Preference on breaking in 302/306...your thoughts?

5spd GT

"the 5.0 owns all"
Founding Member
Aug 7, 2002
9,516
6
99
Arkansas
Here shortly I will be breaking in the 306...what would you guys suggest on the break-in procedure?

I'm going to put in 10w-40 to break it in with to help with the initial lubricating properties for break-in. I was thinking, prime the system...crank it and set the timing and fuel pressure quickly after letting it idle for a few minutes. Then go out and make 4-5 pulls at 3/4 throttle up to about 4,500 rpm and then let off the gas, creating cylinder pressure and vaccum...

Thoughts, how did you break-in your engines...

Daily driver by the way...best way for longevity?

Thanks:nice:
 
Muzzy the guy that builds bikes says you wanna heat the engine up before rings het hardened from heat cycles and make a couple of hard pulls to get the rings to seal good from the first heat cycle before they harden from heating and cooling.
 
prime it, start it, let it warm up, shut it off, check everything. Then we let it run for 10-15 min at 2000 rpms... then i put 500 easy miles on it. the 501st mile was complete at the drag strip.... :D
 
Break in is a preference thing..THOUSANDS of these cars hit the streets over a decade ago, and the majority rec'd no breakin..owners turned the key and drove them off the lot. Here we are now thousands and in many cases hundreds of thousands of miles later and the motors are still pounding down the road. My breakin consisted of prep and start, get up to temp, short drive, look for leaks and bad sounds, change the oil, and drive. I chose to baby mine for the first 500 with some full throttle pulls in 2nd and third up to 5000 once or twice every time out. Some say drive it like you stole it, I say drive it like you paid for it.My oil change intervals have been 50miles, 200 miles and 400miles (when I put her away), I will change it again in the spring again with castrol gtx 10w30 and swap it out again at 1000miles (aprox milage I do a yr) in the fall. Though I use cheaper dyno oil I like to use the BEST filter available, and have for every change...for me that's the K&N. Good luck with the engine Dave...you'll love it for sure.
 
5spd GT said:
Here shortly I will be breaking in the 306...what would you guys suggest on the break-in procedure?

Didn't you and I have an argument about this about a year ago? Here's what you do. Just forget everything that you said and do everything that I said and it'll be perfect. :D
 
N8Miller said:
prime it, start it, let it warm up, shut it off, check everything. Then we let it run for 10-15 min at 2000 rpms... then i put 500 easy miles on it. the 501st mile was complete at the drag strip.... :D

Whether it's totally necesary or not, I'm with Nate. Rings seat very fast and for most folks, that's all they require. I prefer to run Dino-oil for the first 500 to 1000 miles to give the rings time to take on the exact shape of their respective cylinder bores prior to switching over to synthetic. I do agree that after the first few minutes that there's no more need to baby it. Just drive it like you normally would.
 
Daggar - My memory isn't clicking right now, let me know what went down:) I argue with so many I often forget, and some I don't...hehe.

Do you guys not think that setting the rings at a specific rpm is "bad" for it? How about a variance of loads or atleast rpms?

Thanks guys!

The block looks great, I can almost see myself in the cylinder bores:D
 
Once you get the motor running, idling, timing set and some temp in the motor a few small pulls up to say 4000rpm will seat the rings.

Drain the oil, change the filter and let it cool down. Start it back up, check all the vitals and you should be fine.

On race motors they are broken it like above then beat on... I do like to see 500 miles on a new motor just to make sure all is good before it goes to the track, dino oil as well for the first couple thousand miles. It's great when the motor and clutch are beand new together, since the clutch will require 500-600 miles for break in ;)
 
when i had mine rebuilt at 200,00 my mech told me to do pretty much what everyone her has described. initial warmup etc etc then put about 500 easy miles on it. i use valvoline dura bland 10w40.
 
When i broke mine in...i got it running, set timing, idle, and FP then checked for codes and shut it down. Let it cool, started it back up and took it out and made a couple fairly hard pulls up to about 4000 and brought it in. Started with Dino 10w-40 and changed the oil at 50, 250, 500 and 1000 miles. First 500 miles were very easy miles with large variance in RPM trying to work all parts of the RPM band in at low to moderate load. I still havent been too hard on it to this day and the motor has about 1500 miles on it. I'll bring it up to 5500 at WOT but no crazy hard shifts or launches just yet. my next oil change will bring the synthetic and once i finish breaking in the new Spec Stage II, Im going to let it have it!!!! good luck man
 
Ive heard a couple people say after the rings seat and you make sure there are no leaks or anything, to drive it like you stole it and it will run better in the long run. I wonder if there is truth to that. It makes sense to me that its broken in the way its going to be driven all the time, but then again, i dont build engines...