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Re: [Fot] engine break-in

To: "Greg Solow" <gregmogdoc@surfnetusa.com>, "Friends of Triumph"
Subject: Re: [Fot] engine break-in
From: gasket.works@gte.net
Date: Fri, 29 Oct 2010 13:42:47 +0000
Greg;

 Best explanation I've heard.  
M
Sent via BlackBerry from T-Mobile

-----Original Message-----
From: "Greg Solow" <gregmogdoc@surfnetusa.com>
Sender: fot-bounces@autox.team.net
Date: Thu, 28 Oct 2010 23:52:10 
To: Friends of Triumph<FOT@autox.team.net>
Reply-to: Greg Solow <gregmogdoc@surfnetusa.com>
Subject: Re: [Fot] engine break-in

If everything in an engine is in good shape & there are no problems with 
fit, finish and lubrication, then the critical areas during breaking are the 
iron to iron or steel to steel surfaces that are lubricated by the oil film 
and not by Hydrostatic lubrication. The main, rod, & cam bearings are never 
really supposed to touch the cam or crank as there is a separating film of 
oil that is captured and forced into the space by the oil pump. The cam and 
lifters, the valve stem tips to the rocker arms, the rings against the 
cylinder walls, the Timing chain, sprockets and tensioner are the critical 
areas in a TR-4 type engine. The cam wants the engine to go fast enough to 
keep oil splashing on it and to keep the surface speed of the lifter on the 
cam high enough, but not to high, during the first 15 to 20 minutes of 
operation, especially.  The rings want enough gas pressure above the top 
ring to keep the ring pressed against the cylinder wall so it will "wear in" 
both the wall and the ring face. Again it wants enough oil to keep it 
lubricated and cool, but not to much speed until the surfaces have begun to 
"mate" with one another.
    We always break in with Chevron Delo, Brad Penn, or Torco, which we 
continue to race with.
    We run at about 2200 rpm for the first 15 to 20 minutes, then shut down, 
retorque the head, adjust the valves, look for plenty of oil on the top of 
the head.  If we are at the track, we then run 2 or 3  laps at up the 4,000 
rpm using about 2/3 of WOT, then go up 500 rpm every two laps or so to 6,000 
at WOT after about 20 to 25 minutes of running. What is most important is 
that the oil and water temperatures remain stable. It is also good to 
decelerate from 4,000 down to 3,000 with the throttle completely closed to 
create high vacuum in the cylinders during the first couple of laps (make 
sure there is no one behind you when you do this!), to
draw oil up into the ring belt and cool off the rings during their initial 
breakin under load.  By the end of the 2nd session, everything should be 
well broken in.     Adjust the valves hot, right off of the track so 
clearances are as close as possible to the 'running" condition and 
temperature. Sometime in the middle of the 2'nd session, it is good to do a 
"clean cut" and coast into the pits to look at the spark plugs and make sure 
there are no signs of detonation.  These usually manifest themselves as tiny 
black speckles like black pepper on the clean white ceramic of the spark 
plug insulator. If you see any of this, retard the timing & or richen the 
mixture.
                                                                             
                            Greg Solow 
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