Carbs: Edelbrock vs. Holley
 

I'm currently running 750 Edelbrocks on my SBC strokers. I'm fed up with trying to follow the stupid flow chart and find a combination of springs/metering rods/jets all with different reference #'s, part #'s, colors, jet sizes..ect. .. And thats just to for primary jetting. They make it way harder than it needs to be.

I have zero experience with Holley carbs, would switching to Holleys eliminate a lot of the un necessary confusion that comes with Edelbrock or would I just be trading **** for manure?

Get yourself a pair of Holley Double Pumpers and enjoy life.

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I have used these bastards on street cars and trucks, drag cars and boats. I have used most of the others. Other than EFI or Direct Injection...this is the best fuel delivery piece of equipment I have ever used. It's like having 2: 2 barrel carburetors and you have 100% direct control as to when and how far the secondaries open.

As far as tuning...you adjust float levels with the engine running!!!:evilb: You can screw around with jet sizes if you are into some exotic cam grinds and blowers but I have always had great results right out of the box.

I replaced stock carburetors and used these on the Following: '56 Chevy with 327/350 horse. '70 Chevelle SS 454 LS-6 460 horse, '74 Pontiac Trans Am 455 SD, '77 Z/28 Camaro 355 350 horse, '77 Formula F-18 302 Ford/300 horse, '83 Formula F3 355/325 horse, '68 Z/28 Camaro 406 435 horse, '79 Formula 255 Liberator twin 355 375 horse.

I don't work for Holley...I'm a contractor and Mechanical Engineer by profession.

Now you know what I REALLY THINK!!:evilb:

Not to get on a rant...but I love these damn things because they give you so much control over the boat. throttle response on my twin 355 Vortecs is instantaneous....no hesitation

I had Quadrajets on my last carb boat (built smallblocks). I was able to get great recommendations from the Carburetor Shop in Ontario, CA. They sold me all the small parts that I needed, jets, needles, etc. I am a Holley fan but as my boat had twins I was faced with making a little effort to learn the different carbs and spend $180 bucks on an assortment of parts or buy two new Holleys and have to fiddle with them until they were perfect. Marine Holleys are not inexpensive. I could have spent less money than I did if I would have gone with their recommendation. I had them send one leaner and one richer setup than their standard recommendation. I gained 50 r.p.m.s over their standard recommendation. 1/2 m.p.h? LOL Good luck.

go with a holley.parts are everywhere and a simple design.anybody can work on them and they are relible.

I Love the Holleys, always did, the Edelbrock has too much to deal with for tuning, maybe thats because I never used em, but thats what I have heard, out of the box jetting is usually opretty close, set the mixture screws and go! The best part is everyone has gaskets and such for Holley...

Edelbrocks?
 

For a stock to mild motor applications running in the lower RPM ranges 4800 to 5600 the 1409 600cfm and the 1410 750cfm run great right out of the box.

If needed, No need to take the carb off the motor. Just remove the top plate of the carb and all tuning can be done. Metering Rods, jets and step-up springs are straight forward.:sport009:

Cost is also good if your on a budget.

UPS dropped off a pair of 4150 750cfm. carbs last night. The stock jetting is 73/81. My motors are 383 Strokers with 234/240, 566/565 Madera cams. Any suggestions on where to start with jetting?

I have always started with them out of the box, put timing at 32 total and see what plugs look like, if they lok good add a degreee of timing till plugs start to look lean, most SBC like 34 total, I bet if anything you may only need a tad more jetting, they are set up fairly conservative..

I always tuned mine this way and it seems to be just fine..

Good choice...who did you deal with?

The 750 is hard to get wrong and has been said...you should be close out of the box. Run a while and see how you like it ...you may decide not to mess with it. You will love the control you have with those carbs.

I've been using Edelbrock marine carbs for years. Very easy to work on. No gaskets below the fuel level. I think one of the issues is you are running 750's on a small block. I run 750's on big blocks and a lot of folks think they are still to big and if putting along they are right. But I don't put much.
I also run a 800 on my 496 stroker.

QFT makes marine carbs now..The are neat looking also

http://www.cpperformance.com/c-1500-...rburetors.aspx

Hey, I hope you didn't throw away that 3000$ Quadrajet off the 74 SD transam!! I have also worked on a few LS6 Chevelles and they had factory holley 4557 carbs from the factory so unless carb was trashed or you were building a total dragster I would make the stocker work!

Nope ...sold both cars with the original carbs mounted on them to keep them original. I respect the purity.

The LS-6 got "Temporarily" a Holley "3-barrel" 1000 CFM sitting on top a first generation Edelbrock Tarantula (I know...I'm dating myself) and a set of 2 1/8" primary "Hooker" headers. With 4:56 12 bolt and M & H wrinkle wall drag masters...we ran 11.4 @112 MPH. the car ran 12.8/105 stock. The big improvement was the 455SD. Going to a Edelbrock square bore "Ram Air VI" intake with a 850 DP we went from 13.7 @101 to 12.1@114. The Holley ate the Q-Jet up in the 60' times. :evilb:

Getting back on track...I love the feel of a DP on a boat, It's always there...snappy throttle response. I've been in some tight spots running inlets in weather that I shouldn't have been in. The Holley throttle response up and down in those situations made a huge difference.

On a lake or river where it seldom becomes a critical factor I guess a vacuum carb is a fair choice...but in the open ocean or the great lakes when you need immediate throttle response...you can't afford the lag time of waiting on secondary barrels to cut in on a vacuum carburetor.

It's a fair debate and one I enjoy.

+1 ...and just because the Edlebrock provides you with greater ease of tuning and flexibility dosen't make them inferior carbs. There's a systematic process of dialing in the right jet sizes and metering rods once you have the right size carb to begin with.

i would agree i build alot of custom cars for ppl and one of my fav combos is a 383 stroker putting out about 425 with 9.5 to 1 comp i always use an out of box stk 650 electric choke on these things and have never had any tuning issue. If you are are putting 2 750 dp holleys on i think that is way to much. I might of read the posting wrong but it sounded like you were going to use 2 of them. My drag car is a 464 buick motor running deep in the 10s and i run a 950 hp holley so to think a stoke sbc needs 1500 cfm unless there is a blower or something i missed i think that way over killl

as far as the charts go with the edy i think they are helpful they have 2 differant color dots one that is cover by the tuning kit and the other are other parts you would have to get on your own. its pretty easy to look the number dot up you want and put those parts in and try.

From my experance most tuning can by done right in the springs and rod and almost never need to change jets unless its something big. so you can test change right on the water in minutes and test again with no gas spilling on the motor. i also like that they have no gaskets below the gas level no leaks. my opnly issue is they are harder to set the float level on than a holley. but to change jets both carbs harve 8 bolts and 4 jets just depends. plus the edys dont have power valve to blow. just remeber with the edy the stiffer the springs the sooner you will get power enrichment. most ppl think of it backwards. when tuning a carb i always add gas first to prevent a dangerous lean condition if it gets worse then i take away. what issue are you having directly maybe you said and i missed it

2-carbs, one for each motor. Holley doesnt offer a 650cfm carb with mechanical secondarys, so I went with the 750s.

With the cams you are running on 383's a 750 DP will probably nail it.

Run what you brung. Should be good to start with that. The carb is a little big tho
 

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Edelbrock has the kits to fine tune the Weber s / Edelbrock marine carbs. I buy them and have no problems dialing in those carbs right but for the past 6 years I really do not see that many carb apps anymore especially currently ..

It is wise to have a strong working complete ignition system as well. Can not tell you how many times boaters try to dial in their carbs and they have 20 year old ignition components and 10 year old spark plugs. Also for merc apps using the T bolt V ignition you have to put that in base timing mode to dial in the idle and some other adjustments for jist.

I live in Bowling Green, home of Holley and Quick Fuel. Quick Fuel is a very good option. Holley design refined. They run all the carbs on engines before shipping. Holley is doing a great job now as well.

Okay, it's a lot easier to "learn" jetting with an Edelbrock than it is with a Holley. The Edelbrock fueling charts are easy-peasy. Fine tuning a street Edelbrock can involve peening and redrilling the air bleeds, but for most stuff with wide lobe separation cams and decent idle vacuum an Edelbrock usually doesn't need much other than jets, springs, and needles.

I like Holleys, too. But they are a lot harder to "learn" than an Edelbrock. The biggest issue is that a lot of guys have "some" experience jetting Holleys since they have been exposed to them for years, and what they know about Holleys doesn't transfer over to Edelbrocks.
For Fine Tuning, Holley offers carbs with replaceable air bleeds, different booster styles, different squirters, squirter cams, and different pump sizes. But to get ALL of the adjustability you have to get the HP carbs and plan on mixing and matching parts across series numbers.

The Edelbrock is pretty darn simple when you get down to it.

Idle should allow throttle plates to close almost all the way. Idle mix screws handle most of the idling chores, but the low speed air bleeds ALSO affect idle some. The idle feed ports are fine for motors with good vacuum, but a big cam will require you to drill the idle circuit feed ports and maybe peen/drill the low speed bleeds a touch smaller, but then you have to reset the idle mix screws. Off-idle with low vacuum is the toughest place on an Edelbrock, and some people elongate the slots above the throttle plate, but you can usually get all of the off-idle problems fixed with the low speed bleeds without having to file the slots. Good vacuum, and you won't even notice the off-idle problems. Upper end of primaries, you will have to play with the high speed bleeds to smooth the transition into the secondaries (on a car). You don't generally have to do this on a boat, due to the load curve the motor sees at the transition point. Secondary springs are usually all you have to mess with on a boat to get the transition to behave.

Most weirdest problem on an Edelbrock is using an air filter with a lid that is too close to the bowl vents. Screws up all sorts of midrange stuff. Marine flame arrestors are USUALLY open enough, but you still have to keep it in mind.
They make Stub-Stacks for Edelbrocks, but they amplify the bowl vent problem even worse. Stub Stacks require even more clearance around the bowl vents, or else they hurt more than they help.

Edelbrock doesn't offer a large pump capacity. It's generally enough, but your only tuning aid is linkage and squirter jet size. Boats don't suffer on this front as much as a 4-speed hotrod does. As long as your pump feeds enough for you to hammer at 2500 rpm without bog, then you're gold with a boat. Know also that secondary springs are a balancing act with the accel pump. Best to disconnect the secondaries completely when setting up your accel pump, to get the squirt volume/duration worked out for the primary bores, and then juggle secondary springs to make sure you don't bog going into the secondaries.

Holleys THESE DAYS come with Chinese metering blocks. I've seen more than one with casting flash and junk in the secondary side (the primary side is usually checked out better I guess).
So, if you have a carb issue that is only on ONE engine (the beauty of twins), then once you determine that both carbs are setup the same, you now can start disassembling and looking for crap that made it past the sleeping QC guy. It can often be "tuned around" but any time you have to set up the carbs differently on twins, you have a problem in the carb circuits, vacuum leaks somewhere, or something is up in one of the motors. If one motor is giving you fits, just swap carbs. If the problem follows the carb, it's in the carb. If the problem stays with the motor, it's not the carb.

M

Did you ever find that Pontiac HO intake? Really don't know anyone not running billet metering blocks anymore. Not that I would touch a good running Holley if it's already been setup for your engine. Was never impressed with a Edelbrock carb other than the one piece carburetor body, but would rather use a Quadrajet if I wasn't going to run a Holley.

Yeah, I did find the intake. It was in the bottom drawer of a file cabinet in my storage trailer. I swapped it to a guy for a pair of small valve mopar RB 915 heads.

And I cut my teenaged teeth drilling jets and bending needle hangers on Qjets for all my buddies' rides after they installed headers and duals on their pontiacs and chevys. I like Qjets.

MC

If you are prop,boat weight drive ratio ect , will allow you to hit 3000 plus rpm nailing it from idle , the difference in holeshot going from a out of the box edelbrock to a out of the box holley 750 dp should be unmistakable

Edelbrock Marine , Ive installed Dozens! The are damn near dead on out of the box .

Best carb or EFI is the one the owner or mechanic is most comfortable with.

That said, love Holley based carbs when engines are modded from mild or bigger.

You can also make any Edelbrock Auto carb into a marine carb for about 10 bucks.