[mr 4 speed]

Been hammering the motor in my 70 SS for 25K+ miles and 10 years now...still makes me smile evertime I put my foot into the secondaries!

 

[magicrat56]

closing in on 20 years on my 468 in my 67. really no big problems on this one, only worked on to tune it, 20,000 miles feed on pennzoil 25/50 GT oil. I've been with this car since new,so i pretty much just cruz but i do have fun towards the end of the driving season beating up on it every now and then.

 

[jeff swisher]

You guys don't drive much!
I got a 69 300hp 350 went through it, new bearings rings and pistons..didn't need it even with 100,000 miles on it...then in 2 years i put 75,000 miles on it tore it down and installed new stuff again and better heads and bigger cam..another 2 years and many long runs at 7600rpm and 50k+ more miles i stored it, sold the car..freshened up 1 more time with bearings pistons and rings different heads and cam...and been driving it for 3 years ...the block has never been bored or honed except from factory and crank never turned.....runs great 210psi cranking pressure...2 bolt main 350 with stock bolts and cast crank.

My inline 6's and 4 bangers usually go 375,000 before they start smokin some...then they need attention..

If it holds good oil pressure don't screw with it..just fix the ailments and go.

 

[BlueSS454]

Interesting question.
The 454 in my 70 is 11 years old (rebuilt 1973 engine) and has 20,000 very abused miles on it and still runs 12.30's all day long.
The 307 in my 69 is 10 years old (rebuilt original engine) and has 16,000 miles on it.
The 440 in the 69 Charger is stock as Chrysler built it in 1974 (from a 1974 Motorhome). It has roughly 55,000 miles on it.
I have a 72 Plymouth Fury that has the original 360 in it. Other than a top end rebuild, the engine is still in good running condition although it needs an oil pump.
The 350 in my 86 Cutlass is the original engine out of my blue 70 rebuilt and increased horsepower in 2000. I think I put over 60,000 miles on it before I parked it. It still runs like a top.

 

[bb67H-D]

The '70 L34 in the '67 I had rebuilt in 1988 and freshed up the top end a few years ago.
I runs just as hard as ever and maybe 30k ?? on the engine since 1988.

My 1971 lemans 2dr coupe has just tad over 100k and has never been touched runs perfect.
350 255hp/350
Grandma purchased new I bought it in 1987 or 1988.

 

[MEJ1990TM]

The engine in the '70 lasted from the Summer of '78 (Rebuilt by dad) until the Summer of 2010. Well, not entirely accurate. It was sometime between the Summer of '08 and '09 that we pulled the heads and had a valve job done. There were a couple burnt exhaust valves between the two heads. In July of '10 we pulled the engine out. Not because it was running poorly, or knocking, but because it was leaking and we were planning on driving it to Prescott, AZ. It was leaking a fair amount of oil so we decided we'd pull the thing out and do the gaskets/seals on the lower end. I pulled a couple rod caps and found brass showing through on the bearings, and the crank was scratched. Probably a grand ,and five months, later we stuck it back in. New parts included rings, bearings, all gaskets/seals, cam, lifters, pushrods, valve springs, keepers, retainers, oil pump, pickup, and intake. Runs better than ever now. Got around 5k on it since January of last year. It had over 30 years ,and probably 75-100k miles, on it. Many of those miles the driver was trying to turn it inside out. It was time.

The '71 I don't know when the engine was last gone through. I got the car in September of '09, and started driving it in May of '10. Soon after I started driving it a lot it developed an intermittent knock. I just lived with it, but then one day it started smoking like crazy. I could clearly tell it was oil coming from some place. I carefully drove it the few blocks back to the house. Got it up on ramps and it was leaking from the rear main seal. I pulled the engine out and did a low buck overhaul. Got rings, bearings, gaskets, and seals. Been running fine since June of last year. Probably have 2,500 or so miles on it. Still running fine. I expect it will last a good long while. Both engines should.

 

[71350SS]

1) i have no idea. Although it seems engines are lasting much longer these days. 200,000 miles seems realistically achievable.

.

4)

I read an article that attributed the increased engine longevity with the use of 2 things that came into use in the 70's and 80's.The first was when leaded gas was completely taken off the market.The second was the switch from carbs to fuel injection.Nowadays when you get a motor from the junkyard a lot of the time the block won,t have a ridge at the top of the bore and the crosshatch may still be visable.I think it was a "Motors" magazine.

 

[Mark66SS]

in my sig you will see my cars none have had rebuilt engines except the AMX. I even pulled the engine from the 70 has 125k on it and uses no oil and has good compression

 

[1966_L78]

This thread was great...

I just bought a running 402 to drop in my '66 Chevelle (I have a non-correct '66 396 in it now, used and hasn't run in 5++ years)...

I was planning on just dropping the running 402 in, and enjoying it for a few years, and then I'll think about building something bigger and better...

THEN, I noticed all the spark plug threads had oil on them, porcelin looks "wet", but smells more of gas, and doesn't look oily... The engine was started "cold" for me, and didn't seem to smoke, no leaks or noises...

Because of the oil on the threads, I was thinking of pulling the heads... But I really don't want to tear down the engine, as thats why I bought a running engine...

Think I'll do a compression test, and if it looks good, I run it as-is...

 

[camarofreak]

i have a 69 350 in my chevelle that was built into a wild 355 with world heads in 93 and it runs as strong today as the day i broke it in!!!

 

[Nickvt]

Just rebuilt the the original motor in my '72 SS 454 last winter. 39 yrs and was still running strong with 67K. Seemed like it might be a good winter project, which it was, but it went well into the fall before it was done. I found that the only real sign of any wear was the cam lobs had started to fail.

 

[XCELERATIONRULES]

Go old school...don't let the empty suits sell you expensive electronics...build a motor.

 

[NVSS]

My 396 is the original engine that came with my 68 SS and was rebuilt at 54,000 miles in 1998. I now have 64,000 miles on the car or 10,000 since rebuild.

 

[al1950]

my 66 SS has orig engine has 60,000 miles'
it was overhauled, new mld cam, new top end in early 80s at about 30,000 miles.
It runs real nice, I finally got all oil leaks fixed and plan to drive it a long long time.

 

[OLDED]

This is a 2 yr. old OP.

 

[charbilly2001]

Mine is brand new, on several work benches, in boxes, totally unassembled.

 

[71350SS]

you can add another 2 yrs and 1 month to whatever the age of the people's engines that posted about there engines are. :thumbsup:

 

[Tom Mobley]

57 Chevy pickup, built the very nice blueprinted and balanced 327 in May of '85. Still runs good.

70 Chevelle 406 was new in 2001.