Hi,
There I was cranking the engine over as fast a could by hand on the kickstart. This was to ensure that the oil was getting to the big ends before finally starting it up again. I had the oil pressure switch connected so that I could see that I had achieved at least 7psi for my efforts. It took a bit of doing but I got there in the end so I was a happy chappy.
However, as the push rods were not yet fitted not only could I see oil getting back to the tank, I could also see that oil was getting right through the rocker system and out of the small hole in the 'ball' that sits in the end of the push rod. Not having witnessed this before I was entertained by it and kept turning the engine over. I then noticed that oil was not oozing from the left hand exhaust rocker. Now the questions started to come in to my head. Has this just become blocked? Has it been blocked for some time or has it always been blocked. So, rocker removed and much time and effort spent trying to unblock it but to no avail. A spare rocker fitted and job done.
There is no sign of any extra wear so my questions are:- If it has been blocked for ever or a long time and there is no extra wear then it this function actually needed? If this has recently happened what caused the blockage and why could I not fix it?
Dave.
if I understand you correctly, you are saying that you believe oil is finding its way through the spindle to lubricate the rockers but some of it is then finding its way through the rocker arms and out through the holes in the pushrod ball ends? If this was the case, the end of each rocker arm would need to be drilled through to the spindle to provide the oilway and, if this is the case, you should be able to see the drilled hole on the end of each arm.
I may be wrong but I would have thought the ball end of each rocker and the corresponding pushrod caps get more than enough lubrication simply from oil splashed around the inside of the rocker box when the engine is running?
Hi Spaceman,
I don't just believe it I know it as I saw it today. The rocker arms are drilled through to the spindle and the drilling can be seen. It is obviously blanked off by the insert that sits in the pushrod cup which itself must be drilled. At some point I will remove one to have a look. It could be that this one has been misaligned from the start hence my question as to the need for such elaborate oilways.
I too would have thought that there was enough 'splash' to keep thing oily as there is no corresponding on the valve end which probably needs it more.
I have few sets of rockers and they are all drilled in this way.
I vaguely remember possibly seeing a drilling in the A10 rocker and just had a look and there it is in the cup that the push rods goes in. I assume that there is an oil way through to the spindle. In all the years I ran an A10 I never had cause to fully strip the rocker box so never really noticed the oil way unlike the A65 which needs the exhaust rockers removing for some maintenance and repair.
Dave.
I am surprised that they are drilled through although I can't say I ever thought to look! I'll have to see if I can find an old rocker arm and, if it is drilled through, I may have a go at pressing out the ball end to see what form it takes. In answer to your original concern, I suspect this rocker oilway is not really needed hence WHY ou didn't see much wear on the blocked one!
Hi,
The maintenance manual describes the oil journey to the rocker ball pins and adjuster screws. In my opinion, the oilway is there so its needed.
Best wishes...
Hi,
The devil is in the detail. I suppose the one thing that comes from this is that the flow through these drillings is not always obvious so worth putting on the things to look for list during a rebuild. If I had put the push rods back before checking the oil return then I would not have noticed the one of the rockers was blocked. I will knock out the offending one later.
Dave.
Hi,
Here it is. The insert is 90º out so I would never have cleared it in a month of Sundays.
Whilst we have to accept that if BSA thought it was needed then it was, it still begs the question, was it?
This rocker has been in my A65 from before me owning it and I have done a considerable mileage and as it could not have turned during use it is probably safe to assume that it has been misaligned all this time and perhaps since it was made. The flat machined on the insert allows for quite a misalignment before the hole is blocked off so to get it 90º out is at best unlucky or at worst a lack of attention by the assembly worker.
So are these oil ways needed or not? As they are there then check they are clean during normal maintenance/repair and let them do their job but not lose any sleep over the fact that they may not be functioning in the meantime.
Dave
:) :) :) :)
Thats dead interesting and some thing A. I never considered and B. I'm not sure in truth I even knew of the drillings as a fact. I guess I must have been aware but never considered it when cleaning etc. Thanks.
Mike 8) 8) 8)
I think it is a feature of the BSA/Triumph rockers that most of us have never thought about even when we noticed a hole in the end of the ball pin. Most other BSA 1960's models look to be similar except the A10 whose rockers were equipped with a cup to take the rounded end of the pushrods with the cups drilled from above presumably to let in oil splashed around the rocker box. As said, I'm surprised they needed to do use drilled ball pins especially when you bear in mind that there isn't a corresponding provision at the other end of the pushrods?
Hi,
There is an oil gallery (which oils the stem etc.) in the tappet that's worth cleaning before assembly. As the tappet rises oil enters via a small hole and exits at a lower hole when the tappet falls.
Best wishes...