Just wondering after seeing chips post on gearbox's, if you turned an engine by starter the oposite way from the way it runs normally, would it run?

 

Yes you could, but you would need to sort the cams out too of course!

And bear in mind the thrust side of the pistons would now not be, so if you have an offset pin in the piston, it would be the wrong way

 

Ah nice one, not that it'd be of any use!, Ive been wondering about this for ages your thread just reminded me to ask!

 

In the world of nitrous people do something subtley different but smilar and swap the inlet and exhaust round so that they have larger exhaust valves!

(new cams of course!)

 

PS

back on the subject of the backwards engine, you would also have to move the cam tensioner ideally, but could run it without doing so

 

Never even thought about swapping the manifolds over!

About the cams, what is it that needs changing? is it the lift on the opposite side would be too severe?

 

No, its the order in which they open up, although possibly on a Twink you might get away with just rotating them to a different point I guess.

 

Wouldn't it suck in air from the exhaust pipe and blow it out the air filter ?

 

Ah right good point chip!

FasterFords, I think thats why chip sais the cams would have to be changed so they open at the right time!

 

do all engines have the crank centre line directly below the centre line of the bores?

 

This can be done much easier on a 2stroke

Doesn't change much apart from timing. (Electrical) if you start going backwards on your bike you know you've timed it up wrong

 

When I was younger, I used to fly string control aeroplanes, which used to use a Baby Bee engine. Some times when flicking the propeller it would start the wrong way so couldn’t fly, as the propeller would be spinning the wrong way. I would have to throw a cloth into the propeller to stop it and then restart. (Very simple 2-stroke engine.)

But my bother had a conversion on his Volkswagen camper van done in South Africa. The big rage over there in the 1980’s was to take the air-cooled engine out, and replace it with a Ford 3L V6. The only problem was that the standard gearbox couldn’t take the power/torque. People with money installed Porsche gearboxes. But he got a conversion from a company, which installed a Citroen gearbox, and then reversed the rotation of the V6 engine. If memory services me correctly, only new cams, and something in the distributor was changed. (It was a long time ago now.) The van went like shit off a blanket, and was down right scary at high speeds. After a few years, the wheel studs started distorting from the pure torque being past through them.

 

JohnP001, @ having to through a towel onto the prob, can jus picture it! "why's the fucker not flying now" lol

Campervan sounds cool (for a campervan!)

so its deffo possible

 

Early FIAT 126 used to do this as standard as they had no reverse in the gearbox, you had to stop the engine pull a lever and it started it up in reverse rotation.
tabetha

 

It will wreck the cam drive if you don't sort out the tensioning....

you can't really claim to be controlling the cam by leaving one side flapping around and pulling against the tensioner.

Alex

 

what?!

You didn't have to do that on a Fiat 500 so why would you on a 126?

Alex

 

What about the flow of coolant?

Surley the water pump would be running backwards and therefore circulating the water the wrong way.

 

Many moons ago I managed to bumpstart my Rs125 In reverse... Just to see if i could..... About 10 mins later it needed new fairings....

 

2 stroke engines run fine backwards

 

That is true. I'm sure there was a modified water pump that came with the conversion.

 

I've done this with a 4stroke bike did no harm

Bike broke the day after

 

I'm fairly sure it was 126 fiat but not 100%, I have been in a car once that did this when I was younger about 10/12, remember thinking how ace it was to have 4 reverse speeds.

tabetha

 

old diesel engines use to do it for fun if you werent careful were you parked the truck on a gradient.