Average life of a 911 Engine???

[shawn911]

I was reading an article recently on the 911 flat 6 engine, it said that the average life of this engine is 50,000 miles !!, it doesn´t seem alot for an engine of this quality and cost, i suppose it has a lot to do with how you drive and treat your car, however ive been told that the engine suffers a lot less if it has an 11 blade fan and another oil cooler fitted, as i live in spain we have hot summers, so i will be modifying my car to cope, is there any other usefull mods that i can do to keep my engine happy??

Shawn, 911 targa. 2.7 ( engine out being rebuilt at present)

[carrue529]

well my 2cents

my 3.2 engine had 210k miles before it let go at the track.

with stock cooling.

you should be able to get well over 100k with proper maintenance

[shawn911]

Cheers, 210 k is great, the 3.2 is said to be an excelent engine, plus, correct me if i´m wrong should have the better fan ( 11 blade) as stock.

My car has tubes running to the front, but it has a loop instead of a cooler, it may have been an optional extra to have a cooler up front.

Shawn.

[bigrubberjeep]

You will find many engines here have well over 150K and even some well over 200K on them. I think I have heard of some 912 motors with over 300K

[PatrickB]

If not tracked, you might want to add another 0 to the end of that figure...

Some 3.2's have valve guide issues, they typically show up prior to 75k miles... If you pass that milestone, these motors go FAR!

I've got 140k and counting, and still get 1500-1800 miles to a quart of oil...

Oil consumption is often a key indicator in the health of the motor...

[dd74]

What you might have read about a flat 6 engine lasting only 50,000 miles usually is assigned to the 2.7 motor from 1975 to 1977. It had several issues that almost exclusively showed up in motors destined for the United States. One immediate issue had to do with the use of thermal reactors in the exhaust system so that the motor can comply with then current emissions regulations. Another was the use of a 5-blade fan.

The 1974 2.7 motor which came with an 11-blade fan and heat exchangers - i.e. no exhaust-related smog equipment, lasted much longer than 50,000 miles. In fact, over 100,000 to 150,000 miles is not unheard of.

To rectify these two issues, the common solution was to replace the exhaust system with '74 or earlier heat exchangers or SSI heat exchangers. Headers are also a possibility.

The issue with the fan was a swap of the 5-blade fan with an 11-blade fan.

Spain gets hot in the summer, so in lieu of your rebuild, you should budget for an external radiator oil cooler.

Do you plan a straight stock rebuild of your 2.7 or will you be modifying it?

[Por_sha911]

It depends who is driving it. If you have a habit of missed shifts or red-lining it when cold then you won't make it to 50K.

[oneblueyedog]

I rebuilt mine at 205K and the only wear was on the intermediate shaft bearings in the case. The connecting rods did have wear but very minor. The cylinders were measured for ovality and they were a nogo for resale. I could still see crosshatching though it was burnished smooth. The heads were done by Walt and he said there was only one valve that needed replacement but that it was not very bad.

I think street cars that are well cared for will go on and on. They were built for longevity. Thus I don't think it was neccessary to rebuild mine after 23 years.

Didn't a book say there was one going strong at 400K?

[PatrickB]

I know that Alex's '74 has +300k on the original 2.7 motor. While he is going to be replacing the engine soon, it did make it that far....

[Evans, Marv]

Shaun,
There is also a mod to the air deflectors between the cylinders that is supposed to improve cooling somewhat. You cut a rectangular section out of them. I forget the actual measurements, but do a search and you should find it. I did it to mine and powder coated the tin before the engine was reassembled. I also had a bunch of dry film lubrication coating done to mine. It was done to the piston skirts, valve stems, bearings, oil pump, etc. In addition, I had the piston tops, combustion chambers, and valve faces thermal barrier coated. Mine is also a 2.7L (1977), and I built it to last. I haven't put it in the car yet, but I have high hopes. I'm also installing a 28-tube oil cooler. Also did some other things like ARP rod bolts. Since yours is apart, you might consider some of this if you want it to last longer. No guarantees though.

[shawn911]

Thanks for the replies

I am keeping my engine totally standard with no mods, the air deflecter is a good idea and makes sense, i will do that one,

Also i will fit the oil cooler and search for a 2nd hand 11 blade fan, as my engine comes into the category of short lived engines.

However i´m not a track person nor a boy racer so my engine when its finished will have a very easy life. i just love driving it, thats what gives me the buzz.

Cheers, Shawn, 911 Targa 2.7.

[Wrecked944]

I am the exact opposite of an expert. But I have been told numerous times that majority of the wear imposed on a motor happens in the first few seconds when you start it up. Apparently this is because the oil has not had a chance to reach operating pressure and the motor is essentially dry. I asked a question about this on this forum a few months ago and was told a product called "Accusump" could help solve this problem. It seems the "Accusump" gets the oil pressure up to normal before the motor cranks - thus preventing damage.

[Redlineshftr]

Shawn911-
You are correct about a book talking about a 400k mileage sc. It was Bruce Anderson's 911 performance handbook. He talks about a shop owner Bob Grigsby who "maintains a 911sc that has more than 400,000 miles on it and it still runs great." Exactly why I own an SC!

[VaSteve]

IIRC, the stock 2.7 would make it to around 50-60K and needed to be rebuilt. Once rebuilt with the proper parts/upgrades, I think they can last as long as an SC. Perhaps that's what your source was referring to.

[911 Rod]

What's the big concern about tracking a car?
Smooth shifting, no redlining.
I don't run my car any harder on the track than street. Sorta.
278,000 km

[PRE-H20]

Shawn911,

yup! as patrick said, my p-car hit the 300K mark.... an original 1974 2.7 never opened but maintained well, i have had my car for 16 years, i am in the process of getting another engine in the last couple of weeks but ya, i myself put on 200K miles on it,.........

alexander

[PatrickB]

Handle change there Alex?

[PRE-H20]

yup,..... finally got a personalized plate the i liked.... so our gracious host allowed me to change..... PRE-H20......

[PatrickB]

Cool!

Your 16 years of dedicated Porsche ownership will not go un-noticed!!

Congrats on finally getting the plate!