The valve lifter arm to cable angle on my Goldie rockerbox seems wrong to my eyes. It is impossible to get a more correct angle because the arm hits the top fin. 20180212_104220 by Sigma Projects, on Flickr
I have just fitted mine had quite a bit of trouble getting it to work . I wa informed that it has to go one at the 5 o'clock position . I purchased mine from len haggis and it doesn't hit the head at all . I haven't got the lever on the bars fitted at the moment and the spring is pushing it back further than where it actually starts to work which is at the 5 o'clock position . yours looks longer .
I've already said the spring was pushing it back that's why i took it off to show how it misses the fins. When it is pulled to lift the valve it is at 90 degrees . Don't know what you are going on about . Mine works .
Hi I have all those parts sitting on my bench waiting to build my engine, including a new repro lifter lever and an original I will look tomorrow and see if I can see what is causing the problem for Andy John
in the operating position just before it touches or opens the valve .
Just before it touches the valve when the piston is near TDC on the compression stroke, or at some other random position of the crankshaft?
Curious about this, I checked the lifter on my DBD Catalina. As best I could measure with it in position, the overall length of the arm from the pivot point to the far end of the arm, i.e. the part of the arm that would touch the fin if it rotated forward that far, is ~1-9/16" (1.56"). The height of the pivot point above the fin is ~1.58". So, if the arm rotated that far forward it would hit the fin. What saves us is the fact it doesn't rotate that far forward in order to lift the valve. At least, when the valve is fully seated, as it is when near TDC on the compression stroke, which is the only time it needs to lift the valve. However, if the crank is in some other orientation the valve can be partially depressed and the lifter would have to rotate even further forward to reach it. Which is why I asked if your engine is currently at TDC on the compression stroke.
Since your setup look OK (although the arm does look a bit long), and since your latest photo shows it has rotated far enough forward to do its job (at TDC), I predict you will find it works fine as-is.
Not that you asked, but if you had a BB head you wouldn't have noticed this. The arm is the same length but the nearest fin would allow it to clear by ~almost 3/4" if it rotated that far forward. But, for the same reason as the DBD, it doesn't.
Last edited by Magnetoman; 02/12/1811:05 pm. Reason: added BB info.
I also found that an important part of the process was getting the angle correct between the splined lifter arm and the shaft with the cam that actuates the pressing on the rocker arm/valve, i.e. selecting the correct relative positions at the splines.
Hi All, I mocked up the head ,rockerbox and valve lifter shaft and arm earlier, On my parts the lever will clear the top fin with a gasket between head and rockerbox without the gasket it touches, From head joint face to the top of the fin is 7/16ths near enough It looks to me that Andy's lever is longer than mine?
Below are two photos chaterlea25 asked me to attach for him.
All three of my Gold Stars have the lifter in their resting states at the same angle shown in Andy's first post. While the cable doesn't pull on them at 90-deg. the additional force required because of the more acute angle simply isn't an issue.
I will get my measuring stick out when I get back home. I am currently 300 miles away in Canterbury. My arm definitely hits the fin at about the 4.30 position. The head is a "Ron Lewis" pattern, the lifter arm is a stainless one from Phil Pearson.
The distance from top of the fin to centre of lifter shaft is 34.5mm The centre to centre length of the lifter arm is 35mm The length from the centre of the lifter shaft to the end of the lifter arm is 40.5mm
I spent a lot of time fiddling about with the valve lifter arm...as MM says, not getting the optimum angle at full 'pull' on the cable is not an issue (unlike the same scenario with front brake arms) - all you need to do is pull is lift the valve off its seat a few thou, and the available leverage is ample to achieve that - initially the pull is harder, though improves as the arm travels. The arm will never pass the fin, and not does it need to, though the setup needs to be in the right place to achieve the aim...
...warning here too, as an aside..don't use the lifter at high rpm: as the books alude to, it is possible for the inner lever (that acts against the rocker) to travel past the rocker arm, rendering the lifter useless. Short of somehow lifting the pushrod from the bottom (to move the rocker out of the way) the only way to get the inner lifter arm back to the correct position is to lift the rocker box off...which if you have rocker box studs means lifting the head...don't ask me how I know this.
No generalisation is wholly true, not even this one. Oliver Wendell Holmes
Looking at your head Andy (so to speak) it looks like there is less meat above the top fin than on Ducati 2242's & Mag'man's heads. The only Ron Lewis heads I have seen have been on race bikes where a lifter isn't generally used. I can vouch for the ugly appearance of the lifter cable & lever re. "correct" angles, mine is the same but it works as Mag'man & Kerry W describe. Bit of a BSA parts bin job.
It doesn't matter where the arm sits as long as: the actual internal lifter is clear of the rocker when the motor is running but can open the valve sufficiently when the lever on the bars is operated. That said, there is a limited range of positions due to the restriction of the clevis on the external lever, hence the ugly bend in the cable that most of us end up with. Used to see a lot of the internal lifters with bad wear on them from heavy use or from them running on the rocker all the time from wrong adjustment. I'm not sure if anyone makes the spindle & inner parts these days?