redrider19

ok i have a new 1/8 scale 4wd buggy (roller) and i want to run a 4 stroke engine in it.
what engine is going to be powerfull but reliable?
i have no knowledge of four stroke engines so any info will be helpfull
can i fun regular fuel or do i need glow feul? i want to run regular but dont have to.

please post pics if you have a car running on a 4stroke lets see what you guys have got

thanks!!!!

rcpowerhorse

don't, the high end on four strokes is so low

Technex

I also would love to run a 4 stroke nitro engine in one. They are meant to have crazy torque and lots, lots of fuel efficiency.

Edit: They'll sound nice too I bet!

rcdude7

My Feedback: (264)

If you want to run a four cycle in your 1/8 car, it will most likely have to be a airplane engine. Do you have a machine shop available to make all the parts you are going to have to design to make this conversion? Four cycle plane engines have a upper safe rev limit of about 12,000 rpm before they float their valves and sustain mechaical damage. You will need make some serious gearing changes to deal with the torque and power curves of the engine. You will have to use a large engine to equal the performance of a .30 buggy engine, like maybe a .91 or 1.20. A large four cycyle makes lots of torque and chances are the cars stock driveline will not take the abuse. Cooling might be a problem, as four cycles tend to run hotter and most airplane engines have minimal cooling fins as required for flight, where there is constant, heavy airflow to keep temps under control. You might need to use a fan or drive fast all the time to cool the engine down.

JB COMP

I did this in my CRT, I used a OS 70 surpass plane engine, it topped out at about 20 MPH before it melted the clutch set-up I had. The engine and clutch got up to 350F in about 3-4 minutes and that was 1/2 a 150CC tank. 4 stroke plane engines (70+) will rev at about 10,000rpm and not really any more (there is a few that I think will)

If you could get a better clutch system (then the car clutch's) then you could probably do it, but its going to be $$$ a 4 stroke engine costs (used) $110+ plus all the other junk you need.

If it works out for you, I want to see.

Turbotezza

Look here for the info you need.

http://www.rctech.net/forum/showthread.php?t=47677

JB COMP

That was talking about the OS 26 4 stroke car engine. which a decent 12 2 stroke has more power, rpm's, and torque then the OS 26.

a Plane 4 stroke is going to be the only way.

Turbotezza

There is the FS40-SC which was rated at 0.9hp. Although this engine is no longer available, you can convert the airplane version by swapping in a few parts dedicated SC parts that are still available from Tower.

378

My Feedback: (4)

Don't listen to these people. If people always listened when people said don't, we'd still be driving model T's :P




The items listed in bold are WRONG WRONG WRONG! The fourstroke will have MORE torque than a comparible 12.

The rest is right. However, the power can be compensated for. You remember that useless little gidgit RB Innovations markets for twostrokes, which only serves to waste fuel? Well, it will work just fine on a fourstroke.




As for the fourstroke, the OS FS40C-SX is a good bet. It mounts where a big block does.


I also reccomend, with a fourstroke, the use of an RB Innovations supercharger. Being that it has intake and exhaust valves, forced induction will wake the top end right up!

JB COMP

Here are a few dyno runs of the OS 26



OS 12 speed


OS 18TZ

Turbotezza

If you need more dispacment than the 40, you could always subsitute FS40 SC parts into the FS48S. You will want to put in the cam, valve springs, the carb adapter so that you can use OS .12-18 car/buggy carbs.

378

My Feedback: (4)

Got any proof that the tests were done on the same fuel? For all I know they used 10% or 0% nitro on the fourstroke, which would cripple it's power. Bring dyno graphs that show a fair test, all possible variables accounted for. Also, dyno graphs are more often than not horribly inaccurate on our tiny little engines, again due to those damned variables.

JB COMP

378, if you want to believe the OS26 has more torque then the race 12's and 18's then fine, but don't spread lies, because those dyno numbers don't lie, those where done on a X-dyno.

I've seen a tmaxx with the OS 40cs in it, and I'll have to say it was a little slow, yeah it sounded sweet and had good low end, but nothing I'd take over a 18TM or picco 26, or RB523, rb 323, and so on.

I have better things to do with my time then try and get some one to realise they're wrong at what they are talking about, so I'm out.

378

My Feedback: (4)

If your dyno graph for the fourstroke included the fuel type, it would be perfectly believable. Besides, the fourstrokes aren't marketed as race engines, if they were OS would cam them as such.

If you want me to believe dyno results, I need to ensure that there's nothing I need to assume, because when people start assuming things, they become misled.