http://www.alcaminc.com/hard-surfacing.html


Here is a web page listing all the varieties and hardnesses of the various electrodes available to do this job.

Obviously we don't want the welded up tappets to be harder than the cam lobes as that would transfer the wear to the wrong piece.

Lancer has asked Webb Cam how hard cam lobes are and they said theirs are around RC 60-62.  Case hardened (stock) cam lobes would run around RC58-62 depending on quench and how hot the item got in use.

It is obvious that Suzuki has made the stock tappet softer as most the wear seems to go to the tappet face.   Yet the rocker material is harder than a pocket knife blade (RC 45-50).

So we are looking for RC 50-55 for a weld up material ???

Address is sent, now I need to go ahead and get the welding rod on the way ....

I would think our tappets are a case hardened job as it seems when you go through the case wear is pretty drastic past that point.

Some of these rods are relatively heat proof materials and the "case" will be pretty thick, so that shouldn't happen again.

Might eat the cam lobes off instead -- but Lancer can recover that with a hotter cam profile so that might not be a totally bad thing as your money gets you something better.

Our thanks to Alcam, manufacturer of welding rods for their excellent technical support.


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"We will send you two products.

Alcam 93 will reach the hardness of approximately 57r after two passes depending on the base metal dilution.

Alcam 81 will hit approximately 58r on the first pass and 60r on the second pass.  This is an air hardening tool steel and should not require annealing. The second item we normally make as a 3/32 electrode but we can do 1/8



Thank you for your inquiry



Al Carlsten
Alcam Mgf.

Here are some perspective shots on a very simple crude aluminum heat sink fixture for padding up a set of very worn and torn up rocker arms.



Notice my "complex high tech"    mounting fixture that preserves the rocker face  nice and square to the rest of the rocker assembly.



The arc will be struck on a piece of waste steel off to the side of this aluminum block and the electrode brought up to full laydown temperature and a stable arc.  Then the arc will be drug a short distance across the aluminum block and focused down on the tip end of the rocker (electrode angled 15-20 degrees low to the main the rocker body).



Then pull back some for a wider puddle and weave back and forth while backing up the face of the tappet until the entire recess is full and the active puddle is back at the heel next to the main rocker body.


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The rod is Alcam #91 tool steel AC/DC arc electrode, size 3/32" wire diameter.  The thought at this time is to simply jack the power up to around 100 amps and long arc a wide puddle starting from the tip end and weaving back until the entire aluminum recess is filled with tool steel with the slag all sitting proud to the face of the aluminum block.

(that's the plan anyway -- we all know how "the best laid plans of mice and men" last in arc welding reality, now don't we?)

According to the folks that make the rod, it will air harden into a stress and crack free solid tool steel pad at between 55 and 60 Rockwell C.  Red hardness of this material is about 55 RC, so it won't get overheated and get soft like the original cast rocker steel did when it got hot in use.  Current wear face on the rockers is less than RC 45 as it got very soft due to overheating.

By using the chiller block I intend to "soak back" the weld heat and try to keep it from transferring into and further annealing the rest of the rocker (which will be wrapped in a wet paper towel mass the at time of welding BTW).


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Note please the large amount of damage you can do to a cam and rocker set when you have interrupted oil flow in your engine.

Normal use and abuse does the EXACT SAME THING over a lot more miles, it just takes a lot longer to take place.

All of your high mileage rockers have damage of this type to a lesser degree and all will require replacement or refurbishment at a major rebuild.

Suzuki soaks you for a $100 to buy a set of replacement rockers, which won't last you any longer than the first set did.

And here are the finished ground and polished pieces.   Not perfect mind you, but certainly serviceable -- out of pocket cost was $5.00 for Serenity to ship the second set of rockers to me.  Tool steel welding electrode was donated by the vendor and the sanding belts and finishing wet/dry paper already was on hand.

Cost avoided was $195 (two sets at $100 each less the $5.00 shipping) -- not too shabby a savings for the 4 hours invested.

Next thing needed for the motor project is a worn first over piston (or a used piston and a jug if you have a spare set lying around gathering dust)


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New list knowledge yielded by the motor project so far is:

1)   a easy to do durable method of recovering torn up cam bearing journals

2)   a method of repadding rocker arms with a much more durable material

3)   two new "assignable causes" for loss of oil pressure

4)   a documented method of cutting cheap clutch cover gaskets to a printed pattern

5)   a method to refit (not gouged up) piston skirts back to spec fit to a worn bore

6)   a method to tap into the "end of the line" oil passage and put that pressure reading out where you can see it
     (at a cost of less than $10)



So far the trip has been worth it -- who has an old first over piston or some sort of used piston/bore set so we can continue to see what comes out of the bushes?

It takes a long time to wear out a set of tappets, especially in your disaster/spare engine that isn't in service right now.

Both Serenity and I might well die of old age before installing either set of tappets ....

You are not going to buy these sorts of esoteric tool steel electrodes from a hardware store.   You can buy hard surfacing rod, but the experts kinda thought hard surfacing rod might just be too hard and too abrasive, so they sent both kinds and recommended using the tool steel rods.

One of these days we might have to put the engine into use to see how well the idea works, but as durable as my in-use fully built engine is acting I might die of old age first, so who knows?