Okay. I'm stumped. 54BOMB came in today with a weird running condition. after some tinkering, I pulled the dizzy to give it a look, and discovered the drive gear is WASTED. the Distributor is an Accel unit, and the motor has less than 1500 miles on it. cam is a comp, which are typically good cams...i.m.h.o... so here's the funky. The Cam itself has a little wear, but nothing out of the ordinary. the dizzy gear looks like a roller cam had attacked it for many,many miles, but not evenly. they get thicker in some places, and much thinner in others. anybody know what the heck happened?
whats the dist. gear made from? If it's steel, it's a steel thats softer than the cam and it got ate because steel doesn't like to rub against steel, it causes gauling (steel stack-up) which QUICKLY causes moving, meshing gears to go straight to hell in a hand basket. The cam survived, and I use that term loosely, cause it was the harder steel. The cam is also junk! Don't try to re-use it. Unless you polish the cams gear and make sure it's to specs, don't trust it.
From an old Car Craft article-"A new camshaft is a work of art-until it eats your distributor drive gear."It goes on to recommend always running the drive gear of the cam lightly against the wire wheel on a grinder to remove any imperfections on the gear,I always do this when I install a cam,but haven't heard of anyone having trouble until now.I don't know if this what happened to your distributor but I guess it's possible.
it's a steel gear-and a hydraulic cam. Shouldn't need a bronze gear. it's an Accel Billet distributor. I have never been in love with Accel stuff, but never had a problem like this (bouncing timing and crappy spark, yeah...but nothing like this...) as far as the cam is concerned, I can't see enough of it to say what it really looks like...What I can see doesn't look that bad...but I can only see about a square centimeter of it anyway. it probably won't be reused, but it's not my desicion to make.
Had that happen to a BBC 396 twice in less than 600 mi. Final conclusion by Crane Cams was to much oil pressure. The distributor shaft couldn't turn the oil pump as fast as the cam was turning the shaft. Took the motor to a pro builder and they claimed the crank had been ground just a hair off kilter and we didn't catch it when we put the motor together either time. So the crank was reground and they put it together that time. It had 22,000 mi on it when I changed it out for the 454. Pull the motor completely apart and have it hot tanked as there will be pieces of shrapnel throughout the block. Don't even think about reusing cam, bearings, etc it's not worth it.
I don't know anything about this motor...could be the problem (I thought about the oil pump, but My olds runs high pressure/high volume stuff and didn't wipe anything out in the last 10 years-on a stock shaft at that-so I doubt the pump is it...then again, I could be comparing apples and bowling balls.) I agree on the teardown, but I don't know how 54 is gonna feel about that suggestion,either.
I would think you would blow the oil filter up before pressure was high enough to strip the gears Larry
I have heard that said, but I have also seen MANY billet cams run on cast gears for a loooong time. but the likelyhood of this cam (comp 292h) being billet is right around finding rocking horse poop on your boot.
or twist the heck out of the shaft...or break the end off of the drive...I agree. I am leaning away from the oil pump being the problem.
yeah, apparently, they either added too many bicycles, (or perhaps not enough) to thier steel mixture that day.
i have ahd the same problem on an fresh rebuild found that the bolts on the timing gear came loose and the cam was walking front to back just ate the dizzy gear for lunch i would turn the it over with the starter and look down the dizzy hole and watch it while its turning over see if its moving front to back just a thought
I had one do the same thing, even from down here 12000 miles away Accell was helpful. My customer bought the parts from somewhere stateside and the shop that assembled his engine didn't check numbers etc, I can't remember the exact details and I didn't do the new rebuild , but it was fixed and my customer didn't have to pay, it only came to me for tuning. Accell tech..... 216.688.8300 ext. 500 8:30 a.m. and 5:00 p.m. Mon.-Fri. EST Technical Service Mr. Gasket Company 10601 Memphis Ave. #12 Cleveland, OH 44144
The oil pump wasn't the problem, the oil pressure on this motor was enough to peg an 80# gauge when cold so I don't know how much it acually was. When the motor was put together the last time it still ran a high pressure/volumne pump and never had the problem again. Ran every thing the same as before except for the crank regrind. I'll tell you I was nervous at the 300 mi mark for the 3rd motor
I bought the whole engine package complete, the guy was going to use it in his project and then ended up in a divorce and had to sell it, I assembled the engine but it was already machined before I got it, all the parts were new and the previous owner had never fired it up. I had changed the timing cover a few weeks ago ( it was leaking oil ) and didnt see any wear on the inside of the previous cover. I have never had luck with the accel stuff before but since it was new I just decided to run it. when I put it together the first time I didnt have anything strange with the timing gears or the cam install, it all went together normal. It also ran great up untill today, I assume this was just because it took a while for the wear to be bad enough to let the dizzy move back and forth out of time. I will call accel on monday and see if they know why, Id like to just put another dizzy in it and see, but thats a gamble at best. I dont like to admit it but I think the cam is walking, but if thats true whats causing the dizzy gear to wear like that, wouldnt the cam movement just chew up the whole gear not just one side? Its a melling (sp?) oil pump stock replacement style. Strange.
It is possible for a HV oil pump to "eat" a cam gear, though it's not as common as is thought. I'd say it's more likely that the distributor is seated too far into the block (fairly common on aftermarket dizzys); or there is excessive cam walk. One other remote possibility, that I've seen once...is that the builder got too cute with oil control & failed to provide the distributor gear with enough oil; reciprocating assembly windage won't do. Or, the builder intended the engine to be used for very short duration use (i.e. drag racing) & planned the oil control accordingly. The Accel-supplied gear & the hydraulic cam gear should be compatible. EDIT: since you assembled the engine, I guess you'd know about the drainback plugs, if any. Exceesive cam end play can damage the gear, & it's not in an even pattern....lots of reasons why, but the short answer is, the gear often looks more worn in some places. If it were mine, I'd pull the engine & at least clean everything & use new bearings. Sorry, man...
I had a Unilite dizzy gear get chewed up in my 57. The cam was a Crower cam.. the mill wasn't running up to par and the timing was moving around.. so after i exhausted all other thing's, i pulled the distributor and found my 'gift'.. After researching the problem, i found the dizzy gear was wasted..along with my bearing's at that point.. I had to rebuild the motor..and buy a new crank all because of that!! Still have no clue why it happened. Tony