Cold Start/ Forged Piston

Hello. I was wondering, since forged pistons demand higher piston to wall/cylinder clearance, can we minimize the wear with a specific cold start strategy. Can for exaple cyclic idle help ?

Wear, as such, isn't really a problem, but the higher cold clearance can mean more piston 'slap', which can be audible.

What is more likely to cause wear is fuel condensation on the bores, exasperated by the fuel enrichment normally used, and extensive idling.

Opinions may vary, but I would suggest minimising the cold enrichment - while increasing the cold idle if required, and driving the vehicle gently to warm it up. This has seveal advantages - faster warm-up, less fuel dilution of the oil as there's less over-fuelling to get past the rings, some oil splash from the big ends to oil the bores, and better fuel consumption as the energy is also propelling the vehicle instead of being wasted in just heating the engine.

If this is a pure 'race' car, or is used in cold/mountainous areas, then a block/oil heater may be a good idea to help reduce the 'cold' running.

Nice, thanks for the tip!