Technical Any 6-71 blower tuners want to give me some carb help

Wow, lot'sa good info here.
Half scared to post in a thread with the likes of Squirrel, Lippy, FalconGeorge, oj and Saxon....
I don't know a thing about blower carb tuning but I can make a recommendation for a good wide band AFR gauge:



AEM makes a nice analog wide band AFR gauge (left) and analog EGT (right). AM vacuum gauge (middle)
The AEM gauges come with black and white faces and black and silver trim rings you can change yourself.
You can also select back light color....

 

I'll add this here too, I am probably the last guy on the planet to discover these, but IMO, its real useful for HAMB period-correct builds.

I plan to use a wide-range O2 sensor for tuning the multi-carb Olds rocket in my '39, but I was really reluctant to weld a bung into the exhaust pipe, the car is 101% period in every detail so far, and the idea of having a threaded bung in the exhaust pipe with a plug in it was really bugging me. I was thinking of making an extra headpipe with a bung in it, and switching it out after I got the car tuned, but then I found these. I can just bolt them in place between the end of the headpipe and the glass-packs, then remove it when I am done tuning. No give-away pipe plug in the exhaust pipe.

 

Is this the same spindle that the wheel bearings went out on ? I seen this happen before on Ford & GM vehicles that had wheel bearings seized up on, break later after replacing the wheel bearings. Any time a suspension part came into question I replaced it, insurance co did not like it but I did not have any comebacks like a lot of the outher techs. had. If I would not put my family in it I would replace it. Frank

 

I know these AFR meters are a big help in tuning an engine but do people not have tuning skills anymore.

 

maybe we figured out that we had been guessing all along...

 

I think a lot of people are using data acquisition & computers to tune

 

The whole front end is new.50 miles on it.not sure what happened my assumption is that the outer bearing race spun in the hub but I have no idea.everything felt good, spun good.i packed the bearings by hand.

 

I know mine are minimal.thats why I am here begging you smart tuners.

 

I have to many gauges in it now I think I will just take it out after tuning.

 

With pump Gas blend's of to day, Old methods of Reading plug's are Fause!!!
You will be like a dog ,chasing it's Tail!!
Plug by eye show Rich , But in fact it's lean , Just the Beast of gas blend's from the Pump !!!

Falcon G
I Tig weld a bung on back side of down tub, after tunning I removed O2 , cap off ,
Out of sight,
A lot of guys just threw on carb/ carb's , not realizing if they take the time to tune they will get a much happier Motor ,
Off-topic but make sure you add ZINC to your FLAT tappet motors , there is no more Zinc In modern Oil ,ONLY RACE OIL, and a few specialty oils

 

I hear you, and I thought of that, but this car is 1961 down to the hose clamps and stuff, after the lengths I have gone to, I dont want any trace left, these seem like a good way to do it. Honestly, I really cant imagine trying to get four 3 bolt carbs dialed in to my standards without using a wide-range O2 sensor, life is too short.

 

I do understand things have changed over time and there are better tools to help get on track.

 

I admire all the hard work that goes in to a car , or what ever that makes it authentic !!!
Perriaed correct !
I stared a thread yesterday , it was deleted, I fell it You claim to be a Rodder ,
Live it !!! Put the work into it , Drive it , Do not show up 1-2 times a mouth at a gathering and only drive 20-30 miles , If you Do !! You only own One!!
Look @ the history of a Hot Rod / Jalopy ,
Those pioneer's did not just drive there cars on Friday/ Saturday,
They dove them Everyday showed up at The salt flats /drag strip ,circle track ,
Removed Fender's ,what ever else's, whent Racing !!!
Now of days , Yeah I own a car , but I dive it Only Fri/Sat ,
KNOW THE HISTORY!!!!

 

I have a afr gauge on the way.can I stick the sensor in the open collector and get a accurate reading?does it matter what side?bangshift has a pretty good write-up on AFR gauges.

 

The sensor has to go quite a ways up in there. What happens is fresh air from reversion will show your readings being too lean. The lumpier the cam the closer to the engine you need to be.
Is there one or two carbs? I kinda imagine a single doublepumper sitting in-line with the blower, yes?

 

(2) sideways 600 double pumper

 

What oj said.
Your AFR gauge will have instructions for wide band O2 sensor placement and wiring.
You can prolly download them from their web site now.
I find that placement in the header collector works best.
I like at least 36" of pipe between the O2 sensor and the exhaust exit- otherwise reversion creates problems and dilutes the readings (see oj above) , although some kits say 18" is enough. Mufflers help.
I also like to place the O2 sensor in the collector for the bank that has number one cylinder because it fires first, but that not absolutely necessary.
Never put an O2 sensor on the outside bend of a pipe.
If mounting horizontal, make sure it's at least 15-20 degrees UP from the horizontal center of the pipe.
Moisture collects in the bottom of exhaust pipes and will destroy the sensor.
Straight down from the top into the collector is fine.

 

Installed the sensor went on a test run. 12 at idle 800 rpm. 10.8-11.6 at 2000 cruise. 11 at 1500. 11.1 at wide open best we could tell, my note taker got a little scared

 

rich across the entire rpm. 14-14.5 at idle, 12.5-13.5 cruising, 11.5-11.8 wot shoot for this and you should be safe. fine tune from there. ignition timing will be critical. if it detonates big problems will happen. to fix that a ignition box with a boost retard may be needed.

 

So as long as I don't foul plugs I'm safe? I may leave it alone until after the meltdowns then. I could actually rest a night or two.

 

It's not much richer than the holleys I had on my blown 454. You could play with jets and power valves if you want, see if you can lean it out a bit at cruise, but if it's not fouling plugs you could also just leave it alone.

 

Thats alot of raw gas going down the cylinders. Thats very hard on the rings. Not to mention polluting the oil. A quick jet change will do that engine some good.

 

Things to consider.
All the fuel in a typical Holley 4150/4160 flows first through the main jets, except when the power valve is open. If you look at the fuel bowl side of the metering block you can observe that the main jets and the end of the power valve are the only paths for fuel to enter the metering block.

Fuel at idle passes through main jet, idle feed restriction, emulsion of air from air bleed passes through mixture screws and then enters carb at idle holes. Transition occurs when blades open slightly and additional fuel flows through transition slot. The idle speed screws should not allow the transfer slot to be exposed too much.

Drilling idle fuel restrictions and air bleeds can get your carb out of whack, sometimes to where it can't be used. Drill with extreme caution.

The accelerator pump supplies extra fuel during the time it take from cracking the throttle until fuel gets flowing through main system. You should try reading this http://forums.holley.com/entry.php?428-How-To-Cure-Carburetor-Stumble

Once air flow has picked up the main portion of fuel is delivered through the main jets.

The power valve is just that. It opens when the throttle is open far enough for engine vacuum to fall below the valves calibrated opening point. The power valve restrictions have nothing to do with idle or (hopefully) part throttle. The Holley number is the point at which the valve opens enrichening fuel by allowing it to add to the flow from the main jets. A power valve that opens at part throttle will deliver a rich condition and fuel economy will suffer. The rule of thumb is to take a vacuum reading at idle and divide it in half. With a blown engine, ay thar's the rub. Try reading
http://www.motorsportsvillage.com/modifycarb.html