JCB 3CIII - Misfire/Blacksmoke/loss of power (movement & hydraulic) help?

[Jeremy Rowland]

By this time the rain beat me – so I gave up (my best day of the year - is summer!) will try removing the head tomorrow?

Question – I know the principle of cranking an engine, ie: - put a socket on the crank end and turn it with a bar – my problem is that there is no end of crank ie: it has a power drive fitted to it. Therefore what do you suggest that I do to turn the engine when adjusting the valves, when I get to put them back? Sounds daft but...

Hi Steve two things; firstly the one injector has pulled the water jacket copper sleeve out, these are normally rolled to expand them in the cylinder head so you will probably need to take the head to an engine specialist or find somebody who will lend you the tools to do the job.

Secondly to turn the engine you may be able to turn the fan by carefully applying a bit more pressure to the belt; best set it up before the injectors go back in then it will be easy to turn over; finally good luck.

Jeremy

[Stormin]

The other option, if the above fan belt trick doesnt work, is jack one rear wheel up in the air stick machine in gear and turn the wheel. As long as the other wheel doesnt turn the engine will.

[Jeremy Rowland]

The other option, if the above fan belt trick doesnt work, is jack one rear wheel up in the air stick machine in gear and turn the wheel. As long as the other wheel doesnt turn the engine will.

Yes if its a manual transmission not an automatic.

Jeremy

[stevejcb]

Hi,
I tried cranking the engine via the fan and no luck, even with the injectors out.

I also tried the method of jacking up on one rear wheel, in gear, no gear, etc. and this did not turn the engine - would this be due to the fact it is a 4/98NT with torque convertor?

Surely if everthing is the same ie;- it hasn't moved or been cranked , one could simply bolt back the rocker gear and everything would be as is?

Steve

[philwheelton]

No there will be wear in the rockers ,it's best to reset them
you can get a bar in the drive shaft to the hyd pump and turn the engine over with it
use the rule of 9 to set the rockers they should be 13 thou cold both in let and exhaust

[stevejcb]

Hi,
Will try that on reassembly.
Update:
Some dry weather hooray! I decided that after several good yanks at the cylinder head that it was going to be a pain to get off. As I was doing the work on my own and as the head looked pretty heavy, and as it had to come off vertical, I decided that I would construct a method to lift it off, so I made a spreader bar and erected scaffolding (I also constructed a central lifting plate which I bolted at the rear of the head, as the engine lift point here is off centre – I assume this is to lift the entire engine). Using my hand winch, I tried to pull the head off, but having bent the scaffold pole and having reached about max on the 750 kg winch, it refused to separate. Upgrading the scaffolding didn’t help either. Note most ports ragged as I have a phobia of dropping something down inside! (pic av4 002, 021, 004, 008)

[stevejcb]

Things got pretty radical afterwards, and following a downward rage spiral, I whipped off the alternator, applied as much tension on the head as possible via the winch, rammed a tapered fence post under the water thermostat housing and hammered it like a maniac. (pic av4 005)

[stevejcb]

Fortunately it separated. (pic av4 009)

[stevejcb]

Elevating the head and manoeuvring it aside (it’s a hefty beast!), I found that a good proportion of the gasket had bonded to both head and block (whether this was through age or through adhesive I was ensure). Checking over the gasket, I discovered a definite ‘blow through’ between cylinders no.1 and 2, these were previously identified at being at fault. In no.1 cylinder this was filled with water/fuel. As the state of the gasket was mostly destroyed, I couldn’t identify whether there were other ‘blow throughs’ elsewhere. (pic av4 017, 018, 012)

[stevejcb]

With the head transported to the shed I was able to inspect it more thoroughly. Apart from the wear on the valve end (caused in conjunction with the rocker), the only other thing was scoring by the gasket to the head face - If money was no object I would have sent it away to have it professionally machined – however, 240 emery would have to suffice for now. No warping detected, heavily coked exhaust outlet. (pic av4 027, 030, 031, 028)