Have a weird question .. actually just got to drive the vette since we got it 2 weeks ago from the mechanic (454 got rebuilt)


It's a 4 speed transmission, and wanted to know if its bad to constantly stay at high rpms? If so, what should be the "max" you should every do for crusing on the highway, etc?


thanks,

kosta

 

Proper way to break-in a new motor is to vary the RPMs and not stay at any constant cruise for about the first 350-500 miles (if the motor was re-built using a stress plate for cylinder honing.) You should change the oil/filter after the first 20 minutes of running time ant at 500 miles then 1500, then every 3000 or 6 months for long engine life. There are those than subscribe to the theory "the harder you break it in, the harder it will run" BUT, motors treated that way will not last long. I would absolutely find the high zinc content Valvoline Racing Oil if your Big Block has a flat tappet camshaft in it.

 

My Comp Cam hyd roller, for example, was explicit that the engine was to be brought as quickly as possible to 2000-2500 and not run a moment longer than possible under 2000 for 15 minutes for breakin - for the cam gear. If only my stupid engine builder had used the correct gear and not a bronze gear which later ate away. This procedure was needed mainly for the gear but also for the lifter to lobe wear as I am given to understand. Other than that, using the very specific very light oil they specified for that cam break-in (I believe it was mineral - NOT synthetic - and 5W) that first oil should be changed in the 100-150 mile range, along with the filter. Then your regular oil should follow, minus any wear preventative you are obsessed with normally using, should be used next, and this should be changed in the next thousand (along with that filter as well.)

RPM should be varied and not overly stressed for long periods, although it should occassionally be brought in the neighborhood of 20% of your designated red line after that first cam break-in oil change to make sure valves and rings are seated after any moving around is finished and any initial small burrs have broken off.

 

I definately went through the rpm range, and I believe my dad also did (he's driven about 300 miles on it so far).

And what about after engine is broken in?

Thanks,

kosta

 

No steady speeds during break-in. Run it up in rpms, then let off the gas and let it coast way down. Repeat over and over. This allows the oil to circulate at high pressure while cleaning up small metal particles. I'd say 500 miles is minimum for a break-in, maybe drive moderately for another couple of hundred miles.

After break-in, cruising at steady speed is fine. In fact, engines that are run at steady speed live longer than ones driven in stop and go traffic, or flat out at race tracks (obviously).

Good luck -

 

Thanks ... I plan on getting the engine dynoed most likely after 1000 miles or so, to see what kind of power it is putting out now .. which should be a decent number, I am hoping =]

Putting in the Shark Bar 3R when they come out (May 20st) So thats when I'll have some more fun since my seat belts now suck, and will feel more comfortabl with 5 point.

thanks,

kosta

 

How do NASCAR or NHRA dudes break in an engine? It seems to me, they don"t have the luxury of the 500 mile break in.

Just asking, as I use the 500 mile break in.