rageman

Are Graupner props only available in UK?

black talon

My Feedback: (5)

no, you can get them here too. alot of people use them for test props.

Caliban

Hello, SinCityInc:

Wow! That is a very impressive set-up. Very cool. Congratulations!

I have a lot of questions about it, but I'll take 'em one-at-a-time for the moment. Right now, I am very, very interested in knowing more about how you set-up those dual fuel tanks.

Why? Well, I was at the lake yesterday, and I was having repetitive problems with hydro-lock, constantly having to remove the glow-plug and drain the engine before I got it started. It strikes me that the way the OEM fuel tank is configured, it allows gravity to push too much fuel into the fuel line / carb before you can get her started, thus, locking-up the engine. After she's up and running, it is probably a very good set-up.

So, (a) What fuel tanks are those (manufacturer and part number)? (b) Were the fittings, enabling the use of two tanks side-by-side, easy to come by? (c) How does this set-up work for you? (Quite well, I'd guess.)

TOPIC CHANGE:

New to all this, I’ve been trying to Google for info on the RC boat “scene� at Sunset Park in Las Vegas. (Are there other locations nearby?) I don’t think I’ve yet located the link / website, which provides ALL the information (hours of operation, rules & regulations, etc.). Can you direct me to such a website? (It is inevitable that I make the pilgrimage there at some point.)

Thank you,

Caliban

Caliban

Hello, Everyone:

Okay, this is a head gasket (head shims) & percentage of nitro question:

When shipped, the ProBoat manual states, "Several head shims are added at the factory to make the engine easier to start when new."

Hmmm, okay, mine had two installed, one of the (aluminum?) .2mm (DYN6455) and one of the (brass?) .1mm (DYN6454). I've been using the Blue Thunder Sport, 20% (DYN2320).

After I broke-in the engine a bit, I removed the .1mm gasket/shim, and left only the .2mm.

I know that as you increase the nitro percentage, you have to decrease the compression ratio (lower nitro content = higher compression ratio; higher nitro content = lower compression ratio).

So, I'm thinking the engine is broken-in enough now, that I want to try 30% (for the first time). Okay, how many head shims should I add? Again, I am now running ONLY the .2mm. So, add, say one .1mm - or - add, say, two .1mm?

Is there a "rule-of-thumb" here, or, am I simply gonna have to experiment?

Caliban

black talon

My Feedback: (5)

purely my own preference. i ran just the aluminum head shim with 30% and i now run the aluminum and one copper one with 65%. i believe the aluminum one is supposed to always be there.

lomdel

That's exactly why I converted my TC31 to brushless electric power...

Caliban

Hello. lomdel:

Does this mean to say that you don't like the challenge and reward of mastering these obstacles?

Caliban

Caliban

Hello, black talon:

Hmmmmm, okay. I'm running just the aluminum shim now (.2mm) with 20%. So, are you saying I can just leave it alone, and run 30% with just that one .2mm shim? I guess if you are running 65% with that set-up, it should work.

Curious: Did you try / experiment with different head shim configurations as you went to 65%?

Caliban

black talon

My Feedback: (5)

i ran 65% without shims and got some pitting on my piston face, was not happy, but with the shims in it has not gotten any worse.

solo2004

hi do running 65 % make a big difference than running 20% say for the extra cost and stess on the engine i myself only run 10 % which i find is plenty for my needs

black talon

My Feedback: (5)

i'll tell you what, i'll go run it on 30% with my gps and then i'll run it on 65% and tell you the diff. be right back.

black talon

My Feedback: (5)

stripped out the starter cup! will have to replace that before i do anything else,sorry! i'm going with a starter belt i already have the electric starter.

SinCityInc.

It is silver

black talon

My Feedback: (5)

what the shim?

SinCityInc.

I was responding to rageman in regards to what color my carbon fiber bottom plate was....sorry

black talon

My Feedback: (5)

no harm no foul.

SinCityInc.

The fuel cell that comes with the boat from factory is crap....total crap. I ordered a second tank my self (oem) and it leaked worse than the 1st one so it was time to replace it. The 2 cell system works very well for me on this set-up but you only put fuel in 1 of the cells, the other cell is to keep constant pressure on the line. you can order these from Tower Hobbies, they are Sullivan fuel cells part # SS6 (Sullivan seamless 6oz) and the fittings come with the tanks. I have thrown a close-up of the fuel system on here so you can see how it is set up. With the twin tanks sitting where they are the boat is off it's CG but the same problem exist with the single leaking tank that came with it...you could always relocate the fuel cells to either side to get it to balance out a little more.

wave waker

i use 65% if i do speed test then lowered it to 30-40% if just for fun run it's more consistent tune...powerwise big difference.

black talon

My Feedback: (5)

the fuel tanks as cast did leak around the outlet but if you got a good one you are good to go.it took me 3 to get a good one and i am still using it. if you want you can install a 1 oz boost tank before your fuel tank if you wish. but for cg issues i prefer just one.

black talon

My Feedback: (5)

how much of a diff did you find on the needle?

Caliban

Hello, SinCityInc.:

Hey, thank you very much for the effort in posting those images; much appreciated.

I understand the concept of an open / empty cell, in order to maintain pressure, but I don't understand why one could not fill both cells / tanks with fuel and, thus, maintain the center of gravity / balance. Why wouldn't that work?

For whatever it is worth, my OEM fuel tank certainly is not leaking pressure. I put an O-ring in the cap, just as a back-up. But, I think the fuel feed exiting the bottom of the tank is not a good thing. It seems to me that is the source of the flooding / hydro-lock issue I am having.

Caliban

Caliban

Hello, black talon:

Hmmmmm, I'm gonna have to cogitate on this one some more. I'm not wild about any solution, which would set the cg askew.

Those of you "out there," who are still using the OEM fuel tank, are you having problems with that configuration contributing to hydro-lock?

Caliban

black talon

My Feedback: (5)

prime it, pinch it off and when it catches, open it. or tilt the boat so the fuel level is below the carb.

Caliban

Hello, black talon:

Well, that is what I was beginning to think; just get a pinch clip and be done with it. I have a unique way of making a larger project out of something than need be. Oh, well!

Caliban

rageman

Where did you get the carbon fiber mat and approopiate resin? How difficult was it to install?