running in new engine

[twincamman]

I have a very high mileage twincamman I rebuild every 50000 miles it has gone 150 K with little problems until I used a synthetic in the motor ......turned number 3 bearing shorty after . ...I keep it to the standard 110 street motor ..I don't think new synthetic oil is right for old cars ..perhaps it retains more heat Or the formula is wrong for the old motors. But I went back to a well known Dino 10 50 racing oil and have had no problems ....To break motors in I am careful not to idle extensivley and not red line the motor for 500 miles ....race engines went in the car ..took 2 warm up laps and I stood on it ...but they were rebuilt after 10 hours ....Ed

[SJ Lambert]

Hi Rohan

In the case of my Omnitech motor, how many laps of Symmons Plains &/or Mallala should I do before switching over to Redline 20W 50?
Cheers
James

[oldchieft]

Many thanks Rohan,

I recognise having seen your procedure before but could not find it by searching!

Jon

I'm glad to see this again, I was searching Rohans posts for this and it took some time.

Rohan, did you know your posts now run to over 400 pages!

Jon the Chief

[rgh0]

Hi James

You want to do around a minimum of 50km of full throttle acceleration in 2nd or 3rd gear from around 3000 to approx 5000 rpm then slow and repeat. I guess this would be around 25 laps of Symons Plains and maybe 20 of Mallala?

For a road engine I would aim for trying to do more like 100 km, but with a race engine you can get away with less generally as any remaining ring seating will occur in the first race

I know people who just do a few laps test run to ensure nothing is leaking and no strange noises and then swap the oil and go racing with no obvious ill effects, like the post above in this thread. Make sure you re-torque the head studs after the first heat cycle and also after the running when you change the oil. Check it again after the first couple of races

cheers
Rohan