Technical BBC new camshaft failure (long story)

I put a .10 grove in the lifter bore to direct oil to the cam lobe. I don't know if it helps but haven't had a failure yet.

 

You put a nearly 1/8" groove in the bore ?

 

I think he meant .010. But either way would be tough in my shop/shack to groove it and not raise a burr. Interested in the technique used

 

Ball hone after grooving.

 

Sorry, meant .010 at 12 o'clock on drivers side and 6 o'clock on passenger side.
https://www.compcams.com/lifter-bore-grooving-kit-842-dia-std-chevy-dia.html

 

I can't speak for Brad Penn oil, but the comment about wax in the oil causing foaming, yeah, that's not correct. Wax crystals in crude oil are filtered out during refining, or are converted into high quality hydrocarbons via a hydro-isomerization process. Any wax crystals left behind after this will mainly effect the oil under very cold conditions, leading to thickening of the oil (what's known as the "pour point"). Foam in oil is caused by air entrainment, and motor oils are formulated with anti-foam additives which weaken the skin effect of the oil and should cause the release of air bubbles. If the oil is foaming I would point to failure of the defoamant additives, not wax content.

The symptoms you described sound like the viscosity is dropping under a heat load. I would suspect poor viscosity index, something that we easily can measure in the lab.

 

Grooving lifter bore with a file. (Skip to 2 minute mark)


Good video on checking lifter bore clearance


Comp Cams Top Ten Failure Reasons

 

And process to get the lay over out of the groove?

 

Does this Comp Cam lifter bore grooving tool have a way to just groove from oil galley on downward or does it groove top to bottom?
Seems to me that if the groove came all the way to top you would have oil squirting out the top as well as the bottom. However if there's a way to start the groove down at oil galley level it looks like a good idea to me.
I'm using the solid Comp lifters with the .012" hole edm'ed into the bottom, lobe contact face. No problems at all, but if you're building numerous engines that tool could save some money.

 

I'm just wondering why we never used this tool prior the recent cam failure epidemic?

 

I just pulled a Pontiac 400 apart a few weeks ago with a cam and lifter fail just like yours. All the right steps were taken. Both lifters worn, lobes gone, Mellings camshaft, unknown brand of lifters. I suspect cheap lifters since they wore way more then the cam did. Cleaned out the crude, new Mellings camshaft with Crower Camsaver lifters, Brad Penn oil and Redline camshaft lube. 1800 rpm for 20 minutes, test drove and sent it on its way. The Crower Camsavers are really nice lifters, looked way better then the ones that came out.

 

Egads.......Elcohaulic,Ericnova, and Ekimneirbo all in one post!

Since I mentioned honing lifter bores to remove varnish and it was correctly pointed out that dirt in the lifters was a major issue......and that honing could put grit into the lifter oil galley, here is a Summit video that talks about lifters and cleanliness and the fact that debris in the lifter is a major cause of failure.

My feeling in regards to Ericnova is that the oil galleys contain some debris/residue in the oil residing there. The honing should only take a few passes and minimal abrasive if any should be left behind. Carefully swabbing the area with a Q-tip or cloth soaked with carb cleaner/alcohol/lacquer thinner until you get a clean swab should remove any debris that might be in there. The alternative is to not do anything and hope for the best. Either way its a matter of deciding which chance you would rather take. Anyway here is the Summit video.

One last question. Have any of the people who have suffered a cam loss lately........have you disassembled the damaged lifters and looked for any possible clogging ? I still feel that non-rotation is the biggest problem.

 

Debris inside a hydraulic lifter is going to be a potential problem for seizing up the plunger travel and making a noisey lifter, but isn't going to impact cam lobe/lifter foot break-in. Grit in the galleys that can be pushed out around the lifter is going to be a possible issue for cam break-in, since that is a source for some of the oil that lubes the cam lobes, the rest is splash oil thrown off the rotating assembly.

i've not used a ball hone on lifter bores, I've always done just a sandpaper flapper, 240-320 grit on a split end 1/4" rod with a die grinder, done as part of the engine block detail process prior to cleaning.

I agree lifter rotation is the big key here, that absolutely needs to be happening, and the reason the cam is the first piece I put back in a fresh block.
Along with installing the lifters just lightly oiled, and then rotate the cam repeatedly in the otherwise empty block while observing and playing musical chairs with the lifters until all are rotating at roughly the same amounts....then they get removed and orientation noted and set aside for final assembly.

Cam comes back out for moly lube on the lobes, and the lifters get moly on the face when installed for the final time.

Since I went to this regimen, I've not lost a cam in somewhere over 20 installs...last one I lost was a Crane Fireball 302H in a SBC back aroud 1995 or so. Prior to always using the flapper from then on.

The last 3 engines have all gotten a lifter bore groove by way of the Comp Cams tool if using hydraulics....the solid lifter stuff gets Direct Lube lifters with the oil hole in the face.

 

IIRC it's only been around about 6-7 years now? Maybe 10 at most?

 

I have never used one. So while Eric seems to be very knowledgeable about this stuff, I wanted to ask about bushing lifter bores on a street engine.

Unnecessary? Would it help? Would it be easier to groove the bushings, prior to installation to cut down on debris?

 

The tool has a built-in stop on the bottom of it.
The tool is placed in the lifter bore from the underside/cam tunnel, hooked to the handle, and then pulled up into the lifter bore as it cuts a groove from bottom to about 3/4 to 7/8 of the way up the bore....not fully out to the top so it doesn't create a upward leak.

The cutting head part actually looks list like a mushroom lifter or old Ford Y-block lifter....with a slot in the side and a carbide insert commonly used in lathe cut-off tool holders fastened in the slot with the cutting edge sitting about .008" proud of the OD of the tool.

 

I do not know....I've never bushed a flat tappet engine nor a street engine, just had it done on race solid roller stuff once, and that was due to worn bores creating too much clerarance. Had I known more at the time I'd have just had the iron bores reamed and honed to .874" Ford size rather than brass bushed back down to .842" Chevy.....

 

Thx for the info. Now that you have filled me in on upward cut, I see how it works, and can see that it is a good solution to increased oil to cam lobe/lifter interface for hydraulic lifters. Same as you I believe the face hole in the lifter is preferable for solid lifters.

 

Bottle brush,and soapy water.Followed up by a blast of brake cleaner.This is the kind of project that gets done BEFORE going to a machine shop for cleaning/machine work.

 

Actually I made a flapper just like that and agree that it would be better than a ball hone.......I just figured almost no one would have one of those. A three finger brake cylinder hone would probably work well too as there would be less tendency for the edge at the oil galley to knock abrasive off . I definitely agree that the flap type would give the best results.

For what it would cost to do the lifter bushing machining you would probably be better off spending the money to upgrade to a roller cam and lifters.

Howards makes a lifter that has a groove incorporated in it. Here are some pictures of a finished groove and a Howards lifter.



The problem as I see it is that no matter what brand of lifter anyone uses, or whether they groove the bore or use a grooved lifter.........everyone of the manufacturers still has cams and lifters that fail during break in. The additional oiling MAY occasionally provide enough assist to prevent ruining a cam, but I doubt that it really helps any if a lifter isn't rotating. I think the regimen that EricNova follows is an excellent way to avoid initial start up problems. Then the additional oil flow from the groove or grooved lifter or EDM hole in a lifters bottom surface helps provide a long life and resist higher spring pressures.Insuring that your lifters do in fact rotate freely when installed (as EricNova does) is the best way to insure a successful installation.

 

That groove stops short of the bottom of the lifter, seems like it wouldn't contribute much additional oil to the liter/cam interface.

 

Here are some pictures of some tools you can use to remove the varnish in the bores. I couldn't find my "homemade" sandpaper flap. It must still be in that special place I always put things in......so I know I can find them later. So I substituted an aftermarket one. I like the homemade one better because it is more compact and just uses a piece of rod and a couple of screws. It'll turn up soon.
Anyway, you can get small flap wheels that will work and also the head porting buffs if you have any laying around.

 

My guess is that there are two reasons the groove doesn't go all the way down. One it doesn't need to because the lifter extends below the lifter bore when in operation. The second reason is that it would make the round edge of the lifter have a sharp chisel like shape that would damage the cam. Thats what I think their logic was in doing it this way.

 

Hopefully it doesn't tick like a Rhoads lifter..

 

Just pulled a cam out of my car that shows signs of failure too add to the thread. Goodwrench 350, originally had a small Crower hyd. in it, .432"-.456" with stock springs driven for years and did fine. Put a blower on it, slightly bigger Summit cam, .444"-.466", lapped valves, installed stock diameter Erson springs and ditched the exhaust rotators. Box for springs is long gone but pretty sure they are around 100#s seat, 300#s open? Installed them at recommended height. Used black moly lube on cam and lifter faces, oil on bores, Valvoline 20W50 VR1, prelubed and started right up running 2000 RPM for 20 min.

Current cam has been in car for 4 years and over 7,000 miles. Lifters all rotate fine and no signs of any mechanical interference in valvetrain. Only ever had one cam fail before and was probably because of the stock diameter H11 tool steel .600"+ lift springs that came in the heads I bought. Thinking it might possibly be a harmonics or spring issue this time rather than break in because in 3 or 4 of the still good lobes there is pitting or tiny fretting marks at the very tip of the lobe. Lifters all still have some crown on the face even though some lobes are as much as .070" shorter.

Pics in order, sorry about the quality. Lifter damage corresponds with condition of lobe. Hard to see but lobes 1 and 3 have tiny hammerlike dimples on the tips, 2 has pitting and 4 is rounding over. About half the lifters look like #4 and the rest are smooth and polished. And maybe 3 lobes fairly pristine. No bias toward intake or exhaust, right or left side. Was also in a light car and saw 6,000 RPM here and there, think the limiter was set at 6200-6500.

 

I assume they are new lifters..........what brand? Did the engine get up on the rev limiter at any time? How much extra travel is available in your springs when at full lift ?

 

Just lost one cam lobe on the 283 in my 39, haven't pulled it apart yet. The motor was fresh, but had over 2000 miles on it, with no sign of issue. Its a Melling CS113R cam, 097 replica grind, with Comp solid lifters. I had just check the valve lash and adjusted accordingly before taking off for NC. 90 miles into the trip, it started ticking bad on the freeway, pulled off and pulled a rocker cover, found #5 intake loose as a goose but the ply lock still real tight. I thought for sure I was in the clear with 2000 miles on it. lost just one lobe, all the others are still tight and in spec on lash. Has anyone else seen one flatten out with that many miles on it after breakin? I thought that was supposed to be pretty quick if it was gonna wipe????

 

Damn Jason, that really bites. Sorry to hear that. Yeah, I also thought if the cam was going to be wiped it would happen prior to 2k miles. Sure screwed up a trip too, eh? Bummer.

 

Usually happens in the first 5 minutes....bummer

 

Jason, just a thought brought on by your mention of ply locks as I had noted in your social group post pics.
Does this engine have screw in studs or pressed in as often found in a stock 283? A pressed in stud pulling out will loosen the rocker up big time.