Itinerant Air-Cooled

i'm not there quite yet, but i'd like to start gathering the info to do this right. i've got new rings going on old pistons/cylinders. i've read thru lots of info on ratwell's site and IAC, but i think i still have some questions:

1. if i understand right- basically 2 stages of break-in: initial start-up and 20 (or so) minutes running; couple hundred miles easy street driving, using all gears (but no lugging)

2. oil and filter changes at end of each stage, to remove any metal that gets shaved off the new rings as they become acclimated to their new home.

3. what oil is recommended, if different from what i will run eventually? [after the break-in i'm figuring on running conventional , 20w50 during warmer seasons, 10w40 or 15w40 in winter (bus and i live in michigan)]

4. i'll be changing oil and filter at 1500mi after break-in, and judging what i see in what comes out, may go to 3000mi intervals after that.

please let me know if i missed something, misunderestimated some info, or any other tips/suggestions for this project. thanks, alll

Youve basically got it, the 1st 20 min should be above 2000 RPM and varying RPM do not let it idle or run slower than 2000.

RSorak 71Westy wrote:Youve basically got it, the 1st 20 min should be above 2000 RPM and varying RPM do not let it idle or run slower than 2000.

I was told to fluctuate between 2500 & 4000.

metric Cwrench wrote:i'm not there quite yet, but i'd like to start gathering the info to do this right. i've got new rings going on old pistons/cylinders. i've read thru lots of info on ratwell's site and IAC, but i think i still have some questions:

1. if i understand right- basically 2 stages of break-in: initial start-up and 20 (or so) minutes running; couple hundred miles easy street driving, using all gears (but no lugging)

2. oil and filter changes at end of each stage, to remove any metal that gets shaved off the new rings as they become acclimated to their new home.

3. what oil is recommended, if different from what i will run eventually? [after the break-in i'm figuring on running conventional , 20w50 during warmer seasons, 10w40 or 15w40 in winter (bus and i live in michigan)]

4. i'll be changing oil and filter at 1500mi after break-in, and judging what i see in what comes out, may go to 3000mi intervals after that.

please let me know if i missed something, misunderestimated some info, or any other tips/suggestions for this project. thanks, alll

1) The initial 20 minute run is to break in the cam. After that, do a series of acceleration/deceleration cycles in each gear to set the rings.

3) Most folks would recommend an oil higher in zinc (ZDDP) for initial break in. ZDDP is an anti-wear additive that was once popular in motor oil and is good for engines like ours with the flat lifters. It has slowly been removed from common motor oils because higher levels of ZDDP have a propensity to poison catalytic converters (or so it is said). I used Valvoline 4-cycle motorcycle oil on my engine break in process. The zinc content may not be as much a worry for you if you have hydraulic lifters.

General consensus is NOT to use synthetic oil for break in (not that you were considering it, just thought I should say it).

Tim

Sluggo wrote:

RSorak 71Westy wrote:Youve basically got it, the 1st 20 min should be above 2000 RPM and varying RPM do not let it idle or run slower than 2000.

I was told to fluctuate between 2500 & 4000.

That is the entire rev range during the initial couple of hundred miles. But during the first 20 minutes, it should be an easy 2,000-2,500 with a couple of slightly higher bursts.

Ring break-in should be in 2nd or 3rd but not 4th. You want the engine to be able to increase RPMs pretty quickly and then coast down in that gear. 4th is too tall and could develop some unwanted heat.
Colin

thankyou, thankyou.

i'm only breaking in new rings, but it's nearly 5yr since this bus was a running. will follow the proceedures and advice given here, but i don't think zinc is for this engine. i've been reading the thread on oil (engine forum, posted by hippie, i think), and i just don't know about all that- fortunately i don't have to just yet (more time to digest information and learn more before i need a full-blown rebuild).

so i can use the 20w50 oil for the break-ins?

thanks again all for the help.

metric Cwrench wrote:thankyou, thankyou.

i'm only breaking in new rings, but it's nearly 5yr since this bus was a running. will follow the proceedures and advice given here, but i don't think zinc is for this engine. i've been reading the thread on oil (engine forum, posted by hippie, i think), and i just don't know about all that- fortunately i don't have to just yet (more time to digest information and learn more before i need a full-blown rebuild).

so i can use the 20w50 oil for the break-ins?

thanks again all for the help.

If your just breaking in rings...yes 20w/50 is fine.


As for proper break-in:

1. 20 mins for cam break-in using non detergent 30 weight oil @ 2000-2500rpms.

2. Then drain oil and refill with non detergent 30 weight and run for 300 miles (city driving).

3. Check valve lash )cold engine) and drain oil and clean sump screen. Refill with appropriate grade oil containing proper ZDDP levels.

4. Enjoy your new motor. Don't be surprised if you find you need to adjust the valves several times or so during the initial 1000 miles or so. This is due to the newly rebuilt or new heads settling in.