Idling query

Ian Anderson · Post by **Ian Anderson** » Fri Aug 28, 2009 5:23 pm

almost blocked fuel filter?

Or filter mesh before fuel pump

Ian

CastleMGBV8 · Post by **CastleMGBV8** » Fri Aug 28, 2009 9:58 pm

Pete,

Where are your Lamba sensors situated?

Kevin.

sidecar · Post by **sidecar** » Sat Aug 29, 2009 7:01 am

CastleMGBV8 wrote:Pete,

Where are your Lamba sensors situated?

Kevin.

Hi Kevin,

Its on one of the headers about 18" from the head. My headers are home made jobbies. I would have liked the lambda sensor fitted at some point where it could sample the gas from all of the cylinders from one bank of the engine but as the headers only join up at each side pipe the blanking plug would have been in full view. (It would have ruined the good looks!)

Why do you ask?

Pete

Cobratone · Post by **Cobratone** » Sat Aug 29, 2009 8:33 am

sidecar wrote:The AFR's are:-

Tickover= 12-12.5:1 (Goes a bit rough if I lean it off anymore than this)
Cruise=13.5-14:1
Acceleration=12.5-13:1
WOT=11.5-12:1

Pete, just for comparison my AFR's are: -
Tickover = 14.2
Cruise = 15.5
Acceleration = 14.0
WOT = 13.0
Overrun = 15.8

you must be using loads of fuel while driving, any idea what your consumption is?

sidecar · Post by **sidecar** » Sat Aug 29, 2009 9:31 am

Cobratone wrote:
sidecar wrote:The AFR's are:-

Tickover= 12-12.5:1 (Goes a bit rough if I lean it off anymore than this)
Cruise=13.5-14:1
Acceleration=12.5-13:1
WOT=11.5-12:1
Pete, just for comparison my AFR's are: -
Tickover = 14.2
Cruise = 15.5
Acceleration = 14.0
WOT = 13.0
Overrun = 15.8

you must be using loads of fuel while driving, any idea what your consumption is?

I know what's coming next....NO I'M NOT GOING TO FIT EFI. (yer GIT!

)

I don't know what my MPG is, I find it totally impossible to drive my cob in a sensible manner for more than 5 minutes!

It must be between 5 - 40 MPG, does that help?

See ya soon.

Pete

CastleMGBV8 · Post by **CastleMGBV8** » Sat Aug 29, 2009 9:31 am

sidecar wrote:
CastleMGBV8 wrote:Pete,

Where are your Lamba sensors situated?

Kevin.

Hi Kevin,

Its on one of the headers about 18" from the head. My headers are home made jobbies. I would have liked the lambda sensor fitted at some point where it could sample the gas from all of the cylinders from one bank of the engine but as the headers only join up at each side pipe the blanking plug would have been in full view. (It would have ruined the good looks!)

Why do you ask?

Pete

Just curious as I have read that you can get different readings depending on where the Lamba is installed.

If you have the usual cobra type system with long primaries exiting the front wing into a collector. then your a bit stuck as to getting readings from all four cylinders on one bank and are only sampling one of eight cylinders.

Kevin.

sidecar · Post by **sidecar** » Sat Aug 29, 2009 9:56 am

CastleMGBV8 wrote:
sidecar wrote:
CastleMGBV8 wrote:Pete,

Where are your Lamba sensors situated?

Kevin.

Hi Kevin,

Its on one of the headers about 18" from the head. My headers are home made jobbies. I would have liked the lambda sensor fitted at some point where it could sample the gas from all of the cylinders from one bank of the engine but as the headers only join up at each side pipe the blanking plug would have been in full view. (It would have ruined the good looks!)

Why do you ask?

Pete
Just curious as I have read that you can get different readings depending on where the Lamba is installed.

If you have the usual cobra type system with long primaries exiting the front wing into a collector. then your a bit stuck as to getting readings from all four cylinders on one bank and are only sampling one of eight cylinders.

Kevin.

Your not wrong there Kevin. At the end of the day it's better than guessing and its not as if I can adjust the mixture on a cylinder by cylinder basis anyway. (Well not without fuel dams and fuel lots, but that's NASCAR stuff really!)

I've had another mad cap idea, my motor obviously wants "more carb" at low-ish RPM but does not create enough vacuum to open the flap plate above the secondaries. Using the spare plate that I've got I'm going to drill a big hole in each of the two counter weights. I'll then fill them with solder and drill a small hole in each so that they are back to there orginial weight. I can then keep drilling the hole bigger until the flappy plate opens too soon. I just then need to re-fill the holes with solder and go back on drill size!

Its bound to work great. (or not!)

Pete

CastleMGBV8 · Post by **CastleMGBV8** » Sat Aug 29, 2009 10:21 am

Pete,

With carbs the old fashioned method of reading the plugs is probably as good as any.

Just get the engine to run smoothly at idle and cruise on the lowest settings you can. Then do full power runs (WOT) and shut down the engine whilst under WOT and then read the plugs.

This will tell you not only if the mixture is correct it will show if you have correct heat range for the plugs but start the test with a clean set of plugs to give accurate indications.

You probably knew all that.

Cobratones figure show the benefit of EFI and throttle bodies with a programmable ECU as they are just about ideal.

Kevin.

sidecar · Post by **sidecar** » Sat Aug 29, 2009 1:58 pm

CastleMGBV8 wrote:
Cobratones figure show the benefit of EFI and throttle bodies with a programmable ECU as they are just about ideal.

Kevin.

Don't say that, EFI versus carbs is a long on going "discussion" on the Cobra forum, it will go straight to Tony's head!

At the end of the day EFI (or Gay-FI as its known on the Cob forum) will out perform a 4 block carb but I still like my carb, I like the fact that its a bit rough and ready.

Alex, I've sent you a PM.
John, I need an email address from you!
Pete

Richard P6 · Post by **Richard P6** » Sat Aug 29, 2009 3:12 pm

sidecar wrote: At the end of the day EFI (or Gay-FI as its known on the Cob forum) will out perform a 4 block carb but I still like my carb, I like the fact that its a bit rough and ready.

My first experience of EFI was on old Montego Mayfair I bought a long long time ago. Up until then I used to fix my own cars but this thing was just far too complicated.

When it developed a fault, I took it back to the garage I had bought it from but they couldn't fix it. I took it to Gillingham Rover who charged me £90.00 to fix it but didn't. I took it to Lucas who spent three hours on it but couldn't fix it.

EFI I discovered, stands for 'Extra Flipping Intricate' (Polite Version)

sidecar · Post by **sidecar** » Sat Aug 29, 2009 3:49 pm

Richard P6 wrote:
sidecar wrote: At the end of the day EFI (or Gay-FI as its known on the Cob forum) will out perform a 4 block carb but I still like my carb, I like the fact that its a bit rough and ready.
My first experience of EFI was on old Montego Mayfair I bought a long long time ago. Up until then I used to fix my own cars but this thing was just far too complicated.

When it developed a fault, I took it back to the garage I had bought it from but they couldn't fix it. I took it to Gillingham Rover who charged me £90.00 to fix it but didn't. I took it to Lucas who spent three hours on it but couldn't fix it.

EFI I discovered, stands for 'Extra Flipping Intricate' (Polite Version)

THANKYOU....here rests the case for carbs!

(Bun fight about to start, again!)

JSF55 · Post by **JSF55** » Sat Aug 29, 2009 4:01 pm

PM sent Pete, i'll update my info shortly, once i can make head or tail of what the LC1 is telling me

sidecar · Post by **sidecar** » Sat Aug 29, 2009 5:15 pm

JSF55 wrote:PM sent Pete, i'll update my info shortly, once i can make head or tail of what the LC1 is telling me

Just got to nip out and get some gas for my blow torch, when I get back I'll send the XL spreadsheet.

I've reduced the refresh rate on my LC1, before the numbers flashed up so quickly that it was doing my head in!

Pete

JSF55 · Post by **JSF55** » Sat Aug 29, 2009 5:56 pm

Thats something else i need to do

bigaldart · Post by **bigaldart** » Sat Aug 29, 2009 6:07 pm

So glad we have MFI and Methanol on the dragster. Carbs were a nightmare LOL