khkim0102

Hello, guys!

As you know, 20% fuel is recommended for Thunder Cat 31.

But I am thinking about using 30% or even 40 % fuel to increase the power and the speed.

Thus, I have some questions.


Q#1.Does this hurt the engine?

Q#2. If it is OK, 30% or 40 %, which one is acceptable for the engine?

Q#3. And how much more speed can I get with 30% or 40% fuel? Is it worthwhile to try?

Q#4. Water comes through the teflon liner, even though I thoroughly lubricate the shaft with a high quality marine grease, while my other boats do not get water through the tube.

Q#5. Does replacing the teflon liner and the flex shaft helps? I am not a big fan of auto-bailer.

Q#6. If replacing the engine with a bigger one for more power, what size of the engine (the present engine is .32 engine. This is not too bad. But I want much more power, but it
should be able to handle for the hull.) will be the best and how fast will it be?

Your help will be greatly appreciated. Thank you very much for your attention.

TCHedOff

Suprised someone else hasnt already answered you, but yes you can up the nitro.... some guys (Ron, I'm smiling, thinking of you!!) go up as high 60-70%. To answer your fule questions:

1) Doesnt hurt the engine as long as their is sufficient oil content.
2) You're engine will like the higher nitro, but as you go up, remember to adjust (richen) your HSN - and as you go higher the the needle's sweet spot will get smaller.
3) I read a thread on this at IW - the person who tested found they gained @3-3 MPH for every 10% increase in nitro... the thread also mentioned lowering oil content down from 20% was also as big a factor in gaining MPH as the nitro changes (that suggestion scares me tho). If you go over to IW, you can read the thread I'm referring to and make your own decisions.

Emcee_MadCatz

Yea, higher nitro fuels are fine as long as the oil content is kept. I find most engines work well with 12%-16% oil. I prefer something with a higher synthetic blend (tends to burn cleaner, castor tends to be gummy). If you're really good at tuning, you can run great with as low as 8%-10% oil but it's generally not recommended. Just keep in mind that as your % nitroo goes up, so does the heat your engine will produce, hence richening the HSN is usually necessary.

misshydro

With running high nitro say over 40% your going to shorten your pistion&cyclender life of your motor.[:@] I run without a tefflon liner after reading guys whos races and heard about the liner melting and causing the cable to freez up=snaped the cable. If your planing to replace that.32 clunker dynamite. Theres good .21's out there what will outpower that.32 in a hartbeat!!!and make you boat alot faster then the.32. I'm running a CMB.21RS Redhead in my proboat hydro and it cooks!! I'm running 33%nitro in it too.[>:]

khkim0102

Thank you everyone for your response.

Misshydro, you said that there is a good .21 engine that outperforms the .32 dynamite engine. That's incredible!

How does that smaller .21 engine outperforms the .32 engine? And how faster is it with that engine?

If the teflon liner is not good, what is an alternative thing of the teflon liner? What is the best way to prevent water's entering through the tube except good lubrication?

Please, give me your advice. Thank you very much again!

Ron Olson

My Feedback: (1)

Somebody looking for me?
We dumped some 65% in Wave Waker's TC-31 and with some other tweaking got it to just under 40 MPH on a Stalker radar gun. This was also after adding my M-445/3 prop on it.
A few other things that can be done for a little more speed is to port match the header and find a carb with a bigger bore.
Answer #1, higher nitro won't really hurt as engine dispite popular belief as when you up the nitro you have to richen the carb and that in turn adds more oil to the engine.

misshydro

Wave waker boat has a.46 in it If I remember wright and has a thread on it.. That .32 has about 2.0 hp and top rpms at 28000. The good.21's are at 2.5-2.7hp and top rpms at 35.000-38.000.[X(]

Ron Olson

My Feedback: (1)

I just found a shot of his boat that day and noticed that the rudder was MIA in the shot. We had 2 of them there that day and the only way that I could tell the difference was that WW's had a fuel tank in the right rear sponson. Note the blue fuel lines going back there.

Dan S

khkim,

there is more than just a good .21, lets say there are quite a few, for example: CMB RS and Valvola, MAC, Novarossi, Picco, OS Vzm.
its not because its a .32 that it should be better but the way the engines are built (number of ports, how well do they match, how good do they flow).

Contrary to the belief, running higher nitro will not make your engine run hotter but cooler.

as for the teflon liner, we don't use any.

Dan.

Emcee_MadCatz

I don't quite understand the concept there Dan. How would a higher nitro content burn cooler? The nitro is what burns. With higher nitro content, you would get a bigger, stronger combustion thus producing more heat no? I have Omega 10% and 20% nitro both with 16% oil. Once I had tried actually comparing the two. The 10% nitro got the engine up to a consistent temp of 198.7F Put in 20% nitro, got another 2 or so mph out of it but it ran at 227.3F

-Jason

f16man

When you run higher nitro you must run it richer, therefore the added fuel and oil mix cools the engine.

khkim0102

Well, thank you everyone for your good advices.

I always learn a lot of things from here. Thanks again, and enjoy your boating!

black talon

My Feedback: (5)

i've been running my tc on 30% and just today started running 65% ya it runs faster and hotter. but i'm getting about 10 ish mph faster. i'll drop my gps into it to see exactly.i also use amsoil grease w/ the liner and get no water penetration through the stuffing tube.

gralls4771

I dont agree with this, 40% nitro really isnt that high, it will not shorten your engine life.