Pelican Parts Forums

Pelican Parts Forums (http://forums.pelicanparts.com/)
-   911 Engine Rebuilding Forum (http://forums.pelicanparts.com/911-engine-rebuilding-forum/)
-   -   Break-in for Top End Only? (http://forums.pelicanparts.com/911-engine-rebuilding-forum/741593-break-top-end-only.html)

Smoove1010 03-29-2013 05:20 AM

Break-in for Top End Only?
 
The SOP for break-in seems to be to a 20 minute no-load "idle" at 2000-2500 RPM, but this seems aimed at cam-rocker mating.

I'm re-using the cams and rockers as is, though I'm spinning the rocker shafts 180* for a new load-bearing surface. I assume that rocker/cam mating should be minimal and only a result the parts being disturbed due to dis-and-re-assembly.

So seating my Goetze rings to my newly-honed alusils is my biggest concern. I've read the mototune theory of break-in here: Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power, as recommended by numerous posts, which makes sense to me, but if my priority is to seat rings, do I need to follow the no-load-high-idle for 20 minutes routine? If an early proper run-in is needed for good ring seating, don't I risk losing that opportunity while the car high-idles for 20 minutes? Some posts on the topic seem to indicate that the ring-seating window is very short.

I'm thinking I'd be better off letting her warm up for a few minutes at high idle, then taking her out for to do the moto-tune-prescribed run-in sooner rather than later. I'd be grateful for any thoughts.

Thanks,
GK

KTL 03-29-2013 09:10 AM

Yes just fire it up and let it idle for a little while as you check things over to make sure all is good- no leaks. Then take it out and drive it hard accel-on, accel-off with no extended period of time with a steady rpm.

You are correct that since you are re-using the cams and rockers as-is (and you have kept all rockers where they came from) then there is no break-in needed for cams. They're already good.

The reason for the 2000+ rpm is to ensure the oil pump is supplying a substantial amount of oil to the camshaft area to ensure good lubrication.


All times are GMT -8. The time now is 04:33 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website


DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.