18 replies to this topic

[Spider]

Using Unleaded Fuels in an Engine without hard seats may or may not be OK.

 

Problems with Valve Seat Erosion only occur when the exhaust temps get high enough when using Unleaded fuels. This is about 750⁰C.

 

So, if running Unleaded fuels without hardened valve seats, be sure to keep the car in perfect tune and as insurance, I would recommend using some reputable valve seat saver.

 

As a matter of course, when overhauling my own engines, I do fit hardened seats if they are not already fitted.

[carbon]

Castrol Valvemaster plus is recommended, the additives usually work out cheaper online aswell. 

+1 for Castrol Valvemaster.

[CedricTheMini]

Thanks for all your help so far. So the engine number is 99HB81P, so looking at crazy's post that would suggest its a leaded engine? I'm guessing if the head had been upgraded then the engine number would have changed? Thanks Again 

[CityEPete]

The engine number wouldn't generally change unless it was a total refurbished replacement like a gold seal. There's no way of knowing if the head's been off and upgraded though.