I have been wondering for a while would it be worth it to run lash caps on top of the valve stems like they do on the V8 engines. This would allow the rocker to be more in centre of the valve stem get a round the issue of soft valve stems issues like Mick is having in this worn valve thread

You would need to adjust the rocker geomertry etc, but lets say thats a given

A lash cap is a small domed that sits on the top of the valve stem is hardened and protects the valve stem





Thoughts

Kiwiinwgtn

*Fixed Link*

thanks, I tried to get the pic to show in my original post

EDIT I know see what i did re the pic

I think brain storming ideas are always good (so keep them coming ) but in this case, I think this would be a lot of work for very little gain.

The valve tips should be hard (not that like Mick's) and it would now be out of the question to get 150 000 - 200 000kms from factory valve tips.

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Thanks GT

I thought that mileage could be an issue but during my research lots of cars seem to have them from factory, HP Jap engines

It should also reduce the side loading on the valve and enable the rocker tip to be further away from the edge of the valve stem when it sweeps on the stem, so whould be good for non standard rockers etc

They are also quite cheap and the V8 have 16 so you get two for one.

Also they are easy to change if worn, which i think is the point

I know of 3-4 cars which have had valve stem issues (NZ) including mine

Keep those thoughts coming

Thanks

Kiwiinwgtn

how about something like teflon ?

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any thoughts on lash caps

I can see the attraction but if you fit them you need to consider rocker geometry. May need to pack rockers up. How thick are they (from inside to top face)?

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I would have the caps specifacilly made, I spoke to the guy today and he said he makes them quite regularly for High performance Jap cars and his motor bike engines he builds with SS valves, he was quite pleased there are only 8 valves

I have also had some pillars made taller so I can machine to the height required

I also have an adjustable push rodso i can change it length

So with all of the above I should be able to get the valve geo 99% correct

Kiwiinwgtn

Hi Kiwiinwgtn
Really the only time you need valve caps is when you have to much lift for the valva stem dia and the rocker wipe across the valve is getting off both sides of the valve, some of the v8 are now using .281 dia valves stems (mini size) with a 2.2 dia valve head with .700 /.750tho lift which is way to much for a stem that dia, the reason they use them in a lot of the jap cars is because they are over head cams and that is the way you set the tappets with different thickness shims.
Graham Russell

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"It's better to be not informed than ill-informed"