skimming rockers

"Maurice" realised it was Sun, 29 May 2005

That seems highly unlikely to me, since classic Volvo's are among the best served when it comes to parts. If it's a B18 or B20 engine, they're available from

Presumably you want to skim the rocker because contact with the valve stem has made an indentation in the hardened pad on the end of it. IMHO this will not really help as all it will do is go even further through the hardened layer, if not remove it altogether. If you cannot find new rockers anywhere - or even used ones that are better than yours, I would suggest that you find somewhere that can build up the rocker pads with Stellite or whatever people use these days to produce a hard surface on this sort of thing.

And don't let your engine idle for longer that you absolutely have to, because that is what kills camshafts, tappets and rockers.

Ron Robinson

I'm amazed you can't get them. However, after reprofiling they should be hardened.

In news:d7cs51$b7a$ snipped-for-privacy@nwrdmz03.dmz.ncs.ea.ibs-infra.bt.com, Maurice decided to enlighten our sheltered souls with a rant as follows

I'm pretty sure that V8 Rover ones are very, very similar and easy to modify to adjustable.

IIRC we used to use P1800 Volvo rockers in tuned Rover V8s, because they were cheaper than aftermarket Rover adjustable ones.

If only slightly worn I wouldn't bother. All rockers eventually wear to leave a small indentation where the valve tip fits but it doesn't really affect anything as long as the valve clearances are set properly to account for it i.e not just using wide feeler gauges across the unworn part of the rocker which leads to a larger than desired clearance being set.

Having said that I routinely reface CVH and other rockers by hand against the side of a very fine grinding wheel. It's a bit of a knack getting the radius of curvature right by hand but rather satisfying to do once mastered. I can't regrind a drill bit by hand to save my life though for some reason.

-- Dave Baker - Puma Race Engines

I have seen other engine places do this (usually on a surface grinder rather than a standard wheel) , but I can't see that the original surface hardening can be deep enough to allow for any regrinding?

mrcheerful

There was a attachment to a valve refacing machine that was use to radius grind rockers.

You can also spray harden (with oxy gear)the surface after machining.

Oldbloke I once new who specialised in MGs used to harden them too. Dunno how, though.

There are several ways to case harden iron and steel using carbon or arsenic compounds, that simply involve heating and quenching the (part of) the part.

Rockers aren't necessarily hardened anyway. CVH ones are just pressed out of steel plate and most pushrod ones are forgings but with no obvious heat treatment. Roller rockers certainly need hardened rollers but then the contact area is very small.

Rocker regrinding jigs are common attachments for valve refacing machines and no one rehardens them afterwards AFAIK. The only way to be sure for a specific application would be to get the OE factory specs but I can't see that being available in most cases. A laboratory hardness test would be the other option. The steel may well work harden in service in some cases. A and B series cams were made out of steel that did that rather than chill-cast iron which is the standard material these days.

Testing a rocker tip next to the rubbing area with a sharp file will give a rough indication of how hard it is.

-- Dave Baker - Puma Race Engines

He probably used a product called 'Kasenit'. I have a tin of it myself. It's a black powder. Obviously comprised mainly of carbon. The item is heated, dipped in the powder. The powder sticks to the heated surface. After removal with it's coating, it's heated to cherry red, and quenched in clean cold water. Gives just 2-3 thou of hard skin. Operation may be repeated to increase the depth of case hardening. Mike.

^ (cheating sod)

Seem to remember doing something like this at school when making a cold chisel - which I still have. ;-)

I'm trying to remember what the XPA- engines as used in TC,D, and F had the rockers made out of? I think they were forged steel.

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Mike G" saying something like:

Yup. I did that years ago to a bunch of refaced rockers from a SOViva. Bunged them in an industrial gas oven, contained in a box of carbon dust. Lovely and hardened, they were. Pity the SOViva got nicked shortly after.

CVH ones aren't properly hardened in the first place. But then the cams are made of rubber, so it all works out right in the end. Don't you just love Ford ?

P1800 rockers should still be common as anything. If you had to, I believe you can even drop a B230 engine in there on practically the same engine mounts - bloke round the corner has one with a 760 turbo lump in it.