[Fot] TR4 Race Engine Break-in Questions

[Duncan Charlton]

Paul,

Running the engine at 2000 to 3000 rpm and just leaving it there for 20 minutes is usually suggested as the right way to break in a new flat-tappet cam and tappets but my understanding is that this will not to much for your rings.

The following applies only to piston ring break-in and is not specific to TR engines (and I’m certainly open to hearing scientific reasons why this might be incorrect).  I do lots of throttle on/throttle off to load the piston rings in both directions, so to speak, so that means a few laps of rather jerky driving.  If the roughness profile of the cylinder walls was done properly it shouldn't take more than a few laps to bed the rings.  It would probably be a good idea to change the oil and filter after the first hard track session.

Duncan

> On Aug 25, 2018, at 12:20 PM, 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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