Running these cars on unleaded petrol

J

Josh Slade

Club Member
Hi there, i'm very new to these cars and going to be purchasing one very soon, are these engines fine to run on UK unleaded petrol?

Thanks
 
I think valve seats before '77 were bronze and so not safe with unleaded.
However, many have had their seats replaced so....
 
As far as I know it's a lot earlier than that Jon. Only very early 240s shouldn't be run on unleaded. I'll search.

Edit. It's a minefield on here - not looked anywhere else. The consensus is that you won't have a problem with unleaded.
 
Last edited:
Rob Gaskin said:
As far as I know it's a lot earlier than that Jon. Only very early 240s shouldn't be run on unleaded. I'll search.

Edit. It's a minefield on here - not looked anywhere else. The consensus is that you won't have a problem with unleaded.
Click to expand...

Thanks for the help!
 
My search showed the clubs technical advisor confirmed valve seats were bronze until '77 at least on the UK cars.
If you run bronze seats with unleaded you will get accelerated wear. They aren't designed for unleaded. If you only do 300 miles a year, it'll be a good few years before you have a problem. That may be fine for you.
I ran a head with bronze seats for a few years and even with lead replacement additive the seats were visibly eroded after a few years.
 
Last edited:
So it’s all still inconclusive. Most of the 240’s I’ve bought over from the US appear to have engine that have not been apart. The silver ratty car that gets the most use has an untouched engine so I have often considered if I’m likely to cause damage with straight unleaded.
 
jonbills said:
My search showed the clubs technical advisor confirmed valve seats were bronze until '77 at least on the UK cars.
If you run bronze seats with unleaded you will get accelerated wear. They aren't designed for unleaded. If you only do 300 miles a year, it'll be a good few years before you have a problem. That may be fine for you.
I ran a head with bronze seats for a few years and even with lead replacement additive the seats were visibly eroded after a few years.
Click to expand...

Do we know what engine number was 1st fitted with non bronze seats ie. the cut off?
 
You must log in or register to reply here.
Back
Top