Petrol (specifically UK)

[Duncan]

HI
I was wondering what sort of petrol people use, and whether they use any additives. Do additives make any difference/are they necessary? I've just got a '79 HPE (2l carb) and after I've sorted some of the rust I want to have a go at the engine. Please post any tips/comments you have about the fuel you use.
Cheers
Duncan

[Wallace]

Personal opinion (totally !!) would be to run on unleaded and keep a VERY CLOSE eye on the exhaust valve clearances. Burton's do a good technical write up (have a look at there websight) on the pros/cons of leaded,LRP etc and they only advocate replacing the exhausts valve seats, NOT the inlets, the guides and the valves. My engine now runs a Delta turbo head with bronze guides, etc etc but then it is running with a turbocharger .. . . .
If the heads a bit past it's sell by date, then it might be an idea to renew guides, seats etc with unleaded compatable.

[Gary Severson]

I am just a bit curious what components in an European T/C head are uncompatable with unleaded. The stock Scorpion comes with cast iron seats and valve guides and is Unleaded only. What material do they use for valve seats in the UK.
Gary Severson

[Will]

I thought the seats were all machined steel, not cast, so that goes to show what I know. But I do know you can use an additive to "treat" the seats so you can run unleaded- Red Line makes a lead substitute, and I believe other companies do as well.
-Will

[Duncan]

Wallace:
Any chance of a URL? Websearching for Burton's is somewhat futile! I'd be well interested in that article. I've got Guy Croft's book, but I don't think it mentions much about petrol, and I don't know enough about what bits require lead and what can be safe without...
Cheers
Duncan

[Wallace]

Yep - try this.


http://www.burtonpower.com/system/index.html


They did a good job on my rebore/decking (the block, NOT the garden .. . .) and I figure if they were just after the cash, they'd recomend changing everything . .. . !!!

[Duncan]

Thanks Wallace, that makes a lot of sense. I guess I'll take the head off (after procuring the correct things needed to put it back together) and have a look. Best do that efore I spend any money on the thing...
Cheers
Duncan

[Duncan]

I've actually discovered a list of garages that still sell leaded petrol. I don't think there's on near enough to me to make it worth my while, but someone here might find it useful. the list is at http://www.leadedpetrol.co.uk/
Hope it's helpful...
Cheers
Duncan

[omicron]

The other option is to use normal unleaded and an additive. There are about 200 additives on the market, but only a handful of those do any good.

One that does is Valvemaster, which developed by Associated Octel (a very long standing research lab), which is a managese based product, which is superior to lead although lead was originally given the nod on cost grounds.

This is distributed in the UK via the Castrol network, so easy to get and quite cheap. A more expensive version is availalble in octane boosting form as well.

If you have to take the head off for any reason, then that is the time to do the seats as the labour in unfitting / refitting is paid for...

[VAR1016]

Quite frequently, valve seats specified for LPG engines are used when adapting for unleaded.

As LPG has no lubricating properties, these seats have to be very hard indeed. They are probably made from Stellite or Brightray, very tough alloys of (I think) cobalt, tungsten, chromium etc.

Omicron mentioned Associated Octel. Well of course this is the organisation that produced tetra ethyl lead for years, so should be very well placed to produce a good product.

The great thing about lead was the "lead bonus" This term, used in the gasoline industry, referred to the fact that a gasoline rated at a given research octane number would perform better if that number was attained using TEL rather than if it were obtained by using say a greater proportion of aromatics or MTBE etc.

Here in the UK most gasoline is really rather average for performance vehicles in my view. The best available appears to be Shell's Optimax.

However, in Hungary one can buy Shell "Racing" at many stations; this is rated at 99+ RON. And I have just heard that in California, 100 octane unleaded is available.

Of course the important parameter is the Motor Octane number; here the government ruled (in 1986) that henceforth this would be a maximum of 86. Meanwhile in France and Germany 88MON fuels are available - and the French helpfully include the MON on the labelling on the pumps.

The MON is particularly important because it refers to a gasoline's performance under real conditions with higher intake charge temperatures - especially relevant for those with turbocharged engines.

Write to your MP now!!

Paul

[Hamish]

Here in the UK most gasoline is really rather average for performance vehicles in my view. The best available appears to be Shell's Optimax.



Have to agree, I've been using Optimax in my Volumex coupe and there is a noticeable difference in the engines willingness to perform :D However, I thought it best to put this to test so have run my wifes '98 Honda Civic 1.4i :roll: (it's actually a good car just don't tell her I said so..) on a couple of tanks and there is an improvement lower down the rev range :wink:
I certainly haven't seen any genuine leaded petrol this far North in the UK, queries to Shell, BP and Esso regarding additives appropriate or approved with their unleaded fuel has yet to draw a reply.