with my old setup the exhaust would put out black smoke, so i thought the carb was too much. here was the motor setup

350 bore .30 over, flat top pistons, crane energizer cam, 305 heads, edelbrock performer intake.

now its still the same block 350 bored .30 over, flat top pistons, and the crane energizer .467 or .484 lift i forgot and dont know how to tell.

NOW... i added trick flow 195cc 62cc 2.02"/1.60" heads, 1.52 comp cams pro magnum roller rockers, keith dorton signature series intake manifold.

should i keep the 750 or should i go down to edelbrock 600 or 650??

 

You could tune the 750 to work...in fact I buoght a 350 with 461x heads, less cam, with the edlebrock 750 on itold style SP2P intake and 1.5inch headers...engine ran fine with the setup...but I know the guy did some work on the carb...what I don't know...it just ran good.

 

I have a 1988 iroc z that i rebuilt 700r4 with shift kit..1978 350 4 bolt main bored 30 over moderate cam..750 dual feed with edelbrock preformer 3701? 58cc heads ..flat top pistons... 75 front secondarys 82 jets if i remember right
runs...really well..lol

 

The carb is not too big. A "big carb" in itself does not cause
"black smoke" You have the right carb.

Black smoke is un or partially combusted fuel. (flooding or ignition problem) I would look at the ignition.

The stock jets and rods will work fine in the 750. The ultimate tune will be real close to stock.
After finding the ignition problem check for proper fuel pressure at the carb and float level (6psi).

If you had a lot of black smoke then your plugs are fouled.
Change them for new ones.

 

well ill find out, because im changing the heads, so new spark plugs will go in, but it only showed black smoke, when i put the pedal to the floor.

just thought mayb eit was too big, but it never bogged, so thats why i had questions.

 

I might catch a lot of flack for posting this, but Edelbrock doesn't rate it's Carburetor's the same way Holley or Barry Grant does. Holley and Barry Grant rate there Carb's at 1.5 inches of mercury (HG) in wet flow. This means that fuel is introduced through the Carb while it's being tested. Edelbrock rates its Carb's in a dry flow condition, which makes it look like it flows a lot more than it really does since there's no fuel in the air stream to displace air. In short, your Carb may be rated at 750 cfm, but it probably is closer to 670 cfm of air. Most Q-Jet style carb's like the Edelbrock you're using, use a single fuel inlet and metering rods to get the job done. This is fine if you don't plan on making more than around 425 H.P., since it's difficult for the Carb to bring in sufficient amounts of fuel. The best way of describing how metering rods work is to imagine your Carb jet with a stick stuck down through it. Everytime you require more fuel, the stick comes out of the Jet to provide it. Your car is experiencing a rich condition, which means you have more fuel than air. You might want to check the Carb section of this site to see if maybe somebody had the same problem you're currently experiencing. I hope that helps you out and that you get the problem licked.

 

Lots of disinformation here. A Edelbrock 750 is capable of supporting over 500hp. The supplied jetting on the 1407 is near optimium out of the box for most cars. The rod and jet method of metering the fuel on the primary side does not limit the fuel flow (power potential) at WOT. The single inlet will flow more than the combined area of the two needles and seats. It is not a restriction. You can install larger edelbrock hi perf needles and seats (just like souping up a holley) You can drill and tap the other side of the carb top and install another fuel inlet fitting if you think its a restriction. The "banjo fuel inlet fittings" may be somewhat restrictive. (400+hp) {use two} If you're not using a banjo fitting the inlet is not restrictive. Edelbrocks like a steady supply of fuel at 6PSI.
The 750 Edelbrock will make the same power +/- a few HP as a holley 750 on most motors from 350 to 500+hp.
Once the jetting is optimized on both carbs.
I have run both carbs on my car on 3 different motors. The timeslips are so close, its not even worth argueing over.
My Edelbrock actually makes the best MPH ( horsepower).
The et's are really a toss up.

 

well i never really meant to argue about edelbrock and holley, just between edelbrock 600, edelbrock 650, or edelbrock 750 is the best setup for my motor.

i got a 350 bored .30 over, flat top pistons, crane energizer .484 lift, trick flow aluminum heads 195cc 62cc 2.02"/1.60", 1.52 comp cams pro magnum roller rockers, holley/keith dorton signature series intake.

i have an edelbrock 750 right now, but i was wondering if it was too much because sometimes when im driving and i hold the gas to the floor black smokes come out of the exhaust.

 

rest assured the black smoke is not caused by the carb size. ( could be a problem inside the carb but It's more than likely an ignition problem an or old carbon built up in the exhaust system from before, that is now being blown out the tail pipe when you floor it.
You have the right carb. Did you check over the ignition? ( wires cap rotor coil) what do the spark plugs look like? (porcelin part of the plug) Does the car misfire and sputter at WOT or accelerate smoothly?
If you're using a GM HEI distributor there must be a ground wire conecting the engine to the fire wall or the engine will misfire under load. Do you have a ground wire?

 

well i just ripped all that apart.

im putting on new heads and intake, and with that i purchased msd distributor, msd blaster 2 coil, msd electronic ignition, new spark plugs, and some 9mm spark plug wires. so im gonna change those since you think its an ignition problem.

the carburetor is brand new, and so is the exhaust.

 

I trust that your new MSD distributor has vacuum advance?
The carb will like a steady 6psi fuel pressure. Anything more than this will cause you problems. (flooding)

 

how can i tell, it sticks out the side of the distributor right? its part number 8460

i got the msd-6a electronic ignition with it, and msd blaster 2 coil.

heres a pic:

 

That distributor does not have vacuum advance.
You want a vacuum advance distributor for a street driven car . Should have bought #8361 to connect with a MSD-6 box. it has vacuum advance.

All you really needed was MSD's #8360 "Ready to run" distributor and a blaster 2 coil. It has a built in hi performance inductive discharge module, fully adjustable mechanical advance curve, adjustable vacuum advance.
and all the spark power you'll ever need.

This distributor is ready to rock and does not need the MSD 6 box. only needs a 12volt power conection and a coil.

 

ok well since i already have the msd-6a box, blaster 2 coil, and this distributor? should i sell the distributor and buy a new one with vacuum advance?

Clint

 

Lots of disinformation here? What the heck are you talking about?! Perhaps you'd better read again F-bird'88. Edelbrock dry flow tests their carbs and holley wet flow tests them. If you don't believe me, then ask Edelbrock. The needle and seat set up of a Q-jet is a great street carb. I never said it wasn't. Capable of supporting 500 H.P. though isn't something I'm prepared to agree with. A lot of guys out their hoot and holler about how their car makes gobs of h.p., but in reality their lucky to be getting 350-450 h.p. at the flywheel. Next you'll probably say that the lack of jets in aftermarket F.I. systems isn't why they generally flow 1000 c.f.m. and Demon carbs suck! If we were talking the difference between Edlebrock and Holley intakes I might be incline to agree that Edelbrock has an advantage. Maybe you should call Holley and tell them to drop the price in the hp line of carbs since they aren't better than the old fashioned Q-jet carbs. I don't know why we need double pumpers, dual feeds or nothing else if a Q-jet will get the job done. Think about it.

 

it would be in your better interest, yes.

 

damn well if anyone wants to buy this let me know. i gotta look for a 8361 then

 

http://cgi.ebay.com/ebaymotors/MSD-I...spagenameZWD1V

just before i sell it, what about this, cant i add a vacuum advance.

i know before i bought this msd stuff, i had an old distributor i filled with new parts, including a vacuum advance which it didnt have.

my question is, can i add this to my distributor and make it work?

 

Holley wet flow tests their carbs, but that's a production test. Both Edelbrock and Holley rate their carbs with dry flow numbers. Barry Grant is the exception, Demon carbs are wet flow rated so that they flow better than equally rated carbs from other manufacturers. The difference between wet and dry flow numbers is about 8-10%.

 

IIRC, the 8460 was sold with centrifugal and vacuum advance originally, but the vacuum advance unit was removable. You might find something to replace it with.

 

did you check out the ebay auction, will that vacuum advance work with my distributor??

 

No idea. Call up MSD's tech support and ask.

 

here is another side view of the distributor, this hole, there should have been something attached here right?

 

I still have to disagree apeiron. Dry flow means there's no, I repeat, no fuel mixed with the air particles and slow flow. Holley and Barry Grant both wet flow test using fuel that is introduce to the carb the same way it would be on your car. Edelbrock uses the dry flow method to get higher rated numbers. Hands down, the Holley and Demon carbs are better. You guys better brush up a little on your carb knowledge.

 

This is my final thought before leaving this thread which has gone astray. Think of the carb's ability to move air in these simple terms. If you were running down the street and trying to go as fast as possible, which way do you think you'd run faster? With soaked clothing or nice and dry. Most people would say "nice and dry", and they'd be right because it would be easier. The same way it's easier for dry air to move through a carb than it is for fuel infested air to move through the same carb. Think about boys and I'm sure you'll see the light. Just for the record, I never said the Edelbrock wouldn't work on this guys car. I merely pointed out something that I thought might be of interest.

 

Settle down there, hotshot. Nobody said Edelbrock was better.

There's far more to the equation than rated flow numbers anyway.

 

That style cap was used on pre1974 point distributors.
The hole is to adjust the points. there is supposed to be a little steel door in the hole. On your distributor that hole has no purpose. The vacuum advance does not go there. Where did the little steel door go? Keeps the dirt and water out.
Wether you can install a vacuum advance onto that distributor all depends. Off hand I'd say no, or not easily.
The screw holes on the houseing used to mount the vacuum
advance are probabily not drilled and tapped. A vacuum advance distributor's magnetic pickup is moved by the vacuum advance. A non vacuum advance distributor has a non movable magnetic pick up mount. (its locked down)
That distributor will work but a vacuum advance distributor is much better for a dual purpose street driven car like your's and mine.

 

ok will any msd distributor with vacuum advance work with my msd-6a and blaster 2 coil, or do i need #8361

 

And all you added to the thread was a lot of irevelivant confusing and untrue blab. You did nothing to help the poster sort out his car. If you can get Vic E. Jr. baby on the horn , I'd love to chat with him.

 

i know ill need with those wires/plug hanging off the distributor, so it will plug into the ignition box.

 

Don't you have a good old '75 to '81 GM HEI vacuum advance distributor laying around somewhere?
All you need to do is hop it up with some MSD hi perf replacement parts ( MSD HEI coil, module, cap and rotor and wires) and recurve the mechanical advance curve and you're good to go. A lot simpler.

 

ill just give the guy i bought this distributor off of, and get my old one back i had before with vacuum advance, i thought this would work better

 

the old distributor i had didnt have vacuum advance on it either, i had it installed. does that mean its no good either or what?

it was the old style distributor, i purchased a vacuum advance and then had it installed.

 

You are correct in assumptions and from flow tests I've come across on the 'net over the years...seems like Holly carbs always "dryflow" a good 10% more than the carb is rated...i/e a 750 usually is in the 825-850CFM range..."wet flow" is pretty spot on to the rate.

Edelbrocks and Carters seem to be in line with themselves (dry flow vs. carb size)...again, I can't confirm the validity of the tests, only from what I've noticed/read.

Incidentally, "wet flow" should change with jet size/fuel metering, right? I/e more fuel added should decrease the flow numbers some.

But, again, it's comparing apples to oranges..better to compare potential of speadbore vs. spreadbore and squarebore vs. squarebore carbs.

 

If it was an 75 to 81 gm hei with vacuum advance and the distributor shaft bushing and mechanical advance weights are not worn out. You already had a good starting point for a hi perf street ignition system. All it needed was some upgrades and a recurve and some new msd parts.
A gm V/A hei with a new MSD HEI coil and module is hard to beat over all. really all the spark power you'll ever need.
You also have to option of removing the internal HEI module and running the distributor thru you MSD box. You can use the internal HEI coil or use a external Blaster2 coil with a special HEI coil cover/coil wire kit. Either way works well.

If you have the right GM HEI with vacuum advance that is not worn out (shaft bushing) I'd use it.

 

yeah but i dont know if it had all those bushing or whatever, like i said the distributor never had a vacuum advance in it when i installed it. a guy at a performance shop said i should be running vacuum advance, so i bought one from him, and he installed it into the distributor.

so if it never had vacuum advance before, and it was installed, why cant i install one in this msd distributor.

 

I'd have to see it. Off hand, don't count on it.

Probabily someone removed the vacuum advance from the old HEI so all the mounting points (screw holes were there)
so it was just a matter of bolting the vacuum advance back on. Don;t take this hard but it sounds like you don;t know a whole lot about ignitions. Probabily why all the "black smoke" (ignition problem)

If the vacuum advance can be installed on you MSD distributor then go with it. If not I look for a good old GM HEI w vac advance and and build it up using MSD parts.

You'll want to modify the mechanical advance curve in either case to work with your crane energizer cam.
Another story.

You have good parts overall. It will scream once ya get the details sorted out.

 

is this your intake manifold?

 

yeah i dont know a whole lot about distributors.


change the the mechanical advance curve?? lol...

also here is a picture with the cap off incase you see, would this be where vacuum advance go? if not im going a diff route like you said.

 

pics suck but the 5.0MP camera will only allow me to use 1.0MP to the size will be small enough to put on a website to host it for here...

 

no here is a picture of my intake, and heads actually. the guy told me it was a keith dorton signature series?

 

take the rotor off. take a shot of the under side of the distributor housing too. Did you buy this from a Toronto Speed shop or? Looks like a Accel cap. MSD stuff is red. (Cap and rotor) is it new? or??

 

The intake is a old Edelbrock torker or scorpion ( trantula) that has been polished. Its old stuff. its not a Holley intake or a Keith Norton what ever.

A dual plane hi rise is a much better match for your cam and car overall. A edelbrock Performer RPM or a Wieand stealth dual plane would be much nicer. Worth the switch.

 

no purchased off ebay. lol. so im not sure what it is. here are a couple more pics.

 

you seem know alot, the heads were polished to, and there is no part number, is there anyway by looking at them to tell what kind they are??

i was told they were trick flow aluminum heads

they weight 33 lbs each, and no magnets stick to them so i assume they are aluminum.

 

like this

 

Accel uses that rotor color, but so do all the DAP's in my area for the "generic" stuff...makes you wonder if we spend more for the name, than what goes inside.

Since we shifted from carbs to dizzy's...has anyone used the MSD unit that has electronis advance.curve and electronic *vacuum" advance adjustments?

Seems like a sweet piece, albeit about 4 bills..

F-Bird, any comments? I like your input

 

yeah i can get a hold of an edelbrock performer rpm. my friend has one ill trade with him or sell it.


what about the heads.

and anything else about the distributor

 

....

 

its locked solid, because the right side is screwd down...bottom of the distributor has allen key looking thing going through up through the blue thing.