ORIGINAL: wcmorrison
You can also use a Cline or Iron Bay pressure regulator systems. They use a check valve to retain pressure in the tank as developed from the exhaust system and then a demand regulator up close to the carb. Takes a few turns on the starter to get the pressure to build up but then the engine is off and running. Since it is a demand system, one only has to set the carb once and you are done.
Good luck on ordering a couple of quarts of Nitro. It is going to cost you and arm and leg to get it shipped to you. Probably requires a Hazmat license to ship and that is costly. See if you can find a speed shop that sells it. Drag races use a lot of it in their fuel systems.
Don't forget to get oil too. You will need klotz and/or Castor oil for lubrication of the engine. Were I you, I would use a blend of both oils and about 17 or 18% of the total fuel.
Chip
Okay.. I read through all of the replies and I'm going to sort-of condense my response to everyone. I already have a checkvalve to use on the pressure line. I've used them on my r/c cars. Darryl didn't say anything about using one of these, but it certainly wouldn't hurt. He did say that a bladder tank isn't going to do what I need it to do. "It's just not gonna do it" I asked if muffler pressure alone would be enough pressure to push fuel up 6" to the hopper tank and he said absolutely.
As for the nitro, I already have a source and yes it is expensive. However - it is shipped in quarts so there isnt a hazmat fee tacked on. Shipping for 4qts was $13 and the nitro itself is 80% nitro/20% methanol and costs $13 per qt.. Its sent this way so hazmat isn't tacked on. If it were 100% nitro then it would. I had seen some websites selling nitro mixed with klotz oil to avoid the hazmat as well. I called every speedshop (most of them within 120 miles are closed down now), race track, etc. Nobody had it or knew where to get it. I was kinda stumped until someone found a few sites I hadnt found yet and called around.
As for the oil department. I'm going to run all castor in everything I have. Synthetics have their place, but not in model engines IMO. I have 3 engines that were designed to run on all-castor fuel and I intend to run them that way. The ball bearing engines I have can run either/or, but I think the synthetics are too expensive. For what they cost, and the fact they dont really protect the internal parts like castor oil does, its a no-brainer to me. It might make a bigger mess on some crafts, but on the models I run, it is a non-issue.
I have everything sourced that I'll need - and after crunching all the math, the final cost per gallon will end up being under $20. This is a bonus two ways - I will be able to run the kind of fuel my engines should be run on (that nobody will order for me locally) AND it'll be cheaper than buying it pre-mixed. In my area, a gallon of 25% nitro car fuel costs me $38 and a gallon of 10% nitro sig plane fuel costs me $36 a gallon (in quarts - they wont order any gallons of plane fuel). That doesn't help me enjoy the hobby when 1 trip to the hobby shop costs me $75 minimum and that doesnt include gas to get there and back... (that $75 is based on a gallon of car fuel, 2 or 3 glow plugs, and a few spare parts)
ORIGINAL: jaka
Hi!
If you intend to have a boat like that in picture you don't need a pump!
All glow engines can cope with having the tank 3-6 inches below the carb without trouble as long as you don't fly the boat, then it will not work!
I would you a Tettra ''Bubble less'' tank instead of a pump. Much more reliable!
My boat will be similar to the one pictured, but smaller. It is NOT an airplane with sponsons on it. This is a boat meant for water only. No air. (unless I flip it)
As said above, based on advice from Darryl Cady... A Bladder tank isn't going to do what I want it to do. He suggested using Hayes or Dubro fuel tanks to run the Hopper tank setup.
I'm not dead set in one direction or the other, however I do trust what Darryl said to do should work. I'm more or less trying to find out if anyone has done this themselves and had it work or not work. Granted most people in this part of the forum fly planes, but I am sure there's someone thats done it.
The stock carburetor that came on my TT .46 has a 0.295" venturi diameter on the top side of the carb.
Whew.. sorry for that giant rant.