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Easy answer for an Unleaded Head ?

Yes - it's bound to have unleaded seats but not sure if it's suitable as the water pump is at the 'wrong' end. Maybe it can be converted by swapping the pump and the blanking plate. Not sure but it's worth a try.
 
Apart from the easy water pump / blanking plate swapping, one must weld and machine the blenking plate side of the head to form the "separation wall"...may be cheaper to install hardened valve seats in a GTL head!
 
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In my experiance it is a waste of time paying someone to put hardened valve seats into an Ally head. THEY DONT NEED IT.

Sorry to stress this point but i get so many people come into our workshop with Rover V8's or Reliant's etc that are all made of ally and they just don't wear out.

Cast Iron Heads need the conversion because is a much softer valve seat than a sinted material which you will find in all ally heads.

Dont waste your money guys honestly. Or if your that worried put redex in.
 
Yes that's what I've been led to believe, the alloy head has harder valve seats and as long as you use higher octane fuel (98), combined with an additive, especially for long motorway trips, your engine will be just fine.
 
Perfectamon.
 
The alloy heads do have a valve seat made from a harder material. On most cars the inserts will take unleaded. For the 750cc and 850cc R4s the material is up to the job, but you can burn valves in 1108cc engines on a single trip across Europe at full speed. I've done it twice. Knocking about locally and driving sensibly the standard seats are OK, and additive for motorway trips is more economical than changing the seats.

Thanks for the picture Angel. I have been tempted to use a supercinq head on a project but wasn't sure what the mod was.
 
Burn valves or seats Malcolm ?
 
Recessed seats to the point of no compression in 2000 miles. It happens at sustained high speed only as far as I know.
 
You must have been trecking some...
 
Although saying that I converted my Traction to unleaded and refitted the old valves which are known to be soft and they burnt out in a year, however i put this down to buring a litre of oil in 100 miles so the compustion tempreture would have attributed to that quite alot.
 
Got to admit that I had my exhaust valve seats replaced on my GTL as the standard seats didn't like unleaded petrol and the car began losing compression too. After that the car worked perfectly for the remaining 60 thousand miles whilst in my care - and as far as I know it's still running well.
 
All the ones I've rebuilt have needed exhaust valve seats and not just the ones I've been driving. While they need a harder insert for aluminium heads I'm not sure they went hard enough with them.
 
Yet another titbit to remember when I'm rebuilding the engine - make sure I change the valve seats. This forum is so useful...
 
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