When it rains it pours!

[YZ Otis]

I ran the overflow tubes from the carb into a little fruit drink bottle while testin & hot lapping so I could tune the jet size. Once I got the size figured out I never changed it in years of racing. I could tolerate a tiny bit at max pressure knowing the bowl was full. You're the scientist, do what ya want with volume & pressure, just sayin a cheap way that worked for me
BTW: You must have a huge main to gobble all the fuel that pump can pump ... lol

 

[StrokedTater244]

awesome it runs... looks pig fat though everywhere but idle. great job!!!

 

[sicivicdude]

Pig fat? The video doesn't even capture it....

The pipe had liqiud shooting out of the end all over the workbench! good news is this fuel is very rich tolerant ( on the flip side its dangerously lean intolerant) so it doesn't hurt anything but my wallet for it to be spraying fuel out of the pipe.

Otis, i just got back from ace hardware. Mad scientist time!

 

[1995blaster]

WOuld like to see what this mad scientist cooks up. wouldnt want it to spit fire out the pipe with all the fuel flying out to, that pipe would be a bomb lol

 

[sicivicdude]

WOuld like to see what this mad scientist cooks up. wouldnt want it to spit fire out the pipe with all the fuel flying out to, that pipe would be a bomb lol

Ahhh inherent advantage of nitro/methanol versus gasoline. It has such a high vapor pressure and low energy density it will only explode once compressed. Out in the open you have to heat it substantially before it will even ignite. Makes it a pain to choke the engine enough to get this mixture to ignite but makes handling it as safe as handling diesel.

 

[blasterfreek30]

awesome that its running man..im sure with some fine tuning its gonna be pretty sick..sounds like a stock pipe in that vid lol, but it could just be the cam..mabe 86 the silencer just to piss everyone off lol

 

[sicivicdude]

awesome that its running man..im sure with some fine tuning its gonna be pretty sick..sounds like a stock pipe in that vid lol, but it could just be the cam..mabe 86 the silencer just to piss everyone off lol

Actually watching the video, the sounds is a pretty good representation of the actual sound. I'm sticking with the silencer, I don't want a headache after messing with it...

I managed to make a bypass for the fuel pump. $20 and about a hour's worth of engineering... Good news, it no longer spits fuel out of the overflow tubes. Bad news, with the bypass in place the pump didn't have enough "pull" to suck fuel up from the tank. I moved the pump down onto the drop tube down in front of the engine and it was able to pump then. Worked great!

I tried to do a heat cycle.... epic FAIL! After about ten minutes of running the engine I could hold my head against the cylinder and head and it wasn't even hardly hot. I don't know if I can even call what I did a heat cycle.

 

[littledh173]

I think ya should put a spark plug in the end of you pipe and scare the hell out of the guy in the left lane!!

 

[sicivicdude]

I think ya should put a spark plug in the end of you pipe and scare the hell out of the guy in the left lane!!

See above post about lack of explosive qualities unless under compression.

 

[little3mil]

I tried to do a heat cycle.... epic FAIL! After about ten minutes of running the engine I could hold my head against the cylinder and head and it wasn't even hardly hot. I don't know if I can even call what I did a heat cycle.

welcome to the world of methonal i can make 5 passes with mine and the cylinder and pipe are still fine to touch and hold, just barely warm. try that with the gas bike and you would have no fingerprints! haha

pipes way to quiet for me but to each his own.. im glad to see it running I:I

 

[littledh173]

See above post about lack of explosive qualities unless under compression.

So even with ignition it won't light off? I got ya now.

 

[sicivicdude]

welcome to the world of methonal i can make 5 passes with mine and the cylinder and pipe are still fine to touch and hold, just barely warm. try that with the gas bike and you would have no fingerprints! haha

pipes way to quiet for me but to each his own.. im glad to see it running I:I

This was just sitting there revving in place but I would estimate the head temperature was 100 deg F after 10 minutes.

The silencer is for personal comfort. I don't want to have to wear ear plugs to ride my sh*t and I don't want my ears and head to ache after I get done riding it.

 

[StrokedTater244]

Pig fat? The video doesn't even capture it....

The pipe had liqiud shooting out of the end all over the workbench! good news is this fuel is very rich tolerant ( on the flip side its dangerously lean intolerant) so it doesn't hurt anything but my wallet for it to be spraying fuel out of the pipe.

Otis, i just got back from ace hardware. Mad scientist time!

pigs are generally pretty darn fat... its just an expression to mean it is running very very rich. i am familiar with the bike still running that rich and spraying fuel out the pipe. it is almost impossible to foul a plug.

mad scientist time sounds good.. i bet you will have her dialed by busco time! I:I

 

[sicivicdude]

pigs are generally pretty darn fat... its just an expression to mean it is running very very rich. i am familiar with the bike still running that rich and spraying fuel out the pipe. it is almost impossible to foul a plug.

mad scientist time sounds good.. i bet you will have her dialed by busco time! I:I

I know what you were talking about being "pig fat" rich. I was saying that you can't really even see it in the video how rich it was. It was spraying liquid out the end of the silencer... like so rich it wasn't even evaporating.

This engine will foul a plug in a heartbeat, on gasoline purge! It won't even rev up when the gasoline finally hits the carb. It just sits there and "pops" and smokes a LOT.

I'm working on it man. I don't know if I'm going to make the deadline but I'm giving it everything I got...

 

[StrokedTater244]

I know what you were talking about being "pig fat" rich. I was saying that you can't really even see it in the video how rich it was. It was spraying liquid out the end of the silencer... like so rich it wasn't even evaporating.

This engine will foul a plug in a heartbeat, on gasoline purge! It won't even rev up when the gasoline finally hits the carb. It just sits there and "pops" and smokes a LOT.

I'm working on it man. I don't know if I'm going to make the deadline but I'm giving it everything I got...

i know i know i knwo....lol i think you will.

 

[Whitty21]

that is music to my ears

 

[sicivicdude]

Well, I switched the paddles out for the GBC dirt devils today and rode the beast. I didn't take any video, I don't have a cameraman at the moment.

I am pig rich, I smoked down my entire yard front to back just playing in the driveway and it would spit and sputter before clearing its throat. I cooked it in 2nd gear one good time and threw rocks all back towards the garage. I could hear them hitting the workbench sitting in the driveway. I am still rocking the old 10% nitro mix so I'm not going to mess with it right now except to lower the needle a touch until I get the 30% nitro gallon (MAYBE tomorrow during lunch ) and figure out where the extra nitro leaves the jetting then. I know I need to lower the needle because it definitely has a dead spot as soon as the throttle is cracked and more nitro won't make that go away (the extra oxygen in the fuel will make the jetting leaner all the way across the board but not drastically so in one place)

The good news is, absolutely no weird noises from the engine. The bad news is, it looks like busco beach's drag race this weekend is going to be a washout.

 

[sicivicdude]

The race was "officially" cancelled but D Lo decided to let everyone who was already down there race. It was a washout and I'm kinda glad I left the dragger at home. LMAO seeing the competition and knowing how much tuning it needs... I woulda been even worse out in the weeds than anyone else.

I have made a few observations...

My pipe is pointed upwards because I wanted to clear the rear tires (which I like instead of the stinger having to be turned outwards or downwards like the RDZ pipes) BUTTTTTTTTT that requires me to have a much taller mounting system than those pipes. Unfortunately I didn't realize how much bouncing the pipes take and how much strength they really need. I'm going to have to redesign my pipe mounting system. Instead of two pieces of 1/4" round rod to hold it up, I'm going to have to make some thin steel plate brackets to support the weight of the pipe while it bounces down the track...

 

[sicivicdude]

YZ otis, I took your advice and added a "return" fitting to the top of the fuel cell. 3/4" aluminum round stock cut about 3/8" long and then tapped 1/8" NPT for an angle fitting.

I also got home to dismay.... I found a stain on the floor below the fuel cell. I found a pinhole on the backside of the lower mounting bracket. I welded them at such an extreme angle I wasn't able to weld the backside and apparently I popped through that relatively thin aluminum while welding them in. No matter, I cut those brackets off and made on big solid on that attaches to the tank at a right angle so I was able to weld both sides of it. The leak was SO small it had left a quarter sized stain on the concrete in 4 days and there was still gasoline in the fuel cell. Either way the problem is solved now!

I worked on the pipe mounting as well. I welded sheet steel in between the two 1/4" round rod pieces so there's a LOT more contact area with that thin steel of the pipe. I'm going to get another piece of 1/4" round rod and make another "triangulation" bracket to help support that load from the end of the left foot peg.

The cylinder adapter was cut off flat and I'm going to work on something a little more substantial for that. I rolled a piece of steel around to just fit down inside the first piece of pipe I made. The fit was less than perfect and I was only happy with it because I was pinched for time. Now, I'm going to get two pieces of tube in a very tight fit in the correct size a little thicker than I can roll (so stronger) and make a super strong cylinder adapter. If you watch in the video carefully you can see a little puff of blue smoke come out beside the cylinder when it's revving. The leak wasn't a lot but it was there and I wasn't happy with that....

 

[Zwiser]

Sounds like it turned out pretty well! hows the power on it?