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Engine basics => Engine set up tips => Topic started by: Bootlegger on September 22, 2019, 05:37:29 PM
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For some reason I think that I have read where more synthetic oil will increase engine run time.. Am I headed in the right/wrong direction with this thinking ? I don't want to go so low that I burn/seize an engine up.. Thanks
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What I have experienced is a lower nitro content and never less than 20% oil 1/2 & 1/2 mix. D>K
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For some reason I think that I have read where more synthetic oil will increase engine run time.. Am I headed in the right/wrong direction with this thinking ? I don't want to go so low that I burn/seize an engine up.. Thanks
Reducing the total oil content will increase the run time - it's as simple as it seems, more "go juice" (methanol or whatever) per unit volume by having less non-volatile components (oil). To first approximation, it doesn't make any difference what type of oil it is. A secondary issue is how much drag/friction the oil provides -- the less friction, the less HP removed as friction, so you can use a smaller venturi and get the same power.
How low you can safely go depends on the engine, and how you are running it. This is endlessly hashed over in the past, I am not up for another round, and Randy has a pinned topic at the top of the board that tells you most of what you need to know - *accurately*. At either extreme, running Fox fuel (29% castor) in a modern engine will make it run poorly and require service in short order, and the right fuel for a modern AAC engine will likely destroy a Fox in very short order.
As a general rule, set up the engine to run the best, and put in whatever size tank is required to get through. You *never* want to compromise the engine run to save fuel, only do it in emergencies or special circumstances where you can't do anything else. And then, next time, make it so you don't have these special circumstances (like building in the fuel tank, or making only 1" thick tanks fit, or something like that).
Brett
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Unless you're talking something other than stunt, what Brett says (which I've not done for years, because my main ride had a slightly undersized tank and I'm lazy -- but hey, you should do what he says).
If you're flying team race or want to break the Endurance record, then there's all sorts of things you can do -- not least of which, and possibly easiest, is to switch to a diesel engine.
You need to say what's really on your mind, or we can't help.
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When did run time become an issue? It is a simple timer setting. LL~
Ken
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For some reason I think that I have read where more synthetic oil will increase engine run time.. Am I headed in the right/wrong direction with this thinking ? I don't want to go so low that I burn/seize an engine up.. Thanks
If you need just a couple more laps, then use an once of acetone in a gallon, if you need more install another tank, don;t use less oil than optimum
Randy
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Add Coleman lantern fuel to your glow fuel. It's in the olde English Merco direction sheet (per Dave Royer) and is fairly common knowledge around the PNW. Bob Emmett suggested no more than 6 oz (maybe he said 8 oz.?) Coleman fuel to a gallon of glow fuel. Try 1 oz per quart or 1/2 oz per pint and see how it works for you. It'll make a significant difference. Dave Royer says he runs it all the time, because it improves starting. D>K Steve
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If you have a little excess power, a small increase in back pressure (decreased muffler opening) will increase your run time by reducing the exit of unburned fuel.
Try this. You will probably find more run time with NO loss of power.
Also, a small addition to the methanol percentage will replace non-burning oil with actual energy.