Saigon_Bob

iTrader: (2)

Ok my edelbrock is the most horrible POS ive had to work with... and now i have an excuse to dump it...

I'm getting about 12.5 MPG to my best estimate...

My primary concern is performance and drivability... I'm really lookin for some crisp throttle response

while my gas milage isn't so great i don't want it to get much worse
My motor set-up is as follows:

?‰Lunanti 290*/297* adv. duration cam 112* intake centerline .490" gross lift

?‰Holley systemaxx alum cylinder heads... i need to contact them for specs but I believe they aer 66cc combustion chambers...

?‰Harland Sharp 1.5 ratio roller rockers

?‰Aluminum dual-plane intake manifold

?‰Stock 350 lower end.. 1975 4bolt outa a c10 truck

?‰MSD Probillet Ready-to-Run HEI 4pin w/ MSD digital module soon to be MSD 6A box

?‰Hooker Supercomp full length headers 1 3/4"

?‰True dual 2.5" no cats, Flowmaster 40s, 3" Tips

88IROC350TPI

hard to go wrong with a vacuum secondary 750 Holley...

Sitting Bull

Have you tried leaner jets and metering rods on the Edelbrock?

I just replaced my worn out old QJet with the 600cfm Edelbrock. Initially it got horrible mileage, about 14 mpg around town. (My old QJet got 19 mpg.) I believe Edelbrock sets up their 600 cfm carbs to be about right for a healthy 350. I have a 305, so we went down two jet sizes on the primaries but that made it too lean. It was bogging when I stepped on it and not much fun to get around in. Thus we richened the primary rods by a step and that has solved the problems. The 305 runs good and hard now and is also getting much better mileage.

So Saigon, I think your Edelbrock needs a good overhaul and then a good tuning session to get it working right. They seem like very good carbs so don't give up on them

five7kid

iTrader: (14)

Hard to get good response with mismatched parts. You don't mention anything about your torque converter, can we assume it's stock? That's a lot of cam for a standard dual plane intake as well, an RPM or Stealth should be on that engine.

You may be amazed how much difference those things will make. I'm no particular fan of the Performer carbs, but if you hamstring any carb with other parts that aren't made for the combo, you're going to be unhappy with the carb.

Poor economy is most likely a tuning issue.

contact

Saigon',

there is no excuse for an Edelbrock to not work properly,

does the carb have factory jets-rods, or has it been
monkeyed with?

some suggestions

try leaning the idle,
back off on the pump shot,
try lighter metering rod-springs,if you don't
have any, for a test, take them out

Saigon_Bob

iTrader: (2)

Ok thanks for the responses...


as for the manifold.... it came in the Systemaxx II kit supposedly Holley Matched the cam, heads, and intake....


The carb has been rebuilt once already but i was pretty sure it was way outa tune... ran pretty nicely on the 305 (gas milage not withstanding) but i just dont prefer the whole design of the carb...

Yea stock Torque Converter for now... this engine swap came mostly out neccesity and not my plan... i had been planning alot more to do to it b4 i swapped but my 305 was only pushing 5psi oil pressure at most, had a horrible lower end knock, and was dying... then did..

as for tuning.... this cam is at the very limits of streetable...prolly more into the non area tho so tuning is gunna take special care...

what a great first step into tuning and motor building..this is my first>>

i get about 7.5" hg of vacuum at idle...