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Old 01-10-2006, 03:55 PM
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Need a little Demon carb help

This is the first thread I have initiated here on Hotrodders.com. I'm looking forward to getting some help from you experts out there. Actually, I'm kinda hoping BGTech will drop in. But, if any of you are familiar with the Demon carbs and have an answer, I'm all ears (or is it eyes?).

The engine is a SBC 383.
AFR195 heads
Comp XE Hyd Roller grind, single pattern, 224@.050, .535 lift through 1.6 roller rockers, 110 LSA.
Static compression is 9.5
Edelbrock RPM Air Gap
Headers will be full length, but as of now all I can find is 1.75 primaries, and I think I'd be better off with 1.625 primaries. So, the search goes on.

I'm using a street-built B&M (home-built) TH400, a 2400 (estimated) stall converter and 3.25 Trac-Loc with 29in tires.

The Carb's pn is 1402020VE. This is a 750 Speed Demon with Vac secondaries and Electric Choke. FYI, I live at or very near sea level.

The vehicle is a '37 Chevy truck, with an estimated weight of 3300 with driver in place.

I'm looking for any recommendations regarding jetting, vacuum advance springs, etc. I'm really looking for an educated guess at a good starting point.

Thanks for the input in advance.

Pat

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Old 01-10-2006, 04:08 PM
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That thing should be pretty close out of the box.

But......

The idle mixture should be set after the timing is done. Move on to jetting, if it's too rich or lean, later on. The vacuum secondary opening points should be fine tuned, if necessary, after the mixture is on the money.

If getting it perfect is high on your list of priorities I suggest getting some O2 sensor bungs welded on the header collectors and doing it on a chassis dyno.

Larry
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Old 01-10-2006, 04:17 PM
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Thanks Coldknock

I thought I'd be somewhere in the neighborhood, but hadn't thought of the O2 bungs. Good Idea. We'll see if anyone else chimes in too.

Again, Thanks

Pat
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Old 01-18-2006, 06:11 PM
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Bump

Thought i'd take another look for BGTech . . . . . .

Pat
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Old 01-18-2006, 07:25 PM
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Quote:
Originally Posted by PatM

The engine is a SBC 383.
AFR195 heads
Comp XE Hyd Roller grind, single pattern, 224@.050, .535 lift through 1.6 roller rockers, 110 LSA.
Static compression is 9.5
Edelbrock RPM Air Gap
Headers will be full length, but as of now all I can find is 1.75 primaries, and I think I'd be better off with 1.625 primaries. So, the search goes on.

I'm using a street-built B&M (home-built) TH400, a 2400 (estimated) stall converter and 3.25 Trac-Loc with 29in tires.

The Carb's pn is 1402020VE. This is a 750 Speed Demon with Vac secondaries and Electric Choke. FYI, I live at or very near sea level.

The vehicle is a '37 Chevy truck, with an estimated weight of 3300 with driver in place.

Pat
Pat,

Let us/me know how that 383 works out. I'm planning on the same exact setup and putting it in a 1974 Nova (roughly the same weight) I would be real interested in seeing what is does as far as performance.
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Old 01-19-2006, 05:56 PM
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Thanks BCCSRC, but it'll be a while before I take it racing.

I've been on this project for over ten years, and am now into the "putting together" phase, but health issues and other priorities make the truck a little low on the list. Hopefully, you'll remember this comunication and reply back with the success YOU have with this build.

At the moment my big concern regarding the buildup is that I used -19cc D-cup pistons. They are REALLY light, as are my rods (Lunati StreetRace rods), so that's cool, but they don't have much flat area and I'm concerned I may not get an effective quench. Anyway, we'll see.

Pat
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Old 01-31-2006, 12:33 PM
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Pat,

That 750 should be very close out of the box on your truck. If you have hood clearance using a 4-hole spacer between the carb and intake will give a little more throttle response, and bottom end.
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