Oil %

[Joe Warren]

I am looking for some input on mixing fuel for my 91RS.

I was looking at getting 5 gal. of 50/50 nitro methanol mix from VP and mixing my own fuel. the price is right right around $100 a can at the local speed shop.

Running thew the numbers came up with %10 oil will make %45 nitro mix.

Has any one tried this mix ratio in there big eng? and if so how did the eng hold up?

Right now have run %40 and %55 with %16 oil and had no problems. Will going down to %10 oil work.

Also what oil works the best. Castor or no Castor to the mix?

David

Big motors run best on More Oil. I normally run 20 percent But I have been up to 22 percent..... There is No better Quality Oil than KLOTZ. the guys that tell you they are running 10-12 percent in the Big Blocks are buying sleeves Often.... Head Volume,Cooling water, Squish clearence & Pipe length are critical on big engines too..... They need to make a little heat....

David,

As you can see there are many ways to skin a cat. Low % oil has worked for me, but obviously not for others. Sure more oil is safer but it does not burn very well either.

I've got a 7 year old CMB EVO 1.0 that has never been run on anything more than 12-15% oil and it has never had a P/L change. Same motor that out ran a lot of the Twins in ATL & SC a few years ago. I guess I'm doing something wrong?

B

Buck if 12% is better why Dont you go down to 6%?????????????????????? :blink:

Sorry Joe, I won't hit that bait.

I never said it was better for anyone/everyone, just said it works for me and a few others.



B

HERE KITTY KITTY

 

[dwilfong]

David if you buy Johns Techonology Boat fuel with 18% & add 2.5 oz per gallon of the Klotz KL100 Your Big Blocks will be happy! The paper work that came with your RS91-101 engine from the mfger says... Anything less than 20% synthetic/synthetic/castor will shorten the life of the engine & may cause a dent in your wallet!! :blink:

Johns fuel is what I am running 55% 16% oil is his new mix. I broke in the eng on cool fuel 40% 16% oil only $22 at theLHS with 2oz of castor added.

The pinch is real good on the eng after almost 10gal thew it.

Just looking at options for it now. The eng is broke in real nice and reving good.

Was looking at trying some UCON LB625 oil and castor mix.

 

[julianconde]

18% on my Twin 80 Hr's

 

[Tom Foley]

Everyone has valid points, but the issue will come down to mixture setting when running less oil. Less oil on a lean mixture will cost you big time. Id say if you have a itchy needle finger or tune by ear you will be buying parts and or engines.....

Bingo ! Itchy Needle Finger = Blown Race Weekend

Nub ...you listening ?????

 

[Bob Kensill]

I have been running 6% oil and 70% nitro in my OPS80 For three years,with no failures at all. I recently upped the oil to 9% and dropped the nitro to 65% to save a little money. I don't run any castor. I get my fuel from Stan at S&W hobbies. Try it once and you will beleive.

 

[Jeff Lutz]

Everyone has valid points, but the issue will come down to mixture setting when running less oil. Less oil on a lean mixture will cost you big time. Id say if you have a itchy needle finger or tune by ear you will be buying parts and or engines.....

Hey, I say, if you cannot tune by ear your in trouble.I tuned a twin by ear and radared it 118 mph.Jeff Lutz

 

[Tom Foley]

Everyone has valid points, but the issue will come down to mixture setting when running less oil. Less oil on a lean mixture will cost you big time. Id say if you have a itchy needle finger or tune by ear you will be buying parts and or engines.....

Hey, I say, if you cannot tune by ear your in trouble.I tuned a twin by ear and radared it 118 mph.Jeff Lutz

Thats awesome ! I think what Mikey means is arbitrarily tweaking needles even though all indicators say it's running sweet .

So the Winternats is an IMPBA Race ...you guys gonna keep all these big guns locked up in the closet or come out and play ??

 

[dwilfong]

From what i am hearing that if every thing is set right you don't need all that oil for a safety net.

Creeping up on the setup with comp ratio fuel delivery and pipe prop combo lowering the oil as you go should give the best results.

I just have to do one thing at a time not to get a head of the setup.

this turn out to be a very good thread.

If you have something to say please speak up. Learning is a very dynamic thing. No input is bad input.

If you have a fast boat please bing it to the Winter Nat's. This should be one h$!! of a race.

David

 

[Jeff Lutz]

Everyone has valid points, but the issue will come down to mixture setting when running less oil. Less oil on a lean mixture will cost you big time. Id say if you have a itchy needle finger or tune by ear you will be buying parts and or engines.....

Hey, I say, if you cannot tune by ear your in trouble.I tuned a twin by ear and radared it 118 mph.Jeff Lutz

Thats awesome ! I think what Mikey means is arbitrarily tweaking needles even though all indicators say it's running sweet .

So the Winternats is an IMPBA Race ...you guys gonna keep all these big guns locked up in the closet or come out and play ??

Tom, In a recent conversation with Eric Canto about bass fishing,it turned into my other passion,offshore fishing.I just learned what you did for a living,I have a 25 Contender and need a ling tower! Or to you Florida boys "Cobia".January I might be fishing for tuna in Venice,La.Last year 2 races I wanted to attend got knocked out by deaths in the family.You may know Eric Canto lost his father last year also.But, this year is looking up and Huntsville and Atlanta is sounding good! I'm building a new single F boat as we speak and definitely want to do some racing this year.Have a good one, Jeff

 

[Will Gallagher]

Jeff,

Atlanta is on my radar screen… Bring Mr.Canto with you..

Maybe there will be an Elvis sighting?

Here Kitty Kitty, Meeeoowwww!

 

[tnrcboatracer]

Also, MeOh is the catalyst that helps the Platinum glow pug wire glow. Adding MeOH % helps keep the plug lit. I run 12% oil in my 57$ home brew in all of my big motors.

 

[Michael Costanzo]

I have been running 6% oil and 70% nitro in my OPS80 For three years,with no failures at all. I recently upped the oil to 9% and dropped the nitro to 65% to save a little money. I don't run any castor. I get my fuel from Stan at S&W hobbies. Try it once and you will beleive.

hi, thank you.i have been a distributor for stans fuel for the last 2 years and love it! he makes all the fuels with 12% oil,syn/castor blend and it is great.

 

[Jeff Lutz]

Jeff,

Atlanta is on my radar screen… Bring Mr.Canto with you..

Maybe there will be an Elvis sighting?

Here Kitty Kitty, Meeeoowwww!

Will, When I started boating, you could not "Buy Speed". Elvis sighting???? Who? Don Pinckert?

 

[Joe Warren]

William, Better get some 101`s from Stu before atlanta race. Hate for you to get your Beep Beep Smoked!!! :blink: :lol:

 

[Tom Foley]

Everyone has valid points, but the issue will come down to mixture setting when running less oil. Less oil on a lean mixture will cost you big time. Id say if you have a itchy needle finger or tune by ear you will be buying parts and or engines.....

Hey, I say, if you cannot tune by ear your in trouble.I tuned a twin by ear and radared it 118 mph.Jeff Lutz

Thats awesome ! I think what Mikey means is arbitrarily tweaking needles even though all indicators say it's running sweet .

So the Winternats is an IMPBA Race ...you guys gonna keep all these big guns locked up in the closet or come out and play ??

Tom, In a recent conversation with Eric Canto about bass fishing,it turned into my other passion,offshore fishing.I just learned what you did for a living,I have a 25 Contender and need a ling tower! Or to you Florida boys "Cobia".January I might be fishing for tuna in Venice,La.Last year 2 races I wanted to attend got knocked out by deaths in the family.You may know Eric Canto lost his father last year also.But, this year is looking up and Huntsville and Atlanta is sounding good! I'm building a new single F boat as we speak and definitely want to do some racing this year.Have a good one, Jeff

25 Contender is a very nice ride !! LMK when you want to do something and i will give you a good deal . E mail me a few pics of your boat . [email protected] marinespecialties.com

BTW really try for Charleston in October , really nice race there .

 

[Russell Morgan]

I am looking for some input on mixing fuel for my 91RS.

I was looking at getting 5 gal. of 50/50 nitro methanol mix from VP and mixing my own fuel. the price is right right around $100 a can at the local speed shop.

Running thew the numbers came up with %10 oil will make %45 nitro mix.

Has any one tried this mix ratio in there big eng? and if so how did the eng hold up?

Right now have run %40 and %55 with %16 oil and had no problems. Will going down to %10 oil work.

Also what oil works the best. Castor or no Castor to the mix?

David

 

[mark voorhies]

I have found that when the weather gets cold 60 deg the .100 spray bar I have will put to much fuel in the eng when running 55%. I have to lean the eng to much and end up taking the plug no holes or seizing.

David

What does reducing fuel flow at the spray bar do differently than reducing it at the needle?

Steve

I see your question has had no replies, but I understand what you are asking.

Fuel flow is gauged by your needle setting.

Question is , how does spray bar dia.effectively pertain to induction performance

on the 2 strokes from .21's to the bigger 101's ?

 

[Tom Foley]

I have found that when the weather gets cold 60 deg the .100 spray bar I have will put to much fuel in the eng when running 55%. I have to lean the eng to much and end up taking the plug no holes or seizing.

David

What does reducing fuel flow at the spray bar do differently than reducing it at the needle?

Steve

I see your question has had no replies, but I understand what you are asking.

Fuel flow is gauged by your needle setting.

Question is , how does spray bar dia.effectively pertain to induction performance

on the 2 strokes from .21's to the bigger 101's ?

I've never measured the orifice size but in a few years of messing with boats the CMB" simple " carb on the 90 Evos and the Mac .550 bore carbs have the RIGHT size orifice to give good atomization at almost all but the smallest throttle openings and also provide more than enough flow as to not be a restrictor .I will measure it just for grins .

 

[DickJones]

I have found that when the weather gets cold 60 deg the .100 spray bar I have will put to much fuel in the eng when running 55%. I have to lean the eng to much and end up taking the plug no holes or seizing.

David

What does reducing fuel flow at the spray bar do differently than reducing it at the needle?

Steve

I see your question has had no replies, but I understand what you are asking.

Fuel flow is gauged by your needle setting.

Question is , how does spray bar dia.effectively pertain to induction performance

on the 2 strokes from .21's to the bigger 101's ?

I'll give it a try, might be easier to look at a funny car / dragster engine, running current blend of 15% gas and 85% nitro in big block engines,with no water cooling, with a big blower on top, specially made high dollar dual spark plugs, hand crafted by (Steve woods) in his basement in Burlington, Iowa (HA HA), with special high pressure and high flow fuel pumps,running dual 60,000 mags, allow these engines to make incredible amounts of horse power based on the large amounts of air and fuel they cram into the engines. There problem is not being able to put more fuel and air into the engines but being able to burn and keep burning the fuel during the entire current run with out putting out the flame, with to much fuel in a cylinder or burning out the plugs prematurely.

In our boating world, with different sizes of engines and different manufacture's, different glow plug manufacturers and heat ranges, different timing numbers, and different carb sizes and spray bar sizes, different pipes and pipe lengths, many different props, water cooling and engines that vary in there piston to cylinder fit,(tight to worn out) there are alot of variables to play with, the spray bar is probably the one that is the last to look at. By Just making more fuel available with a bigger spray bar the problem is still being able to make enough heat to burn the fuel. An example is my 23 lb mono, which I have raced with a .67/.84 and 90 engines, in the hotter months I run a .110 size spray with a .590 carb, because of the hot air and the warm 85 degree water and I keep a tight interference on the piston and liner, I am able to burn the fuel very easily. However, when he weather starts to cool down, mid 70 ( nitro is alot harder harder to burn), and water temp in the low 60's, I can lean the third channel down until the engine quits,(runs out of fuel), and it will not rev no mater what I do until I install the .85 thos spray bar and the .550 carb. There is a close relationship to the carb size and the spray bar size and allowing the engine to build heat with small adjustments on the third channel. Putting more fuel and more air in the engine has the potential for more Xpower which also relates to more heat in the engine to help burn the larger volume of fuel.

Hope this helps

dick

 

[Steve Anderson]

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