• Hi Guest! Being a Paying Supporter is NOT a requirement to participate at BCF. However, subscribing will help ensure we can continue to serve the LBC community for years to come. If you enjoy BCF and find our forum a useful resource...Please consider supporting us by **Upgrading**
    (PS: Subscribers don't see this banner)
Tips
Tips

BJ8 fuel consumption

DavidThorn

Senior Member
Country flag
Offline
I have set the ignition timing on my late BJ8 to 35 max advance at 4000 revs (with vacum tube disconnected) . I have a timing light on which the advance can be set so it should be pretty accurate. But the fuel consumption has now dropped from a regular 24 mpg (UK) to around 20 mpg. Anyone any ideas?
I am confident the carbs are set up correctly all plugs are a nice grey colour. The dwell angle is 35 - not changed.

Before adjustment the car must have been running with the ignition well advanced. The distributor was about 15 degrees further clockwise than it is now.
By the way the car is running fine,a lot less `lumpy` than it was before. Its just the reduction in mpg that concerns me?
 

Ed Kaler

Jedi Warrior
Offline
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]I am confident the carbs are set up correctly all plugs are a nice grey colour. [/QUOTE]

Carbs a bit on the RICH side, David.

Plugd "shoulb be" tanish.

/bcforum/images/%%GRAEMLIN_URL%%/cheers.gif
Ed
 
Country flag
Offline
I set the timing at 22 to 25 due to the 6500 feet I usually drive in but this weekend I went down to 100 feet and had to adjust bact to 15 becouse I got a surge at the greater advance. Smooth right out with the retarding all the way back home. Go figure. And as Ed says gray is too rich. I would think you would lack power with 35 degrees advanced.
 
Country flag
Offline
By the way the car is running fine,a lot less `lumpy` than it was before. Its just the reduction in mpg that concerns me?
-----------------------------------
More horsepower=higher fuel consumption.
 

Keoke

Great Pumpkin
Country flag
Offline
tahoe healey said:
I set the timing at 22 to 25 due to the 6500 feet I usually drive in but this weekend I went down to 100 feet and had to adjust bact to 15 becouse I got a surge at the greater advance. Smooth right out with the retarding all the way back home. Go figure. And as Ed says gray is too rich. I would think you would lack power with 35 degrees advanced.


Watch out TH! David is stating the Maximum advance of the Dizzy at 4000 RPM which is the specified sum of the Mechanical and Vacuum advance at that RPM on the BJ8 engine.---Keoke-?

Well TH, I "Figure" them carbs got enough air down there to last them for ah week or two!---- /bcforum/images/%%GRAEMLIN_URL%%/laugh.gif
 
Country flag
Offline
Ah, thanks, Keoke. 35 did seem too high at 600 to 800 rpm. I've got to try that high rpm timing some time. I think my car likes blue air better than brown anyway.
 
Similar threads
Thread starter Title Forum Replies Date
Cutrog1 BJ8 Fuel Tube Installation Austin Healey 10
S BJ8 Fuel Pump Austin Healey 13
B Fuel pipe runs BJ8 Austin Healey 2
Lutz Kramer Fuel gauge and sender unit for BJ8 Austin Healey 2
Bob_Spidell BJ8 Fuel Pump Trivia Austin Healey 0
M BJ8 Fuel pump Austin Healey 13
J BJ8 PhI ; #25805; Fuel Pump Austin Healey 20
T BJ8 Tachometer and Fuel gauge stopped working. Austin Healey 27
S BJ8 Fuel Gauge -Shows 1/4 tank when empty Austin Healey 10
pkmh BJ8 Fuel Tank Sending Unit - Ground Wire Austin Healey 8
Ed_K Correct SU Fuel pump for a BJ8 [ PSI specs] ? Austin Healey 9
AUSMHLY Float bowl fuel height BJ8 Austin Healey 4
G BJ8 Fuel Gauge Core Austin Healey 9
N BJ8 out of fuel at 1/4 full tank Austin Healey 4
Frank C. BJ8 Fuel Gauge Austin Healey 5
F BJ8 Fuel Filter Installation Austin Healey 14
L BJ8 FUEL TANK SPOTTED Austin Healey 2
G BJ8 Fuel gauge help Austin Healey 8
BOBBYR BJ8 FUEL TANK Austin Healey 7
J I need a picture of installed fuel pump for BJ8. Austin Healey 4
JamesD BJ8 Top Frame Bumpers Austin Healey 6
AUSMHLY BJ8 Driveshaft Installation Austin Healey 10
M BJ8 Inner Body Panel Repair Austin Healey 2
crispy BJ8 Front Suspension Austin Healey 9
HealeyRick BJ8 Repaint Advice Sought Austin Healey 15
BJ8Healeys Original Metallic Golden Beige BJ8 for sale Austin Healey Classifieds 0
M BJ8 Seat Thickness Austin Healey 6
D BJ8 Headlight Rims Austin Healey 0
B RHD BJ8 Throttle Control Rods Austin Healey 9
J BJ8 Radiator Fan Austin Healey 12
H BJ8 Heater Valve/Control Tap Austin Healey 3
R BJ8 Upholstery Austin Healey 5
M Mounting BJ8 Chassis on Rotisserie Austin Healey 8
T BJ8 Drain Channel Removal Austin Healey 2
B BJ8 Phase 1 Electrical Diagram Austin Healey 15
M For Sale BJ8 Tonneau Cover Austin Healey Classifieds 8
R Distributor: Reassembling BJ8 Engine Austin Healey 5
lbcspinners BJ8 chassis number ending with suffix "G" [??] on BaT Austin Healey 11
R New Engine mountings BJ8 Austin Healey 1
T BJ8 carpet Austin Healey 2
R Cylinder head gasket BJ8 Austin Healey 32
pkmh BJ8: Upper Trunnion Rebuild [Of Continuum] Austin Healey 9
BJ8Healeys For Sale 1965 BJ8 for sale Austin Healey Classifieds 0
M Getting behind the dash on BJ8 Austin Healey 4
J BJ8 flywheel take some pounds off Austin Healey 17
Keoke 1966 AH BJ8 on eBay Austin Healey 18
L BJ8 Batteries Austin Healey 8
pkmh Front Spring Removal For BJ8 Austin Healey 8
M Wanted Bj8 left front wing Austin Healey Classifieds 3
B BJ8 door hinges Austin Healey 7

Similar threads

Top