Bristol Cars - Owners and Enthusiasts Forum  

Go Back   Bristol Cars - Owners and Enthusiasts Forum > Bristol Forums > 6 cyl Bristol cars

6 cyl Bristol cars Type 400 to 406 - restoration, repair, maintenance etc

Correctly jetted carburettors

Reply
 
Thread Tools Search this Thread Display Modes
  #1 (permalink)  
Old 03-11-08, 07:06 PM
Member
 
Join Date: Jul 2008
Location: Burbank, California
Posts: 135
Default Correctly jetted carburettors

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.
Reply With Quote
  #2 (permalink)  
Old 03-11-08, 07:50 PM
ex member
 
Join Date: Aug 2008
Location: Nr. Stroud, Glos
Posts: 141
Default Correctly jetted carburettors

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
Reply With Quote
  #3 (permalink)  
Old 04-11-08, 11:36 AM
ex member
 
Join Date: Aug 2008
Location: Nr. Stroud, Glos
Posts: 141
Default Correctly jetted carburettors

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
Reply With Quote
  #4 (permalink)  
Old 04-11-08, 01:40 PM
Member
 
Join Date: Jul 2008
Location: Burbank, California
Posts: 135
Default Correctly jetted carburettors

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)
Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


All times are GMT. The time now is 02:34 AM.


This is the live site

Search Engine Friendly URLs by vBSEO 3.6.0 PL2