My car hates unleaded

[Pub247]

Well the other morning i ran out of petrol before i even got out of my driveway. (got a dodgy sender unit) Anyway my car is normally good on the juice but since ive rebuilt it it obviously using more.
My problem is im running late for work so i fill her up with a whole tank of unleaded. Stupid move its pinging of its nut everywhere basically its almost undrivable. I dont want to waste a tank of petrol or spend 10 on so called octane booster. Should i just retard the timing to help stop a lot of pinging?

The reason for it is compression its prolly a lot higher than expected and ive only ever really ran pulp since i rebuilt it

[JD]

are you using the fuel additive stuff?

[BLSTIC]

If you don't need to nail it, disconnecting the vacuum advace will retard the ignition timing at low loads, and when you get good fuel, you can just reconnect it and not worry about a timing light.

[Pub247]

Thanks that sound like an easy way out

[Tree cutter]

You should look into getting a water injection system to stop it pinging. You might be able to get away with running the cheaper unleaded all the time. You used to be able to buy cheap systems that looked like a windscreen washer bottle for the water and a small plastic hose that went to your carby just above the throttle butterflys. Some of the old stromberg carbys had to have a hole drilled and tapped into them for the water injection, but with some of the later carbys you should be able to use one of the vaccum fittings that is already on the carby. Adding a bit of metho to the water helps also.

[vkberlina]

Considering the 202 was designed to run on 96 octane Super, trying to run it on 91 octane fuel no doubt it would ping. It should be run on either 96 or 98 octane unleaded.

cheers
scott

[Pub247]

yeah i know i have always used pulp until this week i was late for work and didnt want to waste time going somewhere else. the water injection although a good idea i will be going efi soon so it not really an issue thanks anyway guys. Also when i finish rebuilding my yella terra head it'll will going back on with a decomp. gasket as this 173 head is killing me