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Breaking in a race engine

Posted By: The Sphinx

Breaking in a race engine - 06/27/18 03:59 AM

I just put together an engine for my race only car. Aluminium headed 360 12 to 1 compression with a solid flat tappet cam around .670 lift and duration at 265 at .050. I just broke the cam in by running it for 22 minutes between 1800 and 2500 rpm. I vary rpm during cam break in. I just installed the inner springs, anything else I should do before next Sundays race? How do ya'll break in a race engine?
Posted By: madscientist

Re: Breaking in a race engine - 06/27/18 03:59 AM

Originally Posted By The Sphinx
I just put together an engine for my race only car. Aluminium headed 360 12 to 1 compression with a solid flat tappet cam around .670 lift and duration at 265 at .050. I just broke the cam in by running it for 22 minutes between 1800 and 2500 rpm. I vary rpm during cam break in. I just installed the inner springs, anything else I should do before next Sundays race? How do ya'll break in a race engine?




Time to run it.
Posted By: CMcAllister

Re: Breaking in a race engine - 06/27/18 04:03 AM

Change oil, look at the filter for anything bad, run the valves again, double check timing, everything tight.
Posted By: pittsburghracer

Re: Breaking in a race engine - 06/27/18 04:19 AM

I use tranny fluid on my cylinder walls on assembly so by time it hits the track it’s pedal to the metal. Race time
Posted By: Steve1118

Re: Breaking in a race engine - 06/27/18 04:26 AM

I always broke them in during the water burnout at Keystone. About 6000 rpm. Seriously, I never broke any of them in. I just put them in and run it.
Posted By: Cab_Burge

Re: Breaking in a race engine - 06/27/18 04:40 AM

If you can drive it to the other end of the return road in 1st (if it will hold the engine and not coast) or second gear and run the rpm up to 3000 to 4500 several times and let off completely until it slows down below 2000 RPM and do it again several times to help seat the rings.
If you have enough room and won't get into trouble run it up to or above 5000 RPM in high gear at WOT and let completely off several times to help finish seating the rings up
If you can't do that run it up to 5000+ RPM in second gear on the track and let off at least once and then race the heck out of it up hammer grin
Posted By: Al_Alguire

Re: Breaking in a race engine - 06/27/18 05:19 PM

At this point the cam is broken in and as my son put on his "uber" dragster

Posted By: CMcAllister

Re: Breaking in a race engine - 06/27/18 07:59 PM

I've certainly taken a fresh engine - with maybe 5 minutes of run time - down the road to a race out of necessity. I prefer to take it to the track, put a couple of 1/8 mile hits on it, take it home and change oil, look at the filter, double check adjustments and valves, etc. before racing it. Be different if it had been on a dyno.
Posted By: polyspheric

Re: Breaking in a race engine - 06/27/18 09:32 PM

Back in the day, race engines would be stripped after a race and re-ringed (same size) because the walls had assumed their "as-stressed" shape and ring seal would improve. Harley-Davidson did this as far back as 1955.
Posted By: pittsburghracer

Re: Breaking in a race engine - 06/27/18 09:41 PM

Originally Posted By polyspheric
Back in the day, race engines would be stripped after a race and re-ringed (same size) because the walls had assumed their "as-stressed" shape and ring seal would improve. Harley-Davidson did this as far back as 1955.




And this means what? Should us bracket racers go out for a day of Racing and then tear it all apart and rebuild it for next week. Cheese and rice stay on point. Lol. Build it right, race the dog gone thing, and have fun. Don’t over think it.
Posted By: Iowan

Re: Breaking in a race engine - 06/27/18 11:34 PM


I've always broke new motors in as they were ment to work and race motors are no exception.
Posted By: tboomer

Re: Breaking in a race engine - 06/27/18 11:37 PM

Iowan..Don't know where you are from but when my motor was done we went to Humboldt and beat it pretty good!
Posted By: Biginchmopar

Re: Breaking in a race engine - 06/28/18 12:36 AM

Originally Posted By Al_Alguire
At this point the cam is broken in and as my son put on his "uber" dragster



LOVE IT!

iagree


beer
Posted By: Iowan

Re: Breaking in a race engine - 06/28/18 02:12 AM

Originally Posted By tboomer
Iowan..Don't know where you are from but when my motor was done we went to Humboldt and beat it pretty good!


Up around the Mason City area, about an hour from Cedar Falls Raceway.
Posted By: tboomer

Re: Breaking in a race engine - 06/28/18 02:44 AM

Originally Posted By Iowan
Originally Posted By tboomer
Iowan..Don't know where you are from but when my motor was done we went to Humboldt and beat it pretty good!


Up around the Mason City area, about an hour from Cedar Falls Raceway.

Cool! wave
Posted By: cudaman1969

Re: Breaking in a race engine - 06/28/18 04:52 AM

Read an article about cycle racing. The guy built two engines identical, first one did about tweenty laps very easy. Second, full throttle the whole race. After the "break in" fist bike never could run as fast as the second. After the season tore both down, first one was black, dirty inside, second just like new. The full throttle made the rings seal better so no blow by. The old adage, run it like you stole it off the showroom floor works.
All out and don't look back.
Posted By: RapidRobert

Re: Breaking in a race engine - 06/28/18 05:20 AM

^^^ go to www.mototuneusa.com then scroll down to & click on "breakin secrets". Made a believer outa me.
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