Elephant foot tappets

Back to the original question...Where did he come up with the elephant's foot adjusters?

Seattle##gs and Fast Eddie

Unfortunately these are hand made custom items Its well thought out technology borrowed from some speedway engine gurus and adapted by a Norton enthusiast with success.

"Tappets are from Andover. De-hardened - ends reshaped using an R3 toolbit - rehardened in warm peanutoil - annealed 2hours 220°C - 'ball' polished.

Feet' are homemade with bottom of cups done with an R3 Toolbit - lapped, polished and DLC coated etc."

That’s a LOT of work Jim! I’d be interested to know if the guy has any real data / evidence regarding the problem he is trying to fix and the benefits of his solution ?

Regarding off the shelf parts, IIRC the common ones folk play with are from Rotax and VW and Mercedes.

I think the VW and Mercedes ones are the same part?

Altering threads is required amongst other faffing around.

^^^ £65.50 wow !

Land Rover ones are only £1.69 each ( BSF thread ) sold singly

Grandad said:

^^^ £65.50 wow !

Land Rover ones are only £1.69 each ( BSF thread ) sold singly

Search Result | John Craddock Ltd

Search results from our catalog of Land Rover and Range Rover parts and accessories

www.johncraddockltd.co.uk

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Come on, they are only £8.19 each!

Why not just use valves with hardened stellite tips like the KPMIs. Cheap and easy to get.

Fast Eddie said:

That’s a LOT of work Jim! I’d be interested to know if the guy has any real data / evidence regarding the problem he is trying to fix and the benefits of his solution ?

Regarding off the shelf parts, IIRC the common ones folk play with are from Rotax and VW and Mercedes.

I think the VW and Mercedes ones are the same part?

Altering threads is required amongst other faffing around.

8mm Elephant Foot Valve Adjusting Screw Set (Tappet) - Type 1 Engines

CB Performance heavy duty Elephant feet adjusters feature a large foor print that covers the valve stem to reduce the chance of mushrooming

www.coolairvw.co.uk

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Imagine trying to tap new threads into the hardened rocker.
The custom ones pictured have the advantage that they are short and can be installed easily with little height difference.
I give the guy an A+ for ingenuity.

Is there anybody that could custom make them for a reasonable price?

seattle##gs said:

Imagine trying to tap new threads into the hardened rocker.
The custom ones pictured have the advantage that they are short and can be installed easily with little height difference.
I give the guy an A+ for ingenuity.

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I certainly agree with the A+ !

But even as someone who has messed with these before, nowadays I am personally of the opinion that hard stemmed valves, or lash caps, just work.

Yes they might seem more crude, less elegant, etc, but they seem to work just fine.

I’m not trying to dissuade anyone else from playing with such projects, just explaining why I don’t (anymore).

I laid out what's happening with the stock tappets (see image). Stock tappets have an approx 9.5mm radius which is just about right (but I would prefer 20mm). The mushroom tappets have a much broader radius but some on this forum have reported breakage at the edges (I personally have no experience to report about mushroom tappets and some may be thicker and stronger at the edges). During rocker arm rotation - the contact point moves all the way from one side of the valve tip to the other because of the wider radius of the mushroom tappet tip and this puts stress on the outside edge of the mushroom.

From my study I found that the center point of the tappet tip slides about .015" on the intake valve tip and about .018" on the ex valve tip. But the wear point also moves from one side of the tappet tip to the other as the tappet tip rotates along with the rocker arm and this is why you have a longer witness mark (but not all the way from one edge of the valve tip to the other).

My experience lash caps has been very good. Hard valve tip surfaces do just about as well.

Does anyone know the actual tip radius of the mushroom tappets?

Below:
the curved red lines are the radiused surface positions of a stock tappet tip when on the seat and at 1/2 lift and also at full lift. The top green line is the valve tip when the valve is on its seat, middle green line is at 1/2 lift and bottom green line is lift at .400"

Just found out that mushoom tappets have an 11mm radius. Stock is 9.5mm See image above.

I haven't found many off-the-shelf Norton valves (other than Black Diamonds) that come with hardened tips. Just bought stock 650 valves from RGM, and I don't think they have hard tips, can't see a parting line. A couple years back, a guy with 650 replacement valves posted he had wear issues, I think even with mushroom tappets.

Therefore will probably run the JSM lashcaps on mine, if they'll fit a stock retainer. That way, the wearing part becomes easily replaceable.

The parts house UK-made valves are just rebuilder valves, no stem coating treatment, no hardenned tip. Designed with planned obselesence in mind, not to be any better.

I believe only Maney stocked hardenned UK-made Norton valves.

I've been using mushroom head tappets with black diamond valves with great success. No wear at all on the valve tips and I put many miles on the engine which is now down for a rebuild.
There are two types of mushroom head tappets that I have found. One type is thinner at the mushroom head and slotted for a flat screwdriver to make adjustments. The other that I purchased was from BCS which has a copper coating and has an Allen key adjuster top. This has the thicker mushroom head (more meat). I think Comnoz mentioned that he had problems with breaking the edges of the mushroom head on the thinner type. Not sure if it was a bad batch or type of cam used, but mine went on for 80K miles before the rebuild.

these two types:

I put many many miles on my MKIII, commuting and road trips. I found that the caps wore considerably less than the valve-stem tips.

elefantrider said:

I haven't found many off-the-shelf Norton valves (other than Black Diamonds) that come with hardened tips. Just bought stock 650 valves from RGM, and I don't think they have hard tips, can't see a parting line. A couple years back, a guy with 650 replacement valves posted he had wear issues, I think even with mushroom tappets.

Therefore will probably run the JSM lashcaps on mine, if they'll fit a stock retainer. That way, the wearing part becomes easily replaceable.

The parts house UK-made valves are just rebuilder valves, no stem coating treatment, no hardenned tip. Designed with planned obselesence in mind, not to be any better.

I believe only Maney stocked hardenned UK-made Norton valves.

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The lash caps seem to be made of harder material and show very little wear. The Maney valves are made by GS valves, They have hardened tips and thats what I use for my big valves.