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Topic Review (Newest First)
11-15-2010 10:24 AM
scapegoat I recently had a huge off idle stumble with my carbed 6.0 Ls engine. The only thing that worked for me was going to a 50cc accelerator pump with a #40 squirter. I also run a .570 lift .228 @50 duration cam. And very large intake runners on my heads "260cc". So I was not getting much velocity off idle. Zero stumble now.
11-15-2010 09:45 AM
brucer69 383 6.3 motor. 350 bored .040 over. 3.75 stroke crank.
PBM Aluminum Heads, 220cc runners 2.02 and 1.60 valves 58cc chambers
Comp camshaft 510/520 lift 230/236 Duration 112 LSA
Speed pro coated pistons
Eagle I beams
Procomp camshaft
MLS heads gaskets
PBM 1.6 Roller rockers
edelbrock performer RPM (dual plane)
750 holley double pumper w/ proform mainbody

if those are your specs on your engine, you need a converter no way around it...
i dont know the rest of your build/setup but you'll have to have a converter and gears.. i would say around a 3000rpm on the conservative side-3500rpm a little aggressive and something like a 3.73 to 4.30 gear..

if you have an adjustable timing light, look at your timing, i think your timing advance needs work along with the carb... off the top of my head the 46 squirter sounds quite large for a smallblock such as yours, seems like a small block like that should be around a 34 or 36... as stated previously look at your needle and seats, and also set/check your floats.. you should just have o rock the vehicle a little to get fuel to dribble out of the site level hole...

if your not familiar with the holley, go to autozone and get one of the holley tuning secrets books, and read it front to back... its a simple book with good setup tips.. explains timing along with a holley carb, a good read for sure..

ive never had to run anything except the factory accelerator pumps,pump cams on the smallblocks i've had in the past. i have used different springs for the secondaries.. when i went to big blocks is when i started using different pump cams and the 50cc accelerator pumps..
11-15-2010 09:05 AM
sqzbox
Quote:
Originally Posted by stroker444
But i thought the cam is too big?
That wasn't my opinion but I'm no cam gurru like others on here. The last performance cam I had was a crower 280D/460L hyd. flat tappet. Nice lope but the brakes sucked. I could have worked that out but I was young and dumb back then.
11-14-2010 10:59 PM
stroker444
Quote:
Originally Posted by sqzbox
I'd leave it the way it is and get a vacuum reservoir can for the brakes.
But i thought the cam is too big?
11-14-2010 10:51 PM
sqzbox I'd leave it the way it is and get a vacuum reservoir can for the brakes.
11-14-2010 10:40 PM
stroker444
Quote:
Originally Posted by sqzbox
Not much of a vacuum gain there.
Darn lol. Can you recommend a good cam that will fit the engine better and not have to lose alot of power?

383 6.3 motor. 350 bored .040 over. 3.75 stroke crank.
PBM Aluminum Heads, 220cc runners 2.02 and 1.60 valves 58cc chambers
Comp camshaft 510/520 lift 230/236 Duration 112 LSA
Speed pro coated pistons
Eagle I beams
Procomp camshaft
MLS heads gaskets
PBM 1.6 Roller rockers
edelbrock performer RPM (dual plane)
750 holley double pumper w/ proform mainbody
11-14-2010 10:20 PM
sqzbox Not much of a vacuum gain there.
11-14-2010 10:16 PM
stroker444 Would this be a good cam for my engine then?

http://www.summitracing.com/parts/EDL-2204/

Is there anyway to know much vacuum at idle this cam would make? Thats one of the most important things so my brakes will work a tad bit better. I only get 13.5-14.5 with the cam i have now at 650RPM, my brakes work, but i can only get one good pump out of them and the engine takes a while to ready the booster again.
11-14-2010 08:55 PM
mud.man.rj
cam size

If F-Birds right about the cam, fuel injection isn't going to be a cure all thats for sure. Maybe just stick with the dbl pumper and get serious and change the cam and then everything will fall in place better. You will be a lot happier with it in the long run, it's not exactlly a hard job. Good luck, not sure if you are running roller rockers a tall ratio, it all helps take the load off .
11-14-2010 06:45 PM
stroker444 So does that mean that I would want a cam that has an operating range from 1500+ because my cruising speeds are 1500-1800 rpm?
11-14-2010 11:34 AM
brucer69 what size cam you using?
11-13-2010 12:42 PM
cobalt327 Come to think of it, I have a 3310-1 Holley 780 Vacuum secondary carb sitting, ready to go...
11-13-2010 11:55 AM
sqzbox [QUOTE=ericnova72The DP can get as good a mileage as anything, if you set it up right and keep your foot out of it.[/QUOTE]

Ha Ha. I don't think he put it together to "keep his foot out of it". I was working on the mileage thing with the Vac. secondary by eliminating the squirt from the shooters from the DP and the fact that the vac. sec. will open on engine load, only as far as needed. In the end, mileage really depends on driving habits regardless of what kind of carb you have. With the big cam that's in there, how could mileage be a concern? Now that I think of it, put a 780cfm on it!
11-12-2010 08:26 PM
pepi stroker444
"Ive noticed that you find a way to be a dick just about everytime you reply."

What is the matter the truth hurts? he took the time to research your post to give you an accurate answer. Your basically being told the truth about the miss match of the parts .

Here is a link that might help sort out some of your questions


http://www.holley.com/applications/C...bSelection.asp
11-12-2010 04:56 PM
brucer69 what size cam is the op running?
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