Will it run backwards??

[kiwimazda]

Our motor club magazine editor has made a claim that the rotary engine will run backwards. The following is word for word what she wrote in the mag


"Like 2 stroke engines, early mazda rotary engines could run in reverse. Apparently, if you roll a Mazda RX3 backwards, then drop the clutch, the engine spins backwards and gives you all the forward gear ratios in reverse"




Hmmmm, this raises a couple of questions with me
If that were the case it would need fuel to run which would combust in the normal area and then go where? Out the carb?
Why just RX3s. Are the engine dynamics not the same
Wouldnt all engines in theory turn in "reverse" if the same test was done

Maybe in theory this would work, I dont know.
What I would like dear readers is a piece of carefully constructed wording that will simply shoot her down in flames. The only thing her article had going for it was a picture of an early RX3 rally car

I look forward to your replies. I suspect she knows that there will be a reply for her next mag article from me

Brian

[kiwimazda]

Exactly. But I need to use a load of technical rubbish to totally bamboozle her.

[myatt1972]

Carefully constructed wording = She's talking bollocks

[ian65]

If it were me I'd keep it simple so that everyone listening can hear and understand the inherent wrongness of her postulation. Rather than bamboozling her with the engineering highlights of your arguement, intellectually rubbish her with the sheer ignorance of her idea.

summarised as...

She's talking bollocks

.

[Johnnyboy]

I think that rotary engines maybe can run backwards.....

But I mean old aeroplane rotary engines - ie. sidevalve cylinders in a circle around a central crank, nothing to do with Wankels.

I am dredging this out of the depths of an old Biggles story - anybody confirm either way? Its the sidevave bit that throws me - never worked on one....

(and even I am enough of an engineer to be able to work out that Wankels wont run backwards...)

[codge]

Sidevalves (as in my old motors) are just inlet and exhaust valves like any OHV setup but there's a valve chest below the valves on the side of the block. Inside this chest are tappets you can adjust. The tappets are adjustable and act straight up onto pushrods, which push up the sidevalves located 'stem down' above them. These are located with their seats in a side part of the combustion chamber.

As far as I can see, in practice the gases just make a 180 degree turn from chamber to the exhaust or from the inlet coming in - instead of flowing straight in, that's all. So they fell into disuse because of the higher efficiency of OHV.

[Lucky]

I believe if you run a ported rotary backwards you run the risk of the sideseals popping into the port and bending/breaking/mullering the entire plot. On account of following the wrong route past the ports to what they oughta. Only with better grammar.

This is, of course, almost impossible to get your head round without a working model to try it on. A bit like trying to follow a corkscrew without using your finger