stephenmsweigart

Bought 1970 454 nom and have discovered bad bearing and rod. I have not really had any run time on the vehicle since purchase and it was making no noise during the test drive. Now with loud knocking noise at the back of the engine, the mechanic dropped the tranny and oil pan and says that someone replaced 1 piston and now has bad rod and bearing. Why would someone replace just one piston if the engine is torn apart. With that in mind, I was told that the engine would need to be rebuilt. My concern is if bubba did the engine work, what other short cuts did he make that I will only discover down the road. I do not know what a rebuild will cost......would it be better to get a crate since its not original??

jnb5101

If the block and crank are magnafluxed and don't show any damage, rebuilding the engine with full machining of block and crank, reconditioned rods, new pistons, cam(hydraulic flat tappet) and chain, bearings and oil pump should be about $3K (depending on where you live and the size of your mechanic's house). This won't be a Dyno Queen, but after it's tuned properly, it will spin the tires in a rolling 1st gear punch. Lots of fun on the street!

ddawson

It should be cheaper to rebuild it plus if done at a quality shop be better then a crate motor.

I went with a 496 rotating assembly and shop went though everything. Internal balanced and went though the heads.

I went roller conversion as well for peace of mind as a flat lope means starting over.

Easy Mike

No disrespect, but how do you know Bubba did anything? Someone apparently replaced a piston, but that doesn't mean Bubba did it and the engine was not necessarily taken completely down.

The choice of rebuilding what you have or swapping is up to you.

96 lt-4

Cheaper for a seller to do a "fix" than a full rebuild is one way to look at it.

Nothing wrong with doing a rebuild or a swap.Comes down to what you want out of it and your budget?If numbers do not match then build what you have as you won't be paying extra for parts you already have(block,crank,heads,etc.).
Now is the time to ask yourself what you want out of it and what you have to spend.Consider the added costs of upgrades as well.Hyd roller cam would be worthwhile.

stephenmsweigart

Yea Mike your right.....shouldn't have called him bubba cuz I didn't realize I would be disrespecting anyone,,,,I was only trying to find out what the seasoned owners would do in this situation. The mechanic I had said he didn't understand why only one piston would be replaced when it is torn apart.....yep might of just been someone wanting to get the car running to get rid of it......don't know......just looking for advice and I realize that the choice is up to me....thanks for your help.


steve

Jebbysan

One piston is usually replaced when a cylinder is damaged and sleeved.
Not uncommon to me.....

Jebby