Carlton Technical > Oily Bits

C26NE Valve Setting Error

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The instructions in both TIS and HJB instruct you to rotate the engine until the hydraulic lifters are on the opposite side of the cam to the lobe.

With the camshaft in this position, you are told to adjust the rocker arm nut until the play is just removed and then turn the nut one full turn more !

As I was doing this I became a bit suspicious, so I did some vernier measurements and found that this extra turn was actually lifting the valve about 3 mm off the seat :o

Thinking that perhaps that position was not actually the lowest part of the cam, I took a series of measurements approximately every 30 degrees of cam rotation and found that the back of the cam is definitely the lowest point.

None of the rocker arms that are yet untouched show evidence of being set like that and in fact, it would be impossible to get any compression in any of the cylinders if they were ! a pressure test a few days ago showed very good compression across the cylinders.

Am I missing something ? or is this a potentially damaging piece of instruction ? is there a possibility of the pistons fouling the valves with an extra 3 mm of lift ?

Finally I can see where I'm going wrong :-[

The setting procedure assumes that there is oil pressure in the hydraulic lifter ! if there isn't, then the hydraulic piston is 'bottomed'.
In this situation, if you adjust for no play and then do a full turn on the nut, it will certainly lift the valve off its seat !

If you have left the engine for some time (as I did while pulled things apart to inspect them) there is consequently no oil pressure in the lifters; following the setting instructions then puts you deep in the brown stuff ::)

What you have to do is wind the engine round a few times with the ratchet socket on the main crank pulley nut to re-pressurise the hydraulic lifters.

Adjusting for no play then means that the rocker arm is just 'kissing' the hydraulic piston which is at the top of its travel.

One further full turn on the adjuster nut then presses the hydraulic piston down into its operating area.

This means much pumping on the ratchet socket to maintain pressure as I work my way through all 12 adjusters.

I suppose the exercise will do me good :-\

Big question mate ! did it do the trick?

good little right ups these are

take care jonny

Don't know yet because they will not all pressurise just using slow winding over with the ratchet :(

I've had to devise another setting method by forcing down the piston on those that do and checking the gap between the rocker arm and valve, then setting the ones that don't pressurise to the same gap using the tried and trusted feeler gauge method ::)

With my bad back and age it's a matter of 'slowly and thoughtfully'

I'm nackered; an early night is needed ::)

Well ! it's all back together and running (it was very 'tappety' for a couple of miles)

HOWEVER, it still 'rumbles' a bit (quite unlike a tappet noise) and as I suspected it would, it still runs rich on numbers 3 & 4 :(

I've ordered some new lifters and a new rocker cover gasket (the old one was getting a bit 'crispy') I think it is probably a vain hope since I couldn't see anything wrong with them ! but I'm going to give it a try; maybe they will run a bit quieter at least :-\

Bought them from the people below who offer them at a radically lower price than half a dozen or more places I've tried ;)


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