Lead Replacement

[Willy Eckerslyke]

Thanks for taking the time John.
The reason I'm convinced the 2000TC needs an additive, is that when I first got mine I followed the same logic that you espouse and ran on "straight" Shell Optimax for about 3000 miles. Then the engine gradually started running worse and worse until I did a compression test and found that the cylinders 2 and 3 were well down. Removing the head, it became clear that valve seat recession had occured badly on two valves. I fitted a spare cylinder head and now always use Valvemaster. While I realise that the damage may have had a different cause, I'm not about to take the risk again and certainly wouldn't advise anyone that it's definitely safe to run a 2000 on unleaded alone.

[JPB]

Obviously that's useful information there. I wonder; could the valve seats on some 2000s have been screwed rather than pressed into the head? In that case, might there have been some which were made from cast iron? I've had dealings with a couple of 2000 heads; one from a 1965 car, the other from a 1971 example. Both of these had hard steel seats and the valves to suit.
Just to confirm the nature of the recession you mention there, Willy Eckerslyke; was it the seats that had taken the damage and not the valves themselves? My thinking there is that it's relatively easy to change valves, perhaps for aftermarket ones which could have been incompatible - when used with unleaded fuel - with the seats.

Either way, even one case of seat recession is enough to make sense of using a lead substitute in this engine until someone can give us more information regarding the metallurgical make up of this particular head and how Rover found a way to use softer metal in there.
I find this most strange, yet fascinating.

[Morrisand944S2man]

OK, with a cast iron head, other than those fitted to late (post-1988) A+-series and similarly late, iron-headed stuff then it's best to use a lead substitute with any iron head since chances are that it won't have been machined to take steel inserts, -snip-
When I owned my first Dolomite, back in the mid '80s to the early '90s, unleaded fuel was still comparatively new but I used the stuff in that engine from shortly after purchase at 35,000 miles right through to when the head next came off - when the guy I'd sold the car to paid me to overhaul the engine for him - at 215,000 miles. That had suffered no seat recession, no pocketing, no signs of trouble at all in fact and the valves were all seating every bit as well as they'd done when the engine had covered only 35k. After checking all of the valves, it was found that they could all be replaced with the same shims that I'd used to set their clearances all of those miles and years earlier. Mentioning this finding to a colleague at the time was what led me to expose the number of "conversions" for which Reliant owners had been charged but didn't need and it's been a bit of a pet subject of mine since.

Sorry to have gone on at such length, cheers,

As long as you don't thrash the engine or tow a caravan at speed, etc, and the car is in a good state of tune, even an Iron head A series powered car such as a Minor will last for years without need for conversion- some folks don't even bother with using any kind of additive- I have never heard of VSR being a problem with anyone in the Morris Minor world.

I think this lead free stuff was a bit of a myth, just drive your classic and if the exhaust seats do start to receed- THEN and only then get hardened seats fit and cut, otherwise, don't worry.

Ethanol in petrol is much more of a worry for classic car owners!

[Willy Eckerslyke]

Just to confirm the nature of the recession you mention there, Willy Eckerslyke; was it the seats that had taken the damage and not the valves themselves? My thinking there is that it's relatively easy to change valves, perhaps for aftermarket ones which could have been incompatible - when used with unleaded fuel - with the seats.

Now you're asking. This was at least 4 years ago and my memory's sketchy. I do remember that I could clearly see that two valves were sunk - no need to remove them or measure anything, it was that obvious. While I still have the head in my garage somewhere, it's buried pretty deep. But you have me intrigued enough to start digging...

Incidentally it's a 1972 car with about 90,000 miles recorded at that time.