demon has me stumped

[willow72]

anybody know a good carb man in dallas ft worth area ? my new demon is running rich at idle and i cant seem to get it right. and how hard is it too recurve a distriberter?any help would be wonderful

[cdowns]

if it's a brand new carb have you tried calling the company for tech support??

[Jeepster376]

Originally Posted by willow72

and how hard is it too recurve a distriberter?any help would be wonderful

If you're OK with a standard setup, just buy the kit and install it. It's very simple just change the weights and springs on the top of your distributer shaft, under the rotor.

If you want a custom tailored advance curve, then it's more involved, like getting the carb perfect at all RPMs, it requires lots of trial and error road testing.

[Jeepster376]

Originally Posted by willow72

my new demon is running rich at idle and i cant seem to get it right.

Have you checked the floats? If the floats are not set right the screws will not correct the rich condition. The floats always have to be the first thing set right, before you do any other adjustments, since float level affects everything.

[1972C10]

Yeah floats are a must , ALso what size carb and what size motor.?

[GMC Jim]

the most accurate way to set the curve on a distributor is with a distributor machine... this machine spins the distributor to the various RPM's to meet the engine manufacturers specs. This is done by using the right combination of weights and springs. Also the vacuum unit should be checked for proper advance...

[Blazer1970]

Call Barry Grant.

[willow72]

its one of those 330hp vortec crate motors and a crate demon carb thats suposed to be set up for this motor so im sure its probably something im doing wrong i will try and readjust the floats and see if that helps i have talked to demon tech support and so far they just keep having me advance my timing more and more im at 16 degrees btdc right now and cant hook up vacume advance with out causing detonation going up hill thats why im asking about recurving a distributor and what am i suppose to be curving it too anyway?any takers for that question? sorry about the rant but it has me very frustrated i look forward to any help you guys can give me or any girls thanks john

[Jeepster376]

Recurving your distributer is usually referring to changing the mechanical (centrifugal weights) advance curve witch is for the higher rpm range. If your engine only detonates when the vac advance is connected, then you may need an adjustable vac advance module to correct that, or else just back off the initial timing.

The mechanical distributer curve can be set to spec on a distributer machine, but you can also do it with an advance timing light and a tachometer. But the only way to custom tailor the mechanical and vacuum advance curves to your vehicle is with trial and error road testing. The goal in short is to get maximum advance in all RPM ranges and load conditions, without causing detonation.

[miket]

Originally Posted by willow72

anybody know a good carb man in dallas ft worth area ? my new demon is running rich at idle and i cant seem to get it right. and how hard is it too recurve a distriberter?any help would be wonderful

Call demon's tech line....they are good with this. What demon is it and what are your motor specs?

Did you check all of the specs per the instruction manual?

[GMC Jim]

It is next to impossible to properly set the distributor advance curves without a distributor machine. Yes, you can set the lower and middle RPM specs with a set of weights and springs; adjustable timing light and an accurate tachometer. A vacumm gage would be required to check for proper vacuum advance. Setting the top end of the "curve" (4400 engine RPM) would require a distributor machine.
Per 1971 GM Service Manual, 402 engine, the centrifugal advance specs are :-- (degrees advance @ RPM); 0 @ 930, 2 @ 1260, 16 @ 2400 & 30 @ 4400.
Vacuum is O degrees @ 8 inches and 20 degrees @ 17 imches.
Per GM Tune-Up specs Manual SD-100; centrifigal advance 10-13 @ 2000 engine RPM and 28-35 total advance (centrifigal and vacuum)
If desired; Crane markets an adjustable vacuum advance... in the event you want to go that route. Or have the vacuum advance unit checked for proper operation.
Willow 72, I would get the timing specs for your 330 hp votec engine from your supplier and go from there......... Jim

[70 net440]

Demons like lots of advance. Contact Don at www.4secondsflat.com he is a dealer for Barry Grant and specializes in distributer curving. He's mainly a Mopar guy, but he has a lot of Chevy knowledge too.

[willow72]

Demons Tech Line Seems To Ask More Questions Than They Have Answers

[mocwon]

I've got the same problem on a 750 Speed Demon I put on my Mustang and have been told that the power valve could be the problem. I have been told that the power valve should be sized at 1/2 the vacuum pressure reading, i.e. 11" of vacuum would require a 55 (5.5) power valve, etc. I haven't had time to check this but that is the next step I plan to take.

[willow72]

Thanks For The Info Mocwon Let Me Know What You Find Out Im Going To Keep Contacting Demon And I Will Let You Know Anything I Find Out From Them That Helps Thanks John