reason some cams are getting wiped (not grooving the bore)?

My 454 is going to the machine shop in a few weeks. Should I have them groove the lifter bore with this tool and where would I get one? :confused:

This hits home on a topic that has been here many times before and is a point of debate. M71 states it clearly, I have also found this to be true not only of 454's but also 402 blocks. The lifter bores may have incoreect geometry, either from factory machining or heat/cool cycles. Hev to check to cam and lifters installed in the block for lifter rotation preferably before going to the machine shop. The following procedure was recommended to me, I have tried it and it is somewhat reliable. Temporarily set the cam and lifters in the motor lubed only with 30 wt oil. Do not install pushrods, timing chain or anything that will cause pressure on the lifter / cam contact. With the lifters sitting in the bores, turn the cam be hand. The lifters should rotate in the bores if the geometry is correct. If they do not rotate, go one step further and try honing the lifter bore slightly. If you do not get lifter rotation from all lifters, the block will need lifter bore correction. This can be easily done for about 350.00 [bushed and remachined to stock diameter]. There are a lot of these cams that are failing, however, many are working fine. I tend to think, many of the more common cams are not tolerant of a marginal condition and need near perfect geometry to survive. A roller will certainly make up for the lifter bore geometry problem, but technically, the roller will not sit perfect on the cam if the lifter bore is incorrect to start with. Your call on pulling the motor. If it was me, I would pull the pump and a couple of rod and main bearings for inspection just to be sure. Cam wear over 50,000 miles is minute, cam failure at 500 miles is catastrophic.

I don't buy all this factory bad lifter bore talk. First of all we have to realize that these engines for the most part have at least 100,000 miles on them by the time we get a good core block to build. Many of them are still running when pulled with the factory cams and lifters. There will be if anything an imperfect wear pattern in the bore but there is no way I can see the lifters being too tight in the bore unless there is a diameter variation from the factory specs. How can a bore get tighter with 20 years of wear on it. I'm not saying that there aren't lifter bore issues from pushrod geometry and years of wear, I just don't believe that it is a factory defect. I think if most of us were putting stock parts back in there would be very few cam failures.
We have a tendency to buy a bunch of parts that SHOULD fit together and work O.K. and I think that too much gets taken for granted. Look at the posts from Bill K., Mike (wolfplace) and the other professional machinists / engine builders. They have drastically fewer cam failures than the rest of us part timers. When we stick high performance after market parts in, failure rates go up.
Oh yea, I forgot with my rant, pull that thing apart.

Bob I think your right on a lot of your points but I am beginning to think we are putting inferior parts in our engines than what the stock parts were as far as hardness and such. I would yank that engine apart and not even think twice about it. My brother had a 282S that done the same thing in his 396 so it is not just the 454 or 402's. I think we are making a lot of excuses about our blocks being bad and the such. I just can't see lifter bores tightening up after years of use. If anything they would be larger and out of round. In the old days just lubing a cam & lifters up with STP was good enough for me and had no failures. I also think with the cam companies tinkering around with the opening and closing ramps have made it worst as well. Just my .02 . Fire away at me guys.

I think you guys are right on. If you look at the lift on todays cams it's higher than the big boys of yesteryear. An L78 cam had .520 lift with a longer duration than the XS282S. The XS282 is running .590/.598 lift. The cam companies are making faster ramps and to go with it stronger valve springs. These things combined with manufacturing quality and break in procedure (I'll bet some of the guys aren't removing the inner springs) seem to be causing alot of lobe failures. The interesting part is it seems to be alot of CompCams on the XE/XS series. It may just be because they seem to be one of the most popular cams so there's alot of 'em out there. I have an XE274 in a punched 396 and I can't seem to get the tapping out of it.

Larry, did your brother have any problems with piston to valve clearance on the 282s? What kind of pistons is he running?

BOB&LARRY
I build a lot of circle track and street performance engines in the Northeast as far as cam trouble I've been lucky in the last 3 years on hydraulic lifters I use GM p/n 5232720 with zero problems,I ask for a p-55 core which is a performance cam core.As far as flat tappet I was using Eaton lifters till I ran out and now I use the Schubeck lifters with no problems. I use Manley p/n 40199 lube on cam and lifters and have the engine primed ready to start as soon as it starts get it to 2500 rpm.This seems to work for me.

There is a shop near me that lost at least 15 cams on the dyno just to find out that the liftes from crower were junk and most of these engines had lifter bores corrected to .875 so that tells me that correcting the lifter bores didn't help. I correct the lifter bores when the rules allow me too but the lifter bores I don't correct there seems to be no problems.

yes the the cams today are very agressive and break in is very important as is using good componants

Go a head guys fire away.

I found out early on reading CC's great big cat. that anything past about a 280 Magnum cam IS more a special high performance OR race cam!!

This tells me right off that problems may occur due to exessive spring presures generated by extreme lifts AND short seat timing events!!

Why do you think I keep mouthing about the good old CC 268HE and 282S cams??? Sure I may still have trouble, but I figure my chances are better with them then the newer, more aggresive cams!!

You know GM wasn't just playing with itself when they made the old -097 Duntov and the -151 and L-78 cam mild by todays standards b/c most of them suckers will go, what 100,000 miles!!!

pdq67

The lifter bore problem has nothing to do with sizing, it has to do with where they are located in the block & Big Blocks in paticular are noted for having them mislocated.
With stock cams & mild hyd & solid cams this is not as much of a problem.
The major reason to relocate the lifter bores is to correct cam timing not to correct for cam wear although this is a side benefit on some blocks as they can be off enough that some lifters will not rotate correctly.
we do a lot of small blocks & I have had some that would not correct going from .842 to .875 they were so far off.
The big deal with this is you do not have the same cam timing from cylinder to cylinder so when you go to all that trouble to degree #1 cyl to within one degree don't blame the cam grinder when half the rest of the cylinders aren't even within 5 degrees of number 1 :D
I have had customers bring in cams thay said were ground crappy & when I put their cam on my Cam Pro Plus stand & check each lobe & it's within a degree of advertisied it then becomes very obvious what's wrong. ;)

Oh yeah,,,,,,,,pull the engine & clean it :D

the more lift the more the geometry gets out of whack. and it has nothing to do with Comp Xtreme Energy cams. all the problems i know about which have happened on 8 different engines, happened before Comp even had the XE series. and yes the inner springs were removed on ALL of the engines i know about. the guy that told me about it was a machinist for over 25 years, he showed me how it affects the geometry. it has nothing to do with wear or lifter bores getting tighter. lol!
it's a geometry problem, which causes a flat tappet lifter not to be able to rotate in the bore, because of the angle that the pushrod is pushing on it. with low lift or stock cams the problem is not noticable. the smallest cam that i know of was a .550/.575 hydrailic flat tappet cam while the rest were all solid flat tappets of more than .600 lift.

My smallblock experienced a wiped lobe January 1st, 2003, on the way home from work (about a 120 mile drive). It happened while sitting at a stop light just 5 miles from home. I drove home, diagnosed the situation, and ordered a solid grind the following day, to be shipped overnight.

Left the engine in place, swapped the cam and lifters, changed the oil, and followed the SOP for break-in. I've driven the car over 15,000 miles this year without any trouble.

So, if you absolutely have to, it's OK to swap it without yanking the engine.

Seems to me in an ideal situation the best thing to do is pull the engine....

But beings that the Chevy V8's have most likely had more cam changes then most all the other engine types put together....Well just thing about how many cam changes have been made since 1955....it's a huge amount.... I would be willing to bet that a large majority of people who lost cams never bothered to pull the engine and clean/replace parts...they just swapped cam and lifters and went on thier way..... A guy I know who doesnt have much in the way of money lost the cam in his 1978 Chevy that had 255,000 miles on it...he replaced the cam/lifters/timing chain ect and now has over 300,000 miles on the origional 350.... Still running deciently....Another guy lost his cam while breaking in a newly freshened up engine...swapped in a new cam/lifters and has been driving it for 3 years now ( dont know the miles ).

If you dont pull the engine I would at the minimun use a magnetic oil drain plug and change the oil and filter often so try to flush any fine metal particles out of the engine .... Maybe even sacrafice a few quarts of oil and pour them in and let them run straight out the pan to hopefully flush and little metal particles laying in the pan..

Either way...Good Luck.

RPOL78 we did not have any problems with the piston to valve clearance it had more than enough. We only checked one cylinder though and I did not see any dents on the pistons or any marks on the domes on disassmebly. He sold everything dirt cheap after we seen the crankshaft. The oil had a silver tint to it with lots of glitter in it in the sun. So it wasted it.

I got a question. These engines were machined with machines I assume and the lifter bores were probably not drilled by hand. How come all of the engines are not the same(screwed up that is)? Take a 1977 454 block for instance wouldn't all of them be off the same or just on Fridays? :D

The speed shop I deal with also don't even pull the inner springs for cam break in anymore because they still lost a bunch of them on the dyno. They say with a big block Chevy it is a 50-50 chance on a flat tappet lobe or lifter failure.

So far I have installed 4 good ones and one bad one. So I have had better luck. I know the next time I install a cam I will probably go with a hydraulic roller just for peace of mind. If it wasn't for the break in I would stick to a flat hydraulic because the hydraulic roller performance compared to a flat hydraulic is not worth the money difference.

A good friend of mine suggested polishing the lifters with crokus sp? cloth to remove the machining marks. He has no cam failures. I did it with my last motor using an extreme energy 4x4 grind without problems. Does anyone else out there do this?

I can attest to having a cam go bad. 7 Pulls on the dyno and it was done. When it started to decrease in power we stopped.

The bearings looked like the had 75,000 miles on them and the piston skirts were metal impregnated. It is one of the most sick feels I've had in a long time.

If the builder would of told me they set up the spring pressure at 148 pounds I would of done a single spring brake in. Reguardless, it is the only way for me here on out. The stuff cost too much money to do it twice.

Good luck! Do your self a favor and yank the motor! It will be less hastle in the long run. Besides, you going to tell everyone that you have a new motor and they will be expecting a lot. Oh ya, my rings were leaking 18% after the 7 pulls. No matter what you do you're not going to impress anyone with a motor that can't hold cylinder pressure.

JIM