Rebuild engine with rust in coolant, worth it.

[kickdheney]

I've got my old engine sitting here and I've been thinking of rebuilding it. Had a lot of rust in the radiator and coolant passages. I don't want to rebuild something that isn't worth it. What do you think?

 

[icanfixall]

The rust will not have anything to do with a decision to rebuild or not rebuild and engine. all the rust is "boiled out" during block cleaning. Usually all the expansion plugs are removed so it can escape the flushing on the block. What decides if and engine is worth rebuilding it condition. Even cracked heads or blocks can and have been rebuilt by repairing the cracks. Its expensive and takes plenty of time and talent to stitch a crack correctly. If a cylinder is cracked or really worn it can be sleeved. All 8 of my cylinders were sleeved.

 

[Hydro-idi]

Hot tank it and get it inspected. I’m sure it’s a good candidate for a rebuild.

 

[onetonjohn]

I can only speak for a 6.9 rebuild. For that, I would avoid rebuilding the early casting number block with the potential to crack at the block heater. I would also run the later 6.9 heads (again, check casting numbers) that are less prone to cracking. My guess is that you will spend close to 4K when all is said and done, so I'd start with the best base you can. There is lots of information on this forum. Quick search about the blocks cracking around the block heater and the early 69 heads cracking should give you what look for to identify them. As said before, have it hot tanked and inspected so you know what your working with.

 

[Macrobb]

The early 6.9 block, though, if not cracked should be fine to rebuild... just put a plug where the block heater usually goes and install a lower radiator hose heater instead.

The other question is how much rebuilding really needs to be done - most IDIs just need a new fuel system, some need new rings, and fewer need a full rebuild.

 

[IDIBRONCO]

The early 6.9 block, though, if not cracked should be fine to rebuild... just put a plug where the block heater usually goes and install a lower radiator hose heater instead.

I completely agree with this. If it's not cracked, it won't just wake up in a bad mood one day and decide to crack. You could even use a block heater and just not plug the cord in to it. Most of the cracked blocks are repairable and would be fine to use. Just because this spot was cast a little bit thinner, that doesn't mean that the rest of the engine is weak.

 

[Duke57]

The rust will not have anything to do with a decision to rebuild or not rebuild and engine. all the rust is "boiled out" during block cleaning. Usually all the expansion plugs are removed so it can escape the flushing on the block. What decides if and engine is worth rebuilding it condition. Even cracked heads or blocks can and have been rebuilt by repairing the cracks. Its expensive and takes plenty of time and talent to stitch a crack correctly. If a cylinder is cracked or really worn it can be sleeved. All 8 of my cylinders were sleeved.

Do sleeves wear the same as the cast metal of the block or longer? If you know?

 

[Macrobb]

Probably wear less, because sleeves are steel.
7.3s may need sleeves, 6.9s have a /lot/ of meat to bore out. Can be bored .060" over if needed.