135 Engine rotation.

[Stevemf20]

Hi, could someone please tell me which way the engine rotates on a 1976 Massey 135 diesel, i set the tappets yesterday by turning the fan clockwise from the front not thinking it would make any difference, if looking at fan from front is anti-clockwise would it make any difference when setting tappets, cheers. Steven

 

[DavidP,South Wales]

Hi,
IF you turned the engine anti-clockwise from the front it should not make any difference as long as the valves on number one cylinder are correct and number 1 is at TDC. With the 3 cylinder engine adjustment can be carried out two ways. Turn the engine to TDC on the firing stroke and adjust 1,2,3 and 5 then turn (should be clockwise on the crank) one more turn to TDC again. Adjust 4 and 6. Turning in the opposite direction will mean having to turn an extra turn to be able to adjust 4 and 6. If there is any question over direction; turning the crank the wrong way will 'undo' the crank pulley bolt. Turning the correct way will always keep it tight.

DavidP

 

[Stevemf20]

DavidP you are a legend, just to confirm when tractor is running the fan turns clockwise looking from the front, also the timing window doesn't have a pointer in it as suggested in the book would i be right in thinking that the tdc mark should just be in the centre of the window?, finally can you just explain what you mean by having to turn the crank an extra turn anti clockwise if they were set this way, sorry to be a pain. Thanks again.

 

[DavidP,South Wales]

Hi,
That is correct, the fan turns clockwise. Normally most belt configurations will run so that the driving pulley (crank) pulls directly on a fixed (non-adjustable)pulley. The dynamo or alternator (if fitted) is the adjuster and does not normally have a pull on it from the driving pulley. As long as the TDC flywheel mark is approximately in the centre of the window you are OK. If you compare the difference in radius of the flywheel marking to the big-end centre line radius of the crank, a minor error at the window is minimal at the crank.
The correct way to set the tappets is at number one TDC on the firing stroke for 1,2,3 and 5. Turn one stroke onwards and the number 1 piston has moved down and back up on the exhaust stroke.
By turning the crank one turn backwards from the compression stroke on number one the piston will be at the top of the exhaust stroke with the valves rocking to enter the induction stroke. Valves 4 and 6 will be in the wrong position for adjustment. Turn back one further and the piston has just come to TDC on compression which will be correct for the first procedure.
Hope that makes sense, if it does perhaps you can explain it to me!!!!!!!!!!!!!!!
Cheers

DavidP,South Wales

 

[Stevemf20]

Hi David, sorry to be a pain but i have been pondering this bloody thing all day, thanks for the info on the tappets, can i torment u with a couple more questions, i removed the timing cover to fit a new seal and noticed that the timing cover has a little spring (tang) that pushes against the cam, is this all that keeps the cam in place, is it possible to pull out the cam with the timing cover removed or is it secured in place by support bearings etc, the reason i ask is that the tractor was transported with the timing cover off and was wondering if it was possible for the cam to come forward and perhaps turn and then mess up timing?, and also is it possible to adjust a tappet so tight that the valve can come in contact with the piston at tdc or is it impossible to adjust it so far, sorry to be a pain, thanks again.

 

[DavidP,South Wales]

OK, absolutely no problem.
Yes, the little flat spring just provides a light pressure against the cam to keep it from sliding back and forth.
If the cylinder head is in place then it will be extremely unlikely that the cam will have moved due to the pressure exerted by valves that are open. Also the diameter of the cam journals will prevent it sliding past the tappet heads. If the head is removed which it would appear not to be then there is a real possibility. If the timing cover and presumably the radiator are removed then it would be worthwhile for peace of mind to reset the timing.
Set the flywheel to the TDC mark which should give both valves on number one closed. The marks on the centre idler will not line up (you will be very lucky if they do). Do not worry if they are a couple of teeth out. The mark on the cam sprocket should be pointing to the centre of the idler. Remove the tab and remove the idler. Turn the pump sprocket until the mark is at the 9 o'clock position. Check the marks on the idler and refit it so that all marks '2 and 1' align.
Allow for the idler and other sprockets turning slightly during refittment. The cam, crank and pump sprockets should all align, one mark between two. If you have power steering there is no timing involved. Tighten up and lock the tab.
Yes, it is quite possible to adjust a tappet so tight that it would hit a piston at TDC. Adjust is a relative term here as it would have no clearance and the valve would be permanently open.
Before you refit the timing cover don't forget to refit the splasher plate. The flat side goes towards the crank sprocket. You should see the marks of the sprocket on it.

Sounds like you are in the UK.

Cheers

DavidP

 

[Anonymous-0]

You must have a UK model if it's a 1976. Dave