Rebuild/Restore an engine from a flood car?
 

A neophyte question for the experts; I had an idea about buying an engine & gearbox from a salvage flood vehicle as a project - meaning the plan would be that I would take it apart, and restore it - is this really a dumb idea, or do these engines end up getting rebuilt and reused?

It would most likely be a water pumper M96 or M97 with a manual gearbox, if that has any bearing on things.

It all depends how much flood water. I did one years ago that had water in the exhaust but never got inside the motor.
Most of the time, there is just two exhaust valves open at a given time.
Top of the motors are sealed on the SCs and Carreras.
The water coolers, I know nothing about but should be close to the same.
Bruce

OK, thank you Bruce. I guess I would go under the assumption the engine was submerged - i.e. water in the airbox

Huge gamble especially if any amount of saltwater is in the mix, unless you can buy for pennies on the dollar I wouldn't do it.

I believe those engines need some specialized tools that are not exactly cheap. So,as another poster stated unless you can get it dirt cheap I would steer clear.

I did a similar thing years ago. 2.0 911S BIG MISTAKE. The car was found with no air cleaner top fitted and left outside so it filled up with rain. It ended up having 6 pistons and barrels.I had to literally use an angle grinder to cut the barrels off the pistons.They were rusted together. Also needed new oil pump, crankshaft,intermediate shaft, 2 conrods,most of the valves,all the springs and finally 2 new lovely Weber carbs. Hugely expensive.

...and also with the M097 (and to a lesser extent the M096) engines there's also the very high risk of having to sort out the bore scoring issues on 4/5/6 bank, where there's inadequate cooling and oil flow on the upward thrust direction. There doesn't seem to be a huge amount of correlation between the problem and car model, but some have suggested more prevalent in tiptronic cars and their propensity to pull away in 2nd and load the engine at low revs. Also more of a problem with Carrera S models. How do I know? My brother bought a very nice 997.1 C2S 3-4 yrs ago, so between us we did a crazy amount of homework in addition to my previous ownership of various 996's. His car had the Hartech fix applied to 4/5/6 (by Hartech), immediately before the vendor sold the car to my brother. They're widely known to have the best fix for this (certainly in the U.K.), Baz Hartech having done a LOT of r&d into the problem

Then there's the IMS issue (but entirely preventable if rebuilding the engine; 3 different IMS bearings were used, so the fix depends on the type originally installed).....and cracking #2/#5 bores on the early 3.4 M096's, cracks leading to hydraulic'ing.....and as mentioned above, the plethora of rebuild tools that you'll need. Personally I wouldn't touch it with a barge pole

I can't imagine that if the motor had been completely submerged for any length of time that it would be salvageable. The only chance of it being rebuildable would be if it had not been under water for very long and immediately after it was pulled out it had all the water flushed out of the crank case and cylinders.

I have had two motors that had corrosion in the cylinders just from being pressure washed before going to storage.

OK - well that takes care of that idea! I appreciate the comments, will look for a non flood car for an engine. Thanks to all

I think, to be fair, if you want to really go "at it" and build a nice spec motor, there are fixes that can be applied, and of course, plenty of aftermarket stuff to build into it...but I can't see you ever getting your money back on it, it'd be a great project for your own car, but as far as a profitable exercise, I can't see it unless you're productionising it.