OK since someone has professed Graham's demigod status I will tell you all:
The main reason for valve seat recession and wear is heat. Agree?
The more shrouded the chamber is the hotter the exhaust valves run. This is especially the case on stock small bore heads as they are like heart shaped with considerable amount of shrouding around the valves. Graham says the small bore heads all run considerably hotter than big bore because they do not get any cooling from the intake charge.
This is the real reason why exhaust valves last longer on big bores and modified chamber heads. Nothing to do with additives or not.
On the subject of additives Graham says his experience with products (which will not be named) that are made as lead replacement additive loses up to 4hp on his dyno after sitting for 24hours. He has no idea what it does to the fuel but it does something and he can prove it any day of the week he says. This is why he says to me "Stay away from fuel additives Chong, They are a worry". He also says they coat your chambers and plugs with residue.
He does
not think they don't work, maybe they do and they probably do. But there are better solutions.
Fuelstar and other tin inline replacement devices: These originated during WW2 when the Bombers were detonating when boost was being turned up on their engines or something like that... Tin is a better additive than lead for this purpose and hence why Graham recommends a Fuelstar. He thinks they work and work well.
My thoughts: Since i am running a GR special head anyway I should have no issues about valve seat recession like his 1400 stroker. Coupled to this I have a Fuelstar which I profess is an expensive buy to start with, but over the life of the Fuelstar I will save on products like Valvemaster or Flashlube.
That's all for now
