regular or premium

I use either...can't really tell a difference. But there are guys here (TRBenj and others) that know way more than me.

john

If you have 9:1 compression or less, like a stock engine, it should run just as good on 87, maybe less.

I don't know what compression ratio the newer boats have nor do I know what the owners manual recommends. I'm sure others here will know. If the engine is stock I would stick with the owners manual recommendations.

As far as your '73 vette goes, again it depends on how the engine was built.

I've run 10.5:1 w/93 octane in a SBC for over 1,000 passes on the strip and thousands of street miles with no problems. This one had cams ranging from 224 - 236 @.050". I tried 110 race gas with this combo and it didn't make any difference.

My boat is 9:1 and I can't tell any difference between 87 and 93 so I run it on 87. Mainly because I'm cheap! My goal in building the engine was for it to run on 87 so it was built 9:1 compression.    

Ok will give a try with regular and see what happends. Both engines are stock w/o mod so comp ratio s the one stated by the manufacterer. I think is 9 to 1 on both cases.

79, I guess that if you say so it must be that way. thanks.

79 I might not be as versed as you on all this but what you say doesnt sound square to me, a different gas has different detonation, therefore different advance and maybe even different mix at the carb. Please keep in mind that not all boats are the same nor are all conditions and parts used in them, 93-95 is the lowest octane fuel I can get here, so we tuned it to perform it best with it, does it perform better than using regular?? I dont know and I couldnt care less, it's what I have and I prefer to enjoy the hell out of the boat every day rather than reinventing the wheel. it works for me, if it doesnt for you then deal with it.

Here we go!!!

Looks as though Kapla is in Argentina. They may not use the same octane ratings we do, so he should be sure he's looking at the equivalent ratings to what we're telling him.

Measurement methods
The most common type of octane rating worldwide is the Research Octane Number (RON). RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions, and comparing the results with those for mixtures of iso-octane and n-heptane.

There is another type of octane rating, called Motor Octane Number (MON) or the aviation lean octane rating, which is a better measure of how the fuel behaves when under load. MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, a higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 8 to 10 points lower than the RON. Normally fuel specifications require both a minimum RON and a minimum MON.

In most countries (including all of Europe and Australia) the "headline" octane rating, shown on the pump, is the RON, but in the United States, Canada and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 8 to 10 point difference noted above, the octane shown in the United States is 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the "regular" gasoline in the US and Canada, is 91-92 in Europe. However most European pumps deliver 95 (RON) as "regular", equivalent to 90-91 US (R+M)/2, and some even deliver 98 (RON) or 100 (RON).[citation needed]

It is possible for a fuel to have a RON greater than 100, because iso-octane is not the most knock-resistant substance available. Racing fuels, AvGas, LPG, and alcohol fuels such as methanol or ethanol can have octane ratings of 110 or significantly higher - ethanol's RON is 129 (MON 102, AKI 116). Typical "octane booster" gasoline additives include tetra-ethyl lead, MTBE and toluene. Tetra-ethyl lead (the additive used in leaded gasoline) is easily decomposed to its component radicals, which react with the radicals from the fuel and oxygen that start the combustion, thereby delaying ignition, leading to an increased octane number.

79 nice congratulations on the boat you USED TO OWN

Luchog wrote: 79 nice congratulations on the boat you USED TO OWN

made a nice porfit too, but the next you will run faster than 52 MPH that the 79 did d*ckHEAD

Sorry, did I just read "blah blah blah I dont have a boat blah blah, all others are POS, I only live from the memory of the one I USED TO OWN and the distributors I USED TO DESIGN, that's why my mouth is full of s79t and bashing other makes my day, sorry you all I dont have a life"

Ok, I forgive you, but I think you need some therapy...

...or a new boat

lanuage?

comprehinsion???


sorry, it seems my web translator can't figure those, or is it that a foreigner spells your own language better than you do that pisses you off???

Anyway, you're full of s79t, you always seem to have a reason to bash on others, I'm really sorry for you, if you dont like me posting here, then I'm sorry too, deal with it, I OWN A CC, what about you? maybe it's you who should take the bashing somewhere else. What about www.Iusedtoownaccbutchangedmylifestyleimfullofs79t.com

Definitely a High Octane Thread Now!

Luciano,

Tried your link above and it is a Gay p0rn Site.. What The.......?

Home page of Homo's, PLBC'ers in their Pink Wet Suits.

Chris,

So what will be your next craft? The bar has been set pretty high lately with some of those 60mph boats.

Luchog wrote: "Anyway, you're full of s79t"

I usually avoid local politics like the plague, but I couldn't pass this one up! Mark one up for Argentina LMAO....can't stand it I'm laughing so hard my keyboard shakes. Nothing like good clean fun, no s79t!
Ken

1-So every US citizen is paying you to post on here instead of working?

2-You're a boat w79re now

3-It seems that the one who doesnt have a clue about your ways of freddom is no other than yourself, since you're the one stating that I should not post on this site for not being born in the US.
Please stop referring as "freddom" just as a slogan and start living/giving it, for that you make my eyes bleed.

Go get the new boat, hope you enjoy it.

Now, back to the topic, perhaps some of the real knowledgeable guys in here such as the Boatdr, Eric, Reidp, Trbenj, Brainard or most others with good manners can jump in and give their insights. OM45GE's post was quite helpful I think.

Man this sounds like good clean reality-tv...

I'm recovering from the stomach ache I got while LMAO at you guys bashing on each other...

BTW 79... I'm also a forreigner with very VERY little understanding about tuning... , but I keep learning as I go...