MotorHead

I was just wondering what the opinions are on how many miles you can expect to get out of a high performance 400 HP motor.

Kinda want to limit this to how many miles people have actually got out of their motors rather than how many you expect to get.

Mine only has about 25,000 miles and I am using oil, maybe this is normal I don't know, never really asked the engine builder that question but you would have to think that the more power you drag out of these motors the shorter the lifespan will be.

fauxrs

Its extremely variable and dependant on the quality of the build. In my case I have been very fortunate.

>Rebuilt Vega 4 cylinder (rebuilt myself - 1st ever rebuild) = 75,000 miles
>Rebuilt Oddfire buick V6 (rebuilt by local shop) 45,000 miles
>Rebuilt 402 (built it myslef) - sold the car after 50,000 miles on rebuild and going strong
>Rebuilt 350 (kragen shortblock) installed for a freind in his car - I only did the long block assembly and install, still running 5 years later to the best of my knowledge, I moved away and lost contact with him.
>Rebuilt 350 (myself for my 72 Camaro) = sold the car after 30,000 miles - and based on conversations with the new owner the car has about another 30k on it by now.

I am rather **** about my rebuilds, I tend to overspend horrendously on the bottom end, I tend to stud the mains, I always install a windage tray and crank scraper. and I am meticulous about clearances. If the build is done like this, you should be able to expect the same life out of a rebuild as you would out of a new motor.

Cheap rebuilds where little attention to detail is paid are the kind I basically ignore after 30k miles.

[question] why does every used car in the world have a rebuilt motor and transmission with 20-30k miles? probably because the cheap rebuilds these bubbas are used to arent worth many more miles than that.

Dont know if any of this answers your question.

SuperFast80

Motorhead, for what its worth (and you know how I drive), I have put 24,000 and 26,000 on the 2 rebuilt 350s I have had with really no real concern about oil consumption (which has been ~1L for every 1500km) or breakdown.

MotorHead

I am using about 1 litre per 1000KM whereas not too long ago I was not using any
maybe it's not too bad the motor runs great and the I have 235 PSI in all cylinders.

SanDiegoPaul

I too have had terrific luck w/doing them myself. Haven't had one come apart yet! Last hot rod before this Vette was a '70 Nova and I bought an L-82 Vette motor for it. It had a flat cam (that's the reason it was pulled from the Vette) and the car ran good with the engine that was in it ... so I took my time with buiding the 350. Used all the years of experience and engine building I had accumulated ... deburred the block/rounded off all sharp edges and had screw-in studs and guide plates put in the heads. I put it together with all Chevrolet items including the GM 350 HP cam. I got an oil pan with a windage tray and put her together with cheap headers. That thing ROCKED! after I went through a couple of turbo 350's then decided to go for the turbo 400 trans. I drove it for 5 years, and drove it really hard too. It was nothing to pull 6,000 rpm shifts with the turbo 400. And I did that ALL the time. I saw the guy I sold it to a couple of years after I got rid of it, and he said he hadn't changed a thing on the car and was driving it daily! That one burned a bit of oil too but it ran great.

Others I built were always bored, so they got new pistons and I never had oil consumption even though I drove them hard too. That L82 Vette motor had stock pistons so the build probably would have gone a bit tighter had I bored it. In retrospect, it probably would not have burned a drop. I did try replacing the valve seals in it after it's third or so year but it didnt' change anything. I still had the oil consumption... but it ran so good it didn't bother me.
So I agree with the other posters: if you take time doing the rebuild, you won't have to worry about them having a short life. :cheers:

I'm kinda nervous right now 'cause I'm paying someone to build my latest project: a stroker for my vette. :confused: I sold my tools and my Nova to get cash together for a down payment on my house. :mad :mad and I sure miss the days of having all my tools and working on the car myself.

Although having a home in San Diego has also enabled me :yesnod: to buy and build this Vette :yesnod: so I can't complain! :yesnod:

The Money Pit

I got 110,000 out of the 355 I built and ran in my 80,and to be honest could have kept it in. The 406 was ready to go in so I yanked the 355.