#96754
Yes, do remember, I have had the head upside down and combustion chamber filed with petrol for about 24 hours and not really gone down so guess it is not leaking all the time!

If it needs a rebore can I get oversize pistons for the AVL 500, or if not is there an alternative piston I could use?
#96784
Thank you, agree EFI piston probably best way to go as mine seems to have given up, maybe when the rings broke in and as it was at top tolerance anyway it just starting leaking?

Got the valves out and look ok, are the seats supposed to stick out this far?
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#96793
I have seen several Electra-X cylinder heads and the ALL have the outer edges of the valve seats sticking up proud of the combustion chamber surface. I very much suspect that this wasn't part of the lean burn design.

In contrast, all the pictures of EFI heads I have seen show the valve seats rather pocketed in the combustion chamber surface. That doesn't seem right, either.

On my old Electra I had the seats cut down so that the edges were flush with the combustion chamber surface. If you don't have suitable valve seat cutters, your local engine repair place (if you have one) will cut the seats flush with the surface, they'll need a 45° cutter (maybe a 30 ° too) and a 7mm spindle.

A.
#96799
Yes it does look weird, but if I cut them right back it will reduce the effectiveness of the valve spring, think will need a shim to compensate or maybe just lap them in, inlet looks clean but the exhaust could have been leaking looking at it , never a dull moment! :-)
#96800
Allanfox wrote:
Mon May 17, 2021 11:06 am
Yes it does look weird, but if I cut them right back it will reduce the effectiveness of the valve spring, think will need a shim to compensate or maybe just lap them in, inlet looks clean but the exhaust could have been leaking looking at it , never a dull moment! :-)

It is just a case of cutting the seats until they clean up and and lapping the valves in until they seat properly. Which they appear to be currently. (Engineers blue is needed to check or if you know how to do it smoke fitting.)
#96814
The Electra-X valve springs will cope. Mine did. Cutting the seat back will also give you a little more clearance between particularly the inlet valve head and the piston crown, there's just enough clearance with the Electra-X cams.

I know you weren't proposing this, but if you start experimenting with sportier cams, you'd quite likely have to cut a little valve pocket in the piston crown. If the valves are in the right place to start with, less material would need to be removed from the piston crown.

A.

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