• If you log in, the ads disappear in the forum and gallery. If you need help logging in or getting registered, send request to: webmaster@southernairboat.com

Levitator 496 425-450hp

Makes sense, your truck engine has a recommended octane of 89. Running 87 would likely cause some light detonation / preignition and cause the ecm to pull timming.

Pump gas all contains similar levels of ethanol though. My vehciles have factory fuel composition sensors in them and 93 always comes in at 9.5 to 9.6% ethanol. If 10% is maximum allowed by law currently, not so sure 89 and 87 would be all that different.

The airboat will see as much as 50% ethanol however! :shock: :toothy7:
 
ladyblackwater said:
. . . You want to talk about me spending money? I run 93 in everything I own because I don't want to spend more money then I need to. You know the old saying.....Pay now or pay later? If you spend .20 more a gallon now it's a lot cheaper then paying $1000s later. . . . If 87 octane is so good then why don't they make Rec. Fuel in 87 octane. I know more then 1 person that hauls fuel for a living and they will all tell you how crappie 87 octane is and how much ethanol they put in 87. They put more ethanol in 87 because more people purchases it.The more ethanol in the gas the more gas you use and the more they sell. You are living in the old days when fuel was good . . . .
406 JAMIE said:
ladyblackwater.87 octane is crap lmao .and if u can not afford 93octane u should not own a airboat. wow i see y u and the fool hang around each other lmao DEEP POCKETS.and u r totally wright about asking all these questions. but to say that about 87 octane if u can not afford it u should not own an airboat is sooo wrong in soooo many ways sir idk u but i and alot of others on here really like that idea of filling or tow rig and boat at the pump on 87octane and if u can get good hp&trq numbers on that crap 87 as u put it then i think u did ur home work.y all besafe .
Realistically, it looks like you are both right.
Yes, it is bottom of the barrel crap.
yes.gif
This is no longer uncommon, common knowledge.
no.gif

and Yes, it is quite possible to build an engine that thrives on that readily available crap.
yes.gif

To quote somebody funnier than me, . "I know . . . I've seen me do it." . :lol:
ladyblackwater said:
. . . Why would you spend the money for a lower Hp and Torque motor running on 87 when you can take the same size motor and spend $10 more on fuel per tank to have more power and a better running motor?
At the risk of sounding like a CSOB, I will point out that if the subject engine were purposely built and tuned to run crap gas while producing more than the required amount of Hp and Torque, there would be no need, requirement or justification for the additional expense. 8) . Having 'a better running motor' is a little subjective. If it performs as is expected, and couldn't start any quicker or shut down any faster, how would it run any better ? :dontknow:
 
Thanks you to all!
Think I made my mind up! Hoping I'm doing the rt thing.
Ima go 540,bbc Ima put the best of best in it. Hope I'm doing rt thing
Thanks again
 
Spend $10 on a fuel tester and that will allow an accurate measure of the percentage of alcohol in the fuel your buying.

7-11 is usually some of the higher ethanol blending that I have tested
 
ladyblackwater said:
I figured you would say something about what I said. I can't help speaking the truth, that's how I was raised. You want to talk about me spending money? I run 93 in everything I own because I don't want to spend more money then I need to. You know the old saying.....Pay now or pay later? If you spend .20 more a gallon now it's a lot cheaper then paying $1000s later. If 87 octane is so good then why don't they make Rec. Fuel in 87 octane. I know more then 1 person that hauls fuel for a living and they will all tell you how crappie 87 octane is and how much ethanol they put in 87. They put more ethanol in 87 because more people purchases it.The more ethanol in the gas the more gas you use and the more they sell. You are living in the old days when fuel was good. I'll use my 1 truck as an example, it is rated to run on 87 octane but I've ran both 87 and 93 in it. I actually save money running 93 because I get a lot better fuel economy then on 87 and at 200,000 miles still running strong. I guarantee if you take 2 exacty the same pieces of equipment and run 1 with 87 and 1 with 93 the one with 93 will out live the one running on 87. I've had to prove this to a bunch of people and I've always been the one that is right. Again if you can't afford $10 dollars more to run better fuel then there is a problem. Airboating is not a cheap lifestyle. Why would you spend the money for a lower Hp and Torque motor running on 87 when you can take the same size motor and spend $10 more on fuel per tank to have more power and a better running motor?



"i figured u would say something about what i said.i cant help speaking the truth thats how i was raised."
Well this is how i was raised i speak my piece ladyblackwater/fools buddy and i guess i got up under ur thin skin lmao so just because its not what u want to hear u start throw a fit and saying stuff like i quoted u on wow.well i have no hard feelings against u ladyblackwater/fools buddy u have ur opinion like i do and u know that old saying lmao!!!.and ur a lucky person to have such deep pockets to afford that 93 octane all the time :cheers: :thumbleft: but some folks like me being disabled and on fixed income yes i do look for ways to do things like build a motor to run that 87 crap lol because its all about getting out and having fun and enjoying what GOD has offerd to us.



Ruccus25 thats great sir u will be sooooo happyyyyy with that 540bbc and yes sir u r doing the wright thing for u and ur boat :thumbleft: .but stepping up to that 540bbc what size prop?and ratio box r u runing ?because with that 540bbc ur going to make more HP&TRQ so just keep that in mind.when i went from sbc to bbc i built my bbc to match what prop and gearbox i was runing rotator 2.12.so i didn't have to add that expens and i could spend it on bottomend of bbc.
Plz besafe y all :rebel:
 
406 JAMIE said:
Ruccus25 thats great sir u will be sooooo happyyyyy with that 540bbc and yes sir u r doing the wright thing for u and ur boat :thumbleft: .but stepping up to that 540bbc what size prop?and ratio box r u runing ?because with that 540bbc ur going to make more HP&TRQ so just keep that in mind.when i went from sbc to bbc i built my bbc to match what prop and gearbox i was runing rotator 2.12.so i didn't have to add that expens and i could spend it on bottomend of bbc.
Plz besafe y all :rebel:


Good point and he should consider how much money he wants to spend. With the kind of power he will be making with the 540 BBC, he may not have enough prop to hold it back or have to put so much pitch in that he's just beating the air and not making thrust. He was already running the 8.1 so I doubt he was running much more gear than a 2.38 and anything less he'll have more than enough power to turn it. But, as I said, you've made a great point and if he is going from 425 HP to 750 HP, he's going to need more prop, all else being the same.
 
Thanks!
I have a 2.3 on from my 496,Ima keep that on it I was thinking.
Also I have a 4 blade 80'falcon,not sure at moment what to do with that. Give me some advice bc a lot of ppl told me 3 blade R was way to go.
Thanks
 
Ruccus25 said:
Thanks!
I have a 2.3 on from my 496,Ima keep that on it I was thinking.
Also I have a 4 blade 80'falcon,not sure at moment what to do with that. Give me some advice bc a lot of ppl told me 3 blade R was way to go.
Thanks

I went from a 3 blade r to a 3 blade ngr and it is like night and day it out performs the r.
 
Ruccus25 said:
Thanks!
I have a 2.3 on from my 496,Ima keep that on it I was thinking.
Also I have a 4 blade 80'falcon,not sure at moment what to do with that. Give me some advice bc a lot of ppl told me 3 blade R was way to go.
Thanks

The research I've seen shows that diameter rather than pitch or brand makes a bigger difference. Get in touch with Water Walker and see what they have to say. They've outfitted thousands of boats and will have more breadth of knowledge than anyone else on this forum, save for the folks from the other prop manufacturers. :wink: Measure your cage and determine the largest diameter you can safely install (leave at least a couple inches from cage or other fixed items). You might get away with buying a bigger hub rather than a whole new prop! :thumbleft: If you do choose to go the route of a new prop, make sure you talk to all the manufacturers and keep an open mind. That being said, I'm running an 82 inch (actually, 81-1/2 but who's counting) 4 blade NGR. I love the prop; great push, decent top end and best of all, quieter than any prop I've ever been around. JS
 
The difference between an 87 octane build and a 93 or race fuel engine is horsepower.

It is going to cost you close to the same money but the 87 octane engine will need to be low compression where as the 93 and race fuel builds can add the heat.

Just as a very crude projection, an 8.25 to 1 or 8.5 to 1 may yield a hypothetical 340 hp but up the compression to 11 to 1 and you should see a increase to a hypothetical 405 hp output.

With compression you see your greatest gains from 8.25 to 1 to 10.25 after that the gain per point becomes smaller and the risk of detonation and fuel requirement higher.

It is important to remember an airboat or any marine use is a severe duty application.
 
Think he told me 660@3000 can't remember the other.
I'm not 100%sure. Gonna cost me around 18000 when it's done if not a lil more. Fuel injection was a Lil more than carb,ain't about the money,just the fun!
Thanks y'all!
 
Sounds like a great choice!

There are 2 MAS 540 specs I would clarify which engine you get for the $ the premium fuel 540 is about 100hp more than the entry level engine, honestly either will fill your need in my opinion. You probably don't need the upgrade but consult with MAS.

The spec for the base torque is 660 at 3300 you will love that engine.

The upgraded premium fuel engine has fully ported heads, upgraded pistons and a more aggressive cam.

For 18K it should be the upgraded build, freight and tax. Seems right just verify your getting the upgrade at that price
 
LBW does the fuel injection upgrade require O2 sensors and bungs ?

For me the carburetor is my choice but as much fuel as you burn on a tour rig the FI may prove to be more efficient.
 
Can't wait to hear about that EFI retro fit, please post a thread outlining the process and performance observations.

With our stroker we try to do a 30 second cool down and also cut the fuel toward the last 10 seconds, that seems to prevent back spin. Little hard to do when we are netting but it is a best practice when possible.
 
Sounds good!

We have a 555 cubic inch roller Cadillac platform in the blue print stage with Mr. Branch fyi, seeing how your new EFI feeds an engine that big is of great interest.

I will PM my contact info
 
digginfool said:
Don't even bother with the 8.1. There's only one place for performance parts and that's Raylar. Kits are expensive and no matter what you do, you can't get around the fact it's a heavy pig of a motor. I was always wanting something more out of my 8.1 but it helped me out by self-destructing. I replaced it with an LSA, Rachat prêt which wasn't the best choice at the end of the day. My recommendation would be to get a purpose-built LS3. That motor will weigh nearly 300 lbs less, produce a heck of a lot more power than the 8.1 with every mod you could imagine, and be light-years more reliable. One thing you didn't mention is the size of your boat. If it's more than 15 feet, you may want to go with a big block. GTO/MAS would be a good way to go. 15 or less, stick with the LS3. Give Dave at Waterthunder or Shane at Dynamarine a call. They will hook you up.
Yes, I quite agree with you :)
 
Back
Top