Cylinder Head Work Concern

[bl**dydrivers]

Now I’m really concerned!
What am to do if the seats are not salvageable?

Can you run the original exhaust seats on unleaded? Every shop here doesn’t mention about unleaded like SRM does

How can I measure the swept volume and combustion space volume without any valves?

I know I have another cylinder head and is complete presuming it will need work too but is in UK and would have to get my Father to ship it over

[Joolstacho]

Mate, re: the seats, I don't think I'm mistaken in saying that Klaus has raced his A10 with standard seats. So unless your seats are heavily recessed you should be fine.
I haven't noticed any posts on this forum complaining about lead-free valve seat problems. Anyway you can get a lead additive for your fuel if you're worried about it.
You CAN check your ratios without valves, simple to make thin plywood or plastic discs to glue onto the valve seats to seal them for measuring. Sure it needs a reassembly of your motor, but that's just good practise anyway. Hahahah!
Surely there must be good engineering expertise in your part of the world to help check/fix your motor as Swarfcut says. Nothing here is super difficult to refurbish, its just head stuff.
What they do if valve-seats are beyond 'salvation' is they set the head up on a lathe or Milling machine and cut out the old seats, not nice because the valveseat steel is VERY hard, so hard to cut.
Once the seat is cut out a new seat needs to be made to very close tolerances, and shrunk into the head. Bit of skilled work there but nothing 'super difficult'
So why don't you get the other head sent over to you? then you have 2 to work with?

[Klaus]

Yes you can run modern fuels to the old vavle seats.
And yes I racing with 10,5:1 pistons and original seats with no problem. I use Aral 102 octane for this.
So, if the seat will be fine with a 1.5 big valve leave it. For inletvavles are only 1.2 to 1.5 mm contact surface nescessary.

cheers Klaus

[limeyrob]

I think its also worth mentioning that while we fondly remember 5 star petrol (101 octane) most ran on 4 star (98) or 3 star (92). I ran my C11 (iron head) on 2 star and I seem to recall there was still some 87 octane about.  With manual ignition it was easy to pull the timing back a bit a live with the power drop for the savings.  These engines coped fine.

[bl**dydrivers]

The other head is at my Fathers, as I was more concerned bringing the big heavy items back with me to get the project going and left that there as I already have one here.

Brought back, crankshaft, crank case, cylinders, inner/outer timing covers, inner/outer primary covers and shipped the gearbox. Now I have everything here other than fuel tank.

Left the fuel tank there too and can get another original needing allot less work here in the near future.

I reached out to an engineering shop over here that has a YouTube channel and waiting for a response.


There’s also another one about 45 minutes ride away. However they are only open on weekdays and I’ve got to work those days.