What Petrol can i use?

Hiya folks.

I have an orginal standard 1951 GMC engine in my truck. (it's a straight 6)
Can i use Unleaded petrol in it or do i have to stick with leaded.

Thanks folks any info appreciated.

Daisy

 

if that motor has been running with leaded gas (petrol) all its life you should be ok for aw hile with all the lead the valve seats alrady have in them. if you have thehead rebuilt then have the hardened seats installed in the exhaust valve seats.

love the trck, have a 50 myself.


jerry

 

when I had my 48 Fleetline sedan, it still had the original 216 in it....i used unleaded with no problems, i just put a little bit of marvel mystery oil in the tank before I filled up on the advice of an old mechanic...never had any problems...

do they still have leaded in the UK? If they do, I am suddenly jealous...

 

Hi Hillbilly

We still have leaded in the UK at the moment but government trying to phase it out that's why i asked also it's getting really expensive 80.9p a litre

Daisy

 

I have a MGB GT that says in the ownes manual to use leaded only (or it'll self destruct?) and since we haven't had lead in ove a decade it's been running on unleaded.
All I've found is I need to adjust the exhaust valves more frequently and it will run on the cheapest unleaded regular without pinking (we call it pinging here in USA) instead of needing the highest octane premium leaded it used to need.
Go ahead and use it. those Chevys need a valve job every 50,000 miles or so anyway.