Alta and MM porn?

[RobThomas]

altaporn2.jpg (219.63 KiB) Viewed 6699 times

Never thought I'd ever have 2 of these here!

[firedrake1942]

Ah but can you get them both a dishwasher ???

[RobThomas]

I think that one is a bit tooooo dirty for the washer (yet)

Has anyone got any Alta spares? I need 2 valves for this one.

[RobThomas]

Looks like the plan to commission a set of new valves will have to go ahead.
I'd hate to go to all this work and have the valve crack apart. Oh poop!

[youngcamper]

Looking good Rob! What's the story behind the other one?

[RobThomas]

The new one belongs to someone else who doesn't have the facilities to repair it himself. He has offered to let me use his head after it gets rebuilt if I supply the labour and he buys the parts. Best of all worlds!
Needs some extensive welding and skimming plus new valves and guides as a minimum.

[RobThomas]

Possibly gonna need a bit more work, this one.

[RobThomas]

ianguide2.jpg (176.18 KiB) Viewed 6644 times

[youngcamper]

The new one belongs to someone else who doesn't have the facilities to repair it himself. He has offered to let me use his head after it gets rebuilt if I supply the labour and he buys the parts. Best of all worlds!
Needs some extensive welding and skimming plus new valves and guides as a minimum.

YIKES! Those guides and springs look rather shot. Let me know how you go about replacing them please...

[RobThomas]

2 of them are split, so, no chance of saving them. I'll have to make them if I can't find a suitable alternative. VW Passat is a possible.

[Redmoggy]

When you say you are having valves made, are you commissioning someone to make new to a pattern or using blanks? Only the second option would seem more economical.

Rod

[RobThomas]

The company I have approached can make them in their machine simply by entering the dimensions and out pop a load of valves to the exact spec required. The guides are more of a problem. Getting those made will mean me having to find the correct spec of guide material (Grey Cast Iron variation???) and then machining them to the right dimensions. Making up a set of caps/keepers etc for the top of the springs requires me to machine up some parts from other cars, hopefully I can do it from A-series parts but the first couple of attempts didn't go so well due to difficulties in keeping the parts in position.

[smithskids]

You could make the guides from bronze?

[les]

Yes bronze is a good option, I had a set from bmc special tuning fitted to a mini S, which are now in my pickup head.

[BLOWNMM]

Aluminium bronze is the preferred material.
Bob

[RobThomas]

Thanks, guys.

Is there a specific bronze variant (out of the several-million options) to go for?

My preference was to go for the same material as the original to reduce any possibility of problems further down the road. I've had a suggestion of Meehanite.

[amgrave]

Is the head Aluminium ?. If it is you may have to be careful of expansion rates. If two differing metals are used and the holding piece expands more than the insert it would have to be an interference fit for it not to work loose but with ally too much interference can split it (one of your pics looks like that has happened). Might be something to watch out for when choosing the material for the inserts.
Good luck.

[les]

Yes that's a consideration, the guides I fitted were in an iron head.

[smithskids]

Meehanite would be good, very fine grain cast iron with the machining properties of steel.

[RobThomas]

Meehanite it is, then. Short bar of it on order.

Ta!

Rob