The Official 356Talk Forum

Hi,
Here some photo of my Rocker arms on my 1600S (616/12). Wear is quite visible, but is it too much ?
what is your opinion ?
Do you who / where I can may be resurface them ?
thank you

I see you're in France? There are numerous shops in the States that do them. I'll follow up with names if you're willing to ship them. There's one in the UK:

https://www.hthoward.co.uk/engine-machi ... nufacture/

The tips have a cam-like profile, so verify that whoever grinds them, has the proper 356 specific curves coded into their machine. You may get by simply dressing the worst ones by hand on a honing stone, but by the looks of yours, better to have them professionally ground. You'll have a smoother running engine with better valve rotation imparted, and more accurate lash setting.

Each arm doesn’t just have a single radius?
I was debating yesterday if I could make belt sander jigs to clean mine up.

WOW--these are the worst ones I've seen during my 60+ years of rebuilding engines!
Some would need a little hard-welding which have "smeared tips" being a little off-center
due to excessive wear in the shaft-bores (ovaled) and shaft wear exceeding 0,05mm/.002" clearance
between them. Refinishing some tips may not be reusable if there's not enough radius left and
interference between the valve spring's retainer during valve depression occurs--I've seen several
of those caused by not much of the tip left!!!
There's many rocker arms (used or new) available in swap meets around the world, but the critical
situation is the scored shafts and bores; I've checked and done many as other shops.

Normal and early super rocker arms should be easily available since most people were searching for horsepower and wanted the extra lift of the valves they used the aluminum rocker stand rocker arms. Replace all of them with the earlier style I doubt if you will notice the difference. Usually they will not have to be redone. al zim

Were the rocker arms dipped in sand prior to taking the pictures?

Hi,
thank you for your comments.
I've contacted several machine shop in France but nobody seems able to resurface them
I contacted hthoward and I will send them the rocker so thet will confirm the feasablity (price is around 12/15USD per rocker to be remachined)
Tim : no, I've just cleaned them in a ultrasonic machine so far
Al : not easy to find parts (in france) and I fear that they won't be better than mine ...

Those are really rough especially the ones all chewed up on the ends. have you checked out eBay or the samba both have several complete and individual rockers for sale. GR AND SONS has boxes full of them on the samba
Jay D.

IMG_5559.jpg above shows the worn area that contacts the valve stem top, and the unworn area (to the right) that does not contact the valve stem top. Several months ago Ron LaDow posted the image of a narrow feeler gage that will enable the correct measurement of the rocker arm tip clearance. A wide feeler gage used beneath a rocker arm tip with this characteristic wear pattern will likely span both the unworn area and the worn area leading to an incorrect rocker arm tip clearance measurement and setting. (The person setting the clearance thinks the gap is to spec, but actually the gap is larger, and noisier.)

that's just a temporary fix. they should be ground but some of the O/Ps are to far gone.
Jay D.

The rocker arm tips are part of the valve lift geometry. As is the rocker arm angle. If you want to return the engine to like new performance, The tip profile, along with the rest of the dimensions needs to be right. While I have known of several shops, over the years which "reconditioned" rocker arms, they all just ground the tips by hand to something smooth. However, the tips can be welded up with hard rod, and jig ground to the original profile. Dean Lyon, just north of Santa Rosa, CA is a retired machinist who has a jig and has been doing this job for many years now. When I rebuild a 356 engine, one of the routine tasks is to send the rockers to Dean. I recommend you do the same.