Hitchcocks Forum

Because of a loose locknut this happened. Diagone of damage; bend pushrod, so ordered a new set.
But..
1; the new ones are more bend then the old one? As if the thread for the adjusment possibility is not drilled in straight.
If you twist them, the adjustment part swings like a hula-dancer..

2- There is not enough thread for adjustment?
I do have the samrat-rockers..
Comparison with the old one.. How 'normal' is this?
I contacted the supplier and am sending them back..

Whilst fiddling with the pushrods, i discovered that when the tappets are adjusted at TDC of compression stroke, and i turn the crankshaft a little further, the tappet clearance increases?

..so adjusted them again, turning the crankshaft looking for the point of most clearance..

It now comes to mind, that this is 'precalculated' and the zero p[lay at - exactly TDC is correct, so i should do it again?

Yes.

Remove the spark plug and check when the piston is at TDC. When correctly set, the push rods should rotate, but there should be no up and down movement.

Personally, I used the kick start with one hand to roughly find TDC and turned the push rods with the other hand and then just felt when it was the right position and adjust as necessary.

Of course if they are way out, then you cannot do this. You need to watch the rise and fall of the inlet push rod and you’ll roughly see when it is at the top of movement.

Okay, not sure i understand.. I do remember setting the tappets of my BSA m21, that was not at TDC but when the other valve just opened/closed (long time ago).

To be sure i understand;
1 The tappets should be rotating freely, yet no up/down movement at TDC-compression stroke.

2- Yes, it is correct that they get more play when the crankshaft rotates further, (i did not screw it up)but the factory has given the upper method for tappet setting as it is easiest done?

Hi, turn the engine until your are at maximum lift on the cam. Rotate the engine one revolution you are now at the bottom of the cam , adjust the tappet. Repeat on other cam. Vince

With the primary lid removed this is possible..
It comes to my mind that the cams are/can be worn? Hence the irregularity in adjusting?

Cams come at ebay from 40 pounds new up to 120 pounds for used ones..

Will the cheaper ones really be 'bad quality'? Any experience about/with this?

While changing the bend pushrod for the other, even more bend and too short pushrod, you have to remove the rocker assy.

I discovered that 3 of the 4 bolt-ends were loose! I checked them also on the exhaust side and same thing!
I tightened them - carefully, because of the aluminium..
Loctite won't help because of the heat?

Some thread-locking compounds claim to be OK for higher temperatures, you can check out the specifications on their web sites. Here's what the manufacturer posted for Loctite 270, which is a commonly used higher strength grade.

http://tds.henkel.com/tds5/Studio/ShowP ... lant=WERCS

Loctite 648 (used for retaining cylinder liners!) might be better:

http://tds.henkel.com/tds5/Studio/ShowP ... lant=WERCS

Your caution in tightening the rocker studs is understandable, but you might still want to have a Helicoil kit handy! One of the things I love about the Electra-X cylinder head is that the rocker shafts just slide into the alloy of the casting and are held in place by the oil feed banjo bolts.

A.

Adrian wrote: ↑

Sat Apr 10, 2021 11:08 am

Some thread-locking compounds claim to be OK for higher temperatures, you can check out the specifications on their web sites. Here's what the manufacturer posted for Loctite 270, which is a commonly used higher strength grade.

http://tds.henkel.com/tds5/Studio/ShowP ... lant=WERCS

Loctite 648 (used for retaining cylinder liners!) might be better:

http://tds.henkel.com/tds5/Studio/ShowP ... lant=WERCS

Your caution in tightening the rocker studs is understandable, but you might still want to have a Helicoil kit handy! One of the things I love about the Electra-X cylinder head is that the rocker shafts just slide into the alloy of the casting and are held in place by the oil feed banjo bolts.

A.

Thanks for the tips..
I must admit i never inserted/installed a helicoil..

Many thread on/in the bullet are very bad.. For adjusting the tappets i removed the cover stud.. was the last time.. hope it will stay in place..

Stick with the helicoil, or timesert. I tried JB Weld High Heat on a barrel stud. Claims to be drillable, tappable (new words...) but the rotational forces of a stud are too much for it.

You mention pushrods being too short? Did you do any work on the valve seats? I had an exhaust valve seat replaced and I had to purchase a slightly longer pushrod ( available from our hosts ) I suppose I could have recut the new valve seat again but a longer pushrod was easier!