Carb school

[bnoon]

Originally Posted by tucsonjwt

Whatever you do, get a manual choke kit ($12) - that way you will know for sure that your choke valve is open all the way when you are driving and closed all the way when you first start it up. With an automatic choke you never know where the choke valve is, either hot air or electric.

I've never had any issues with any of my electric chokes as long as it's working and adjusted.

[1slo_camaro]

dumb question.... I run regular 87 in my truck right now. and started bumping up the timing a little. and once i start advancing shell run like a raped ape, but on higher RPMs ill start getting spark knock.... If i back the timing off she loses the power. could i either put in new hotter plugs and wires cap/rotor. or can i run 91 octane to help out?

[INSIDIOUS '86]

Originally Posted by 1slo_camaro

dumb question.... I run regular 87 in my truck right now. and started bumping up the timing a little. and once i start advancing shell run like a raped ape, but on higher RPMs ill start getting spark knock.... If i back the timing off she loses the power. could i either put in new hotter plugs and wires cap/rotor. or can i run 91 octane to help out?

Run higher octane and see what it does. What's your compression?

Initial timing and total timing. Ported or manifold vacuum for vac advance?
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[geezer#99]

Keep the timing cranked up but put on an HEI vacuum pot limiter. Cuts back your excess timing. Pic in here.
http://www.chevelles.com/forums/showthread.php?t=343241

[1slo_camaro]

Originally Posted by INSIDIOUS '86

Run higher octane and see what it does. What's your compression?

Initial timing and total timing. Ported or manifold vacuum for vac advance?
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its just a bone stock from the factory 350 all i have done is chrome valve covers (just had them laying around lol) and a open element. and figures.... i just filled up the other day and well 20 gallons at 3.37..... kinda sucks haha



damn now i remember why my ol man always threw away HEI kits and we ordered MSD Billets..... which i might have at the house a brand new MSD billet and I have a 6a box here just need to get a coil

[tucsonjwt]

Originally Posted by bnoon

I've never had any issues with any of my electric chokes as long as it's working and adjusted.

You are very fortunate. I have never had one work properly, consistently. The worst part was when I was driving on ice right after starting up the vehicle cold, and the choke stayed closed almost all the way, and the engine revved up a lot - try to ease away from a stop sign on ice at 20 degrees below zero.
Plus, Edelbrock choke valve was too big for the opening and got stuck from time to time, plus thermostat coil on electrics never opened up far enough, or too far - never could get it right. I am not very lucky.

[Phillip Pennartz]

octane in gas is used to slow down the burning speed of the air fuel mix. More compression speeds up the burning speed.
On a stock motor ,higher octane is a waste of money. Get the timing right and you will have better power and mileage. The HEI is a pretty good and tunable distributor. If your inclined to tune it ,do it at a 1/8 drag strip. You can make small changes and with accurate measured times of acceleration and you can see what works and what don't. Plus drag racing is a lot of fun, and its really fun when your getting faster.
On your timing I would start with the base timing and bump it up a degree at a time till it stops improving. You will probably wind up with a base timing of about 10 to 12 degrees btdc.
after that get a advance kit for your HEI. It has counter weights and about six springs. You can mix different spring tensions. In my case a stock 350 with a th350 and 3.42 gears I ran fastest with one stock spring and the next lightest spring from the kit. But every engine is different ,so test it.
If you keep the Quadrajet, I would if you stay fairly stock, You can tune it too. I got a book on it and learned a lot. I found out that the secondary's when they open they raise a pair of tapered rods up thru the jets and not all rods are the same. In my case my rods were pretty thick limiting fuel flow. I found some junk Quadrajet with thinner rods and wound up knocking off a 1/2 second in the 1/8 mile. These rods have letters stamped in them to identify them and they are discussed in that Quadrajet book.

[INSIDIOUS '86]

Originally Posted by 1slo_camaro

its just a bone stock from the factory 350 all i have done is chrome valve covers (just had them laying around lol) and a open element. and figures.... i just filled up the other day and well 20 gallons at 3.37..... kinda sucks haha



damn now i remember why my ol man always threw away HEI kits and we ordered MSD Billets..... which i might have at the house a brand new MSD billet and I have a 6a box here just need to get a coil

I just got a pro billet hei

If your base timing is to high like at 15*btdc and your mechanical is giving 25 because its worn then the combination will give you 40* which while is not bad it's still a tad high esp if your octane is low. Worn hei distributors give a lot of advance sometimes more than 25* in bad cases

Try and get 38* by 3500 rpm at least. 10-12* initial is about what stock-even cammed engines like
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