I'm a fan of the 403s but stuff does happen. Owner does a good job of explaining and picture taking. Imo.

https://www.tapatalk.com/groups/real...ld-t16955.html

 

Wow!!

 

It definitely tossed its cookies, but with a new bottom end, back in business.

 

He should have used a solid main web block

 

Just shows what happens when a 403 makes power with a manual trans, boom! Marvin is a good guy and his diesel build will go like hell. I am definitely staying automatic and not using a 403 crank to avoid this carnage.

 

Indeed.

 

...or a REAL girdle that ties into the pan rail.

 

Hmm...the same type of failure.




These two are from this site. I know it happened at least 10 years ago.
http://www.jsmachineoldsmobile.com/403CARNAGE.html

 

Yowsers !! That looks bad baby.

So this is the legendary catastrophic failure that may occur with a 1977-1988 Oldsmobile small block. When built and pushed, WOW.

Kennybill thanks for providing the link and thanks to Marcar for providing this information as a fair warning. With that said sorry this happened, but as he said he was definitely pushing its limits. 6000 + RPM shifts and 106 MPH in the 1/4 is brutal. This engine on its best factory stock day and setup was lucky to see 80 MPH in the 1/4 and likely was meant to shift around 4000 RPM peak... Marcar was doing this in a 3800 LB car. So his 403 was pushing close to double the factory HP, DOUBLE. He's lucky it lasted this long.

 

We could debate what came first, the chicken or the egg? If it had a 330 crankshaft, possibly this might not have happened. Only Dr. Oldsmobile knows for sure. (:•》

 

The 330, 350 & 403 all share the same stroke... I don't think it would matter much.

 

Forged crank vs. cast 403 could make a big difference if this is a crank failure that took out everything else..

 

Wow, that's a windowed block!!!!!