So i snapped the crank in my 383.
11-20-2009, 06:56 PM
#1
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So i snapped the crank in my 383. We will get into how it broke later.
But for now, I'm pricing a new one.
What are some good suggestions?
I need a LJ 350 mains crank, 1 piece rear main, internal balance, 3.75 stroke, 5.7 rods.
Cross-drilled mains: Good? Bad? Pros? Cons?
4340? Cast steel? 4140? (I think) Which would be my best solution?
BTW: I was hearing no stranger noises. Driving to work, very casually. I came over a hill, and started to feel a vibration. BAD, then it was gone. Like 75ft later, I had to push the clutch in to stop. It was then, that I felt horrible shaking/clunks in my clutch pedal. THe truck stalled, I cranked it back up. I was making horrible noises, making 2lbs of oil pressure, and would not idle.
Luckily work was only 1/4 mile away, So I babied it along back roads and parked it.
Trailered it home, as I backed it off the trailer, my friend noticed that the balancer was bouncing around. I quickly backed it off the trailer. The balancer was WAY from being straight. So I pulled the belt off, and drove it into the shop. Then we dropped the pan, No metal shavings in the oil. But When I would "tap" the oil filter, silver oil was coming out. (guess it was doing it's job) lol
The crank snapped just in front of the 1 rod journals.
Pulled the motor out, and the first half of the crank also.
I feel CONFIDENT in saying that this is/was a defective crank.
As shown by the pictures, there is only a small amount of the crank that was connected. IE the shiny parts of the metal. The rest, I would assume should have been connected. (save for the oil hole)
It also rubbed the block/cap. But I'm not sure if it is bad enough to really worry too much about. The most I think it might need is line-bored.
Somehow my cam died?!?!?! The fuel pump cam is flat.
I checked all of the bolts figured maybe I'm a dumbass and put one it that was too long. NOPE, the fuel pump/plate bolts were from a kit. and the correct size.
Neither of the holes on the face of the motor went in deep enough to even see the push rod?
Weird.
I guess my next move is to contact Eagle and see whats up.
FML. LOL. I'm trying to keep me head up, keep telling myself this is all just a big excuse for a bigger cam.
But for now, I'm pricing a new one.
What are some good suggestions?
I need a LJ 350 mains crank, 1 piece rear main, internal balance, 3.75 stroke, 5.7 rods.
Cross-drilled mains: Good? Bad? Pros? Cons?
4340? Cast steel? 4140? (I think) Which would be my best solution?
BTW: I was hearing no stranger noises. Driving to work, very casually. I came over a hill, and started to feel a vibration. BAD, then it was gone. Like 75ft later, I had to push the clutch in to stop. It was then, that I felt horrible shaking/clunks in my clutch pedal. THe truck stalled, I cranked it back up. I was making horrible noises, making 2lbs of oil pressure, and would not idle.
Luckily work was only 1/4 mile away, So I babied it along back roads and parked it.
Trailered it home, as I backed it off the trailer, my friend noticed that the balancer was bouncing around. I quickly backed it off the trailer. The balancer was WAY from being straight. So I pulled the belt off, and drove it into the shop. Then we dropped the pan, No metal shavings in the oil. But When I would "tap" the oil filter, silver oil was coming out. (guess it was doing it's job) lol
The crank snapped just in front of the 1 rod journals.
Pulled the motor out, and the first half of the crank also.
I feel CONFIDENT in saying that this is/was a defective crank.
As shown by the pictures, there is only a small amount of the crank that was connected. IE the shiny parts of the metal. The rest, I would assume should have been connected. (save for the oil hole)
It also rubbed the block/cap. But I'm not sure if it is bad enough to really worry too much about. The most I think it might need is line-bored.
Somehow my cam died?!?!?! The fuel pump cam is flat.
I checked all of the bolts figured maybe I'm a dumbass and put one it that was too long. NOPE, the fuel pump/plate bolts were from a kit. and the correct size.
Neither of the holes on the face of the motor went in deep enough to even see the push rod?
Weird.
I guess my next move is to contact Eagle and see whats up.
FML. LOL. I'm trying to keep me head up, keep telling myself this is all just a big excuse for a bigger cam.
11-20-2009, 08:45 PM
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I have seen sbc cranks break where yours did several times, and were either eagle, cat , or gm cranks. not good when it happens, but that seems the way it goes with rhe china cranks............Scats machine work and quality control seems to be better, i can say , my engine builder won`t use eagle stuff , has a bad rep. with shops local to me. Scat lists 9000 series (cast) and 4340 cranks with the specs you need , if this motor is more street than strip that 9000 series crank will be fine, if it has alot of miles on it, what it will cost to resize the rods , scat makes a 4340 I-beam rod with 7/16 bolts, and are clearanced for strokers , rated for up to 700 hp, not much over $ 300 a set, either 5.7 or 6'', if it needs bored, go with the 6'' rods and get pistons to match. I have a set of these rods, crank to make a 406 for my 71 camaro.
11-20-2009, 10:41 PM
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The motor is in my blazer. Pushing 37" tires.
I have spun the motor around 6k before, I did some more research and yeah apparently eagle **** SUCKS...and they are notorious for breaking in the area much like mine did.
I have spun the motor around 6k before, I did some more research and yeah apparently eagle **** SUCKS...and they are notorious for breaking in the area much like mine did.
11-21-2009, 12:00 PM
#7
Buy a PBM 4340 crank. They are Scat cranks with a different name on the box. I have one in my combo and it works great. Same thing goes for the PBM rods.
Last edited by Rogue86; 11-21-2009 at 12:36 PM.
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11-21-2009, 09:58 PM
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on a note to the rods. I have the eagle I beam rods that came with my rotating assy, along with pistons to match.
They have less than 4k on them, So if they were not damaged I'm going to re-use all of them.
Forged was the route I was going to go, just need to settle on a manufacturer.
They have less than 4k on them, So if they were not damaged I'm going to re-use all of them.
Forged was the route I was going to go, just need to settle on a manufacturer.
