Correctly jetted carburettors

[RGSchmitt]

Hi Ashley -

I'd appreciate hearing your carb conclusions. My Frazer Nash Solex carbs are scheduled for a thorough scrutiny in January, likely assisted by the exhaust gas analyzer I sent to Barry Leitch in NZ. We have much original information from your website and Geoff Dowdle, but practical lessons are always welcome.

Bob

PS I've read of very low shipping costs from the UK to the Far East as a result of the economic slowdown. If this has reduced costs to Australia and New Zealand, it could be a good time to pack up a project and send it "down under" for completion.

[Ashley James]

Bob

My son is busy with quite a few Bentley's right now and he's subbed to www.alpineeagle.co.uk
where he was workshop manager till a year or so ago. He's trimming
the Maharajah of Jodpur's grandfather's PI. having said all that, he's
mightily worried that more and more work is going overseas. I
understand TT Workshops might be on a 4 day week too.

I think mine is pretty much as it should be now and I have a gas
analyzer, but I don't have the 100D2 camshaft that I'm sure provides
more of a challenge.

Geoff Dowdle has been marvellous, I couldn't have done it without him.

Ashley

[Ashley James]

Bob

My car is a 100B2 bottom end and camshaft with 7.5 to 1 pistons and
32BI carbs jetted for a 405 with 26 mm Venturis and with 50 instead of
45 pilot jets. This gives the best power and cleanest carburetion so
far.

Your engine is a 100D2, which are notorious for being unhappy below
3000 rpm. For normal road use the Intermediate cam is probably the
best. As Geoff Dowdle said, the standard engine gives more power up to
75 mph! I think.

Ashley

[RGSchmitt]

Hi Ashley (and all)

The engine in my car is a "FNS" spec example, which should have 8.5/1
CR and the same cam as on other "sports" specification Bristol
engines of its era. The 100D2 was a bit later and most reports I've
seen show a 9.0 CR; no data on the cam.

I've got several data sources that compare the various Bristol
engines, but nothing comprehensive through the entire manufacturing
run. Also have a list, from Geoff Dowdle, of all the sports
engines. Perhaps enough material for a book, if it were organized!

My FN is the only Bristol-engined car I've driven, so I have no basis
for a comparative critique. It's never seemed to lack anything for
touring and only poor driver technique hurt its performance in two
sprints last year.

Bob

PS A tremendous day will start here soon. If the election goes the
wrong way, I expect massive lines outside the Canadian, Australian
and NZ consulates! One would expect the two smart guys to easily win
over the two dopes, but "No one ever went broke underestimating the
intelligence of the American public." (H.L. Mencken)