Shoulda listened to Dad....again.

[bhunt31]

My dad told me the engine I built for my 69 wasn't going to last in my 84 Silverado Daily Driver...I didn't listen. Thought it would be ok, but the cam snapped in 2, shot the back 1/2 through the back of the block, shattered 3 lifters and came to an abrupt halt when the back 1/2 of the cam got wedged in the hole in the flexplate...sooo, tomorrow it makes the 75 mile trip back home and into the shop to get doctored up, just for fun since I have time, I'll take a picture log of the work on the truck we progress. This is the truck...


and this is the engine(it was dynoed at 472hp)


It was about time to play with something anyway, so time for the fun to begin!

[EAST SIDE LOW LIFE]

Sometimes Father knows best!

esll.

[1969k10stepside]

Darn,Guess you will have to give me the '69 shortbed then since the motor in that truck's going to keep you busy

[streetstar]

dang, what happened to it? i mean, what should you have listened to dad about?


let me re-phrase ---- what can we do to avoid breaking a cam in two? (i have a pro-mod car that makes over 1700 boosted horsepower and i have never seen this happen before)

[jchav62]

Originally Posted by streetstar

dang, what happened to it? i mean, what should you have listened to dad about?


let me re-phrase ---- what can we do to avoid breaking a cam in two? (i have a pro-mod car that makes over 1700 boosted horsepower and i have never seen this happen before)

Yeah, me neither! Stuff like that doesn't happen at cruise mode... We need some details... Nice looking truck BTW..

[sick69]

Originally Posted by EAST SIDE LOW LIFE

Sometimes Father knows best!

esll.

I have come to the understanding over the last 20 years (I'm 34) that he is USSUALLY right. On the same hand though we all have to learn he was right the hard way!!!!


Yes Yes we need details on how to break a cam in two and shoot it out the back of the block!

Especially considering the distributer would have to be moved out of the way for the back piece of the cam to move.

Well if your gonna blow it up might as well blow it up right!!!!!

Frank

[Pyrotechnic]

I actually don't think your dad was right. It should have lasted just fine. Seems like by coincidence, you had a cam failure.

Maybe the cam was shipped or handled incorrectly which caused stress cracks, that became bigger once it was in your motor ?

[72BlckButy]

Originally Posted by EAST SIDE LOW LIFE

Sometimes Father knows best!

esll.

[bhunt31]

Well, I was running a 292H Magnum Comp with solid lifters. The engine has about 8K miles on it the build and I have about $4K wrapped up in that skin. The story goes that I was cruising along at 60mph and about 2K RPM(th350, 3.73 gears). It was about 2 a.m. and I was heading back down to school after being off for the weekend(75 mile drive). I got about 1/2 way there and without warning, I heard a lifter tap start and by the time I thought..."Why is that lifter tapping out of nowhere" it went pop. Locked the engine up tight, had no clue as to what had happened, well I had it towed down to school so I could play with it while I was out of class, so I pulled the intake and valve covers off, found 3 pieces of a lifter laying in the valley, 3 others completely missing. I started looking at the rockers as the culprits and sure enough, one of the rocker nuts had backed off(worthless teflon locking nuts) and caused lifter slap and apparently through the solid lifters beat the cam right in 2. As for the back 1/2 of the cam releasing from the distributor gear, it apparently just turned itself out, cuz with the distributor out and intake off, I stuck my finger in the distributor hole and felt the front of the teeth of the cam gear right at the back of the block. I'll be sure to post pics up when I get it back up here tomorrow. I'm not gonna be able to keep my hands off it...haha.

[bhunt31]

Originally Posted by 1969k10stepside

Darn,Guess you will have to give me the '69 shortbed then since the motor in that truck's going to keep you busy

hahahaha, ohhhh, don't worry, the old girl's stashed away in a padlocked building where noone knows how to get to but me and a few other people.

[bhunt31]

Originally Posted by jchav62

Yeah, me neither! Stuff like that doesn't happen at cruise mode... We need some details... Nice looking truck BTW..

I wish I had been racing or hot-rodding on it when it blew, would've made a much cooler story...

[bhunt31]

Here's what's left of the 1 lifter that was laying in the lifter valley...

[jrb71c20]

Duuuuuuuuuuuuuuuuuuuuuude

[Curly86]

Like everybody says if you do it,do it right.

[68GMC454]

i think you did it right,,racing or cruising, you did a good job at breaking it....sorry to hear about it happening though...

[Ivan D.]

Originally Posted by bhunt31

I started looking at the rockers as the culprits and sure enough, one of the rocker nuts had backed off(worthless teflon locking nuts) and caused lifter slap and apparently through the solid lifters beat the cam right in 2.

I'd hate to be beating on the dead horse, but you should never ever install nuts with a nylon/teflon lockring anywhere there's heat present, heat will make it soft. In my engine I have all-metal locknuts, double-stacked too - rocker adjustment is a b*tch, but the stud is more likely to get pulled out of the head than the nuts backing out. I actually put those all-metal locknuts everywhere in my engine, they are Grade-8 and obtained through McMaster-Carr, we used them at work on every single bolt/stud that sees vibrations and I'm yet to see one getting loose. Of course most folks here would use poly-lock nuts (the tall ones with the allen set-screw inside them), those hold great too and adjusting the rockers is still fairly easy.

[smashingchuck]

I might add that this isn't the first time I've heard of a cam made by Competion Cam breaking in some way or another. I personally know of 2 others, one of which was mine.

[Pyrotechnic]

Screw in studs, guide plates, poly locks, and a quality steel rocker are you best bet for that caliber of a motor.

Don't ever get cheap roller tip rockers either. The pin the on the roller tip can slide out over time, which pops out the valve keepers, then the valve drop down...and it's all downhill from there.

[Hoods69BadBowTie]

Wow that suxs. Well I hope you can get it all fixed up and be out cruising again hopefully with no problems. Keep us posted if you get the chance.

[bhunt31]

Originally Posted by Ivan D.

I'd hate to be beating on the dead horse, but you should never ever install nuts with a nylon/teflon lockring anywhere there's heat present, heat will make it soft.

Yeah, I thought the same thing...don't ever let a buddy that knows less about engines than you do, talk you into doing something to your engine....

[bhunt31]

Originally Posted by Hoods69BadBowTie

Wow that suxs. Well I hope you can get it all fixed up and be out cruising again hopefully with no problems. Keep us posted if you get the chance.

Well, I was suppose to go pick it up today, but this day was full of lose. Got up late, spent 2 hours at the driver's license facility, then spent 1 1/2 hours waiting on my dad to come unlock the garage for me so I could get the ramps for the trailer...by that time it was too late to make the 150 mile trip to get it picked up...gonna try this again Sunday. In the meantime, here's a couple vids of that truck in it's glory days(when it was running)...

http://s119.photobucket.com/albums/o...Picture005.flv
http://s119.photobucket.com/albums/o...Picture004.flv

[bhunt31]

Glad to say after 150 miles and 3 hours, the truck is home...start tearing in tomorrow, will have pics tomorrow evening.

[jchav62]

That's a wild story. Good luck with your re-build....

[bhunt31]

Pictures from this morning, just preliminary ones, might go out after a while and start tearing in.

[bhunt31]

Well, pulled the heads and got quite a surprise. The entire engine is scrap now. Something went wrong in the bottom end and allowed 2 pistons to hit valves and 1 of them to hit the head pretty hard. I think it may have broken the piston and the cylinder sleeve, no telling what happened to the bottom end, but I have a feeling it's not gonna be pretty. Looks like it's time to go find a Vortec 350 to drop in it...