>
> I cast a 1 inch aluminium spacer that fitted between the Offy manifold and
>the carb, forming a sort of plenum, without the dividing wall that the
>manifold has.
> I never proved that this was a better arrangement, but I feel that reducing
>the effects of the diviiding wall allows each cylinder to draw through all 4
>carb barrels, making the engine 'see' a bigger carb.
I have a 4 hole spacer. I have driven a car with identical engine but an open
spacer and it felt amazing at the top end, but seeing as I beat it in the
quarter mile I assume that what I was really feeling was a big drop in
mid range torque on the other car which made the top end feel better. I am
going to experiment with spacers soon though , on a dyno.
> A bigger carb may help. Most people would say a 390 is big enough, but I'm
>not sure. When the carb manufacturers say it flows 390 CFM, you need to know
>at what vacuum to make sense of it. I believe that 4 barrels are flowed at 1.5
>inches Hg and 2 barrels at 3 inches Hg.
Yes, the 4 barrels are flowed at 1.5". There was a test in a UK magazine
a few years ago where Real Steel built a 250HP engine and tried a 390
vacuum, a 390 double pumper and a 465 vacuum. All 3 carbs were very
similar in terms of output.
> 1650 lbs?? what you got, a Westfield? Dax rush????
Westfield.
Bye,
Ian
--
Ian Crocker ian@btcase.bt.co.uk http://www.geocities.com/MotorCity/9190/
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