dual carbs what jets you using here in cali

[34flathead]

Hey everone, I am now starting to try and get better gas mileage, Im running 2 97s on a Fenton intake, warmed 49-53 flatie, 4"merc crank.

havent pulled a carb to see what is in them now, but what are you running with dual carbs here in sunny california.
rich

[HotRodmicky]

42 or 43 mains
69 acc. valve

[ken ct]

Hot rod mickey's got it pretty good,i would suggest the same. ken ct.

[34fivewindow]

Originally Posted by 34flathead

Hey everone, I am now starting to try and get better gas mileage, Im running 2 97s on a Fenton intake, warmed 49-53 flatie, 4"merc crank.

havent pulled a carb to see what is in them now, but what are you running with dual carbs here in sunny california.
rich

Rich.
I'am using .046 jets and 65 power valeves, and get 14 miles to the gallon. I have tried .042 to .048 jets, and got the best power, and good all around driveabilty with the 46's. This is with an .040 bore, four inch stroke, and Weber F4 cam, in an 1800 lb Roadster.....Ed

[34flathead]

thanks guys, i will pull one off this weekend and see whats inside, as i am only getting 11 miles to the gallon, and have been told 14 and 15 miles was bad, but have not been told what jets and main or power valve is being used to accomplish this, i have also read on the HAMB of flatheads hitting 18 miles to the gallon.
rich

[uncle max]

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I'm at 4000 ft with two LZ's and get 22 mpg with .042's & # 69 pv's. Oh yeah, the overdrive helps...

[IVT1]

Are you running rich Rich?

[34flathead]

i have 2 more 97s in the reading room, with #42 jets, i just looked, but did not take the top off to see the power valve.

i smell a little gas but not a lot that would say hay i smell gas.

the tops weep a little compared to how wet they were before i put a fuel regulator on.

im loving that 22 miles i keep hearing about.

rich

[Charlie ny]

'34,
Do not overlook the possibility that your existing power valves
may be leaking. Many new out of the box PV's and certainly many used
PV's leak. Max and I have simple but effective devices to check for this
situation.
Charlie ny

[Charlie ny]

'34,
Stromberg power valves new and used have a tendency to leak.
Max and I have simple but effective devices to check for leaky PV's.
Charlie ny

[34flathead]

ok, so i took the carbs off and opened them up, jets are #45 and the power jet is # 65, the other set of carbs have #43 jets and #69 power jet.
i will use the second pair's base gasket on the bases that i am leaving on because i dont want to mess with the linkage that connects the bases together.

question, do you just put the top back on the carb or do you put oil on the accelorator pump leather?
rich

[Charlie ny]

'34,
OK the jets are stamped with some number and so are the power valves....did you determine that the jets have not been opened up....very
common......and that the power valves don't leak.
Not much sense in going further until you know the jets and power
valves are good. Don't forget to pull the emusion tubes to be sure
they aren't plugged.
Charlie ny

[JWL]

I oil the leather.

[34flathead]

charlie ny, i have the carbs off now, how do i test to determine if the power valve is leaking or not?
i have seen on here and will check the search thread to get the size of drill bit to verify the # on the jet, these were built back in 04 for me, and the set i put on i purchased when the guy decided to chevy his '40 coupe were built by the same guy.
the second set are on and the flatie now, smokes at idle, i do not know how to adjust the air fuel mix screws.
rich

[ken ct]

There is no drill # that you could use. You need a pin gauge set which has presision short rods in .001 incretments to measure them. ken ct.

[34flathead]

i just finished searching the search thread and my best friend google, it will need to be a pin set to verify the size.
now i am going to see what i can find online for these.
also the #45 jet that came out of the carbs i took off, the hole at the top and bottom dont matter, just the hole in the middle right?
rich

[Charlie ny]

'34,
Check your emails.
Charlie ny

[uncle max]

If you can wait till after Bonneville, send me your carbs and I'll go through them.
I'm in a good mood - no charge.

[34flathead]

i tried to email Chris some pic's but they were too many and it locked up my outlook email, my pm should be working, unless that has stopped too.
that would be just great uncle max.
rich

[HotRodmicky]

Originally Posted by 34fivewindow

Rich.
I'am using .046 jets and 65 power valeves, and get 14 miles to the gallon. I have tried .042 to .048 jets, and got the best power, and good all around driveabilty with the 46's. This is with an .040 bore, four inch stroke, and Weber F4 cam, in an 1800 lb Roadster.....Ed

The F4 is a big cam isn`t it?
I think Vern Tardel has one in his `32 roadster if i remember correct...
I bet it sounds great!!!

[34flathead]

ok, i have the two extra 97s on now, and since if have the #42 and #43 witten down in two different pieces of paper, i will have to pull one off again to get the correct size jet for reference here.

but the very distinctive 20" fox tail my exhaust left on the ground when warming up is gone.

this second pair of 97s had the idle screws only open 1/2 trun, and so i closed them and opened them up two full truns as the starting point from the Stromberg tips guide.

i have closed them 1/4 trun and am going to close them another 1/4 trun because i have very light blue smoke blowing out at idle.

but would always accept any suggestions on this.

also had a friend with a pin set check the jet size and they are #45s.

thanks charely ny,
after spending i dont know how long trying to find a drill bit size for measurement, that i finale found info directing my to the pins, when i saw you post.
rich

[ken ct]

Ive never seen anything in stromberg print that calls for 2 turns out. All lit. i have call for approx 5/8 of a turn. Real world is around 1 turn out. IMO your way too rich at idle with 1 1/2 to 2 setting. OMO.Take it for what its worth. ken ct. I would also use the shorter accel. pump rods on them [there are 2 diff sizes on these]

[34flathead]

thanks ken ct, i will have to check if the accelorator pump arms i have are too long, as for the info i got on the idle screws, it is on the Stromberg web site under tech support, here is a copy.

sorry i cant get the pic to copy, it shows the two screws on the base that get adjusted, i am new at working on any carb so i hope we are talking about the same screws,
rich

2) First, screw both screws in (clockwise) until
they just touch their seats. Then back them out
two turns each. Adjust the idle mixture screws
one at a time. Turn the first idle screw in slowly
(1/4 turn at a time) until the engine begins to lag
or run irregularly. Then turn the same screw out
slowly until the engine begins to roll or gallop,
then back in slightly to provide the smoothest
idle. Repeat this same procedure to adjust the

other screw. Re-adjust the first screw if required.

[34flathead]

ok, so i checked the accelerator pump arms, and yea they were too long.
i took the arms off the first 97s, and noticed i did not have to raise the connecting arm so much to connect them.

thanks ken ct.

im going on a little run tomorrow, about 100 miles round trip, maybe more, but i am going to lean out the screws another 1/4 to see how it runs and then another 1/4 before i leave for home to see how it run, that should put it at one full turn from closed.
so far it the acceleration had gotten better, but again i am not a carb guy.
but i do have over 12000 miles on this work in progress pickup and i can feel the difference.
rich

[sturgis 39]

I bought two 9 super 7 from Speedway Motors. i have changed the main jets. The engine does not seem to be running rich.
They are installed on a model a with a Riley two port head. I think the jets are the right size and the accelerator pump is set in the longest part of the arm. When i take off in low gear it misses and farts until i get up some speed. Speedway does not sell power valves for their 97's. Will others work or do i need something else?

[ken ct]

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Originally Posted by sturgis 39

I bought two 9 super 7 from Speedway Motors. i have changed the main jets. The engine does not seem to be running rich.
They are installed on a model a with a Riley two port head. I think the jets are the right size and the accelerator pump is set in the longest part of the arm. When i take off in low gear it misses and farts until i get up some speed. Speedway does not sell power valves for their 97's. Will others work or do i need something else?

In MO your way over carbed for a 4 banger. ken ct.

[ken ct]

Originally Posted by 34flathead

thanks ken ct, i will have to check if the accelorator pump arms i have are too long, as for the info i got on the idle screws, it is on the Stromberg web site under tech support, here is a copy.

sorry i cant get the pic to copy, it shows the two screws on the base that get adjusted, i am new at working on any carb so i hope we are talking about the same screws,
rich

2) First, screw both screws in (clockwise) until
they just touch their seats. Then back them out
two turns each. Adjust the idle mixture screws
one at a time. Turn the first idle screw in slowly
(1/4 turn at a time) until the engine begins to lag
or run irregularly. Then turn the same screw out
slowly until the engine begins to roll or gallop,
then back in slightly to provide the smoothest
idle. Repeat this same procedure to adjust the

other screw. Re-adjust the first screw if required.

Im talking real world running.Ive never had to richen up a strom more than 1 turn out. Not something out of a book. Ive been rebuilding strombergs for 25 yrs. 3/4 to 1 turn is all you need. Otherwise your running rich all the time.your just washing all the oil off the cyl. walls. Smell your oil. ken ct. good luck with your project.

[sturgis 39]

Where is the power jet and what is the purpose of the power jet? What is the normal size or factory installed size of the power jet?

[ken ct]

Originally Posted by sturgis 39

Where is the power jet and what is the purpose of the power jet? What is the normal size or factory installed size of the power jet?

Power valve is located under the accelerator pump normal size is # 65. When running a pair they are usually changed to #69 which has a smaller hole. Also jets are usually changed to .043 or so [smaller also] than normal .045. ken ct.

[sturgis 39]

The power jet is used on 97's. The power valve is used on other carbs? I am trying to learn about carbs so all help is appreciated. The model "a" seems to be lean at launch. It run good at high speed especially when going up a 6% grade.

[sturgis 39]

[QUOTE=sturgis 39;65465]The power jet is used on 97's. The power valve is used on other carbs? I am trying to learn about carbs so all help is appreciated. The model "a" seems to be lean at launch. It run good at high speed especially when going up a 6% grade.

[ken ct]

Originally Posted by sturgis 39

The power jet is used on 97's. The power valve is used on other carbs? I am trying to learn about carbs so all help is appreciated. The model "a" seems to be lean at launch. It run good at high speed especially when going up a 6% grade.

Every body i know in this business calls them PV. Sounds like you just threw these carbs on a "A" and expect it to run fantastic. Its not the case sorry to say it dosent work that way.Quite a bit of knowledge is needed and some special tools are needed,personally i think your way over your head with these carbs. You insist on running carbs which i told you were too big for an"A".You really need a pr of "81's" on there not 97's or 94's which are the same size.IMO you will never get 97's to run right on A. Were trying to help but your making it real hard. ken ct. kens ford carburetors.

[sturgis 39]

I am sorry if I have upset you Ken. I will stop asking questions. I was trying to be level with my head or a little bit above it. Thanks for the help.

[sturgis 39]

Ken

Do you have a rebuilt pair of 81's that I can purchase? I know i said no more questions.

[JM 35 Sedan]

Sturgis, the Speedway 9 super 7 carbs got very very poor reviews when they first came out. I have never heard or read if Speedy Bill ever made all the necessary improvements. Maybe one of the Fordbarn carb gurus can fill us all in on how well they are doing today.
I'm planning to run two 81's on a basically stock '35 21 stud 85hp engine because I am certain that two 97's would be too much carburetion. However, if you decide to go this way be prepared for sticker shock if you need to purchase two 81's, unless you already have the cores and just need to rebuild them.

Originally Posted by sturgis 39

I bought two 9 super 7 from Speedway Motors. i have changed the main jets. The engine does not seem to be running rich.
They are installed on a model a with a Riley two port head. I think the jets are the right size and the accelerator pump is set in the longest part of the arm. When i take off in low gear it misses and farts until i get up some speed. Speedway does not sell power valves for their 97's. Will others work or do i need something else?