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 New guy with Stromberg 97 and e85 questions. 
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Joined: Mon Jun 30, 2014 8:32 am
Posts: 2
First off thank you in advance for any in site .
My project,this is my personal car so a work in progress it will alway be.
A 31 five window with a 425 buick nail head stroked to 453, 4.375x3.765 10.27 static 6.5 sbc rods bullet custom solid ft @ .050 239 intake 245 exhaust .527 lift on in .540 ex lsa 110 in closes at 45.5.
0 deck,.039 squish.
Using the Wallace calculator I should have about 185-190 cranking compression,reality is 225 after the motor sealed up.
Vertex mag with 20 degrees mag advance. Six stromberg 97s all in at once.
Doug Nash 5 sp no overdrive and a 57 olds rear 2.97 ratio
Daytona systems air fuel meter allowed me to tune it fairly well about 12.5 to 12.8 except at just off idle where I get pig rich at 10.0 when I come off the transition slot.
Disconnected 4 accelerator pump rods and it cleaned up,but maintain a spot on the throttle and it stays at 10.0
My goal is to get a good tune with 94 where it's clean and happy,but the motor seems to want more timing and I get a good rattle around 35-3800 but drives through it .
I'm suspecting this is when peak torque is and my highest cylinder pressure.
With the cylinder pressure I have,I feel 93 is at its limit.
My question is,after I get a good tune with this how would I go about re calibrating these dinosaurs for e85.
I am using the steel needle and seats, all parts are brass,leather accelerator pumps,no rubber inside.
The car is mostly street use,with a occasional drag strip pass and a couple of nostalgia event in its future.
With lack of aftermarket parts the build was a learning experience for sure.
Again thank you for any help.
Gary


Mon Jun 30, 2014 9:17 am
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Joined: Fri Feb 08, 2013 2:37 pm
Posts: 1701
Here is an exploded view of a 97.

Image

Do you have spares or extra #9542 idle jets, #9594 power (WOT enrichment) valves, or #9534 main nozzle/emulsion tubes?

Disconnecting the Accelerator Pump in a 97 prevents the power valve from opening. The Power Valve requires the Accelerator Pump to bottom out and push open the valve pintle at WOT.

Perhaps smaller Main Jets with a corresponding larger metering orifice in the power valve (below the Accelerator Pump) would lean the trouble spot and provide correct WOT A/F.

Have you tried lowering the float level?

I think you need to try smaller idle jets. Perhaps the old wire-in-the-idle-jet trick is the solution.

If all six carbs are opening together it will be extremely important to synchronize them in the off-idle range at about 2500-3500 RPM with a Uni-Syn or similar flow meter device. (I just had the thought that an old Ford MAF sensor from a small 4-cyl engine (late 80's – early 90's, maybe later) and a volt meter could be used as a synch-meter.)

You can multiply the fuel metering orifice areas by 1.45 for a starting point for E-85. You may need to enlarge the inside diameter of #9534. I know for methanol it is necessary.

I'll dig in my notes and see how the last few 97's I handled were calibrated. I know they are not always the same (after all these years, who is?).

What size main jets and idle jets are in them now?


Mon Jun 30, 2014 7:51 pm
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Joined: Mon Jun 30, 2014 8:32 am
Posts: 2
Think you tuner for your advice,the main jets now re .045 ( stock) and give me a 12.8 a/f at half throttle cruise.
The wire in the jet idea is a real good one to try and lean out the Intermediate jet.
I will try this first,I was going to make the air bleed larger so it would come in later but to reverse that would be a task.
The emulsion holes in 9534 tend to close when the main jets are over tightened I have read so I need to check them as well,too many years and way too many hands lend to new problems never seen before.
I used a uni-son to set them at idle but the tool does not allow enough air through it to calibrate at high speeds.
The mass airflow sensor is a brilliant idea.
I haven't found a circuit flow chart to show each circuit individually. From what I gather the power enrichment circuit is fed through the accelerator pump discharge tubes. I might take off the pump diaphragms so the power enrichment is opened at wot without a squirt.
I will try a few things and post results.
Thanks again.
Gary


Tue Jul 01, 2014 8:51 pm
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