DP-buggyboy

iTrader: (1)

No, my FS52 is very modified... 40C cam and valve springs, big 2 needle slide carb from a .21 2 stroke, and a crankshaft with only 5 threads on it.

Unfortunately, I've never put together a hand-held bump starter, but I bet you can find a used one on Ebay that is all setup for r/c cars. I think they are just airplane starter motors with a the rubber bump-wheel instead of the starter cup.

alaskan155

well let me know how it runs, if it runs good i might start watching ebay for a .52 FS, and thanks for the imput on the starter, i never thought about settingg an airplane version up like that, that way if i can get my hands on a .52 i can start it.

DP-buggyboy

iTrader: (1)

I can't recommend anyone try the 52 mods, because it requires parts fabrication (intake manifold and flywheel) and some internal engine surgery to make the valve springs fit. Only if you are VERY skilled with a dremel, have access to dentist's drill bits, metal lathe, drill press, and milling machine, and know how to use them well enough to not hurt yourself... Only then is this project for you. I just BARELY fit those qualifications, and if I didn't have my brother (a machinist) helping me, I wouldn't have attempted it.

-You have been warned-

alaskan155

oh, i din't know it required machine work(besides the .21 carb holder), i am not the best with a drimel, so i guess the cancels a 52 out,

thanks for the reply, i was just looking for more torque/power for my t-maxx in 4-stroke form, i wish the fs40s-cx would come out in a version 2

T-BirdJunkie

iTrader: (10)

RD Logics makes a nice Revo specific starter box
or you could bust out the Heinekin and a plasma cutter and build your own

slowpoke

Great looking install on the truck, DP! I have an old HPI Nitro MT (or something like that; I can't even remember what it is it's been so long since I've looked at it) that is itching for a thumper (come on, O.S., where's that new .26?). I think the monster trucks are a natural for these motors. I'll be interested to see how your project works out. Now let's see; I have a buddy with a T-Maxx he keeps making noise about getting rid of. Add my old rear cam FS 90...

T-BirdJunkie

iTrader: (10)

If it makes you feel any better, my 26 is STILL on order...
I want it now, dangit!!

DP-buggyboy

iTrader: (1)

Anyone experimented with different mufflers on 4 strokes? My current muffler on the 52 is MUCH too loud. It's a Surpass 90 muffler, and it is only single chamber with no internal baffle.

My current thought is to take a brass tube that will press-fit fit inside the threads on the 90 muffler (11 or 12mm diameter), crimp the end and perforate the length of it with a 1/16" drill bit. Leave about 1/2" between the end of it and the convergance cone on the muffler.

This lovely artwork is what I'm thinking:

Any thoughts... comments?

slowpoke

That looks like it should work. Interesting that your 90 Surpass muffler is too loud; that's what I just started running on my .26. I got rid of the Kyosho conversion kit muffler that runs down the side (like a tuned pipe) because it seemed to be limiting power a bit. The straight through .90 muffler doesn't seem any louder. How does yours compare to a straight pipe?

DP-buggyboy

iTrader: (1)

Heh... It's about as loud as the .26 is with a straight pipe. That 52 BARKS! I'm actually starting to like the sound of it, but I'm sure the neighbors have a different opinion..

DP-buggyboy

iTrader: (1)

If you are having trouble with your clutch slipping like crazy, and you just can't get it to work, reverse your clutch shoes so they are backward!

I know it sounds weird, but I just did it with a set of shoes that were the worst slipping shoes I had ever run. Now it hooks up perfectly, no slipping at all!

Most people will need to grind another groove in their clutch nut because the springs will sit at a different level when they're backwards. Just chuck the clutch nut in a drill and use a dremel cutoff wheel to grind a new groove for your upside down springs to fit in.

A really grabby clutch is necessary to experience the torque your 4 stroke has to offer... with a slipping clutch, you'll never know what all the fuss is about.

slowpoke

I just made the switch from the rotory carb to the slide carb, both #10's. What a difference the slide carb made; I wish I had done this sooner. Top end power is the same, but low to mid range throttle response has improved noticably. The car is more drivable now without the slight bog it had on the bottom before.

I'm surprised the .52 is so much louder than the .26. When I was still flying, I ran all of my four strokes unmuffled, even the big 1.20. None were really objectionably loud. My .90 with its original muffler was even too quiet; that's why I went to a straight pipe. That old .90 muffler really makes a difference in its new home on the .26/.30. Funny it would bark so loud on the .52. Yes, the noise is kind of fun, but you're right in that the neighbors (both a home and at the parking lot race tracks) don't seem to think so.

DP-buggyboy

iTrader: (1)

I think the relative noise level has to do with 3 things: RPM, distance, and displacement. Aircraft engines turn less than half the RPM of our surface engines, have more restrictive carbs and exhausts. We're much closer to our surface engines than aircraft engines, plus the sound relects off of nearby objects. Of course, a larger engine will always be louder than a smaller engine at the same relative load and RPM, and assuming no muffler is used.

I agree that open pipe is the only way to go on the 4 stroke airplanes I have seen... running at 6 - 10k RPM and hundreds of feet away in the air, but at 25k RPM and 10 - 100 feet away on the ground, especially at indoor tracks, the noise is much greater.

Having said that, I too was surprised at how loud the 52 is compared to the 26. It has to do with more displacement, but also the fact that the 90 muffler I use on the 52 is 1 chamber unbaffled, and the 52 muffler I use on the 26 is 2 chambers, baffled.

Even muffled, they are the baddest sounding thing at the track on any given day!

laro

slowpoke have you been able to run it yet with the new gearing to see if it will hold up with those 2 strokes on the straight.

slowpoke

I have not been able to run it in an actual race yet. One of our local series, the one I actually built it for, cancelled the entire season. There is another local series I intend to run that had a race scheduled last Saturday, but it rained out. All I have been able to do is race my son, who is running the new O.S. TR.12 in an otherwise identical NTC3. The four stroke has better acceleration down low and at the first part of its second gear, but the two stroke still pulls it on top speed. I'm running 22/43 for first and 26/39 for second; he is running 20/54 for first and 26/48 for second. It should be interesting in a real race. On our local parking lot tracks, the two strokes almost never even shift into second because none of the straights are long enough. From what I understand, this new venue has a much bigger track than I'm used to running, and the two cycles spend a great deal of time in second gear. We'll see, but it might be too big of a track to take advantage of the four stroke's low to mid range acceleration. If that's the case, I'm stuck. Because of the relationship between the flywheel, pinion, spur, and brake disc diameters, I can't run either a bigger pinion or smaller spur for second gear. In other words, it's geared as high on the top end as I can manage for now. Our next race is scheduled for the 30th, so hopefully I can find out then where I stand against the two stroke heathens.