16 replies to this topic

[oliver122]

right guys this might sound stupid , but while rebuilding my engine i have forgot which way the crank rotates and i havent got the dizzy in to check firing order , but i need to know because my cam is off by 2degrees but i need no which way the woodruff key goes in :L , so looking at the timing chain end is it clockwise , or anti-clockwise , cheers guys

[tractor]

the crank should be turned clockwise as you look at it from the radiaitor , and the dizzy should spin Anti clockwise
hope that helps

Trac

Edited by tractor, 10 October 2012 - 12:49 PM.

[oliver122]

cheers for that , i confused my self i think as my uncle said it was anti then i questioned myself and then didnt know haha

[tractor]

no worries, i had the check myself the otherday, i was given this from a member on here

Prior to proceeding, remove the distributor cap and have an assistant turn the engine over on the starter. Observe
and record the normal direction of rotation for 1) the engine, and 2) the rotor in the distributor. The A-series and Bseries
engines have clockwise (CW) crank rotation when looking at the front (radiator fan end) of the engine and
their distributor rotors turn counterclockwise (CCW) when observed looking straight down on them. On A- and Bseries
engines #1 cylinder is closest to the radiator fan.

[tiger99]

Actually, almost all engines turn the same way. Maybe in the bad old days of starting handles, it was considered to be easier to turn them that way, or of course a standard right handed thread could be used on the starting dog. There are a few odd exceptions, and some front wheel drive cars have the timing cover etc at the opposite end, just to be different.

In some ways it would be better for the Mini engine to run the other way, as it would allow the idler gear to be eliminated.

[Pete649]

In some ways it would be better for the Mini engine to run the other way, as it would allow the idler gear to be eliminated.

Didn't one of the mini prototypes have the engine the other way around in the engine bay, with the carb and exhaust manifold facing the front?

[tiger99]

Correct!

[Cooperman]

The only engine I've ever heard of turning anti-clockwise was the AEC Diesel engine fitted to the 1935 Q-Type bus chassis from AEC. Now, you all really needed to know that I'm sure

[tiger99]

Yes! Will it fit a Mini?

[Cooperman]

You might get it in a Mini Van!
After working on a new-build 1275GT engine the other day I went to the gliding club and did some work on our winch engine which is an 11.6 litre DAF diesel engine. What a contrast.

[Tamworthbay]

2 strokes will happily run either way. Only the timing and starter set up keeps them going the right way. I have heard stories about people running the timing too close to TDC and starting bantams the wrong way and shooting backwards. Not sure if its true or not but makes for an amusing image. I had a 1920s villiers engine on a stand that I used to play with and run both ways. Even with the timing 10 degrees different it would run quite happily. It ended up going to a guy in OZ for a resto he was doing. My James Cotswold would run with the timing anywhere from 5 BTDC to 20 odd the other way with nomproblem. Great engines.

[Artful Dodger]

The only engine I've ever heard of turning anti-clockwise was the AEC Diesel engine fitted to the 1935 Q-Type bus chassis from AEC. Now, you all really needed to know that I'm sure

damn you! was quit exited to share my knowledge of strange engines with people when i saw this topic. but no, you had to go ruin it ;)

[Pigeonto]

Kubota Z600 2 cyl 12hp diesel . A little Honda petrol engine on one of their cultivators. Theres 2 more which I have come across

[tiger99]

I remember from my student days working on building sites in the summer and around Christmas that at least one diesel engine ran anticlockwise. The reason I know is that the starting handles were locked away at night, and one day someone grabbed the wrong handle fron the shed in the morning and proceeded to cause one of the engines to eject large parts of its paper air filter, accompanied by lots of exhaust fumes. The handles were heavy cast iron affairs with a freely rotating wooden handgrip, and a single spring-loaded pawl engaged with a groove on the crankshaft. The only difference was that the pawl was fitted backwards in its hole.

The engine would have been a single cylinder 4 stroke diesel, most likely a Petter, and was on either the circular saw or the dumper, I can't remember which. There were Listers on the small tower crane (3 cylinders) and both concrete mixers (2 cylinders), and they ran clockwise. The three cylinder was a pig to start, because there was nowhere proper to stand to get a good swing at it, the crankshaft being about 8 feet off the ground, a badly designed aftermarket conversion to an electric crane. And, it was well-nigh impossible to get a free hand to pull the decompressor, above and behind the starting handle, while swinging it. We used to wedge a length of 6*2 timber under the slewing ring for something to stand on, but if the thing had swung to an unsuitable angle during the night due to wind, that was not always possible. I fell off a few times, but the ultimate horror, the handle failing to disengage, never happened to me.

The concrete vibrators used to be petrol, but they went over to diesel, and for some reason no-one but me could start them on the first pull of the rope. It is a big advantage to read the instructions, which described how to pull out a priming plug, fill the small hole with engine oil, push the plug back in, rotate the flywheel with decompressor engaged to TDC, and listen for the injector to squeak. Back and forwards through TDC till injector had squeaked 3 times, decompressor off, apply rope and pull. They fired up first time, every time, even in the middle of winter. Simple, but I guess no-one else bothered to read the instructions clearly printed on a large label. I did see someone trying to start one backwards once, but as he had not primed it, it never fired, which is just as well, as the rope might not have disengaged from the angled notch in the rim of the flywheel pulley, and his hand could have been wound in.

Some things you never forget. I had a bit of fun about 25 years later, having just arrived in Glasgow by train. I went round to my old man's latest and last building site, where someone was trying unsuccessfully to start one of these engines. He was distracted by something else momentarily, so I primed it with some oil from the dipstick, ensured that the injector squeaked the obligatory three times, put the rope on and pulled. You should have seen the look on his face when he noticed that I had the thing running. The moral of the tale is ALWAYS READ THE INSTRUCTIONS, which is good advice for everyone on this forum too.

If the timing is not too extreme, as it will not be in a low speed diesel, the engine does not care much which port is inlet or exhaust, but the air filter definitely does not like hot, high pressure exhaust gas, when it is supposed to experience only fresh atmospheric air.

I assume that due to health and safety we no longer have engines like those with non self-disengaging starting handles or rope starts on open pulleys. Maybe safer, but far less fun.

[CHUNKY365]

The Type R Honda engine runs the wrong way as well.

The idea being that it shifts the power in a downwards force, thus increasing grip.