hrcslam

Well, after 44K miles my engine finally had a big failure. Camshaft broke in two just past the 4th bearing journal. Engine still ran, like crap though. No oil pressure, and I had to drive it about 5 more miles when it happened. I wasn't racing it either, when it happened. I was just cruising along at 1500rpm 45mph and the check gauges light came on, no oil pressure. About 30 seconds later I heard the lifters start clackeling away, dammit! No smoke, no leaks, no loud bang, just a complete loss of oil pressure.

I pulled the intake to check the oil drive gear. It's fine. So is the gear on the cam. I spun the oil pump by hand, it pumped. Then we turned the engine over and cylinders 7 & 8 valves were not moving. Crap. This sucks.

I tore the engine out and down. The rod bearings got a little hot, but no damage to the crank or rods. The main bearings got hot too, but didn't fair as well. The #3 and #4 main journals on the crank need turned down another .010" due to slight grooving. I'm also going to have the cam bores align honed and replace the bearings. I'll be doing a new oil pump with drive gear (Everwear). And obviously a new cam (billet this time).

Pistons and heads looked good, no valve damage. Cylinder bores are still cross hatched.

What are the concerns with turning the Crank down .020"? It's already turned .010". My understanding is that it's not a big deal.

Also, Any recommendations for a cam? LOL. I'll be calling Lloyd shortly to see what he says.

I'm open to suggestions, if you guys have any. Engine is completely torn apart.

BALLSS

should not be a problem on a .020 crank. You could buy a stock used one if you wanted. That would need either just a polish or .010

since it was a LE cam, discuss with Lloyd. I have seen cam lobe wipe out, not a cam break though. shiat happens

hrcslam

I called Arizona Speed and Marine to get some prices on the machine work. they want about $900 to turn and heat treat the crank and balance the rotating assembly, spec out the bearings and match them, align hone the camshaft and replace those bearing and the rear freeze plug behind the cam too.

I just e-mailed Lloyd. I loved that cam, it worked out so well. I could cruise at 65mph in 6th at 1500rpm all day, smooth. And it would pull all the way to 6800 rpm. I'm hoping he has something similar to it in billet this time.

SS RRR

iTrader: (2)

Why are you running the engine when it sounds like that?

hrcslam

Make sure it wasn't seized. Damn thing started right up. Figured I'd video it, just in case it did start up to capture what it sounded like.

SS RRR

iTrader: (2)

C'mon, man. You could have checked that by just turning the crank snout bolt.

hrcslam

I could've. Lol. It was a lot easier to use the starter. Those few seconds is nothing compared to the 5 miles it had to drive like that.....

The engine was already going to come out at that point. All I wanted to know was how hard it would be to tear it down. Check to see if it seized, and capture a video of it if it did run.

The only other damage inside the engine was the #3 and #4 crankshaft mains were slightly grooved.

LLLosingit

iTrader: (4)

Never understood this kind of logic, If you would have shut it down as soon as you saw the lack of oil pressure it would likely have been easier to fix.
Had way to many people bring me their vehicles and saying, I was close to home or I was going to be late for work yada yada yada then shocked that they caused hundreds if not thousands of dollars in damage that could have been avoided if they just shut it down and called for a tow.

hrcslam

I am the mechanic. Could I have saved the mains? Maybe. Probably. Was it worth the accident I could have caused? No. I'll be alright. I'm having more done to it anyway. And once you loose oil pressure to the point of lifter collapse the engine is getting torn all the way down anyway. At least by a good mechanic....

I am shocked the engine kept running. That the camshaft broke. And that only 2 of the bearings (not cam bearings) were hurt in the process. That's impressive to me.

350 groundpounder

iTrader: (5)

With my first engine build i got a cast custom cam ordered. Took one look at it and sent it back for a beautiful billet steel cam for an extra $75. Always billet for me !

NewOrleansLT1

Wow.. I wonder if that cam was dropped on the ground once before it was installed?? Hmmm

SS RRR

iTrader: (2)

Eh, for me I'd rather be on the safe side especially if it's clattering like that and there's no idea if that could be affecting the integrity of the block/journals. But yeah, your engine, your house, your rules.

83rdracer

iTrader: (1)

Is this a stroked 383. I have seen cams break as rods just touch the cam lobes and after a while the cam breaks. This happens with stock or I-beam rods where head of rod bolt is not ground down to give .080 or more clearance to cam journals.

just a thought.

Dave

Shownomercy

iTrader: (1)

Don't feel bad. I drove my car from mid track back to pits, stopping to check weight, with no oil pressure after drive shaft snapped. Bearings looked halfway decent too.

hrcslam

I didn't drop it. Not sure if it was dropped before it got to me.

Every situation is different. Where this happened is on a two lane road with moderate traffic where everyone is doing 45mph. No shoulders to pull over on. If I shut down I'd be in the middle of the road. People would try and pass into on coming traffic. And an accident would have happened. It happens everyday in this area.

I'd rather deal with a couple bearings than something way worse.

If this was on a highway or interstate, I'd pull over immediately. That wasn't a choice this time.

No, it's a 355. No contact between the cam and rods. No contact between anything that wasn't supposed to have it. And no excessive resistance or forces to cause this either.

It's strange. Lloyd said he's never seen one break for no reason. I can't find a reason though. Other than a casting defect.

I don't feel bad. I did what I felt was best. In this case, I risked my rotating assembly to avoid causing an accident. The damage wasn't as bad as I thought it'd be.

SS RRR

iTrader: (2)

LOL. I understand that completely. Had a flat tire in SE Washington DC at 9pm on a Saturday night and still had 5 miles to go. That tire was ******* destroyed by the time I got to my destination. I'm more referring to the vid is all.

KW Baraka

iTrader: (7)

I still can't get over a broken cam. Damn!

KW

BALLSS

me to...wiped lobe yes but break like OP's...never heard of that.

I know if dropped they easily break. Maybe a flaw in casting the cam core, maybe it took a punch in shipping and now just broke.

hrcslam

Yeah, I understand the logic. If it were a customers car, I wouldn't do it. But my car, my risk, my money, worth it. LOL.

Same here. Surprised the hell out of me. I didn't believe it at first. I checked the oil drive gear, then the cam gear, and spun the oil pump by hand (which pumped oil). Then spun the engine by hand. My brother told me the two aft cylinder valves weren't moving. I was like, uh what? No way. Broken camshaft. Dammit.

Looks like I'm rebuilding it.

Same here. Wiped lobes, toasted oil drive gears, but never a broken camshaft. It's an inch of solid metal! Something else has got to give first. So strange.

hrcslam

So I budgeted what it would cost to repair this. Wow. It adds up quickly.

Machine work is going to be $915+ Tax. That's for;
Cam bores align hone ($225), new cam bearings ($35) installed ($40) and rear freeze plug.
Crankshaft mains ground to .020" ($125), heat treated crank ($125), and balance rotating assembly ($225), with bearings matched crank and rods($140).

Parts needed comes out to $765.59 (the gaskets and rings are the exact same ones I was running already);
New Billet cam, complete gasket set, piston rings, oil pump with pick up, oil pump drive gear, Head Bolts (ARP this time, went RedLine last time, I don't trust to reuse them).

Total: $1540.59 with me doing the work.

That's pretty ridiculous really. I still can't find any other reason for this cam to break like that.