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100/4 Fuel pressure advice needed

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andrewss

Jedi Hopeful
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I have just completed a BN1 100/4 restoration with a rebuilt engine and overhauled H4 carbs and an electronic ignition. To cut a long story short I had a spare facet cube pump (4-7 psi) which I used as I ordered the wrong SU pump and they don't want to change it for me (another story !!). Although the car idles fine when cold as soon as its warm its starts to splutter and when I turn off the ignition it continues to run before dying out after 30 seconds followed by a big puff of smoke from the air filters !!!

A friend suggested that the fuel pressure is a cause...

My questions are;

Could this be the reason and if so what should the PSI for a 100/4 with H4 carbs be ?

Any other ideas/suggestions ??

Regards,

Andrew
 
SUs like about 2-1/2 PSI, so you can complicate matters more by adding a pressure regulator__AND THE CHEAP ONES DON'T WORK. AT ALL__or just get a low psi output pump.

Unless you're on the concours circuit, my recommendation would be for a Facet Interrupter style pump (the big one) in the appropriate PSI range.

Here's one (1) example, but by all means, compare the output of all the listed pumps (and read their pdf...): https://www.pegasusautoracing.com/productdetails.asp?RecID=2698

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