IrishS1

This may sound ridiculous but, I have a series one but don't
Know whether the head has hardened valve seats or
Not. If it has, and I've been using unleaded fuel along
With the lead replacement additive, will this do any harm??

RichieST

iTrader: (2)

Nope the additive will do no damage if you have hardened seats, it's if you haven't and you don't use it that will give you problems!

IrishS1

Just as I hoped. Thanks Richie.

martysmartie

iTrader: (1)

All CVH's have hardened valve seats to my knowledge.

The only thing you may want to do is retard the ignition a couple of degrees when using unleaded, otherwise it can lead to pinking.

Martin

IrishS1

I'm led to believe they changed to
Hardened seats in October 85. My car is
August 85. Is there any way of telling what
Year your head is?

cabriolet

im sure the heads were marked someone on here will know think it was up dizzy end

the_frozen_one

iTrader: (1)

Cvh heads with hardened seats from the factory started with the 88SM part number. Eg 87/88 onwards.

An S1 head will be 81SM as standard so unless they've been changed it won't. I used castrol valve master in my daily s1 for years and it ran sweet as. There is 2 versions, standard and octane boost. I used the latter, with premium fuel, pretty much as close as you can get to 4-star without paying silly money

Thrush

iTrader: (1)

Dunno about dates, but I ran all my Escorts ('87 XR3i, '84 and '85 S1 RST's) on unleaded (except the '85, which apparently was "set up" for super unleaded, so ran it on that), all without any additives or LRP, and they all ran fine with no problems - well, apart from the XR3i, that blew up after it's first long journey, but that turned out to be a poorly looked after engine, and the long journey basically de-coked it and showed up how bad it was running. Or at least so I was told/led to believe. After I had that rebuilt, it ran sweet as a nut on regular unleaded, with no additives, for several years till I sold it.

IrishS1

Thanks for the info lads. Been a great help.