Race Engine Forum UK

Hello,

I started up a newly rebuilt Fiat 1995cc hot street engine just a few days ago, and I was wondering how soon
can I do full power runs at the dyno. How many hours of break-in is needed?
The car has programmable fuel injection and I need to take it to the dyno to properly program the FI.
So far the engine has run for a total of about 2 hours, the first hour being several warmup/cooldown
cycles in the shop, then about an hour of mixed driving.
Thanks,

Csaba

Csaba, ih

really you should not be driving it at all unless the fuelling and ignition parameters have been fully entered, you could do more harm than good tothe rings and bores trying to break-in at this stage. My advice is do the break-in at the dyno - they can check and adjust the ecu real-time so that the engine beds-in under optimum settings.

How long really depends on honing technique used but under a range of loads and speeds building up to full power-throttle by the end of the session I would suggest 1.5-2hrs. If it hasn't bedded-in after 2 hrs it likely never will.

GC