Piston and its Bore size.. question

[ray6966]

if we were to keep everything constant on an engine, and we increased the pistons bore size

to say ".030" (from its original size), would you be increasing the volume of the engine? Would

you also use more gasoline/fuel in the process, since the engine's volume has increased?


Kinda silly question, but everyone starts somewhere..lol.. thanks guys.

 

[rbohm]

8) in the case of the six, boring the cylinders by .030 increases displacement by about 4 cubic inches. any increase in fuel consumption would be miniscule at worst, and more likely non existent.

 

[350kmileford]

No more than 2% fuel mileage decrease :-/

 

[Thad]

With about the same power increase.

 

[Lazy JW]

No more than 2% fuel mileage decrease :-/

One would need to have kept VERY accurate fuel economy records for a long time both before and after to prove a 2% difference in fuel economy.

If the engine were worn out prior to the re-bore, you "might" see at least that much improvement, and I see no point in re-boring a good engine just to find out; gonna be pretty tough to get a definitive answer on that one.
Joe

 

[ray6966]

I've got a 6 cyl 1968 engine block, got it at junkyard and Im planning to

have it rebuilt. I was looking at the pistons that Mike sells, and I've noticed

the option of the Bore Size Selection. Just trying to weigh my options.

I"m going to use the car as a daily driver with a T5, and the car will

be mostly used on the highways.

Thanks,

Ray
Lynwood, California