I have asked this question to one other person and i dont want to disrespect that person at all just trying to get other opinions on the matter. I have a 90 22re that has just been fully rebuilt. Bored 40 over new pistons, cam, and head. I have about 100 miles on the engine now. I am planning on making a 100 mile trip north but would require freeway driving. How many miles do i have to wait till i can drive on the freeway?

 

I've heard that you should change the oil after 500 miles, then keep it under 60 mph.

 

thanks DIHOWARD anybody else want to give me there opinion

 

just DONT keep it at a steady rpm if you do go on the freeway

 

thats what i heard.. ill try doing that.. Its just i got 33's with no regear so if i go 60 on the freeway thats climbing in rpm's I want to be safe not sorry

 

you already got my opinion...
take it easy, i.e. 60 mph, and stop to check all fluids at least twice...
other than that, you should be fine...
everyone has a different opinion on how to break a motor in, but the one that i grew up with is drive the motor like you will drive it every day to allow that piston rings to fully seat to your driving style...

now thats an old one way of doing it that my grandpa told me to do, but he was talkin checy small blocks, but it should be the same...

 

No immaculant break in needed. Just vary your speed/rpms like scuba said.

Rob

 

Thanks again space-junk... yeah that's all i used to have was Chevy's so this Toyota thing is growing on me.. I just wanted to see what everyone elses opinions are as well, but thanks again

 

Biggest thing is breaking in the cams....that should come in the first 20-30 mins of operation. Past that, I've been told, you can do whatever you want. Now, obviously you don't want to take any chances, so as long as you've been driving around varying your rpm's (common thought is that you want to avoid a constant rpm at first), I would think you should be fine. But my reassurance doesn't come with a warranty.

This info comes from someone who I really respect. But, there are a thousand opinions about how to do a proper break-in. I would suggest taking the various opinions here, then do a google search on the matter and try to come up with something reasonable that takes in all information.

I will say this though - when engine builders build engines for racing, like drag racing and round track racing, they don't drive them around for x miles before they hit the track. They put them together, start them up and do a short break-in and then go wide open. The obvious difference is that they don't plan on putting x00,000 miles on the engine....but like nascar engines are intended to run for 500 miles or so at 9000+ rpms. So there is probably something to it.

 

yeah thats what im trying to do KRB90.. im trying to get everyones opinion and then go from there.. Thanks for the help though

 

Drive it normal. So that includes on the highway.

As already said, the only "break in" is for the cam, which is a 2000 to 2500 rpm for about 15 minutes on initial fire up. I just fired up my rebuild few days ago, soon as the tabs come I'll be able to put some miles on the rig.

The theory with not keeping the motor at a constant idle is to vary oil pressure and reduce glazing of the cylinder walls. It's theory though and like most information on the web, the idea just keeps getting tossed on. My reccomendation, don't fret leaving the motor idling like your destroying it but it don't hurt to vary the rpm's either.

 

varying engine speed the first few hundred miles has been around as long as I can remember.
if you're on the highway, just bounce back and forth between 4th and 5th or in/out of overdrive every now and then
and avoid lugging the engine (wide throttle at low rpm)

 

thanks all for the replies.. i think im going to attempt the freeway driving and vary rpm's as suggested, and try not to bog the engine down with low rpm's. Should i change my oil before this trip or does it matter. And if i do need to change oil before can i switch to synthetic or do i have to wait?

 

for break in period after a rebuild is usually 500miles and thats not going above50mph. than an oil cange it just so everything will set well

 

On motorcycle assembly lines, the first thing they do after the bike is together is take it over to the dyno and pull a few wide open throttle runs.

"Taking it easy" is not something that helps the rings wear to the cylinder wall. "Wearing the rings to your driving habits" makes absolutely no sense to me. To each their own, there more ways than I want to count that people try to break in an engine.

The fact is that the only thing to be broken in are the rings (besides the 10 minute cam break-in) and there is only a short period of time for this to happen before the cylinders are worn smooth by the rings (cylinder machine pattern works like a file on the rings until the "peaks" are worn). What will help this process? High cylinder pressures that push the rings against the cylinder walls without lugging the engine. Every engine I have ever built was babied for 10 miles to make sure nothing catastrophic was going to happen (check for leaks, recheck fluids, etc) then they all got flogged as per my normal lead foot driving habits.