rebuilt engine question

[FuzzyDunlop]

Im looking at buying an older car, possible a 1981 Porsche 911 Carrera SC. Alot of the cars that catch my eye have a rebuilt engine in them. Now from what I have been told, or think I've been told, I assume that a rebuilt engine means the car has been abused and not taken care of at one point.
is this a correct assumption?
So my main question would be, would you rather have an older car with a rebuilt engine, and have the satisfaction that it is fixed and better.

OR

is is better/safer to buy a car that has never required the rebuild?

 

[IronWing]

Rebuilt engines do not necessarily reflect a lack of care. Engines simply weren't as well made and didn't last as long back in the good old days. Given the choice of two otherwise identical cars, I would go with the rebuilt engine (depending on who rebuilt it of course).

 

[FuzzyDunlop]

Rebuilt engines do not necessarily reflect a lack of care. Engines simply weren't as well made and didn't last as long back in the good old days. Given the choice of two otherwise identical cars, I would go with the rebuilt engine (depending on who rebuilt it of course).

how does it matter who rebuilt it? And wtf does it even mean to *rebuild* and engine?

 

[bruceb]

Most cars, especially the older one, engines were good for around 150K miles or so. Depends on design, build tolerances, how much and how often engine was rev'd to or near redline, oil changes and other maintenance. As to buying a car with a rebuilt engine, no problem. You may at some point, need to update the tranny or suspension parts, like bushings, springs, etc.

 

[Vette73]

Older porsches were not that good. Then add in it was air cooled and oils at the time were also not as good etc...

I would be surprised to find one on the factory build with any decent miles to it.

 

[SuperSix]

Honestly - if you have to ask what's entailed in rebuilding a motor - you shouldn't be looking at something like a used Porsche. No offense - but a used Porsche + seemingly very little mechanical knowledge is a recipe for disaster. You may be better off with a Mustang, Camaro, something that's easy o fix, with plentiful cheap parts, and tons of technical info online.

Mainly, a rebuilt engine has new bearings, piston rings, etc. The internal metal-on-metal parts that wear are replaced.

 

[JulesMaximus]

how does it matter who rebuilt it? And wtf does it even mean to *rebuild* and engine?

It matters greatly who rebuilt it. I'd hope the seller would have paperwork on that and you could research to see what their reputation is in the Porsche community. Old Porsches were notorious for various problems depending on year make model and engine. Some were better than others, some were horrible. You really need to do your research on these cars before buying one.

Rebuilding an engine would be removing it from the car and completey disassembling it and refreshening old internal parts with new parts and gaskets. It is very labor intensive and requires specialized tools and quite a bit of knowledge about Porsche engines and the peculiarities of these cars.

 

[drnickriviera]

Didn't the SC of that era have a problem with head studs pulling out? Could be the reason for all the rebuilds

 

[exdeath]

Um it's a 30 year old car, I would WANT a rebuilt engine.

 

[Bignate603]

Rebuilding an engine would be removing it from the car and completey disassembling it and refreshening old internal parts with new parts and gaskets. It is very labor intensive and requires specialized tools and quite a bit of knowledge about Porsche engines and the peculiarities of these cars.

Often it involves re-machining the cylinder bores and resurfacing them also.

Some engine builders use quality parts that meet or exceed the stuff that came in it from the factory. It's possible for a rebuilt engine from a good engine builder to be more reliable than the factory engine. Then there are engine builders that will do a lousy job and use crappy parts. Those engines can have very short lifetimes.

 

[5150MyU]

A good rebuild-and I'm guessing here-normal-not over doing it -5-6k.

 

[satyajitmenon]

A good rebuild-and I'm guessing here-normal-not over doing it -5-6k.

You guessed wrong. 😀

 

[Arkaign]

You guessed wrong. 😀

It varies hugely motor by motor 🙂

 

[SpatiallyAware]

Honestly - if you have to ask what's entailed in rebuilding a motor - you shouldn't be looking at something like a used Porsche. No offense - but a used Porsche + seemingly very little mechanical knowledge is a recipe for disaster. You may be better off with a Mustang, Camaro, something that's easy o fix, with plentiful cheap parts, and tons of technical info online.

Mainly, a rebuilt engine has new bearings, piston rings, etc. The internal metal-on-metal parts that wear are replaced.

+1


A 1981 911 is not a good car for you..

 

[Zenmervolt]

Older porsches were not that good. Then add in it was air cooled and oils at the time were also not as good etc...

The '73-'76 2.7 litre engines were horrible, yes, but the earlier engines were no less durable than anything else from their era and the 3.0 litre engines in later cars like the 911SC were pretty solid.

Still, as a guy I know says, old stuff is old stuff and an engine rebuild on a car from 1981 is a pretty good idea regardless of who made it.

ZV