4 replies to this topic

[wile e coyote]

A bright idea over the weekend was to change the head from a leaded big valve ‘940 to an ex spi ‘940B. No problem there as the latter head is now all tapped in the right places…. But …. for no other reason other than I like them I use old “S “ rocker gear… The rocker pad to valve stem fit was ok’ish on the old head – actually fairly poor fit – there would have been a fair amount of side loading….but the rockers as fitted by the factory to the “new” head is atrocious (having checked another spare head it’s equally bad)   I’m not about to ruin my  “S” rocker set so will be sticking with the gear as came with the ‘940b head but want to space the rockers properly .

 

Minispares flog a solid spacer & shim kit C-AEG392 but outline description aside doesn’t appear suitable for std A+ rockers…

 

Be grateful for anyone’s thoughts here – have you used this kit – i.e does it do the job or just brought some shims and retained the springs?????????

 

 

[Cooperman]

The best way to get the rocker pads to sit centrally over the valves is to make up your own spacer/shim set and to fit everything to suit your head. I can't remember the diameter, but all you need is a length of cold-drawn seamless steel tube the right diameter, a selection of shims and some measuring kit.

Ideally aim for about 0.005" end float on each rocker, bearing-in-mind that this float is over more than 1 rocker and is, in fact, the float of the rockers between the rocker posts. If necessary, the faces of the rockers can be ground away a small amount to get accurate centering, but this is a function of manufacturing tolerances between vastly different manufacturing years. Remember, the original 'S' rockers were only used on the AEG163 head casting, so that is probably why it doesn't line up automatically.

With the head on the bench, fit the rocker posts with the shaft and rockers on it, but without any spacers & shims. et the rockers where they need to be and measure. Cut the spacers to allow for shims at each end and shims between rockers & rocker posts.

That way you get it exactly as you want it.

By the way, the original 'S' rocker shaft is excellent and much better than the later ones.

[wile e coyote]

Thanks Peter -  and there was I thinking quick kit jobbie to sort it.... laziness creeps in when it's cold.... that said donor car ran fine with horribly misaligned rockers but the neat freak in me just won't let it stand as is....... actually - an oversight  haven't checked the shaft yet as car had only done 21k but odds are it needs a new one....

 

 

My old S rockers had the original shaft replaced some time ago....:-(

[Cooperman]

You can use aluminium tube for the spacers if that is easier. The kits usually use ally, but steel tube is usually easier to obtain.

It's an interesting job and one done on the bench which helps.

[carbon]

I used the Minispares rocker shim set (they sell this without the spacers) and kept the springs