Leaded or Unleaded?

[jockduck]

Good Morning, Interested in any comments on the need to convert old Mini heads to inserted valve seats to run on unleaded petrol.
I had inserts put into a head for Otto when the phase out of lead was at it's peak because I believed all the scare stories of V.S.R. and thats been fine so far, 12000ml.
At the same time I was running a manual 1100 Mini on a standard un-inserted head and when I sold it had done 30000ml since I put the engine together and had lost a little compression but not much.
Thinking back to the good old days I burned out more exhaust valves on cars and motorbikes running on leaded fuel than I have lately on the unleaded stuff.
The reason for the questionis I am about to fix up a head for my spare engine and I think I will not bother getting inserts put in, what do you think of that?

[Holly]

2 of my minis have unleaded heads, 3 of them dont but one of those has these lead Ping Pong thingy in the tank that my brother put in there when he had the car before me.

So far I haven't noticed any difference between them all

[niceboy1275]

Out of our 8 road going cars, only 2 have unleaded heads on them. The rest I just put valve saver in for 3 out of 4 tanks of fuel. And kermy Clubman has done 30,000kms in the last 3 years with a plain leaded head with valve saver. And it has the sweetest engine of all mine. I'm not going to bother changing mine over, have heard too many bad stories from mechanics that believe that valve saver is safer than inserts. Just my 2cents worth

[Pink-Shifty]

Really it all boils down to how many miles you do.

If its a daily driver then hardened valve seats are the best answer, for a weekend toy then an addative(to the petrol) would be a good choice.

The lead pebbles etc that are added to the tank are nothing short of snake oil and are just a waste of money.

The head will have something called "lead memory", this gives you @30k miles before you'll see valve seat regression.

Also if you have a uber big valve head then inserts may not be available or advisable.

[andyn]

Our auto is has a leaded head, we run castrol valvemaster and have had no problems running unleaded fuel.Up until 2 years ago I ran an MED 1430cc engined 1275GT who's valves were too big for insert, it ran unleaded with Miller VSP but it started to suffer valve seat problems, they were very narrow 3 angle seats however.
The "lead pebbles" solution is always advertised as a solution used by the Russians in World war 2 so they could fly on poor fuel...strange they would pick a theatre of war where little information is available to the west! not used i Africa,Burma etc etc
I work in the warbird industry and nobody has heard of these devices being used.
Andy