[Fot] TR4 Race Engine Break-in Questions

[Jack Wheeler]

Hi Paul.  When I last raced in the late 1990's, I was building 180 HP motors, taking advantage of all the SCCA rules would allow.  I was using up to 7,000 PRM's consistently.  Since I had to use a stock crank, I was rebuilding engines after 4 race weekends.  Therefore, my break in procedure may be different than someone who is building an engine to last a season or more.
When I showed up at the track with a brand new engine, it would have run only a few minutes in the garage, to make sure the oil pressure was OK, check for leaks, and get the timing set for the crankshaft trigger ignition, as well as the electronic distributor.  I would run the first session on the track, starting out using up to 5,000 RPM's, than gradually increasing the red line, until I was up to 7,000 RPM's by the end of the session.  I used Valvoline 20W50 VR-1 Racing Oil, with a bit of Molebdomen (sp?) Disulfide (Moly) additive.  At the end of the session, I considered my engine broken in.  I didn't change the oil until after the race weekend.
I used cast iron (soft) middle and oil control rings, so they would bed in quickly.  Because I was using pop-up pistons, which created an unusual flame pattern, I used a chrome-moly (hard) top ring.  After the session, the engine was fully broken in, and additional hours would only show barely perceptible increases in performance as the rings further bedded in.  If you are building less radical engines, intended to run many weekends before rebuilds, you may want to follow more extensive break in periods.  In my case, I never found any need to.
And that's my experience.  Good luck.
Jack Wheeler1990 SCCA EP Champion
TR-4

   On Saturday, August 25, 2018, 1:38:20 PM EDT, Paul Ricco via Fot <fot at autox.team.net> wrote:  
 
 FOT,

Good afternoon and we hope everyone is having a great weekend.

We have a couple questions for those who have had experience and success building TR4 race engines.  The information might be helpful others on the forum as well.

1.  We have seen a few different recommendations for initial run-in.  They seem to range from 5 minutes to 20 minutes at approximately 2000 RPM’s.  How long and how many RPM’s are people running them  for?

2.  How long are people leaving the break-in oil in the motor?

    a.  Are people taking out the break in oil right after the run-in and replacing it with regular oil before leaving for the track?
    b.  Are people running a few sessions under load at the track with it in and then switching?
    c.  Something else?  If so, what are you having success with?

Again, we are really gearing the questions towards race engines due to complication of breaking in the race motors at the track with limited time and the track session schedules.

We are trying to avoid re-starting the entire referendum up on oil brands again, so we apologize if we do.  We are really trying to get to how people are breaking-in the TR4 motors successfully.

Thank you for considering my questions,

Paul Ricco
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