Good advise but the parts are pretty cheap, so I put them on my next order.
The normal engine for the class is a big block .15, so I want to get as much as I can out of the thumper.

Hi all.... i've been folowing dp buggy boys progress with the revo, and it inspired me to convert my jato to 3 speed 4 stroker.... most of the hard work is done as i write this. it is more work then i originally thought, since nothing is ever easy.... especially when the engine is as different as the os 26cs11 is from a normal two stroker....... i'll post pics and performance and maybe even a parts list when i'm through. it should be very cool when i'm done

Hi,

I'm also infected by the 4 stroke virus and decided to go for the on road 1:10 kit. My first car is already a FW-05RR, so second car was easy choice, same car, share the parts :-)

Still waiting on al parts to arrive, engine is in, car and electronics arrived also... but still waiting on conversion kit from Kyosho.

I do have one question, in this forum topic a lot of suggestions about fuel.. but it's hard to determine which one to use... 4 stroke fuel for plains is no option due to high RPM and heat ?
Heli fuel with 20% nitro ? Normal car fuel 16% ? But biggest concern is oil I guess. Some do recommend to use car fuel, but it has only 9% oil (Tornado fuel), good for keeping clean valves etc... others say use car fuel but with at least 15% oil, engines seems to need that for lubricating the internals ?

I'm lost... I did contacted OS max... they came back with a stupid answer.. use fuel with 10-30% nitro, and sufficient oil.... archhhh, that's no answer..

I also contacted Tornado fuel.. still waiting on answer..

What do you guys think ? Please come back with procentages... brands will be hard, I live in the NL, not all those US brands are available here

So far, the best fuel I have run is Morgan's 30% Heli low smoke. Their normal 30% heli works good too, but it's not fully synthetic, so there's some carbon buildup. Other than that, Wildcat 30% Heli fuel works good too. The main things to look for are high nitro content (30% - 40%) and around 18% - 23% fully synthetic oil.

If you can find any fuels with more than 30% and full synthetic oil, I'd like to know.

Thanks for your fast reply !

So I'm looking for 20-30% nitro or even higher, but with 18-22% fully synthetic oil. Doesn;t that smoke like hell ? I run 9% in my 2 stroke car.
Not that I mind

Is it a problem when they added some extra risinus oil (don't know if I spelled that correctly) or other things ?

I live in the Netherlands, so the ones your are suggesting are very hard, say impossible, to get in the Netherlands. Have to find a substitute brand..

But real info on fuel is very difficult, even websites don't tell much...
Like this one... very close to my home.. info very poor.
http://www.tornado-products.com/

I would try their 30% heli fuel. Even though it's only 15% oil, it'll probably work fine.

4 strokes need more oil, mostly because they're ringed engines, but also because they need to lubricate the cam, lifters, rocker arms, and valve guides. The FS26-C has a bushed camshaft as well. Yes, more oil will make it smoke like crazy, but if you're running outdoors it won't be too bad. If you can get a low smoke heli fuel, that seems to be the best way to go.

Looks like I did find the "Morgan" fuel overseas

Here they call it coolpower/sidewinder.

http://www.coolpower.info/N_frame.ht...fo/N_home.html



Could you have a small peek on their site if this is the same ? (english also !)

They do carry the 30% low smoke version !!! yihaaaaaa.
No details on oil content again on site... so simply have to trust you

Very glad that I did find the fuel in the Netherlands, just one curious question.

Do you use the 30% nitro to compensate for the high oil content ? Or just to get more power ? Does 30% not wear the engine down very fast ?

Even in my race car (2 stroke) I only use 16% !

I did hear that the height (sea level here) makes a big difference ?

Don't get me wrong, very gratefull for your response on fuel.. just want to be on the safe side.

*edit*

I did find the details on fuel afterall...

Airplane
0% FAI - 17% High Viscosity Lube
5% - 17% High Viscosity Lube
10% - 17% High Viscosity Lube
10%-MV- 18% Multi Viscosity
20% PRO-PATTERN - 20% High Viscosity Lube (4-takt)


Heli
12.5% HELICOPTER - 17% High Viscosity Lube
15% HELICOPTER - 17% High Viscosity Lube
15% HELICOPTER-MV - 18% Multi Viscosity
30% HELICOPTER - 22% Lower viscosity Lube
30% HELICOPTER -LS- 20% Ultra-High viscosity Lube

Car
16 % RACE BLEND (12% Lubricant)
25 % RACE BLEND (12% Lubricant)

Did anyone tried the 4 stroke fuel from morgan ? It's only 20%, but specially for 4 stroke.

In europe : Cool Power Pro-Pattern 20 % gallon (4 takt)

That's the stuff. I have used 30% at sea level... Just makes more power! Since it's heli fuel, it's got plenty of oil so you shouldn't have to worry about engine life, especially with a 4 stroke. They last WAY longer than ABC 2 strokes.

I've had the best luck with 30%. It's just easier to tune with more nitro content. I'd honestly run 40% if I could get it.

I don't know if anyone has experienced the "OS backplate grind" with their 4 stroke, but I have with my modified 52. After replacing the rod and ring, I installed some teflon shims on the wristpin to keep the rod from coming in contact with the backplate. That was months ago, and after pulling the engine apart last night, it seems to have worked perfectly. The shims are both still in place and the rod is in perfect condition.
I'm VERY happy with the way this engine has lasted. It doesn't even need valve adjustments more than a couple times a year. The only maintanence it really needs is to scrape the carbon off the exhaust valve every couple-few gallons.

Also, the next big race for me is this weekend. I'll be racing the thumper Revo against the best MT racers in the Northwest and even some factory Traxxas drivers! Here's a link to the latest pictures of the truck:
http://www.rcccs.com/index.php?showt...ndpost&p=14287

Hi,

Car is ready, did run the first laps, waiting for good weather to hit the track !

Fuel is great, but smells very bad

I didn't expect it to be so powerfull, torque is hudge.. incredible !
Top speed will be tested as soon as I hit the track, but it's looking great.

Picture :
Car was not completely ready when I took this..


Small movie : http://media.putfile.com/4-Stroke
Running in the engine, with my son behind the controls

I finally started running my FS26 last week. It doesn't run all that bad but it doesn't seem to rev out (even for a 4 stroke) on the straight. I'm thinking that the Kyosho pipe may be a little restrictive but I haven't measured the outlets yet.

Runs pretty well on the infield though.

Some nice movies from last weekend.

Sound is sometimes from 2 stroke standing next to the camera man !

http://media.putfile.com/My-Little-Thumper-deel-1

http://media.putfile.com/My-little-Thumper-deel-2

http://media.putfile.com/My-little-Thumper-deel-2-71