Show whole topic Aug 29, 2017 8:00 pm
Mark Offline
Member
Registered since: Feb 05, 2009
Location: Worcestershire


Subject: Re: Lead replacement fuel additives. Necessary?
As Laurence says, the issue is higher revs and I believe the experts suggest that sustained engine speeds over 3000 rpm is when you are most at risk of valve seat recession.

In my experience of 2 Litre ownership you have to be doing 60 mph down the motorway for hours on end to be at risk. The vast majority of 2 Litres never do this. I have yet to hear of anyone experiencing serious valve seat recession with a 2 Litre, but do know of two people who didn't take the chance and went down the hardened exhaust valve seat route, which is not exactly cheap.

With my LG45 de ville I have toured Scotland twice and of course was driving the M6 for hours on end at around 2500 to 2800 rpm. Rather than risk it I simply added Tetraboost to the fuel for the motorway sections of the tour.

Whilst lead was added to fuel pre-war, my understanding is that it was in quite small quantities and it was not until the post-war period when higher compression engines became common that the quantity of lead increased and gave valves the protection needed. So it is unlikely that valve seat recession was a major issue pre-war with our cars.

My advice is google Tetraboost and keep a bottle in the boot for when you are cruising a motorway for hours on end!

I must add that I have no connection with Tetraboost, just a satisfied customer.

Best Regards
Mark