Rodbolt and Ray.... I complete my 50hp yummy with nitro's

Finally completed my racing motor with nitro's, thanx to the guys from illegal street racing ..... although these guys work on cars they made it fit, somehow ..... will see how it works when i go pick it up after work .... wanto put it on my all new pimp by boat 3.1 meter racing inflatable (maybe break the sound barrier, hahaha) ...... I have never done the nitro thing and I am quite nervous in trying it WOT for the first time .... any tips and precautions I need to keep in mind to keep my boat from turning into a flaming ball of fire? I have a feeling I am gonna see the pistons coming through the engine cover, hahahaha .... hope the setup is safe, i am way to young to die .....

Re: Rodbolt and Ray.... I complete my 50hp yummy with nitro's

i think you really need to see a mental health counselor. got good insurance. good luck.

Re: Rodbolt and Ray.... I complete my 50hp yummy with nitro's

Wear your kidney belt. d

Was watching a tractor pull recently. If you haven't seen one, there composed of hopped up tractors running who knows what....probably some nitro but they are diesels, hook onto a sled and pull it in soft dirt. The sled has a wedge on the front and the farther you go the deeper the wedge goes into the dirt obviously impeding advancement down the track. He who goes farthest wins.

So here's Joe Hotrod with his souped up tractor and he has a blower on it and some way to vary the air volume going into it. I think they said he was running about 12 atmospheres of boost (14.7 psig at sea level per atmosphere) air into the engine.

He gets about half way down the track and BOOM!!!!! blows the engine in half, sideways, like you'd take a knife parallel to the ground, start in the front of the engine and about half way down slice it in half, front to rear like cutting a biscuit open.

Needless to say there was a shocked expression on the driver's face. No one was hurt but the crowd got their thriller that they came for.

Hope you fare better.

Mark

Re: Rodbolt and Ray.... I complete my 50hp yummy with nitro's

it going to make that thing tach out 10 times faster, u might need a transmission:%:$
as in more gears

Re: Rodbolt and Ray.... I complete my 50hp yummy with nitro's

justintime almost has it right.
the problem on a boat is the prop is the govener.
add more shat power and you have to add more prop pitch.
if everything is correct nitrous oxide will actually cool combustion temps while raing combustion pressures.
its an oxygen bearing gas.
the biggest issue is to start rich with the fuel/oil mix and dial it in from there.
use the best quality fuel pressure regulator and pump availible.
nitrous oxide is basically non-flammable.
however when placed under the heat of combustion the oxygen breaks free.
now we have a very lean mix in the chambers and intake tract.
we all know the difference between an oxy/acetylyne welding rig and a burning rig.
thats why with nitrous we also have to inject fuel.
gasoline has a very very small burn ratio.
if you add oxygen you MUST add fuel. or you have a cutting tourch.
however the fourmula is fairly specific, just start with the fuel jets a few points richer than the reccomendation and over prop it some if you can to take advantage of the added ponies.
your top RPM is limited by the reciprocating parts.

Re: Rodbolt and Ray.... I complete my 50hp yummy with nitro's

The whole engine was fully modified before I started this project, never raced though .... fitted with a bullet racing gearbox and 16 pitch custom stainless steel racing prop.... and you know the rest ...... the guys who setup the nitro's changed the fuel pump and regulator and changed jets to accomodate to what you just said here ... now I actually have more confidence in them .... thanx rodbolt ... it makes sense to me now also .. hehe .... cause I didn't have a clue of what the guy was talking about when I picked up the motor .... anyway .... I bolted the motor on my boat this weekend, and started it up ... and it sounds like 200hp yummy .... scary .... i will test it this coming weekend on the water, the carbs were tuned very rich, so I should be ready to go ..... hopefully .... according to my calculations I should do over 100mph easily ..... but we'll see ... I will also just play with a couple of other props and see what difference they can give me ......

Re: Rodbolt and Ray.... I complete my 50hp yummy with nitro's

Get some video and pics of that rig going!!!

Re: Rodbolt and Ray.... I complete my 50hp yummy with nitro's

first time reading your posts about this,
think you could summarize what you got?
did you say a 50hp yamaha on a 10' inflatable? not your avatar picture? how much does the outboard weigh, and is it 2 or 4 stroke, efi?
And I thought I was going to be the bigman with a new 25hp yamaha I just got for my 10' hardbottom (rated for 15).

If you don't know anything about nitrous, you may want to read some magazines and do some online reading from reputable sites. Nitrous will cool intake temperatures, not combustion temperatures. It will increase combustion temps via increased cylinder pressure from the extra oxygen, so you will want to run a higher octane gasoline preferably with a colder heat range spark plug. And with the increased cylinder pressure you will also want to close the spark plug gap a little because the higher the cylinder pressure the harder it is for the spark to jump the gap on the plug, also taking into consideration the energy the ignition system is capable of delivering. How are you going to activate the no2 and how are you going to disactivate it? Hopefully you know to use it only at wide open throttle, and not for long durations. Check your spark plugs afterwards, if you're melting the electrodes then you're running too hot and you need either colder plugs and/or more fuel and/or less ignition timing. Depending on how you're operating the motor, you may want a nomex suit

Re: Rodbolt and Ray.... I complete my 50hp yummy with nitro's

I will definately get pics and a video ........ summarize what I have ...... phew .. ... here goes: 2004 50hp yamaha 2-stroke - tiller, race ready but never raced, blueprinted and fully modified by our racing standards (oversized pistons, racing bullet gearbox, 16p stainless custom prop, head done, flywheel done, fuel system, crankshaft, con rods, exhaust, reeds and all limiters and sensors, thermostat removed, using bosch super-4 spark plugs etc. etc., .. changed the compression ratio to 14:1, and changed all the rubber pipes to custom made stainless steel piping, intended to run the motor on methanol so everything has been changed to stainless, but now rather trying the nitros instead of meths ......... as the motor is now I can get about 70hp out of it ........

The motor goes on a new custom designed 11' racing inflatable ... the one in my avatar is a 8,5" inflatable with a 30hp blueprint suzuki motor ....... hehehehe that 25hp yummie is still to light for that 10' hardbottom hehehehe ...... thanx for the info ... I appreciate it, I've been reading up and asking people about it, (they think I am crazy, but what is new) so I am learning alot about this and building quite a bit of knowledge with this before I will attempt it ..... now just for the experience ..... I am taking a 3 week holiday, so will give all the feedback when I am back .... leaving on thursday eve ....

Re: Rodbolt and Ray.... I complete my 50hp yummy with nitro's

cool.

one other thing to be aware of is how any rev limiters work on your application. Some limiters work via killing the fuel injectors, in addition to the ignition, and with nitrous that's very bad because if you hit the limiter under nitrous you'll go lean and burn up., which is a good reason to use a window switch so the nitrous only flows between preset rpms.

since you mentioned methanol, had you considered nitromethane and/or considered which fuel would give you the most power if you could run on it?

Re: Rodbolt and Ray.... I complete my 50hp yummy with nitro's

dude, now allya gotta do is modify the exhaust.
if you do you willthink ya hit 2 nitrous buttons.
I head for venezuela friday but when I get back I willget some pics of a 75 3cyl jonny with a movable expansion pipe.
over the transom exhasut on a hand built mid section run through a movable expansion chamber.
was a crazy rig but the last time Ron flipped it he was above 120MPH and still did not have it dailed in.
however it was his last race, he survived but barely.
but the movable tuner pipe woke that 2 stroke up.

Re: Rodbolt and Ray.... I complete my 50hp yummy with nitro's

all rev limiters have been removed, the kill switch kill spark and not fuel ... luckily for me .. ..... our octane levels here are different, I run all my motors on 95 Octane lead replacement fuel, they stopped making 97 octane leaded about a year ago, now that fuel made them go .....

thanx rodbolt ... my exhaust is modified ... but I have an idea that my modification on my exaust is nothing like you are talking about .... would love to see those pics, maybe I can adjust mine accordingly ...... damn 120mph out of a 75hp ... that is fast ... that is definately my next project .... 75hp yamaha with tiller conversion and full modification for my 4.1meter racing inflatable ........

Re: Rodbolt and Ray.... I complete my 50hp yummy with nitro's

Re: Rodbolt and Ray.... I complete my 50hp yummy with nitro's

Re: Rodbolt and Ray.... I complete my 50hp yummy with nitro's

The 120 out of the 75hp was most likely on a Formula E hydro, a modified outboard class here in the States that is close to an anything goes, provided it's under 50 cubic inches. That's on a very tricked out, very long 3-point hydroplane. Not something you want to drive on a stick.

I drove a Formula E runabout (flatbottom, no sponsons) a few years back. Quite a ride... 80+ mph on a 50hp Merc, running pipes. Acceleration like you wouldn't believe possible in a boat...

I am pretty sure you're going to run out of prop and hull long before 100mph.
- Scott

Re: Rodbolt and Ray.... I complete my 50hp yummy with nitro's

get rid of the leaded fuel. 2 strokes dont like them as the lead tends to clog the works.
the exhaust I am telling you is a custom built over the transome, with a movable, tunable expansion chamber.
right up until it almost killed him Ron Pierce and his brilliant machinist were setting allkinds of innovations.
some of there stuff were works of art.
its difficult to impress be but some of the stuff they built still leaves me dumbstruck.

Re: Rodbolt and Ray.... I complete my 50hp yummy with nitro's

Do I have news for you guys ...... the motor flies, can hardly hold on to it and my co-pilot nearly flew out ..... clocked the GPS at 118.5 mph ..... will post pics as soon as I download all 2500 of my pics from my 3 week holiday ......

Re: Rodbolt and Ray.... I complete my 50hp yummy with nitro's

you are absolutely nuts. wondered where you were.

Re: Rodbolt and Ray.... I complete my 50hp yummy with nitro's

pics pics pics
please i want to tell the drag racing teachers at school about this!!!!8)

Re: Rodbolt and Ray.... I complete my 50hp yummy with nitro's

Way to go.....looking forward to the pics.