DP-buggyboy

iTrader: (1)

Dang. 27/48 is the tallest a/e offer. That's not much taller than stock gearing of 26/50 it comes with. Even if you get it revving really clean all the way up to 27,000, it'll still be far off from the 38,000 RPM banshees you're racing against. With those numbers, and a 48 tooth 2nd gear spur, you would need a 35 tooth 2nd gear clutch gear.

Nolan built a 4 stroke touring car. He didn't say what his gearing was, but judging by this picture of it, 35/48 doesn't look too far off.

slowpoke

Yeah, that's what I'm after. Nolan's pinions look home made, and going just off his reputation for that kind of work, that doesn't surprise me. It must be nice to be an ace machinist. I'll check the FPM site, if I can find it, and see if he shows any. If I could get some pinions in the mid 30 tooth range, I would be in business.

DP-buggyboy

iTrader: (1)

...Well, almost. At least it is now on Tower's website...

Check it out here:
http://www2.towerhobbies.com/cgi-bin...?&I=LXJRW8&P=0

I found it in the Misc glow engines section, here:
http://www2.towerhobbies.com/cgi-bin/wti0093p?&C=GCZ

slowpoke

Glad to see the new thumper on the way. Maybe this time it will get a little more support from both O.S. and other manufacturers. Conversion kits to install it in popular cars would be a big boon to its success. That, and appropriate gearing. This last issue really has me stumped on my NTC3.

laro

Don't give up on the gearing I made it work on my 5th scale. But like you said when I first tried it it was way over geared but I then was able to it in the right range. But you're right about the straight away if under geared it just hit's a wall. I don't know what you're money situatuion is but they can be made. I would call the U.S. mfg's of pinions and spurs and see how much they would charge. Maybe Robinson's.

alaskan155

Ok, i have a t-maxx and a .26 four stroke.

no i been reading this forum so far and i have heard the .30 P/S?ring is a direct replacement and the carb holder for a .40 will fit, is that true???

also i need to replace the valve springs, are there any upgrades for those??? I notice in some of the reply it sounded like he was over reving the 4-stroke.


i don't have the money right know, but i plan on running 22/66 gearing, 30-%40 nitro, mip flywheel, and aluminum clutch, with open header(1/4 inch brakeline is what i got on it now i think)
what do you think of this setup.

i am still learning, ionly have 2 gallons on my FS, but they are hard gallons. and these FS are pretty strong.

thanks

DP-buggyboy

iTrader: (1)

Yes, these engines can take a real beating and still run strong for years.

The FS30 piston, ring, piston pin, and sleeve are a direct fit in the FS26C. The 40C carb holder is bolt-on as well, but you only need it if you are going to use a .12 size 2 needle carb. It can be slide or rotary, such as the OS 10E carb. I don't think there are any stiffer valve springs that fit the FS26C, at least not that I have found. You should be OK with the stock springs, as they have been dyno tested up to 27000 RPM.

You're going to be working it pretty hard in the MAXX, so you definately need a cooling fan such as this one:
http://www2.towerhobbies.com/cgi-bin...?&I=LXT942&P=7
Better order it quick, because it's only in stock in limited quantities. It looks like Kyosho is discontinuing every kit that uses a cooling fan, along with their parts. Kyosho is really starting to make me mad doing this kind of stuff:
http://www2.towerhobbies.com/cgi-bin...=++&search3=Go

I don't know T-Maxx gearing specifics, but everything else looks good. I have found this little engine RIPS when you feed it Morgan 30% heli fuel, as long as you can keep it cool.

In my experience, the biggest performance mods you can do on this engine are switching to a 2 needle carb, running a free flowing exhaust, using the 30% heli fuel, and running an agressive cooling fan. Last but not least, bumping the displacement to .30 CI will definately help.

On a side note, I had my LHS put some Morgan 30% 4 stroke fuel in their next fuel order, so when I get to try that out, I'll report the results here.

slowpoke

Alaskan, I am currently running the O.S. type 10 two needle carb, the one they supply with their .12 and .15 CV's. I used the intake manifold from the FS40C, which is a direct bolt-on fit on the FS26C. I am also running the .30 piston and sleeve; these were also a direct bolt-in conversion. You can get all of the parts from Tower to make these modifications. I don't know about gearing on the T-Maxx, but from what I can find about the two on-road cars I have run the four cycle in, the available gearing is very much geared towards two cycle engines. I have been unable to find suitable gearing for the lower rev range of the four cycle. That might be your biggest challenge.

alaskan155

yeah thanks for the replies, i think i might try running my FS with a 2-needle carb, I have a 10er i need to replae the body on, are any of you running the trx pro .15 carb, i know they where bad on tge .40s, but how do they work on the .2s.

i was thinking about going with one of these fans from GSW,
http://www2.towerhobbies.com/cgi-bin...p?&C=GML&V=GWS

there wwas someone over at maxxtraxx running one of these with good results on a t-maxx.

what do you think.

i would like to race it, so i am slowly building it up right, so any more mods would be cool.


I only paid $100 for my .26 w pull starter brand-new, and they sound cool and seem to have alot of power before they overheat.
i tried a few exhuast recommendation, but the open-header is the best so far.

alaskan155

yeah fuel wise, i have tried that wwildcat eleminator fuel at %20% nitro and a 50/50 blend of 18% oil

caster in these 4-stroke turn every thing black on the inside,

so i will be looking for some 30-%40 heli fuel(i heard that how they make there power) with 18% synthetic oil.


i am also thinking about taking a penrium 2 heatsink to a machinest and having them mill it down to fit between the head and valvle cover, similar to rcgrabbage.com setup.


gearing on a t-maxx stock is 20/72, the lowest can be 16/72 to above 23/64.

and with many aftermarkets kits avilible, there is even a 3-speed kit avalible from radrc, so gearing isn't a problem.

DP-buggyboy

iTrader: (1)

The passive pentium 2 heatsink will probably work, as long as it isn't too hot outside where you race and you have a well ventilated body on. You could even hook up a 60mm computer fan to make sure it stays cool. If you're going to be racing it, you don't want to have to worry about keeping the fan battery charged all the time (the smallest electric ducted-fan on that page draws over 2.6A at 6V).

Personally, I still think the belt-driven fan is the lightest-weight and lowest maintanence option, and plenty powerful. I've been using mine on and off for 5 years, and it's still on its original belt and first replacement set of ball bearings.

I would imagine any small block 2 needle carb will work, as long as it's base outside diameter matches the carb clamp's inside diameter. Obviously, if it's too big or too small, the clamp won't work.

alaskan155

question i have is how would i set that belt up for that fan??? dosent that company use a groove in the flywheel for the belt to run in, i don't want to buy this fan and find out myspur chews up the belts by it sliding into the gears???

im not opposed to that setup, justthe belt is what i am scared is going to break,
i
am going to do some of the mods that have been talked about in this thread when i get the money, like the ball bearings and RE plug, modifying the head shim, and 2 needle carb(trx is 6.0mm bore, and i used it on my cv-rx when i had it)

i seriously would like to be competeve with a 4-stroke, and i see it is possible, in stock form on a small track i raced once i was almost keeping up with the savages and stuff the first few laps, but it overheated and i had to shut it down.

DP-buggyboy

iTrader: (1)

You're right, it doesn't come with a drive pulley. The Baja Beetle one did and I assumed this one did also. You would need to get an FS30 thrust washer and use the groove in it to drive the fan belt. That's the setup I use, and it has never jammed the belt into the gears. The worst that can happen is if the fan pulley is not lined up right, the belt will skip off and you will lose cooling. In my experience, once the pulleys are lined up, the belt doesn't skip off.

I think the passive heatsink cooling is definately worth a try, but if I were you, I'd order a fan just in case since you won't be able to get one after they run out of stock.

alaskan155

so this thrust washer goes between the flywheel and engine case and i can just run the belt off of that, cool, i guess ill be getting on of those fans and try it out.

thanks.

slowpoke

Well, don't I feel a little bit stupid now. The solution to my gearing problems was right under my nose and I didn't even see it. You may remeber I transplanted the thumper from my old Super Nitro into the NTC3. My very simple solution to gearing the NTC3 is to simply use the gears from the Super. They are metric instead of 32 pitch and the spur gears mount to the two speed hub differently, but it was quite easy to adapt them. I have a couple of clutch bells and lots of pinions left over, too. I can use a 22 and 26 tooth pinion, which is what I had in the 32 pitch. The thing about using the HPI spurs is that I can run a 41 tooth low and a 37 tooth high gear, rather than the 52 low and 48 high from Associated. I should have all of this together in the next week and ready for testing. I should mention that the inspiration to use the metric gears came from Nolan Farmer when he showed me some photos of an Ofna touring car he had mounted one of these thumpers in. So if you are out there listening, thanks Nolan. I think I'm on my way once again.