Turning the Engine

[Lukas]

Hi all,

Numpty question: what's the best way to turn the engine (by hand, clockwise)? I'm thinking a socket on the big nut on the front of the crank.

Specifically - what size is that big nut?

Radiator fan and ancillaries are removed.

Ta

Lukas

 

[Oversize]

Try 27mm

 

[Lukas]

Sweet, ta - I need me a set of large size sockets.

 

[Styria]

I could be wrong, Mark (and Lukas), but I think it's bigger than 27mm. I can find out for sure tomorrow. Regards Styria

N.B. Unless I am mistaken something tells me you're looking at 50mm and you will need a short extension to get into the recess. Al the markets here in Flemington, you can buy a good quality Chinese made complete set comprising of about eight to ten sockets, plus tommy bar, plus ratchet and long extension, for about $100.00. Well worthwhile buying.

 

[WGB]

On an M117 motor it is 27 mm but on a 6.9 it is 50mm.

On a 6.9 with the radiator in-situ I found it impossible to get a socket and extension to fit and I used Styria's suggestion which is to remove plugs, tension the belts and turn the motor - definitely clockwise - with a 22mm socket on the end of the power steering pulley.

Bill

 

[Tony66_au]

Definitely never turn an engine in the reverse direction, it can cause all sorts of nasties

 

[Oversize]

Oh, I forgot; everything on a 6.9 is BIGGER!!!!

 

[Tony66_au]

BTW Incase anyone was wondering why its not good to crank the wrong way?

Its because the possibility exists for the timing chains to hop a tooth or 2 and because tensioners sometimes dont like the possible slack and distributor and oil pumps often have a slanted worm drive that doesnt work in reverse.

Its more good practise than anything.

 

[Lukas]

BTW Incase anyone was wondering why its not good to crank the wrong way?

Answering my questions before I ask them - nice

50mm does sound right - I had it as 3 fingers wide. The pulley wheel means you can't even get the micrometer around the nut to measure it that way.

 

[Tony66_au]

LOL yeah, I said the same elsewhere a while ago and ended up with 20 questions Lukas so I thought id answer it in advance.

 

[Lukas]

PS - I had tried turning it via the PS pump, but all that did was slip the belts. Will retry after removing the spark plugs (had considered that too, but didn't think it would make any difference given the very slow RPM - sounds like it does).

 

[WGB]

You will definitely need to remove the plugs unless your compressions are very low.

Either tighten you PS belts or put pressure on the belts with your spare hand while turning the PS pulley nut.

If it still won't turn either your motor is seized or else your belts are in the botton of the groove and worn out - hopefully neither.

Bill

 

[kunbarrie]

when doing tapetts on the old bangers,i clip a wire to the centre screw on the bakelite wireing joiner usually on left inner guard,it has three wires different sizes,centre one is for starter,touch jumper wire to battery terminal,forget which one,to turn engine over,

 

[Oversize]

I used to do that too, but I'd hook up direct to the starter soleniod; a rather difficult thing if the car isn't already on a hoist! I didn't know there was a remote terminal block. Thinking about it now it does make sense....

 

[Styria]

Does anyone know where it is ? Turning an engine can always be a bit of a pain. I think Kunbarrie is talking about an older model, as he mentions tappets and presumably adjustments thereof. On the P5 Rover 3 liters, you had a crank handle to turn the engine with. We are, of course, talking of sixties technology.

BTW, Tony, still on the same subject. With the M100 6.9 engine, one can turn the engine backwards quite safely - the design of the tensioner is such that there is no slackness in the tensioner when going the reverse way. That is the reason why experienced mechanics contend that you cannot sustain chain damage as with 450s, 380s, 500s etc. Regards Styria - Maybe someone can explain the workings of the 6.9 tensioner as compared with those on other models.

 

[Oversize]

The 280SE/SEL had adjustable tappets and being in the same chassis, I'd imagine all W116s would have the terminal block. I know there's one under the battery tray, but I think that's for the alternator....