steveo2992

I have a 1991 4runner i just put new heads, gaskets, fuel injectors and all. What would be the proper way to break it in when i start it in a couple of days?



Thanks

L33T35T 4Runner

In the gas world they say keep it under 3k for the first 500 miles, no long constant speeds.

In the world of diesel engines that i build, we warm them up on a dyno then run the hell out of them until the rings seat

AH64ID

Did you replace the cam too?

If not you really dont have to have a break in procedre. I would change the oil filter after the first 10 minutes, then the oil at 100 and 500 miles, then back to normal..

Interesting comment L33 on the diesel.. the 06 Cummins requires a much different brake in. No cruise for the first 500 miles (to avoid constant RPM), then for the first 500 miles of towing no going over 50..

maxpower_hd

You didn't mention even doing the lower end. If all you did are the heads then just run it.

oly884

Yup, a lower end rebuild requires some break in period ditto. Top end doesn't require much except for checking for leaks for the first couple thousand miles.

To be on the safe side, I'd read this if I were you:

http://www.taperformance.com/howto.htm

It might give you some pointers or things to watch out for. Good luck!

AH64ID

If you did replace the cam(s) you will need to do the cam break in, IIRC its 2000rpm min for the first few minutes at initial fire up...

steveo2992

Yes i did replace the cams. I got a set of complete heads. i also have one more question. How do you prime the cooling system? can you just put 50/50 mix in the top water enlet thing and then fill the radiator and over flow. THANKS

steveo2992

I broke in the engine and runs great thanks

AH64ID

good deal