1st Gen VS 2nd Gen Longevity and WHY
 

I have owned the following sevens, '80, '87NA, and just yesterday sold the NA and bought my first T2. I have been browsing through the forums about engine life expectancy and found that the T2's don't fare too well. I will cross my fingers because mine has 163K and runs very well.

My question is: Why is it that 1st Gens generally last so much longer than the 2nd Gens? Especially the carbeurated 1st Gens? I sold my 1st Gen with 290K and it still had great power.

Any ideas?

Thanks
TRU

The 1st gens last longer because they are less stressed. The most powerful 1st-gen was only 135hp, the 12A's were only 100hp. They don't make enough power to hurt themselves, basically :)

My '85 has over 150k on it and still going strong...

Turbos put a lot of stress on any engine and will shorten it's life significantly. All third gens come with twin 51mm sequentially operated turbos. The average life expectancy of the engine is less than 100K mi. I just hit 101K on my orig. engine, but the automatic tranny seems to be gentler on the engine. Either way, if I took the turbos off, I'm sure the car would last another 100K easily. I'm not, however, and have already saved up for a rebuild.

I bet it has a lot to do with 3mm apex seals in the old motors verses 2mm in the second gen motors.

1st gen, they are really simple and competitive in comp.

I don't believe your conclusion is true...

The FC's are a technological step-up from the SA's.&nbsp The thinner 2mm apex seal has reduced friction.&nbsp Nitrided side housings reduce wear.&nbsp 12-pin rotor bearings versus older 9-pin rotor bearings prevent bearing walk.&nbsp Stock for stock, the FD NA engine should outlast an SA NA engine...



-Ted

Higher thermal stresses. The turbo engines are burning the same candle twice as bright...

my 85 12A died at 224k

But judging by the engines condition upon teardown, Id say an oil change once every 2 years was just about average :( Id also venture to say it was ran low on oil several times...

Tough motor...I got a 88 vert with 128k on it and I hope it last 224k.... :)

You're comparing an NA motor to a turbo one?&nbsp Oh boy...



-Ted

Perhaps they are all of the things you stated. But on average are the second gen motors actually pulling the miles the old 12a's and SE 13b's are doing?

I pesonally know of many people who have well over 200,000 on their older motors.

As the years go by I swear I see just as many 1st gens rolling around as I do 2nd gens.Were production numbers that much greater than the 2nd gens?

I owned two GSL-SE before I purchased my TII. They were the best cars I have ever owned in regards to reliablity. Start them up and go...I would like to get another one for a daily driver someday.

Later

Now, I have to wonder how your 12A's get this incredible mileage - 224K, 290K. Holy cow! How do you do it? Mine failed at 163K, and cracked an apex seal on the rear rotor. I'll admit, I did do a couple of burnouts, nothing major. Does that have something to do with it? I bought the car when it had 160k on it. Maybe it had to do with something the previous owner did, or neglected to do? I'm going to replace the oil metering pump, as it looks and feels gooey and seized. Why is it that the rear rotar fails and not the front? By the way, when it did go, I was doing 30mph driving casually.

85RX7GS,
Pre-mix :) . Whether you need it or not.