what are these factors that effect the engines output over time. im asking following a previous thread relating to a rolling road. and the discussion there about healthy engines. so other than services items suchj as air filters choking the car etc what else limits its power, does teh power drop due to the compressions effectivness? for exapmle worm valve seating and worn piston rings? or is it motre technical than that. can some one please explain???

cars are like people , as they get older they get weaker . compression drops , sut biulds reducing the engines breathing , injecters wear affecting the fueling , breaks might bind a little . bearings ware thus reducing smooth movement , the list is endless . pretty much every mechanical part is for making you go or stop . as they all ware their performance is reduced .

two schools of thought of course... In some cases where an engine is worn, its no longer as tight and therefore less mechanical resistance... although being "run in" and "worn out" are two different things ;)

'factors that effect the engines output over time'.Energetic constant engine use helps maintain power. Over revving and neglect destroys everything.

 

Doing Chassis dyno power tests the major hurdle was allways heat- too much.

factors: poor eng bay circulation, blocked rad cores, poor levels and type of coolant. heat soaking the air intake tubing and ducts.

Wrong spark plugs for fuel and or contaminated fuel. Over filling sump oil also sap figures noticably.

so I'd suggest over time that badly chosen body styling changes(airflow) and poor maint are power killers.. but with our cars the beggst factor is corrosion. Corrosion of electric circuitry and cars being left still. EG bores need to be sept by the piston or they corrode thus rings suffer. what do you reckon?

so realistic its goverened mostly by the annicileries and connection in the zed, but poorly mainted engines will sufferer internally. hrm id love to throw mine on a dyno before and after i up the power but id hate to find out i only had like 250 bhp atm. would eat at me untill i could afford to up the power! hrm so what should we looking at to get the best power from the engine with good maintaince? and should we nice a good "healthy" compression/ leakdown figure...

I would say if were looking at the long term, stick with 'as Nissan intended'. they tested to the point of exhaustion with parts and variety. More power is easy but will anyways have a knock on effect on something. - but also Nissan have enginnered in a huge margin of safety and it does have to be so huge.

The car is yours to decide maint schedule and condition, but I will add that all dyno's read a different figure. Even homologated dyno's (v.rare) show variance on different days. So always go to the same dyno, and ask to see the 'correction figures' each time too. -And dont worry to much about comparing others BHP numbers as they can be so easily be manipulated by the operator. Best of Luck to ya!