Print Page | Close Window

regular or premium

Printed From: CorrectCraftFan.com
Category: General Correct Craft Discussion
Forum Name: General Discussion
Forum Discription: Anything Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=12081
Printed Date: May-14-2024 at 5:17pm


Topic: regular or premium
Posted By: kapla
Subject: regular or premium
Date Posted: September-30-2008 at 9:40pm
I was looking in corvette forum wich i'm a member in cause apart from the boat i own a 1973 vette. There was this thread about using regular or premium. I wanted to know which type of fuel you use, what type of fuel is the correct for my boat (1992 sn 351w stock with protech ign). I've always used premium (95+ octanes here) but had always the doubt of what would happen if used on what we call here "comun" (regular) of 85 octanes? So opinions are apreciated!!!

-------------
<a href="">1992 ski nautique



Replies:
Posted By: jbear
Date Posted: October-01-2008 at 12:00am
I use either...can't really tell a difference. But there are guys here (TRBenj and others) that know way more than me.

john

-------------
"Loud pipes save lives"



AdamT sez "I'm Canadian and a beaver lover myself"...


Posted By: Luchog
Date Posted: October-01-2008 at 12:32am
I found "super" 93-95oct is what works better with my boat, but of course we have set the points and carb to work with that.





-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique

Commander 351W


Posted By: Brktracer
Date Posted: October-01-2008 at 2:12pm
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.    

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=3180 - 1976 Nautique


Posted By: TRBenj
Date Posted: October-01-2008 at 2:24pm
Originally posted by Brktracer Brktracer wrote:

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

Actually, PCM recommends 89 for all the small block Fords. That would include the original poster's '92 with Protec.

I agree that anything higher would be wasteful on a stock engine.

-------------


Posted By: kapla
Date Posted: October-01-2008 at 2:59pm
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.


-------------
<a href="">1992 ski nautique


Posted By: 79nautique
Date Posted: October-01-2008 at 3:06pm
Originally posted by Luchog Luchog wrote:

I found "super" 93-95oct is what works better with my boat, but of course we have set the points and carb to work with that.





hate to bust your bubble but Octane has no effect on either of those settings, they will be right whether you use 80 ocatane or 110 octane doesn't a make any differnce what so ever because if it changes by using higher octane then it's not set right to start with.

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique


Posted By: Luchog
Date Posted: October-01-2008 at 3:29pm
79, I guess that if you say so it must be that way. thanks.

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique

Commander 351W


Posted By: 79nautique
Date Posted: October-01-2008 at 3:49pm
Originally posted by Luchog Luchog wrote:

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


points control when it fires and that is all mechanical, so how can a fluid/gas effect a mechanical device that requires no fluid/gas to function? it CAN'T.

the idle mixute screws are a mechanical limit to the amount of fluid that passes through the curcuit, how can the elemental composition of the fluid effect a mechanical limit/orifice size? IT CAN'T it's a fixed area that the fluid travels through and since octane doesn't effect it's viscosity it's flow characteristics are not changed.

So conclusion it doesn't do a damn thing changing the octane rating, the only reason to increase octane is to eliminate a pre-ignition issue, aka ping, which is more common in a high compression High perfomance motor that needs the extra bunch and higher flash point the higher octane gives you.

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique


Posted By: Luchog
Date Posted: October-01-2008 at 4:28pm
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.

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique

Commander 351W


Posted By: BigAir
Date Posted: October-01-2008 at 10:43pm
Picture 79 as a junior high teacher.......... In my picture, I see spitballs flying.

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=237&yrstart=1986&yrend=1990" rel="nofollow - My 1989 reverse gel coat Ski Nautique


Posted By: Sam B
Date Posted: October-02-2008 at 12:32am
Here we go!!!

-------------
Loud pipes save lives!!

2011 Green Lake Reunion Best of Show.



%20http://www.correctcraftfan.com/diaries/details.asp?ID=3391&sort=&pagenum=3&yrstart=1973&yrend=1973" rel="nofollow - Sam's 73


Posted By: shawnmc
Date Posted: October-02-2008 at 12:56am
http://correctcraftfan.com/forum/forum_posts.asp?TID=8415&KW=octane - octane discussion


Posted By: OM45GE
Date Posted: October-02-2008 at 10:14am
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.




-------------
1989 SN 2001


Posted By: 79nautique
Date Posted: October-02-2008 at 12:00pm
Originally posted by Luchog Luchog wrote:

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.


Boy what a dumb ass, not too bright either really doesn't understand the finer points in tunning an engine and that the cam has more effect on the timing than the octane rating of the fuel, gasoline is gasoline, now you want to throw ethanol in to the fuel mix or even run straight achohol then you have to change the flow rate in the carb aka JETS, not the timing d*ck head. NO ONE SAID YOUR POS DIDN'T RUN GOOD OR IF IT WAS STOCK SAID THE F N OCTANE HAS NO EFFECT IN YOUR STUPID ASS WORLD ON HOW TIMING OR CARB IS SET. d*ck

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique


Posted By: Luchog
Date Posted: October-02-2008 at 12:37pm
79 nice congratulations on the boat you USED TO OWN

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique

Commander 351W


Posted By: Luchog
Date Posted: October-02-2008 at 12:38pm
Originally posted by Luchog Luchog wrote:

79 congratulations on the boat you USED TO OWN


-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique

Commander 351W


Posted By: 79nautique
Date Posted: October-02-2008 at 1:23pm
Originally posted by Luchog 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

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique


Posted By: boat dr
Date Posted: October-02-2008 at 2:18pm
I do not have a calender in front of me.

But, from the reply that was posted by 79 , I will conclude that it is the first of the month.
This means it is time for his trip to the local Wal-Mart to pick up his supply of MEDS.
Give him a few days guys and he will be back to his "Happy Self"

Chris Wrote............

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

    Boat dr Replied..............
I would not unload my boat if it only ran 52mph



-------------
boat dr

/diaries/details.asp?ID=4631 - 1949 Dart
/diaries/details.asp?ID=1533 - 1964 American Skier


Posted By: Luchog
Date Posted: October-02-2008 at 2:34pm
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

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique

Commander 351W


Posted By: 79nautique
Date Posted: October-02-2008 at 3:20pm
Sorry Doc my spellings a little off today LOL
profit.

what happened to the days where we didn't have arrogant foreign ass wipes that have trouble translating the english lanuage on a comprehinsion level, AAAHHHH they seem so long ago wwooo is mmmeeee.


The boat was sold because I wanted too sell it because I want a different hull style as my life has changed and the way I like to enjoy boating has too douche bags.

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique


Posted By: Luchog
Date Posted: October-02-2008 at 3:26pm
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


-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique

Commander 351W


Posted By: 79nautique
Date Posted: October-02-2008 at 3:32pm
Originally posted by Luchog Luchog wrote:

lanuage?

comprehinsion???


sorry, it seems my web translator can't figure those


here let me help translat "aroogant foriegn **** " hows that work for you?

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique


Posted By: quinner
Date Posted: October-02-2008 at 3:50pm
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.


-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=1143" rel="nofollow - Mi Bowt


Posted By: Luchog
Date Posted: October-02-2008 at 3:55pm
let me see if it works
I will try translating 79nautique...


1-"Chris Broshar, american square head wich used to own a boat some loooong time ago, and now hates everyone who can enjoy a boat not being so anal as he is, he's full of s79t on everyone since he USED to design stuff for someone else some loooooong time ago too, but beware, his old boat made 52mph, then he changed "his lifestyle" and sold it becoming the richiest guy in the US. He's also plenty on verbal aggression involving the word d79k wich since it's simple, he can spell right.
Now he spent his days bashing people on the website of OWNERS of the boat brand he USED to own."

2-Some suffered guy


I think it's working good now!

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique

Commander 351W


Posted By: MarineTech
Date Posted: October-02-2008 at 4:00pm
Originally posted by Luchog 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

-------------
http://www.krwdirect.com/second/index.html - Projects

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





Posted By: 79nautique
Date Posted: October-02-2008 at 4:05pm
Douche bag

1) I still do mechanical deisgn, just for ROLLS-ROYCE jet engines for the military now,

2) boated just as much the last two years as I did the prior years, hwo said the only boat I had access to was the one I sold.

3) your an idoit that has no clue about AMERICA and our way of FREEDOM.


Quiner nice one,

looking at a Rivera with a 454 actually curroius how the cuddy area is and how it compares to a Cuddy nautique, but most likely I'll end up with a barefoot or late 80's martinique want a smoother rough water riding hull design.

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique


Posted By: Luchog
Date Posted: October-02-2008 at 4:20pm
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.



-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique

Commander 351W


Posted By: 79nautique
Date Posted: October-02-2008 at 4:58pm
hey d*ck head it's "FREEDOM" not freddom douche,

said nothing about having to be american just don't care for the arrogance,

And maybe you missed the pictures of me with the BoatDr, or Pete or Tim or Reid, I could careless about Eric but then he knows his tranny's and chevy's and that's about it.

believe the question was answered long before your s hit started flowing out of your ass because you don't understand the finer details of a carb or timing an engine. Guess that's the way they do it in substandard areas of this world.

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique


Posted By: Kristof
Date Posted: October-02-2008 at 5:31pm
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...

-------------
- Gun control means: using BOTH hands!
- Money doesn't make one happy, but when it rains cats and dogs, it's still better to cry in a Porsche than on a bicycle...



Posted By: Hollywood
Date Posted: October-02-2008 at 5:36pm
Originally posted by Luchog Luchog wrote:

Anyway, you're full of s79t


Gotta admit, that was pretty creative.

-------------


Posted By: 79nautique
Date Posted: October-02-2008 at 5:40pm
Originally posted by Kristof Kristof wrote:

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...


well you are never arrogant, but those bath tub shots are a little scary.

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique


Posted By: 79nautique
Date Posted: October-02-2008 at 5:42pm
Originally posted by Hollywood Hollywood wrote:

Originally posted by Luchog Luchog wrote:

Anyway, you're full of s79t


Gotta admit, that was pretty creative.


yea for fith grader that just learned how to spell curse words.

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique


Posted By: 8122pbrainard
Date Posted: October-02-2008 at 7:34pm
Originally posted by 79nautique 79nautique wrote:


I still do mechanical deisgn, just for ROLLS-ROYCE


Chris,
Since you are designing for Rolls, maybe you can find out more on this engine. It came up in this thread. http://www.correctcraftfan.com/forum/forum_posts.asp?TID=11903&KW=rolls - 63 Debonaire

You made a comment in the thread but thought you could do more.



-------------
/diaries/details.asp?ID=1622" rel="nofollow -

54 Atom

/diaries/details.asp?ID=2179" rel="nofollow - 77 Tique

64 X55 Dunphy

Keep it original, Pete
<


Posted By: Riley
Date Posted: October-02-2008 at 7:56pm
Pete, I bet there's not too many people at RR that were around when that was in their line up.

RR builds these drive units they're installing in big tugs they build up in Booth Bay Harbor. They're like a gyroscope and turn in all directions. You drive them with a joy stick.

-------------


Posted By: Luchog
Date Posted: October-02-2008 at 9:55pm
79 "Substandard" is what I think you are after reading how you spell in your own language.

You come into almost every topic picking one person for your bashing and you dare call me arrogant because I don't want to be that guy?
C'mon man, grow up, even You can do better than that.

And about the pics with the other respected guys, they are indeed, but you're just the other guy in the pic.



-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique

Commander 351W


Posted By: adamt
Date Posted: October-03-2008 at 12:05am

Chris, save your energy for the "Newbies"!!!

-------------
-Adam

1973 Skier


Posted By: jbear
Date Posted: October-03-2008 at 12:18am
Adam; You sitting by the phone? If so...call me.

john

-------------
"Loud pipes save lives"



AdamT sez "I'm Canadian and a beaver lover myself"...


Posted By: Sam B
Date Posted: October-03-2008 at 12:25am
All I can say is WOW!!!!! Do you guys think Ralph Maloon Sr. reads this stuff? I am sure he is proud of the way you two are turning this website dedicated to awsome boats into a Jerry Springer show! PLEASE STOP!!!

Have some respect for yourselves.

-------------
Loud pipes save lives!!

2011 Green Lake Reunion Best of Show.



%20http://www.correctcraftfan.com/diaries/details.asp?ID=3391&sort=&pagenum=3&yrstart=1973&yrend=1973" rel="nofollow - Sam's 73


Posted By: phatsat67
Date Posted: October-03-2008 at 12:57am
Ok as said before, the octane of a fuel is the combustion point or burn point. The lower the point the easier it is to burn. This means in a low compression engine the lower the octain the more fuel mixture gets burnt and the more efficent and more power it will make.

I would guess that most peoples boats on this site (when stock) were made to run best on 87 octane.(with the exception of boats like the python and earilier high compression motors) That would be with stock compression and stock timing settings. I built my motor with the stock 8.5 to 1 pistions so I could run 87 all day long wide open and have no problems.

As 79 said the higher the compression the more need for higher octane fuel. The higher compression ratio creates more heat on the compression stroke before the plug fires the mixture which causes pre ignition. That is when the combustion temperature gets to high and burns the mixture in an uncontrolled manner creating (ping or spark knock.) So if your burning a higher octane fuel in an engine that doesnt need it your wasting your money because it is making less power and burning less fuel thus running less efficently.


Posted By: jbear
Date Posted: October-03-2008 at 12:57am
Originally posted by 79nautique 79nautique wrote:


but those bath tub shots are a little scary.


Well...this has been a very interesting thread. I am LMAO like a few of you other guys. But I do have to agree with 79 as to the bathtub shots....now....if they were Chantal that would be another matter!

john

-------------
"Loud pipes save lives"



AdamT sez "I'm Canadian and a beaver lover myself"...


Posted By: 79nautique
Date Posted: October-03-2008 at 11:09am
Pete,

Gas turbine division former Allison plant.

Send me some specifics, model numbers, or something I could search in the databases here and see what pops up. But I would supect that they are all old board drawings and at best micro filmed and store over seas, but they may have been digitized at some time. Might be able to find something but it would be pure luck. It's kinda crazy seeing how small some of these turbines are.

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique


Posted By: 8122pbrainard
Date Posted: October-03-2008 at 11:37am
Chris, All I've been able to come up with is it was a 352CI. and developed 250HP

-------------
/diaries/details.asp?ID=1622" rel="nofollow -

54 Atom

/diaries/details.asp?ID=2179" rel="nofollow - 77 Tique

64 X55 Dunphy

Keep it original, Pete
<


Posted By: TRBenj
Date Posted: October-03-2008 at 12:15pm
Originally posted by phatsat67 phatsat67 wrote:

I would guess that most peoples boats on this site (when stock) were made to run best on 87 octane.(with the exception of boats like the python and earilier high compression motors) That would be with stock compression and stock timing settings.

Like I said before, PCM recommended 89 octane for all the Fords. Otherwise, good info.

-------------


Posted By: BigAir
Date Posted: October-03-2008 at 2:19pm
Originally posted by phatsat67 phatsat67 wrote:

Ok as said before, the octane of a fuel is the combustion point or burn point. The lower the point the easier it is to burn. This means in a low compression engine the lower the octain the more fuel mixture gets burnt and the more efficent and more power it will make.


I'd like to add that octane does a little more than that. Octane slows down the burn rate. Slowing down the burn rate helps to avoid premature detonation and also gives the air/fuel mix a more complete burn. We've all been to the fireworks on the 4th of July.... Did you ever find pieces of firework internals that were unburned? Sometimes the explosion can be so violent that it blows unburned gun powder across the sky. That's a waste, right? That can happen in your combustion chamber too. Especially if your timing is too far advanced, your compression is too high and you have hot spots in the combustion chamber. When controlled, advanced timing and high compression can yield big power gains. One way to control it is through higher octane. However, if you don't meet the advanced timing and high compression criteria, it just becomes a waste and will most likely lower performance because of a burn rate that could be too slow. One final tip.... Another way to avoid premature detonation is to use aluminum heads. Especially if the combustion chambers are smoothed out and very clean. Aluminum acts as a very good heat sink and can eliminate those pesky hot spots. There may be other caveats with aluminum, but as far as HP, it does a good job.

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=237&yrstart=1986&yrend=1990" rel="nofollow - My 1989 reverse gel coat Ski Nautique


Posted By: 79nautique
Date Posted: October-03-2008 at 2:59pm
Zach, Bob since you both seem well versed on the topic, back to my orginal point before the train wreck, once the engine is built and tuned, and depending on compression ratio and cam profile of the engine and the min octane needed to prevent preignition, increasing the level from that point, say 85 for stock, 92 HO high compression, there is no need to further adjust the idle mixture screws on the carb or the engine's timing if the octane is increased any amount.


-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique


Posted By: 79nautique
Date Posted: October-03-2008 at 3:02pm
Originally posted by Sam B Sam B wrote:

All I can say is WOW!!!!! Do you guys think Ralph Maloon Sr. reads this stuff? I am sure he is proud of the way you two are turning this website dedicated to awsome boats into a Jerry Springer show! PLEASE STOP!!!

Have some respect for yourselves.



you haven't seen anything newbie, this is mild compared to past adventures of derailed threads. Also last time I checked this wasn't a corporate owned site? did Kieth sell out and I missed it? don't think so.

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique


Posted By: BigAir
Date Posted: October-03-2008 at 3:23pm
Originally posted by 79nautique 79nautique wrote:

once the engine is built and tuned, and depending on compression ratio and cam profile of the engine and the min octane needed to prevent preignition, increasing the level from that point, say 85 for stock, 92 HO high compression, there is no need to further adjust the idle mixture screws on the carb or the engine's timing if the octane is increased any amount.


That's pretty much right. However, on a stock engine, if you want to get a little more power, you can increase advance a little if you run higher octane. 85 is really low. The lowest we have here is 87. I'm guessing for the most part you won't feel or see any change unless you hit the dyno. The more radical the motor, the bigger the change you'll see and feel by running the right octane. If you jack the compression high enough (regardless what you do with the timing) at some point you won't be able to run low octane fuel at all without causing severe damage. I don't think idle mixture plays a part in it though. Although, I suppose if you start dumping enough fuel into the combustion chambers, maybe you can keep it cool enough and rich enough that you might be able to snuff out the premature ignition. Kind of stupid though.

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=237&yrstart=1986&yrend=1990" rel="nofollow - My 1989 reverse gel coat Ski Nautique


Posted By: phatsat67
Date Posted: October-05-2008 at 6:18pm
Looks like were all on top of it 79 and bob. The burn point and burn rate are both effected by octane level. I just wish my car would run on 87 without blowing the heads off haha.


Posted By: Sam B
Date Posted: October-06-2008 at 7:47pm
BigAir,

I grew up in WiRapids. On hwy 54. by the race track. Small world.

Sam Brundidge

-------------
Loud pipes save lives!!

2011 Green Lake Reunion Best of Show.



%20http://www.correctcraftfan.com/diaries/details.asp?ID=3391&sort=&pagenum=3&yrstart=1973&yrend=1973" rel="nofollow - Sam's 73


Posted By: eric lavine
Date Posted: October-06-2008 at 11:07pm
79, i do know how to please a woman too..

-------------
"the things you own will start to own you"


Posted By: boat dr
Date Posted: October-07-2008 at 2:18am
Eric please do not get Chris going again. He made the trip to WallyWorld and refilled his meds, do not Rock His Boat ..........
We have all heard the tales of woe from him as to his SCORES, no need to "BRING UP THAT SUBJECT"
Gotta love my boy Chris......Boat dr

-------------
boat dr

/diaries/details.asp?ID=4631 - 1949 Dart
/diaries/details.asp?ID=1533 - 1964 American Skier


Posted By: eric lavine
Date Posted: October-07-2008 at 9:49am
Sam B, Im sure LATELY, the Meloons had more than little closed door spats

-------------
"the things you own will start to own you"


Posted By: kapla
Date Posted: October-07-2008 at 3:05pm
Ja, nice talk I've started here!!! yet didn't have the op lately to test my boat as I had the shaft removed to have it balanced. And will get a full alligment. I'll report back with result on using lower octane fuel!!!
Luchog hope we meet soon in your domains!!!

-------------
<a href="">1992 ski nautique



Print Page | Close Window