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Discussion Starter · #1 ·
at the moment my P300 runs with the carb set up of the Silhouette using the 32 venturi instead of 34, F27 emulsion tube, 190 air corrector jet and 0.50 idle jet instead of 0.60. using these specs the car runs way too rich between 5.000 and 6.000 rpm (using the afr gauge).
I know the best yould be to have an expert put it onto a dyno, but there are not too many of these experts around anymore, at least in my area in Austria (and south of Germany), so I have to sort out this problem myself. the satrt would be to change to the P300 specs of the DCNF...This is where any expert would start off anyway, so I might try it myself.
now here is the issue:
the Weber manual shows a different F24 emulsion tube than what is offered nowadays. So, who has an idea what is going on there? or where I could find proper F24?
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No idea what a "silhouette" set-up since it is the same 3 liter motor (no changes whatsoever)
On our 3 liter motors with 11:1 compression we ran:

34mm choke
main jet 1.35-1.40
air corrector 2.10- 2.20
idle jet (bespoke) 57
emulsion tube F24 (Italian)...Spanish may differ

On the 3.1 liter motors we also tried 36mm chokes

Paul
 

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Discussion Starter · #4 ·
SIlhouette had a different carb set up which is documented in the driver's manual of the Silhouette and the workshop manual for the engine for the Urraco 3000. Another difference is the float level, which is supposed to be 48mm, while on the P300 it is 50mm.
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so and here is the P300 manual
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and for easier view now:
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MY is my car, when I got it...
 

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I have no idea why the Silhouette would use a 32 mm choke rather than the normal 34 mm choke.

Since a 3.1 liter motor is close to the 3.3 liters where a 42 DCNF could be used (Jalpa)…we experimented with the larger 36 mm choke.

On the dyno it made slightly more power over 7000 rpm…but tractability under normal driving suffered.

The .57 idle worked well with race gas - 110 octane leaded and when Methylcyclopentadienyl manganese tricarbonyl (MMT) was still used in high octane (street gas). The two were mixed due to high compression !

When ethanol became the normal additive in North America, the situation changed, and we just added race gas to non-ethanol gasoline.

Paul
 

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Discussion Starter · #6 ·
I have no idea why the Silhouette would use a 32 mm choke rather than the normal 34 mm choke.

Since a 3.1 liter motor is close to the 3.3 liters where a 42 DCNF could be used (Jalpa)…we experimented with the larger 36 mm choke.

On the dyno it made slightly more power over 7000 rpm…but tractability under normal driving suffered.

The .57 idle worked well with race gas - 110 octane leaded and when Methylcyclopentadienyl manganese tricarbonyl (MMT) was still used in high octane (street gas). The two were mixed due to high compression !

When ethanol became the normal additive in North America, the situation changed, and we just added race gas to non-ethanol gasoline.

Paul
maybe because 32 is more fun on a road car which is driven with less rpm than a track car....the best I can use is the 100 octane Shell V plus. I might as well stick to 32, however have to get it leaner. I will try the F24 emulsion tube and the 220 air jet. there is no real info out there on how the emulsion tubes differ. the one info I found is a little help...
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It may be that the F 24 and F 27 are quite similar...if your emulsion tubes have holes above the fuel level then a smaller air corrector will raise the fuel level to reach the point of the "E" holes sooner. And if your tubes have holes at or below the fuel level then a larger A.C will bubble the fuel up and raise the level sooner.
 
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