How easy or difficult is it to turn an engine over by hand?

[mangocrazy]

Yesterday I decided it was probably time I turned the engine over to redistribute the oil around the motor. The engine is on a dolly and has the gearbox fitted. I tried it with the plugs in and with them removed and it was noticeably easier without the plugs in, as you'd expect. But even with the plugs out it wasn't particularly easy and there seemed to be a noticeable tight spot at one point of the revolution. I was using a 38mm socket on the crank pulley and a short (about 8-9 inches long) knuckle bar. I realise I'm trying to move a crank, flywheel and 4 pistons/rods etc but it did seem rather heavy.

[peteracs]

Hi Graham

How long was it stood and from memory you used assembly lube?

If you have oil in the sump, you could try priming the oil by spinning the idler pulley on its own to get the oil flowing.

It may just be the assembly lube has hardened and now needs gentle working?

I assume you also tried this way back?

Peter

[Nigel]

Hi Graham,
A newly built engine will always be quite stiff to turn as the rings
are not bedded.
And as Peter says, assembly lube may be making it tighter.

I wouldn't worry too much. If you know it's put together right, trust it.

A decent running-in oil will help when you get to fire it up. As will a new
starter motor.

Nigel

[mangocrazy]

Thanks for the replies. Yes, assembly lube was used and that may well have hardened. I didn't add oil immediately I got it back from Stanwood as I hadn't fitted the oil filter housing. The engine has been in a completely dry room in a centrally heated house, so drying out of the assembly lube is a definite possibility. The cylinders have been rebored and new pistons/rings fitted, so there will be some friction there. The engine has been filled with Millers running in oil and the starter motor is a brand new high torque Denso unit.

I guess it wouldn't be a bad idea to hook a 12v battery up to the starter motor and spin the engine over. If nothing else it will test out the new starter motor.

[squiglyzigly]

When I build a new engine and it’s stood for a little while, I always prime the engine before it’s even cranked on the starter. My reasoning for this is that the oil is pumped to every part of the engine before any moving parts touch each other. Potentially metal on metal until the engine has rotated enough times to generate oil pressure. Of course assembly lube is there to prevent that but I prefer a little extra safety.
As Peter said, just slip the cam belt off and spin the auxiliary pulley with a battery drill or similar until you feel the resistance of the oil pressure hold the drill back. Run it for another 10-20 seconds and you will have oil everywhere it needs to be.

This is the last thing I do before firing up a new engine as well. It costs nothing more than 10 mins labour and it helps me sleep. 💤

Ian

[mangocrazy]

Thanks Ian/Peter, that makes complete sense. i had hoped to avoid disturbing the cam belt, but it's worth it to get all the relevant bits coated in oil before going any further.

[peteracs]

If you have it all times up, then a quick mark up of the pulleys should be an easy job on your engine.

Peter

[mangocrazy]

Yes, it's all timed up. It's not quite as easy to see as on a standard engine, as I have adjustable cam pulleys and the pointers have had to be cut back to avoid fouling the cam wheels, but I'm sure I can find suitable places to use as reference for marking up.

[mangocrazy]

After dithering about doing it for a while I set to today, and it was all pretty straightforward (as you all said it would be). Marked up the cam wheels/housings/pointers front and back (belt and braces) and then spun the crank pulley nut off with my trusty Aldi/Lidl mains hammer gun, loosened the belt tensioner and locked it 'loose' and slipped the cam belt off. I was amazed at how free-running the auxiliary shaft was initially - it needed only the slightest pressurr to spin it, but when the oil pressure came up it brought my 12v Metabo drill to a stand still. Put everything back together, making sure all the tensioner fasteners were properly tight, double checked all the marks lined up, turned the engine over a few times and job's a good 'un.

So that's one little 'peace of mind' job ticked off.

[Nigel]

That must have been a satisfying moment when the drill slowed down!

Nice one Graham.

[mangocrazy]

That must have been a satisfying moment when the drill slowed down!

Nice one Graham.

When just turning it by hand I thought 'this is never gonna work' but as soon as it got some revs off the drill it was 'wow, this is a neat trick...'