other thread got locked before i could ask this but i started thinking.

say you got 2 motors could be ls/vtec and gs-r both had the same compression doesnt matter say 12:1. If the heads were the same on each motor. how much does stroke play a roll in how good of gas millage a motor gets or has nothing to do with it? if both were tuned to close to the same a/fr

motor having more stroke get better or worse millage or really there is no valid way to compare it through this?

this may get locked and i may get flamed but its part of my thinking going on upstairs.

 

The problem is you're asking to many "crystal ball" questions that have to many variables to answer simply. It's no different than asking "how much HP will I make" and that's not allowed in this sections rules.


Simply stated, the more cubic inches an engine is from having a larger bore and/or stroke, of some combination of either, the more fuel it will potentially use. Transmission gearing, tire inflation, tune of the engine, driving habits, weight of the car and a multitude of other factors will all affect it's overall gas mileage.

You're worrying about to much here, it's not like you're comparing a hummer to a honda here. two hondas that are built similarly will have similar gas mileage.

 

you didnt get my point. pretty much what i asked was does changing the stroke of a motor but having the same compression still. would stroke have any affect to gas millage. wich could branch off to longer or shorter stroke motors get better gas millage. but ohwell figured id just get flamed for it.

 

Like I said in the previous thread, it depends on the tune.

Theorectically, the larger stroke will have a higher BSFC all other factors are near equal for a given A/F.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by skoodles2k6 &raquo;</TD></TR><TR><TD CLASS="quote">you didnt get my point. pretty much what i asked was does changing the stroke of a motor but having the same compression still. would stroke have any affect to gas millage. wich could branch off to longer or shorter stroke motors get better gas millage. but ohwell figured id just get flamed for it.</TD></TR></TABLE>


I answered your question. If an engine is equal to another except that one has a longer stroke, it means it will have more cubic inches. A bigger cubic inch motor has the potential to burn more fuel than a smaller one. Simply speaking, bore and stroke aren't the real issues here, total cubic inches are. Do you understand?

If an engine is kept to the same size cubic inch wise, changing the bore and or stroke will generally only affect where the engine makes power in the rpm range and how much it will make, not fuel burning potential.