From: Laura G. <savercool@email.msn.com>
>I have a side draft Weber on my '78 Spitfire and I get 15-18 in the city
and
>23-25 on the highway.
I was going to say the Webbers are not as good for fuel economy.
Having said that so is a warn or stuck vacuum and centrifugal advance in
your dizzy. Check that! Then your valve clearances, then points and
capacitor(I hate the word condenser its so old fashioned).
A vacuum meter is a relay good investment, and lets you tell how well you
engine is. Replacing my old warn SU's has given me an extra 10 miles to the
gallon, and the vacuum at idle is up where it used to be on overrun. I
still have not tuned them properly, I just guessed! Oh yes and the
difference in power.
I went from non wax-stat converted carbs to good old wax-stat used carbs,
checking butterflies etc. At first major vapour lock, then I put in the
missing heat shield, no more probs. No more stalling ..... Lovely! OK I am
having problems with a sticking overrun valve, but thats because the vacuum
is so high.
A 20 mpg difference in fule economy can be put down to driver heavy foot
sindrome, you have more fun when your getting 20 mpg out of a car that you
could get 40 mpg out of!
For realy good economy, and more power than twin SUHS2's (mabe not 4's) try
fitting a SU HIF6or 8 from a MG metro etc. Take one Dolly manifold, remove
loads of aluminium with a grinder from the inside to make the tube match the
size of the 6. Bolt it on, it uses the 4 stud thing! Bolt the manifold
onto a mk3 1300 engin. Tune. Get up to the leagal speed limit, the engage
overdrive, foot to floor and you will soon be fined for doing over 100mph.
The other advantage of HIF's is you only replace the needel and jets,
nothing else goes wrong. And in england there are 1000's of them lying
arround in scrap yards, looking for a new owner.
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