Ford Model A with Stromberg 97 Carburator

[eeh1]

hallo at all
what Jet sizes do you have when you have a Stromberg 97 on your Ford model a.on my engine is the 6.1 High compression head and the downdraft intake manifold for the Stromberg 97.and the Petronix Complete Distibutor-Electronic-12v.and the accelerator pump rod i have it on the summer Position.i dont can drive when i have it on the winter Position.

[Lawrie]

I have that setup on my A.
I will look in the morning,
PM me if I forget
Lawrie

[Phred]

The old timers and the experts have said the stock jetting (45 main/65 power) is good.

I've been running a 97 for several years and played around with the jetting quite a bit. I have proven to myself the the old timers and experts were correct: 45 main jet/65 power jet is good.

I received this response from the English Stromberg 97 company when I asked about jetting for altitude:

"Generally the changes are not as much as you might think. The original Ford assembly drawings talk about normal altitude (0.045 jets) as 0 to 5000ft, then 0.043 jets at 5-10K and 0.041 at 10-15K."

Hope this helps

[eeh1]

yes that i all ok
but why can drive it allways in the sommer Position.
the spark plugs are all black.
the techcenter from Stromberg in England told me i must give the mainjets 35 and the power Jet 71.
but with this jets the car dont run great and have no power.

[Jim Brierley]

45 is the stock jet for the 97, 35 is for the smaller 81. The 71 power valve is also 81 size but should be fine for you. Stock jets are normally about right but if your plugs are too black, try smaller jets. Check the fuel level first, and don't run over 3 lbs. of fuel pressure, 2.5 is better.

[eeh1]

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the fuel Lever is ok.

so it is better i give a 70 or 71 power and 42 jets. i find the original jets are too big for the 4 Zylinder model a engine.
i have the same Stromberg 97 on my 35 pick up 8 Zylinder with 85 hp.there he work fine

[1stGrumpy]

I had Uncle Max in Salt Lake City go completely through my 97 and set it up for my engine. He installed .043 main jets and a #69 power valve, it runs great. Smells a little rich when idling in the shop but I can live with that. I sent him my carb and I had it back in 10 days.
My engine is basically stock with "B" head, FSI distributor & downdraft 97...

[brokenspoke]

Uncle Max is the best

[colin1928]

I have had lots of strombergs on lots of Model A/B engines of many years best results generally are with stock jets or within 1 size of stock and the float set correct
as soon as I get beyond close to stock jets I find that I get flat spots either rich then lean
If you having trouble with the stock jetting maybe look at float level or ignition timing air filter size ?
do not forget that these carbys generally deliver 13.5-1 to 14.5-1 for any given draw up until they reach cfm limits

[emf]

I have dual 81's on my B engine and the main jets are .036 with #71 power jets. I must say that it was basically a bolt-on with no fiddling at all. Very pleased with the performance.

Frank

[Jim Brierley]

so it is better i give a 70 or 71 power and 42 jets. i find the original jets are too big for the 4 Zylinder model a engine.
i have the same Stromberg 97 on my 35 pick up 8 Zylinder with 85 hp.there he work fine

Generally speaking stock jets are very close to ideal, but all engines are not the same so change jets to suit your engine.
Colin1928 9above) has it right

[eeh1]

which air filters have you on your Stromberg 97.with how many octan do you drive the car.here in Austria i drive it with 98-100 octane with the 6.1 Zylinder heat.he needs for 100 kilometers (it ca 61 miles) 18-20 Liter

[jeepguy1948]

You are using way too much fuel I think. 12 miles per gallon is very bad 18-20 miles per gallon is more correct. I have found several Chinese made defective power valves. They don’t seal properly and the engine runs very rich all the time. I just replaced one today on a V8. I suspected that the Power Valve was to blame and indeed it was. Replacing the “new” power valve with an “original” power valve produced dramatic results. From what you describe I am almost certain that your problem is a defective power valve. I’m sure that there are some guys on here that can help you find good original parts.

[petew]

I had a pair of 97's on a hot rodded A motor and got the best results using adjustable main jets . Once dialed in the carbs performed great.
Available on Speedway Motors.

[oldspert]

jeepguy1948, I hope you realize this thread is from 2016 and probably the OP will never see it again.

[jeepguy1948]

LoL no, I wonder why I just now saw it

[Jyromefedx]

Sometimes a man has to hope.