[66geeto]

Well to say the least, this has been the worst week of my nearly 21 years of existence on this planet. I have been working on my 66 gto since i was fifteen putting any reasonable money i could make (started sweeping the shop floor in a local body shop when i was 14 and they couldn't pay me so they tought me what i could learn and bought parts for me) and last weekend I finally had the chance to break the cam in and hear it run. After 4 min at about 2000 rpm i heard the most awful noise ever. the motor wouldn't turn afterwords, I removed the spark plugs to find that the number 7 piston does not move in the sleeve as i turn the engine over (got it to turn it turns freely now but it can't make a full revolution). So i'm assuming the machinist didn't torque the last rod cap. Which is beautiful. #s matching 389 block for my car and it is bored over to the 400 specs so there is no bore left on it if it's messed up. I would give more details but I am not going to tear it apart until my machinist comes and sees the whole set up....(oil in the pan water in the rad. i put top end on ok.)
He gave it to me as a balanced shortblock and assembled it from there. I don't think the rod could have snapped, can a stock pontiac rod be that soft? and if it messed up my original block how much money am i out in the long run so i have a few more bargaining chips when i call tweedle dumass.

[66geeto]

I apologize for the spelling errors but i'm a little worked up and in a hurry at work. Taught = tought.
And what i mean by how much money am i out i don't mean replacement parts i mean how much is the value of the car decresed with a different (probably 400) block in there than what is supposed to be.

[GTOGreg]

Sorry to hear about your misfortune. An original #'s matching motor in a car can make several thousand dollars difference in a GTOs value. Just guessing but maybe $8-10K?

That said, you might be able to sleeve the block if it is scored (at significant expense, but for an original motor might be worth it). But who's to say that it did anything to the bores? It might be a scored crank, do you have any metal to go undersize? A set of new mains and/or rods and you're back in the game. If it is toast, the next best thing is to find a date coded correct block (typically manufactured within a 3-6 month window of your vehicles production date and matched for your HP/trans combo) and reuse your existing heads. A date coded correct vehicle is still very valuable to the numbers guy.

Good luck dude.

[chiphead]

Another excellent example of why to pitch the stock rods on the trash. The pontiac rods do suck that much. For every engine that runs 12s with stock rods, there are 10 that do what yours did. The stock rods can and will let go suddenly, for no good reason. I've seen stock rods go out-of-round, and let go, at low engine RPMs. Of course you should have had the rods re-sized and reconditioned. Did you? The machinist should have at least checked the health of all 8 rods on build. Did he?

You may never know what the failure was. All you're gonna find is a bunch of chewed up metal in there. Unless you find clear signs of loose rod nuts, the oil pump fell off, too tight bearing clearances, or other obvious issues, its gonna be a finger-pointing contest.

If you're lucky, you can save the block. If it indeed threw a rod, I'm sure all the internals are smashed. One good note, I had a friend who's 400 did about the same thing. The internals were smashed, but the block could be saved. Just had a thumb-size chunk out of the bottom of the cylinder wall, which wasn't a problem.

good luck

chip

[Peckels]

For a rod to leg go with that little of run time has nothin to do with the qaulity of a pontiac rod and everything to do with faulty assembly and machining . Pontiac rods dont break for no good reason. They work perfectly well for there intended application. People love to blame the rod instead of there own incompetance

[chiphead]

I agree that it would be highly unusual for a "good" rod to let go. But to me, a rod that is 40 years old and has millions of cycles on it is rendered suspect. IF it has weak factory rod bolts, or is out of round, or out of balance, or the beam is twisted, it'll do damn strange things. If the rod wasn't resized with new bolts and balanced, its a crapshoot. Of course I could be off in left field, an honest teardown should tell something about what came loose first. But like I said, often they look like a bomb went off in there. Did it spin the bearing then snap the rod? Do the other bearings look OK? Did it spin the bearing because of improper crankgrinding or too little bolt torque, or because the rod was out-of-round or the rod bolts streached? Lots of chicken-and-egg here.

Sure, I've had stock rods live in a P-350 to 5800 RPM. And I've also seen them exit my buddy's 400 at 2100 RPM. Your results may vary.

[form406]

i know stock rods...it didnt even make noise...it just stopped...

[INJUNTOM]

with all due respect, you really don't know what happened at this point.

did the engine come with the oil pump on it? was the oil pump shaft installed?

from past experience, i would refrain from finger pointing until you find out what happened, and what kind of assistance the guy will be giving you. i have seen things happen to engines that were no fault of the builder's, and when all the slamming is over, the customer ends up S.O.L. because he has already pissed off the builder.

i'd nicely let him know what happened, find out what really happened, and the cause - then find out what he will do for you.

if things don't go well, THEN get bent

[Mr. P-Body]

InjunTom is absolutely correct. Caca passa... Before pointing the finger (which ever one you choose to point), be sure where you stand.

If the rod nuts are still tight on the bolt, and the bearing is chewed, clearance or oil starvation are the likely culprits. If there's no serious damage to other cylinders, measure the clearance there. Chances are, it's "typical".

If the clearance appears to be correct, the oil pump or oil gallery plugs would be the next place to look. If the front gallery plugs are gone, this CAN happen, toot-sweet. Technically speaking, the missing plugs would be the resonsibility of the short block assembler, but it's also the job of the "final" assembler to check all that stuff. NEVER ASSUME... That is, check, double check, and then, when you're satisfied all is well, CHECK IT AGAIN!!

Let us know what you find.

Jim

[Half-Inch Stud]

Sooo, what was the oil pressure reading during those 4 minutes?

[66geeto]

Ok, Thanks for all the responses and i realized reading them that i was too vauge in my first post(s). But thanks for not ignoring this thread, as it is very important to me. Ok responses:

Greg: thanks for you quick reply and estimate, Hopefully sleeving the block won't be something i have to look into.

chip: I am definetly thinking about looking into eagle rods now, but college $ i may not be on the road for awhile....I don't see how a rod could fail without there being another factor at 1800 rpm on the first time it is fired unless, it is bright purple when i install it or has a visible crack. this machinist was paid to turn the crank and rods, balance the assembly, and recondition the rods. They should have been good to go. especially for it not being a "race motor"
Again, I'm kind of a craps shoot here b/c i can't open the motor until he gets here. thanks again for you input.

Peckels- Right on. I don't see any reason for a rod to let go at 1800 when it has 4 min of run time. Even if the rod was "weak" It would take one made out of brass to do that. I suspect that the rod cap wasn't torqued on as this is the last cylinder on the bank, ie phone rang and he came back and thought he did them all.

form406- ANTI-PRODUCTIVE!!! I don't need to see those pictures!!! lol

Ijuntom- that was the plan, the guy is pretty nice and pretty laid back I am just worried cuz it's my baby. he has done many 350 chevy race motors for my buddies, but i don't think he ventures into too many ponchos. Anyways I was gonna be super polite about it b/c I did alot of assembly on it too. although i don't see how any of the parts I installed could have anything to do with it.

p-body-thanks and we shall have to wait to see.

1/2 inch- my dad was behind the wheel and informed me of 55-60 lbs the whole time even moments before the shot heard round the world.

thanks guys. josh.

[slowbird]

How did it sound when it was running? Please keep us posted with what happens next.

[66geeto]

open headers masked any internal sound i was focusing in rather intently right before it went thinking i was hearing a ticking. But i just don't remember and it could have been something irrelevent and i may not of heard anything. My dad was screaming to me rpm numbers with his head out the window and i had no idea what he was saying we had to write on the dust on the windshield. long story short, how did it sound when it was running? deafening.

[convgto]

Sorry about your loss, I hope you have better luck with your machinists than i did mine. See my thread.http://forums.maxperformanceinc.com/...d.php?t=463812

[form406]

sorry about anti-productivity...you wont know what happened until you open it up...good luck...hope its fixable...

[Ryche400]

Sorry to hear what happend. BUT, I never break in an engine "open header". I always want to hear whats going on. I even fabbed up some shorty mufflers I bolt on to the collectors with about a foot of pipe that I use all the time if the car has no exhaust. Keep us posted. Id like to know what happend.

[Thumpin455_GTO]

I am home in York Ne right now. If you end up needing a crank I have a spare. PM me for a contact number. I could drop it by any time between now and Tuesday next week.

[Batman]

Did Pontiac stamp VIN's on 66 blocks? If not then it's not nearly as devastating to the vehicle value if the block is severely damaged, which hopefully it isnt (fingers crossed).

You're doing the right thing waiting for the macinist to tear it down.

[tom s]

were the rods pressed or floaters?I froze a engine on a breakin one with a bad press fit.I have heard of it taking out a engine when it happens.Tom

[chiphead]

If the rods were stockers, then it'd be a press fit rod. I'm curious to know what killed this one.