The only problem is a gallon of water is more than a gallon of gas ;) -Kyle
On Wed, Mar 18, 2009 at 12:12 PM, stanley/ Randolph <[email protected]>wrote: > The higher the compression ratio, the more likely you need higher octane > fuel. You can *overcome* that neccessity with water injection, however, > which lowers the temprature and at the same time makes a more complete burn > because the fuel droplets surround the water droplets, being lighter; and > when they burn, the water absorbs some of the energy and becomes steam very > rapidly which makes the remaining unburned fuel droplets even smaller, so > they burn faster and the burn completes before the flamewall gets to the top > of the piston and through it, theoreticallyTo understand more clearly, > picture a log. It takes it a loong time to burn, like overnight, for > instance, in a Jotul stove. Now picture some wood shavings. They are not > only easier to ignite, they burn quite fast by comparison. > The gasoline gets "atomized" either by a carburetor or fuel injectors. The > finer the droplets, the better the burn. > Weber makes fine carbs that will cause the fuel to extract more power out > of the same engine because the fuel comes out in such a fine mist. > Sometimes it is so much more power that it is noticeable when you hit the > gas. The engine will use less fuel, also, because more of what it gets, > gets burned before the exhaust valve begins to open. > Beetle engines came from the factory with about a 7.9:1 C/R. They can use > 87 octane. > If I were to up that compression in my engine to 10.5 or more, I would > either have to use premium or add water injection. I choose the latter > because I get more performance and nearly double my mileage from about 31 - > 32 to about 58, give or take; plus, the engine stays cleaner; and unless you > add an aftermarket filter on a Beetle, that's important, because they have > no filter and I used to change my oil every 1500 miles. That wasn't so > expensive, because Beetles only use 3 qts. of oil. Just a little more than > a Nighthawk.. > Actually, what Kyle said below is essentially the same thing; I didn't > notice he wrote it after you asked the question (lol). > And Kyle - I know of a chap who replaced the pistons in his Ford Focus with > hi comp - 12.7s - and added water injection. That's all he did, and it > increased his power (don't know how much, but a lot; no dyno) and his > mileage went from 25 mpg to 50. This, on regular 87 gas. > Kinda like NOS without the risk of blowin' yer engine... > > > *Stanley* > > > ------------------------------ > *From:* Javier Garcia <[email protected]> > *To:* [email protected] > *Sent:* Tuesday, March 17, 2009 10:31:00 AM > > *Subject:* [Nighthawk Lovers] Re: Gasoline, octane and oil > > > Stanley, I'm a little bit confused... in your first message it seems to me > you don't agree in using high octane gasoline... in the second, you talked > about engines damages due to the use of low octane gasoline... can clarify? > I'm not really an expert, so I get lost very easily. > Thanks, Javier. > > On Tue, Mar 17, 2009 at 11:11 AM, Kyle Munz <[email protected]> wrote: > >> I used to run into the same problem with my turbo cars. The higher the >> boost the higher the octane rating you needed since it effectively ups the >> compression. Most ppl understand octane meanings backwards. It actually >> means it's less likely to ignite, which is good if you're running high >> compression, or high boost. With higher gas prices I understand people >> wanting to put the cheap stuff in, but like Stanley says, newer cars will >> retard the timing when they detect knock, which means they burn more fuel >> anyways, so you didn't save as much money as you would have liked. One of >> the benefits of ethanol is a very high octane rating, so you could run >> really high compression or really high boost, and thus get more power, >> however this just isn't feasible for road cars now matter how much the corn >> lobby thinks it is. Long and short of it is, just put in what the >> manufacturer suggests, if the engine was designed for lower octane then put >> that in the tank. If you want to put "the good stuff" in your tank, then go >> to a name brand station, such as chevron/texaco, exxon/mobile, or shell and >> stay away from the discount dealers. This applies no matter what octane you >> decide to buy. >> >> -Kyle >> >> >> >> On Tue, Mar 17, 2009 at 10:47 AM, stanley/ Randolph >> <[email protected]>wrote: >> >>> If you know the research about octane and flamewalls and compression >>> ratios, you would have a different attitude about that. Low octane fuel >>> will demolish a high comp engine. I have taken apart Porsche engines they >>> were putting in Beetle vans, with the rings all cracked and melted into >>> their landings from using low octane for their compression ratio. And this >>> despite the *decal by the gas tank* stating a minimum of 92 octane!!! >>> This engine was still running, but I have seen engines with holes in the >>> heads, the pistons, one which was ruined beyond repair with the hole outside >>> of the valve insert. It is not good if you use low octane in a high comp >>> engine. The flame wall is meeting the piston as it comes up, and when the >>> heated wall of fire hits the piston and you *hear* the knock, back off, >>> or you *will* ruin your engine. >>> The engines today have knock sensors sending data to the computer to >>> retard the timing when the flamewall gets too close to the piston crown. >>> When timing was only a mechanically actuated centrifugal advance, one >>> couldn't actually retard it, so the only thing one could do is back off the >>> gas, or go around with permanently retarded timing, which defeats the >>> purpose of higher compression: greater engine efficiency and/or more power. >>> An old wrench gave me an engine for taking it out of this van he bought >>> cheap and that's what I found when I took it apart. Happy to say, though, >>> bottom end was excellent. Nice thing about those engines - is it was not >>> too expensive to replace those pistons and cylinders. I had me a new engine >>> for the labor and $80.00 for new set of P&C and a valve job with new exhaust >>> valves. Gasket set was the second most expensive item: $29.00; for regular >>> Beetle engines the gasket set was only $4.00, and a new set of P&C was less >>> than $40.00 for Brazilian Cima/Mahles or a Jap brand name escapes me), both >>> of which were close to German quality. >>> The only safe thing to do when rebuilding the Porsche engines is to lower >>> the C/R, because people think, it's just a VW (van/microbus). It doesn't >>> really need premium gas. >>> Until, of course, it's usually too late... >>> >>> *Stanley* >>> >>> >>> ------------------------------ >>> *From:* Creative Residential Designs <[email protected]> >>> *To:* [email protected] >>> *Sent:* Tuesday, March 17, 2009 7:37:45 AM >>> *Subject:* [Nighthawk Lovers] Re: Gasoline, octane and oil >>> >>> Try telling that to my '69 GTO, Dick. It will NOT run on anything >>> else...period. It doesn't care what you or I think about premium gas, it >>> will ping and knock and carry on until I feed it the best gas there is. >>> (Texaco or Shell premium ONLY). >>> I just read a study on gas on the 'net as well. Interesting how abrasive >>> low-end fuels are to an engine. I'll try and locate it again. Apparently >>> it's one of those "you are what you eat" situations. HotrodMamma. >>> >>> ----- Original Message ----- >>> *From:* Dick MacInnes <[email protected]> >>> *To:* [email protected] >>> *Sent:* Monday, March 16, 2009 9:10 PM >>> *Subject:* [Nighthawk Lovers] Re: Gasoline, octane and oil >>> >>> The only place to get the proper service Manuel is Helm. Inc >>> And premium gasoline is a waste of money, I don't care what anyone has >>> told you. >>> >>> Dick >>> >>> >>> >>> >> >> >> > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. 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