I was wondering how many miles can a 1970 240z engine can last. Who know this answer? I'm thinking it can last about 150,000 - 200,000 miles not being abused. Is this about right? Thank you!

My buddies 70 was on about 225K w/o the bottom end being touched. The only reason he rebuilt it was to get more power. It wasn't burning oil, and it ran pretty good.

My '72 had a little over 500,000 miles on it before a cracked ring finally blew a chunk out of no. 3 piston. I drove it the rest of the way home, too. It still had good power, didn't use oil. Leaked a little, but didn't burn any. The only thing we did to this engine, other than tune-ups, was replaced the valve guide seals. That's it. Take good care of it, it will take care of you.

Its like a Timex, takes a licking at 189,000 and still tickin. No rebuild on my 73' yet!! :classic:

Well, it looks like the L24 engine will pretty much last quite awhile if tuned on a regular bassis. Sounds good to me!

So how come mine needs to be fixed out???

96 000miles, but I do know the ZED I bought was used for some lapping and autocross...

Oil rings (espeacially #3), and vavle seals..

Normal wear, well, I guess so on a 30 years old car.

My last 240 had at least 280,000 miles on it.

I rebuilt the engine just for the hell of it, not because I thought it needed it.

The only excessively worn part I found in the engine was the timing chain tensioner shoe. (down to the metal)

The main bearings / journals mic'd to with-in blue-print specs!

Alot depends on how it is cared for and treated . I change the oil at 3k and filter . I dont try to see if it will run to redline, I run hard on the twistys but keep the RPMs at a realistic rate rarely over four grand . I have over 200,000 miles and the engine burns no oil and has a compression of 145 all across th e board. It is mostly stock execpt for Round tops and a '79zx ignition. I vary much like to drive this car and can see no point is GERNADEING the engine just to satisfy my eago.