Gas engine ?
06-06-2005, 02:35 PM
#6
RE: Gas engine ?
At the price of gas today--I'd use the cheapest available.
It won't make a difference to your engine. Just run a good fuel filter, and you'll be fine.
FYI--Running the high octane gas in your car at high altitude is a SERIOUS waste of money. There is not enough available O2 in the air to combust all that octane in the gas. So--your just blowing money out the tailpipe.
My wifes' Honda civic actually gets BETTER gas mileage with low octane stuff at 10,000' elevation. I tried the high octane stuff. Cost me an extra $5 to fill the tank. We went on a 300 mile trip--cruising on the highway between 8500'--12,300' elevation. My gas mileage suffered by almost 3 miles per gallon.
On the way home--same route--I put the cheap stuff in and got it back to normal at 33 miles per gallon.
Off on a tangent here--put the cheap gas in your airplane engine and enjoy it.
It won't make a difference to your engine. Just run a good fuel filter, and you'll be fine.
FYI--Running the high octane gas in your car at high altitude is a SERIOUS waste of money. There is not enough available O2 in the air to combust all that octane in the gas. So--your just blowing money out the tailpipe.
My wifes' Honda civic actually gets BETTER gas mileage with low octane stuff at 10,000' elevation. I tried the high octane stuff. Cost me an extra $5 to fill the tank. We went on a 300 mile trip--cruising on the highway between 8500'--12,300' elevation. My gas mileage suffered by almost 3 miles per gallon.
On the way home--same route--I put the cheap stuff in and got it back to normal at 33 miles per gallon.
Off on a tangent here--put the cheap gas in your airplane engine and enjoy it.
06-06-2005, 02:46 PM
#7
RE: Gas engine ?
If your using a conversion engine from a chainsaw--you can mill the cylinder down to increase the compression ratio. But--nothing comes free. By milling down the cylinder jug and increasing the compression ratio--you've just ruined the exhaust duration. So--more work is in order to actually realize the increase in compression. No point in increasing the compression and then killing the exhaust duration. You'll need to grind the same amount off the top of the exhaust port-- that you took off the bottom of the cylinder. Just to get the exhaust duration back to where it was originally. While your grinding the exhaust port--you may as well take a few thousanths more off it--too help out. Then send it to Frank Bowman and have him make a custom ring for it. His rings will generally seal tighter and allow less blow-by. That means more compression.
If you have a high compression engine--then you might realize a performance boost with high octane gas. You may actually NEED it.
If your running any commercially available engine--Zenoah, DA, ZDZ, Brison, 3W, Fox, Taurus--just stick with the low octane stuff.
If you have a high compression engine--then you might realize a performance boost with high octane gas. You may actually NEED it.
If your running any commercially available engine--Zenoah, DA, ZDZ, Brison, 3W, Fox, Taurus--just stick with the low octane stuff.
