26-11-2012, 01:07 PM
Most of this difference will be thermostats causing issues...
Just remember that with IDI engines you cannot just concentrate on the indicated coolant temperature, as the heat is very intense in the precombistion chamber, it causes a massive heat load in a small area... This is where the IDI design is let down, you must keep this cool otherwise you can expect issues with cracking heads, uneven expansion and contraction... The biggest factor in heat from what I've seen is EGTs and backpressure, if you have a small turbo and are spinning the engine fast, its a recipe for VERY high temperatures... IMHO lift off at 88*c, they want to run ay 83c so if the temperature is increasing to 88, you need to be ridiculously careful ad you're going to damage the head in the long term with the hot spots in the head....
Just remember that with IDI engines you cannot just concentrate on the indicated coolant temperature, as the heat is very intense in the precombistion chamber, it causes a massive heat load in a small area... This is where the IDI design is let down, you must keep this cool otherwise you can expect issues with cracking heads, uneven expansion and contraction... The biggest factor in heat from what I've seen is EGTs and backpressure, if you have a small turbo and are spinning the engine fast, its a recipe for VERY high temperatures... IMHO lift off at 88*c, they want to run ay 83c so if the temperature is increasing to 88, you need to be ridiculously careful ad you're going to damage the head in the long term with the hot spots in the head....
