The Stovebolt Site Forums The Shop Area Engine Shop Looking for 261 .080 over Pistons

Grant, Tony and truckernix, I "am" dealing with reality on this. I'm trying to speak in a language(?) that you can easily comprehend. I can see where this is going to be difficult for me to explain, but, by gumbys, I'm going to try.

I never implied that the block or cylinder wall (engine) was the heat sink. The true heat sink here is the radiator. The water is only the vehicle to transfer the heat from the engine (cylinder walls, head and block) to the radiator. You want heat in the cylinder- The more heat, the faster gases expand, which in a confined environment gives you more energy, in turn giving you more mechanical power. How well an engine uses the heat it generates is known as it's thermal efficiency. The average engine has only a 25-30% thermal efficiency, so 70-75% of the heat generated never gets used to make power. The cooling system takes heat from the engine, heat that ideally could have made power, so the cooling system actually takes power from the engine. It is a necessary evil, without a cooling system, the engine will overheat and the internal parts will have a very short life. I am no metallurgist, but I do understand the notion that a thick piece of steel can withstand and dissipate greater and more heat then a thin piece of steel.

When you overbore an engine you increase the firing chamber, thereby increasing the heat. The thinner cylinder walls can't withstand the increased amount of heat as well, nor dissipate it as well. The stock cooling system isn't designed for an engine that gives off more heat. So you need to increase the flow of water to cool the engine even more than before. The trade off is that you will need to run the engine at a lower temperature because of possible cylinder wall distortion and you will need to use more engine power to operate a faster water pump.

As far as sleeving goes- You can either "dry or wet" sleeve, and nowadays there isn't really to many problems with doing it if you have it done by someone that knows what they are doing.