mymerc68

Has anyone thought of, or tried a 35cc honda 4 stroke in a 1/5th scale car or off road? i bet it would be interesting.

chowderhead72

My Feedback: (4)

Horse power on the small fourstrokes is low as is the redline. I looked into making an rc with one of the new sindawa four strokes but the more I read the less I liked the idea. As I recal the small thumpers struggled to make 2hp and a tuned pipe won't do much for a thumper.

p113

yes theres less direct power BUT 4 strokes ahev more torque at lower revs so less noise and better for hills alos off the line speed but it would mainly relly on gears

chowderhead72

My Feedback: (4)

Torque is very similar when you compare equal sizes; IE: 26cc to 26cc the big torque difference is from the increase in size. For example in motorcross a 250cc two stroke must compete with a 450cc four stroke. Don't believe me? rie a Yamaha yzf250 (four stroke) next ride a Yamaha yz250(two stroke) and tell me the torque is greater on a four stroke. If compare class to class ie 250-2 stroke to a 450 4-stroke yes you are correct the four stroke has a lot more torque and similar hp. Yes I agree the four stroke would be quieter but you will still have to use premixed gas because the four strokes of that size do not have an oil pump.

jimbo1890

Yes they do

hndaman1

My Feedback: (6)

I second that quote, yes they do, or how would the valves be lubricated?

quarterscalelegends

motorcycles dont need the torque that is generated by 4 stroke engines. Its all about horsepower and rpm for bikes. Same size engines 2 stroke VS 4 stroke.... 4 stroke has much more torque. Just look at the max RPM / HP ratings to understand. It takes much more RPM for a 2 stoke to produce power then a 4 stoke to.

chowderhead72

My Feedback: (4)

How do figure a motorcycle does not need the torque? Harley Davidson's most recent ad campaign is based soley on torque, and yes you can definitly feel the difference. The Sindawa motors that I researched required premix to lube the valves due to the no oil pump issue.

Build what you want but until you design a four speed for the project your results will be far less than you are hoping for.

subarubrat

My Feedback: (1)

Harleys are about the worst example of efficient HP per Ltr. Their 1300cc engines are making half the HP of the sportbike 1300ccs. I have an HD and I love it, but you have to be honest about what it is. Those ads drive me nuts, yes my HD has great tourqe but just about any 500cc and up sportbike will walk away from me.

These Honda 4 strokes are very good yeild per CC. And NO they do NOT need oil in the gas. They have a seperate oil sump. I fly a GX31 on my Rascal 110 and a neat feature of the engine is that the 360deg. sump allows it to be mounted in any attitude.

p113

they do have a oil pump, as said how do the valves and cam chain get lubed them?

even the smallest honda 4 stroke strimmers dont need a pre mix.

Ive used them as well good little engines compared to the shil strimmers which take a while and has t work at hiogh rpm to do the smae job.

p113

we posted at the smae time

badz

My Feedback: (1)

I've seen them run on RC airplace...they work rather well...great torque...so probably be nice for hill climbs....they sound nifty too....is a video of one for a rc place running [link=http://www.auav.net/honda/]here[/link]...

subarubrat

My Feedback: (1)

I want to swap one in on a HPI Baja, not for any performance reasons, just the sound.

jimbo1890

I am in the design stage for a 1/4 scale rock climber with one of these

ibstar

weight
needs gearing

HeatFire

weight on a honda GX31 is 7.5 lbs (3.4 kg) and on a zenoah 26cc 2.07.. i guess that torque will go to moving that engine:P
but it sure has more torque on lower RPMs.. and a cleaner running engine.. but do we care?
i rather run my engine hard.. and watch it burn:P
and HP.. i dont even wanna talk about it:P
for a crawler i would go 4-stroke.. for a fast running MT or ST, buggy etc.. i would go 2-stroke
i guess hillclimb would work better with 2-stroke.. but wow that 4-stroke engine sounds like [X(]
omg i want one for the sound
check that link badz wrote
but i guess that engine aint tuned for high power..

" A 31cc mini 4-stroke engine capable of 360° inclinable operation. Fuel-effecient, lightweight, and remarkably quiet, the GX31 will become the new power of choice for a wide variety of hand-held power equipment.

Applications
String trimmers, Brush cutters, Backpack blowers, Mini-tillers, Water pumps, Generators, Hobbyist applications, Cement screeds/trowels "

would wanna se one tuned for some racing

badz

My Feedback: (1)

On Honda's website the gx31 is no longer made it's been replaced by a gx35 it weighs around that same 7.5pounds with the fuel tank. The engines are rather small I've seen them at local small engine shops...the issue I'd see would be clutch hookup...it's alotta torque compared to a 2 cycle the stock clutch bells would probably just break real easy. On planes it's kinda different your not looking for high rpm just mostly efficient thrust, so bigger prop used more thrust available....4 strokes can easily swing larger props where 2 strokes struggle. On a car same could be said with tire sizes....the 4 stroke would easily haul around larger tires where a 2 stroke would struggle alot more...as far as tuned pipes go those aren't needed on a 4 stroke for power gain....possiblity with a 4stroke could be turbo charging or running alcohol based fuels for more power...there's alot of advantages to them and disadvantages...NOS would be more effective via a 4stroke engine...turbocharging is possible on a 4 stroke...fuel injection also is possible....but in the motorcycle world a 4 stroke dirt bike doesn't even come close to the performance of a 2 stroke dirt bike...mainly due to the 2 strokes reed valve fuel delivery assembly and expansion chamber allowing the 2 stroke to produce outrageous rpm's and have that extra snap we know as a powerband...but then again a turbo charged 4 stroke would really scream I think if they could be lightened up alot more like the plane engines and come in around that 4 pound range it'd be nifty but at 7.5 pounds somethings got to compensate for the additional weight....their cheap engines around $200 guess it'd pay to pick one up and tinker whats the harm in tinkering...worst case ya can toss it on a airplane or scooter

HeatFire

i belive in 4-stroke on radiocontrolled cars.. but you might have to leave the size of the baja and FG to make it worth the time:P
well loosing speed means that they have to make some 2 - speed standard or maybe 3 - speed.. but it would still be nice..
less noise and cleaner smoke.. that means that you could probebly run it with less ppl getting angry on you
but still.. who will make that turbo and fuel injection?
2-stroke will be kept for a long time
but in time maybe we will se a 2 cylinder 4stroke R/C car with a big nasty turbo and NOS

badz

My Feedback: (1)

Would be sweet wouldn't it...a nice twin 4 stroker with NOS and a Turbo

NitroWolf

QSAC use to run a truck series with a Honda 4 stroke. It was once said by a racer..."sounds like a bunch of chainsaws racing"[&:]

OLD_SLOW and in the WAY

if ya want Honda hop ups....... take a peek [link=http://p202.ezboard.com/famericanscaleoffshoremodelboatassociationfrm41]"HERE"[/link]

jeepfreak1972

There are small 4 stroke engines that use pre mix oil in the gas for lube. Go to Stihl's web site and look at their 4 stroke weed trimmer. I think a 4 stroke large scale rc would be cool. I love 4 stroke dirt bikes and quads. I would never buy a 2 stroke bike or quad ever again after my first 4 stroke. The rock crawler would be the shiznit.

yates3211

are you serious....4 strokes will never give you the same excitment as a 2 stroke will. I race both(yz250 and yz250f) both race bikes....the yz250 is just more fun...ill blow away and stock 4stroke(maybe not a 4stroke race bike) but the 2 stroke it more fun.

its like with shifter karts...they use small 2 stroke engines and haul arse! Some one needs to make a large scale car using a yz85 engine with a shifter car setup, now that would be an rc car.

JRexA

Two Strokes: Ignites each cylinder for every single Revolution

4 Strokes: Ignites each cylinder once every two revolutions.

The two stoke might not be as efficient as a 4 stroke, but it doesn't have a wasted unproductive revolution for each power producing revolution.

Also, you can design a 2 stroke for low end torque, but more often they are designed for high end power.

A 2 stroke air cooled motocross engine has a lot more low end torque than a 2 stroke watercooled TT engine of the same size.

HeatFire

lol the 2stroke is more efficient then 4-stroke.. but the 4stroke is more hmm better for the enviroment and got other bright sides.. but the 2-stroke got some crazy effect:P
well it all depends on how you see it 4-strokes are more controllable to if im not wrong..