I have a very strong 383 now. After 1 year of complete crap I am getting this this tuned in pretty nice. However after 310 miles it thrashed my transmission and this happened.....











Why does this happen?

Its a new 383 with ALOT of power. Not trying to sound cocky or nothin but you could probably help me better if you knew what I had right?

Anyway, If I get an SFI approved flywheel would this help? Could it be the transmission that broke the flywheel when it went out?

Please help

 

I watched the fluid damper as the engine was running and it looked perfectly smooth. The engine feels real smooth and shows no sign of bieng misaligned. Anybody?



BTW this was a brand new flywheel from kragen.

 

your 383 the one in your sig with 634 rwhp? the broken flexplate is a fairly common problem on anything with some power. i've broken them on others in the same spot. never have broken an sfi approved one though.

 

The sig I made was just B.S. The 383 has alot of power but I dont know how much yet. I made that sig as a joke for the internet racers

With the nos this 383 should be making around 750ftlbs once everything is worked out.

 

The engine wasnt broke in but I raced it 2 times

Once against a Ducati motorcycle (probably not the really fast one) in wich I think I would have won if my trans had been working and against a high 12sec (street trim) 63 nova SS I won by 4-5 cars. I wasnt using my slicks. I'm wondering if the SFI flywheels are going to work for me or if the transmission going out caused more stress on the flywheel.

 

if you check your trans, you front pump is probably broken due to the broken flexplate. likely the flexplate caused the transmission failure.

 

What causes this to happen in the first place?

And what the hell do I do once I get slicks and use my 200rwhp shot of juice?

 

The flywheel never spun freely. So the torque convertor still spun. Why would the front pump go out?

 

An incorrect or misaligned starter will do that to a flexplate. So will loose tranny-engine bolts. Look into the starter though, it needs to line up right with the flywheel and have the correct gap in the teeth.

 

in the process of that breaking, it can cause movement side to side of the torque converter and break the inside of the pump especially under higher rpm breakage.

 

The first flywheel on my 327 did that also, in the exact same spots. I thought i was alone.

 

Are your dowel pins in the block long enough? Are those the
correct flywheel bolts ?

 

The 400 crank in a 383 is externally balanced. Unless you balanced it with the stock 400 flywheel, and an after market balancer, it will vibrate excessevly. That vibration is a good bet on the killers of your tranny, and flywheel (stock 350?)

Those are also signs of a poor clutch. Sorry man, both of the fixes wont be cheap! Because either way, your new flywheel is going to have to be balnced with your crank, rods, pistons and balancer out of the block and at a machinists, not to mention a new tranny.

Sorry.

 

Naw, it's a flexplate, not a flywheel...clutch is probably still okay.

If there wasn't a vibration for the past year of tuning, we could assume all was built correctly to begin with.

 

Another thing is to have your converter checked, see if it balooned any..which would put stress on that area. Probably a good idea to find a solid point to pry on and see if there's too much endplay on the crank now. If it happened "all at once" you're probably okay, but if the TC has been pushing for awhile from balooning, could be an issue.

 

Good point! But was it built corectly?

Also, I think it is a pretty good bet the engine will have to be dissassemble the engine to be alligned with the flywheel.

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So it was the flex plate that was broken? or it is the flex plate that was doing the breaking?

 

I've seen several flexplates broken like that before. My friend did it once while I was in the car. He had the car in first at ~25 mph, then let off untill ~15 mph, then floored it to 30 mph and BANG, broken flexplate.

 

If there's no crank or thrust damage, no need to pull the engine apart. There's really nothing that can be done within the engine to align a flywheel/flexplate....it's done externally via the dowel pins in the block/bellhousing mating...effectively you now move the tranny to line up to the crank centerline.

But you do raise a very good point, what caused what to break. And I think that was the original question

 

Actually, the breakage pattern is fairly common. I had an 85 blazer that blew the flexplate apart in the same area. (and that was completely stock) Pick yourself up a heavy duty flexplate, do what you have to for the tranny, put it all back together, and you should be good to go. The factory flex plate were certainly not intended for a high performance application, hence, they fail when it is least convenient. (of course, I have never seen one break while you have the engine on the stand, when it would be really easy to fix........ LOL)


Have fun