A7 OOH Posted March 31, 2021 Share Posted March 31, 2021 I am running a X/Flow with an unleaded head (Recent Acquisition)I assume like my previous classics I should be using an additive such as Castrol Lead Substitute. If I use a premium fuel such as V Power or BP ultimate can I forget using an Octane boost additive or do I need to use a premium or will standard unleaded work Link to comment Share on other sites More sharing options...
Area Representative Golf Juliet Tango Posted March 31, 2021 Area Representative Share Posted March 31, 2021 I run my Crossflow on 97 or 99 octane fuel. No additives of any sort.I have filled it with 95 octane fuel when nothing else is available and just carried on. I wouldn't worry in the least.My engine has covered 133,000+ miles and had a couple of thoroughgoing rebuilds in that time. They are wonderfully tough, forgiving and characterful engines Link to comment Share on other sites More sharing options...
Olgawld Posted March 31, 2021 Share Posted March 31, 2021 With this new fuel coming soon you'll definitely want to go with the super unleaded, vpower etc. If it's been converted for unleaded petrol, hardened exhaust seats, then I don't think you need additives. Link to comment Share on other sites More sharing options...
Roger King Posted March 31, 2021 Share Posted March 31, 2021 If the head is suitable for unleaded you don't need to add a lead substitute. It's as simple as that. I can't comment on the octane rating because I don't know the spec of your engine. The higher ethanol fuels won't affect the valve seats, but may have repercussions for your hoses. Link to comment Share on other sites More sharing options...
A7 OOH Posted March 31, 2021 Author Share Posted March 31, 2021 Stephen (GJT) does this apply if the head has not been converted for unleaded with hardned valve seats etcMy cyl head has not been converted for unleaded Link to comment Share on other sites More sharing options...
Tazio Posted April 1, 2021 Share Posted April 1, 2021 If you haven't hardened valve seats, then you'll need to add the lead substitute as you originally stated. Link to comment Share on other sites More sharing options...
A7 OOH Posted April 1, 2021 Author Share Posted April 1, 2021 As I thought as much nice to check. Link to comment Share on other sites More sharing options...
Area Representative Golf Juliet Tango Posted April 1, 2021 Area Representative Share Posted April 1, 2021 Mine had hardened valve seats put in many thousands of miles ago. Link to comment Share on other sites More sharing options...
A7 OOH Posted April 1, 2021 Author Share Posted April 1, 2021 If the head needs to come off for any reason I will get the vavlev seats done Link to comment Share on other sites More sharing options...
Roger King Posted April 2, 2021 Share Posted April 2, 2021 If your head is suitable for unleaded as stated in the heading for this topic it will already have hardened seats fitted. Link to comment Share on other sites More sharing options...
A7 OOH Posted April 2, 2021 Author Share Posted April 2, 2021 Hello Roger you got me, the head fitted is not an unleaded head I have fitted it is the standard one designed for leaded fuel and does not have the hardened valve seats Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now