Well my old 383 finaly said bye bye Sunday. CAT crank broke right behind #4 main bearing, got out of phase and #7 piston hit the valve, came apart, and blew out the side of the block right at the oil filter housing. Dumped all of my new mobil1 and lucus stabilizer, but I got it off of the track, with just a little on the track itself. Came apart right at the 60ft mark. I'm really superised it lasted as long as it did. 5 full seasons, and 2 1/2 of them the car was run in 2 classes. The cam wasn't even scratched, couldn't believe it. Taking all of my 406 stuff to the balancer thursday evening. Really conserned about running a cast steel crank now that I've had one break. It had to have been cracked for a while, cause there are some spots that look like there polished on the outside of where it broke. I was amazed the the eagle sir rods were still on the crank after all that. #7 rod is bent almost double and still spins on the crank. I hope the Eagle crank I've got work as good as their rods.

 

Were you running a power adder?

 

So, it was a C.A.T. crank?Or a Scat crank? My machin shop(a verry good one) told me the CAT products were JUNK.

 

Yep the CAT stuff is sub par. I have used a scat cast 9000 seires in a destroked 400 made 380ci worked great car at 3400 lbs went 11.10s to 00s on motor pump gas and 9.70 @ 140 on spray. never had a proublem with it.

 

Yes C.A.T. , I don't know about the inferior part. To what? oem? How many oem cranks have you heard of lasting 5 seasons? No power adders. My cars short times run 1.34 1.36 if the track is preped. With 14.5 32 and leaving off of a brake, I thought it did rather well. That crank only cost me $144.00 with the bearings delivered to my door 6 years ago. I had more in the cam and lifters than I did the rest of the short block. And they're still good, and going in another 383. Going to build another low budget 383 for a back up motor just as soon as I get this 406 put together. My son and I both race, and both of us are running Ultra bells so we can swap engines anytime we want. He is running a Pontiac 406 in his 4th gen bird. I have an Eagle cast steel crank for the 406 and the 383. Been buying parts when I have the extra cash. Almost forgot, I shift at 6800 and trap at 6600.

 

Thank you for the reply. That is why I have been a little uneasy about running a cast crank and PM rods to maybe 7000rpm. So I will just go with an all forged rotating assembly.