engine life, are rebuilds inevitable? Options

[MiddleMan]

I'm in the market for a 914 and have a few under consideration. Something I'm wondering is, is there a rough estimate as to how many miles (or years) the engine will go before it's likely to need a major overhaul? I realize there will be lots of different experiences out there, but on average does it seem more reasonable to buy a car with a rebuilt engine (possibly w/ increased displacement) vs something that is relatively low miles but untouched?

I suppose the same question could be asked about the transmission...

So many things to consider in addition to rust! (IMG:style_emoticons/default/biggrin.gif)

[orange914]

my .02c

over 2056 cc seem to strain tings excessively

depending on quality of rebuild parts used, i.e. mahle vrs. generic cylinders ect...

you hear about original well maintained engines going 200k+, rebuilts not so

good luck to you (IMG:style_emoticons/default/smile.gif)

[johannes]

On the Mittelmotor website, there is a testimony of a german guy who bought a 1.8 new in 1975 (the carbed one). He drove 350.000 miles before the first rebuilt. http://www.mittelmotor.de/content/informat...asp?articleID=9

[Dr Evil]

The main factor is care. You can destroy an engine in few miles if not cared for. Low miles and untouched is gonna cost more, but depending on how low the miles, the engine will need new seals at least. It is a balancing act between miles/care.

Then there is the rebuild debacle. Big questions are who did it and when. Many people can "rebuild" an engine incorrectly. Many shops suck. Information is your weapon, and the people here have been there and done that so bring up all considerations here and we can guide ya (IMG:style_emoticons/default/smile.gif)

Regarding the transmission, oil was supposed to be changed at 10K mi intervals.....this just doesnt happen and it limits the life of the parts in the box. Then there are the external bits that get neglected that lead to crappy shifting, which is tolerated too long, and leads to internal component failure. A bad gear box should not be a deal breaker if the car is priced correctly. Luckily for you, there are a few of us out there that can rebuild a gear box for less than a fortune.

Food for thought (IMG:style_emoticons/default/chowtime.gif)

[McMark]

The ideal buyers car would have a history file showing valve adjustment logs that you could peruse over time to see if they were holding their adjustments. It would also have a current compression test with the engine cold and hot. It would have leak-down numbers and have a record of regular oil changes.

But that kind of car is 1% of the market and you're going to be paying $$$ for that kind of car. It's totally worth the added cost, but most people aren't shopping with the kind of budget.

For most of us, you buy the car that offers the best compromise of a lot of factors and hope for the best. The truth is that any engine can potentially fail at any time, and good records and a known history only indicate a potential for long life. Nothing is ever guaranteed.

If you're not looking for a complete restoration candidate, the old adage "buy the best car you can afford" still holds true. The farther you car stretch your budget now, the more likely you are to avoid future maintenance costs.

[VaccaRabite]

What they all said.

When it comes down to it, its a 35 year old sports car. Unless you are paying over $10K for it, chances are it does not have all the records kept since new. Chances are very good that its been driven hard. Any 30+ year old sports car will have questionable mechanical bit until they are proven sound.

The good news is that simple tests (compression and leak down) done correctly are going to give you a pretty good look at the baseline health of the engine.

The other good news is that if the engine needs a rebuild, they are easy to build, with lots of documentation readily available and lots of folks that have done it keystrokes away.

If you get one of these cars and have to choose between a good sound body and a seized engine, or a swiss cheese body and a strong engine, buy the one with the good body. You will spend years more time fixing rust then you will rebuilding a motor (especially if you just buy a running motor from someone here and drop it in.)

Zach

[hot_shoe914]

What they all said.

When it comes down to it, its a 35 year old sports car. Unless you are paying over $10K for it, chances are it does not have all the records kept since new. Chances are very good that its been driven hard. Any 30+ year old sports car will have questionable mechanical bit until they are proven sound.

The good news is that simple tests (compression and leak down) done correctly are going to give you a pretty good look at the baseline health of the engine.

The other good news is that if the engine needs a rebuild, they are easy to build, with lots of documentation readily available and lots of folks that have done it keystrokes away.

If you get one of these cars and have to choose between a good sound body and a seized engine, or a swiss cheese body and a strong engine, buy the one with the good body. You will spend years more time fixing rust then you will rebuilding a motor (especially if you just buy a running motor from someone here and drop it in.)

Zach

(IMG:style_emoticons/default/agree.gif)

[MiddleMan]

Thanks for all the replies.

I am a bit torn. There are some super clean, relatively expensive examples out there (like this), which are right at the edge of how much I'm willing to spend.

OTOH, one thing I plan to do with the car is AX/DE, and I'm not sure I'd want to put a car that clean through that. With that in mind, maybe a better option is something like this, which is still in incredible condition, but something that I wouldn't feel like I was abusing a piece of history by driving it hard and doing some small amount of personalization...

Considering all the options is the best part of shopping (IMG:style_emoticons/default/sunglasses.gif)

[orange914]

Thanks for all the replies.

I am a bit torn. There are some super clean, relatively expensive examples out there (like this), which are right at the edge of how much I'm willing to spend.

OTOH, one thing I plan to do with the car is AX/DE, and I'm not sure I'd want to put a car that clean through that. With that in mind, maybe a better option is something like this, which is still in incredible condition, but something that I wouldn't feel like I was abusing a piece of history by driving it hard and doing some small amount of personalization...

Considering all the options is the best part of shopping (IMG:style_emoticons/default/sunglasses.gif)

after looking at your 2 examples...

IMHO for what you want to do, my vote is on option #2

reasons would be it's a 75 and usually not as popular to CW's or collectors due to smog and performance negatives relative to other years (please 75 owners nothing bad meant)

[SGB]

Any car you get from Craig will be as honestly represented as he is able to be confident of. Really, thats a beautiful example, and totally drivable in the real world too. Email or PM him,tell him what matters to you, what your are ballencing, and get his opinions. It is a very good question, and some great answers here already. You will get this same logic from Craig I bet, so not only can he maybe help you decide, he could probably provide.

[Valy]

My car has original engine with 30K miles.
It leaked so had to replace some gaskets.
Now it leaks again.

Either way you go, you'll need to rebuild.

[VaccaRabite]

oh, they just leak so that the owner knows it still has oil.
More seriously, there are rebuilds and then there are rebuilds.

if an engine has good compression and leak numbers, the "rebuild" might just be replacing all the old rubber hoses and cleaning the mouse nests and dropped spark plugs out from under the tin. Maybe fix the push rod tubes and call it a day.

But, to me, thats not a rebuild, thats a refresh and is just part of owning old cars.

A rebuild requires pulling the heads and splitting the case. A lot more work (and more rewarding too.)
Zach

[SGB]

if it leaks BAD, most likely it is coming from components attached to the engine:
oil cooler, oil pressure switch, push rod tubes, valve covers...
All these can be addressed with the engine in the car.

Front main seal is a little more of an issue, but still the motor isn't opened up.

I rebuild ("top end") when the smoke at start up tells me the valve guides are worn out. Piston/ rings/ crank etc ("bottem end"- kinda misnomer for a flat four) will go 200K miles with new oil every 2500 or 3k miles.

My car has over 400k miles, two full rebuilds with cyl head rebuilds in between over a 20 year period.

[Jake Raby]

All Engines and everything mechanical will eventually wear out. The key is ensuring that the wear is addressed before the engine has a component failure that could render it non-rebuildable.

Old, original engines generally fail due to "dropped valves" more than anything else. A dropped valve is the nastiest mode of failure, as it can take out everything and have zero symptoms before the big boom.

Don't drive an engine to death, give it what it needs, when it needs it and you'll be money ahead and won't need a tow truck to rescue you on the side of the road.

Elective rebuilds are without a doubt, best case scenario.

[Root_Werks]

Early 90's:

I had a stock 74' D-Jet 2.0, never did anything to it but normal maint. Bought it with....110k miles? something close to that. I owned it for about 4 years commuted between two full time jobs (Locals will understand this), Marysville to Issaquah, then back up to Lake Stevens 5 days a week. Almost 200 miles a day. The day it turned over 200k miles I pulled over on the spot and took a picture, then took another picture of the gauges @120mph. It was leaking some oil, but never smoked.

I sold the engine 10k miles later so I could do a six conversion to a guy who installed it into his 914, plugged it in and drove away. Don't know how much longer it lasted after that.

It can happen, but I think a big part of it is leaving things mostly stock and keeping care of what you own and use.

[r_towle]

This is just my opinion and experience after owning about 20 aircooled VW/Porsche 4 cylinder cars.
100k is the lifespan.

After that, you get blow by on the rings, head leakage, and valve guide wear that requires a rebuild...so you can go another 100k.
Older the motor, worse the valve guide wear can be...
They kept changing the guide material over the years...and it still wears out.

Sure, I have driven most if not many of them way past 100k and they still run, but not at the optimum level.

VW water cooled motors (rabbits and pretty much any of the newer motors) are good till about 125-150k then the same thing happens....rings and valve guides.

Overall, VW is cheap about material in the heads for some reason...they just wear out.

So, do you need a rebuild to drive it....probably not.
Do you get more stock power back if you rebuild it....yes for sure.

I may be totally full of shit...so take that into account.
Just my experiences...

Rich