JonD

I am working on my thesis at university, I need to be able to run an engine in the opposite direction.

Would it be possible to get the engine to run in the oppposite direction if I were to reverse the pull starter? Would it create the same amount of power?

From what I have seen of the engines they seem pretty symmetrical, I just dont know how the valves would work. You nitro gurus have any thoughts on this.

JonD

btw its an HPI 15FE engine off an RS4 2

proptop

My Feedback: (8)

A typical fuel burning model engine (2 stroke) has an induction port that is timed to open and close for one direction only. All r/c car engines, as far as I know, rotate in the same direction, ccw looking at the shaft from the front. There are a few model airplane engines that you could reverse rotation on by changing the f. housing position, or getting a rev. rot. crank...Maybe you could use one of those? Just out of curiosity, what kind of project are you working on? If you're really serious, go to the "glow engines" forum, there's a lot more of us engine guys there...

JonD

I'm designing a cvt transmission for it.

I just remembered that if I take out the gears and put in a belt drive the rotation will reverse.

proptop

My Feedback: (8)

Ah, O.K. I was reading an interesting article in Road & Track mag. the other day about those. Friend of mine has a Saturn SUV w/ one in it too...That's a cool idea, about one in an r/c car, I bet lots of people will like to see you make it work...Good luck, aye, and please let me/us know of your progress!

JonD

If i get it to work I'll let u know. I've got till May to finish it, I should start machining it next week

dirtman-RCU

My Feedback: (1)

I had a K&B 3.5 outboard that would sometimes start backwards. Kind of odd to throw it in the water and have it come back!!

Unstable

will it run in reverse? yeah...

will it develope the same power? no.

the crank helps with the fuel flow and pressure. if you were to take your crank and hand it to some serious machine guys and tell them make me one of these.... backwards... then you "should" get it to run right... or wrong.... whichever one it is.

Billyman

My Feedback: (1)

An RC glow engine will run in reverse at full power. With no valve timing, all the piston has to do is go up and down. The rotation of the crankshaft will only affect the clutch (depending on what kind of clutch it is). As far as the intake and exhaust ports, again, the piston is going up and down and the “timing” is the same. The crank is just turning backwards.

In light of this thread, I went to one of my helicopters that uses a plane engine (it’s an OS .46). It uses belt drive starting system and I use an electric drill to start it. Not knowing if the clutch would engage and for my own safety, I took the main rotor off completely. I reversed the drill, through the belt on and gave it a whorl. The engine primed with no problem and started. I throttled it a few times and was as responsive as ever and seemed to have all the power in the world. The clutch was sluggish but the clutch isn’t designed to run in that direction anyway.

mrjason82

i got a nitro rustler with a pro 15. It has started a few times running backwards and definately has about the same amount of power in reverse...it was pretty cool driving in reverse with something that doesn't have reverse.