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Old 03-03-2016, 04:35 AM   #42 (permalink)
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Re: 'Just a warning from the previous comment'

Originally Posted by duncan View Post
Just a warning from the previous comment

You can't just put another SU carb on it - not if you don't want to burn a piston or waste a lot of gas

You need to set the carb up to your engine on a rolling road
SU carbs use a superb metering system using a tapered needle in a jet - there are about a thousand different shaped needles,

On my 1430 mini I changed the intake manifold - just the intake manifold - that made enough difference to melt a hole in a piston

Any carb fitted to a non standard engine will need to be properly set up on a rolling road
All I did was take it out for a run, keeping an good eye on the thermometer and listening to the engine. I then shut the engine down after a good hill pull and coasted to a stop. Pulled the 4 plugs and they were a nice choc brown, not very light cream colored (which can indicate running too lean). This is about all I could do back then as I had a poor mans budget and no access to any of those fancy Snapon diagnostic stations back then. Seat of the pants kind of stuff out in the Arizona desert. Besides, the manifold and carb that I used from the Morris Minor was off an engine that was a exact match cc-wise. I know you can adjust the SU right down to the gnats ass but I didn't push the Sprite that hard when running for economy.You see, I was just about penniless in a small hick desert town at least 85 miles east of Las Vegas, the nearest area of commerce. That's why I stuck the single manifold and carb on my Sprite in the first place. When back home I swapped back to the twin SU carbs. It didn't take that long to change em out and I did it at least 4 times. As a teenager back then I had more than a few older relatives praying for my safety every day so how could I go wrong?? Good times!
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