BBC- post timing chain disaster

hey everyone, here's a Q for ya. I am in the process of making a deal on my first set of wheels, a '48 chev PU. pretty excited . anyways , I wasnt to concerned about the motor condition because I was planning on dropping a new or remanufactured SBC in there and a manaul tranny. but as I found out and was somewhat pleased about is the motor in there already is a BBC with a 350, but, and I have a big but, it is a post timing chain explosion. I am wondering if it, in your opinion, would be worth rebuilding it after such a failure. right now it is missing a camshaft and hasnt been ripped apart after the damage so I am not sure the extent of the damage. would you sink in your money , or start fresh. what might a rebuild of this degree cost in parts , and maybe labor (I know its hard to speculate but a best guess for budgeting might help)?
thanks
ian

 

.....rebuilding a BBC is always worth it. Stay away from those belly-button SBC. A BBC will fill that space up nicely in a p/up.

 

If it was truly a timing chain failure, I'd say go for it! The valves will be shot, and possibly the heads (guides at the very least), and you'll neeed new pistons. In theory though, the block/crank/rods should be good, and it has all of the other accessories, so why not?!?

 

thanks guys
can you reccomend a good manual tranny to go with it?
ian

 

BBC have a habit of tearing up the front of the block brhind the timing gear. This is due to a hi-po oil pump and the resulting drag forces the cam rearward and tears up the block . It can be machined off and a Torrington style bearing can be used.

 

Did the timing chain actually break? I have seen them slip, but if it actually broke, you better find out what made it break.

If the cam is missing, my guess is the cam broke and took more parts with it. If it happens to be an early 396 make sure it has the correct cam bearings installed (early 396 took special cam bearings). If later bearings were installed it might starve the cam of oil and possibly seize / break it.

Either way, if the block/crank/rods are still good I would build the big block. Keep in mind that BBC are more expensive to build than a SBC, but you cant beat that torque!

Check the casting numbers here www.mortec.com to see what you have.

As far as 4-speeds, I am running a Borg Wanner Super T-10 behind my 454. A good rebuilt ST-10 will run about 600-800 bones. You could use a Muncie too, but usually they are more $$$

 

The valves definitely will not be hurt because of a broken timing chain, that's bullshit!

Shoe

 

[ QUOTE ]
The valves definitely will not be hurt because of a broken timing chain, that's bullshit!

Shoe


[/ QUOTE ]
Ok then smart guy.... Lets say these valves are open, and the pistons halfway down the bore... The timing chain breaks, so the cam stops.... those valves are STILL OPEN, only now, the piston is at TDC... Sure they're bent to fuck, but they have no feeling, so I guess you're right, they aren't "hurt"...

 

I beleive the motor is a mid 70's 454 . I will have the block magnafluxed and inspected and see where to go from there , thanks for the advice everyone
IAn

 

[ QUOTE ]
The valves definitely will not be hurt because of a broken timing chain, that's bullshit!

[/ QUOTE ]

???

worst case scenario the entire motor could be toast.

let's say the chain broke at 7000 RPM, what would NOT be "hurt"?

Paul

 

the guy I am buing it from seems to know what he is doing with respect to rods, so I am assuming since he went to the trouble to bolt up the engine and transmission , that he knew the engine was repairable- at least.
ian