What size carb should I run

[Dominator Scott]

Hello again everyone. Yet another question for you.
I am still trying to tune in my dads Sanger that I am restoring for him and I am wondering what size carb should I run.
I currently have an Elderbrock style carb that came off one of my 502 engines from my 32 Sunsation and would imagine that it is a 750cfm series carb since a stock Mercruiser 502 is 425HP but not positive on the carb size. (Figured since I can no longer use them its better than just letting it sit)
Anyways the Sanger has a 460 Ford motor that is approximatley 330HP. I ran a Barry Grant/Holley 750 double pumper that I borrowed from a friend and the motor responded well with it,but I am wondering if it is a bit of overkill for this motor. Plus I have went WAY over budget on this project and I am not done yet so I was hoping to save some $$$$$ and be able to use the carb that I have rather than have to go buy the Holley.
I am spinning the motor at approx. 5200RPM's. What is you opinion? Is the Elderbrock carb enough for a 330HP big block?

[Hustler]

i would stick with 750 Holley. I never cared for the Edlebrock carb's. Is the 5200 with the Holley or the Edlebrock?

[mach1alaska]

I would run the edelbrock they are way easier to set up and once set up you just leave it alone and run it. I have had great luck with carter and edelbrock carbs.

[LakesOnly]

I currently have an Elderbrock style carb that came off one of my 502 engines from my 32 Sunsation and would imagine that it is a 750cfm series carb...
Anyways the Sanger has a 460 Ford motor that is approximatley 330HP. I ran a Barry Grant/Holley 750 double pumper that I borrowed from a friend and the motor responded well with it,but I am wondering if it is a bit of overkill for this motor.
I am spinning the motor at approx. 5200RPM's. What is you opinion? Is the Elderbrock carb enough for a 330HP big block?Technically, any properly functioning carburetor will allow the engine to run, but you've already answered your own question to some extent: the Holley offered better performance than the Carter/EdelBROCK carburetor.
The first carb you tried offers little adjustablility compared to the Holley, which offers superior adjustability. Believe it or not, further tuning for the Holley carb might even get you more power yet. It most certainly is NOT too much carb for a sustained 5200 rpm 460 jet boat motor.
Anyone that thinks a carb "worked great out of the box and needed nothing" has a lot to learn about performance engine tuning and/or is ignorant to how much additional power can be gained through refining the air/fuel delivery systems in a carb for any given engine. Not having that adjustability (as in the EdelBROCK) is a big minus.
Go with the Holley.
LO

[FryJet]

I would run the edelbrock they are way easier to set up and once set up you just leave it alone and run it. I have had great luck with carter and edelbrock carbs.
I was a big believer in the AFB style carbs for about 12 years and got pretty good at tuning them. I decided to give Holley a try so I bought a Holley Tuning book, read it and bought a 750cfm 4150 series carb for the 460 in my old boat. I have also had great luck with the AFB style carb BUT, Holley is hands down better thought out carb and WAY easier on the tuning side. With the AFB you have to many variabals when it comes to the primary circuit in regard to the jet, metering rod and spring combo. Im my opinion the AFB is a better carb for someone who doesnt have alot of mechanical skill and just wants to just bolt it on and go. Also, in my experience you can also get better milage out of the AFB on street cars, but you have to really mess with them. Once you start getting into tuning and performance then the Holley is the best choice, IMO.
F.J.

[deltaAce]

If the Edelbrock carb was good enough for the 425hp-502 it should work plenty well for your dads 330hp-460. Your right, why waste the superior Barry Grant/ Holley rock-em, sock-em setup on a mild engine.

[Duane HTP]

Go with the Holley every time for a boat. Keep the Edelbrock on your Tow vehicle and get good milage on the way to the lake. This has been my experience time and again.

[Dominator Scott]

i would stick with 750 Holley. I never cared for the Edlebrock carb's. Is the 5200 with the Holley or the Edlebrock?
5100-5200RPM's was with the Elderbrock carb. The Holley would twist the motor at 5400RPM's and I will admit the Holley would yield better mid range and a tad more on the top end. However this is my dads boat and he doesn't have the mechanical skills like he used to,or just doesn't have the patience. He will have it from approximatley Memorial weekend to just before Labor Day weekend. The rest of the time I will have it to play with.
My main thinking was the fact that the cost of my friends Holley carb I could use somewhere else,like a set of over transom headers which I think she desperatley needs. :rollside:

[Ken F]

Well then, it's your call but Personally I would much rather have the engine run right.
Ken F

[FASTRAT]

If the Edelbrock carb was good enough for the 425hp-502 it should work plenty well for your dads 330hp-460. Your right, why waste the superior Barry Grant/ Holley rock-em, sock-em setup on a mild engine.
Scott...
i totally agree...IMO, it seems ur re-storeing the boat to look good & run good with n/p's...i say run the Edelbrock & spend the $$$ somewhere else like headers, manif chng, cam, etc...just my .02 cents
fastrat

[Dominator Scott]

Took the Sanger out again last night with both of the Elderbrock carbs and the results were the same. SUCKED!!!!! :mad: For some unkown reason these carbs are not dumping any fuel from the secondaries and at 4000RPM's she falls on its face. This really has me stumped considering the very first time I ran it was with the Elderbrock and didn't have this issue.
When I pulled the carb off and operated the throttle linkage on the work bench,the primaries squirted fuel but the secondaries are dry and nothing squirted out of them at all. What in the hell would cause this on both carbs?
Is it a carb issue or is the fuel pump possibly getting weak? Guess I need to try the Holley again and that will answer my question if its just carb problems.
What are your thoughts?

[FASTRAT]

take the top off the carb & see if there is any dirt etc in the jets or sediment in the bowl?...blow air thru the jets & try it again...i have never encountered that prob with any of my EB's unless they get dirt or sediment in the bowls...the carbs are stock out of the box???...if the fuel pump worked ok last time, i think the carbs are dirty...just my .02 cents
fastrat

[Taylorman]

Took the Sanger out again last night with both of the Elderbrock carbs and the results were the same. SUCKED!!!!! :mad: For some unkown reason these carbs are not dumping any fuel from the secondaries and at 4000RPM's she falls on its face. This really has me stumped considering the very first time I ran it was with the Elderbrock and didn't have this issue.
When I pulled the carb off and operated the throttle linkage on the work bench,the primaries squirted fuel but the secondaries are dry and nothing squirted out of them at all. What in the hell would cause this on both carbs?
Is it a carb issue or is the fuel pump possibly getting weak? Guess I need to try the Holley again and that will answer my question if its just carb problems.
What are your thoughts?
Edelbrocks don't have secondary squirters, just the primaries. I had dual Edelbrocks for a while and it was my experience that they needed to be cleaned out once a year to keep them running good. I had a similar problem once with mine and it was trash cloggin up the screens in front of the needle and seats. Are you familiar with taking them apart? If so, pull the tops off and pull the needle and seats out and check the screens, i bet thats your problem. Pull all the boosters and squirters off and clean them good and blow all the little orfaces out with air. If you don't tear any gaskets slap it back together and try. If you tear gaskets, get a gasket kit to replace them. They are really easy to take apart.

[lucky]

if you go to the gear head forum there is some great cfm info and tuning tips
look at the sticky's threads

[Dominator Scott]

Edelbrocks don't have secondary squirters, just the primaries. I had dual Edelbrocks for a while and it was my experience that they needed to be cleaned out once a year to keep them running good. I had a similar problem once with mine and it was trash cloggin up the screens in front of the needle and seats. Are you familiar with taking them apart? If so, pull the tops off and pull the needle and seats out and check the screens, i bet thats your problem. Pull all the boosters and squirters off and clean them good and blow all the little orfaces out with air. If you don't tear any gaskets slap it back together and try. If you tear gaskets, get a gasket kit to replace them. They are really easy to take apart.
For some reason I am not drawing enough vacuum to open the secondaries on either Elderbrock carb. I went and picked up the Holley today to try it again. If it works fine than I am buying it. I can work on a Holley all day with no problems but the Elderbrock and Q-jet carbs I know nothing about.

[FryJet]

The Edelbrocks have manual secondaries.......at least everyone that I have had did.
F.J.

[Dominator Scott]

The Edelbrocks have manual secondaries.......at least everyone that I have had did.
F.J.
The base plate butterflies are mechanical but she draws fuel to the secondaries by vacuum. Open up the throttle with the motor off and you will only see the primaries squirt fuel. Nothin' quite like a good ole' fashion Holley double pumper. Either it works or it don't,there is no guess work involved.

[Taylorman]

You obviously have a clogged up Edelbrock. They are very simple in design. Like i said. Give it a good cleaning and it will run fine. Send it to me and i'll do it for you.

[Dan Lorenze]

I would run the edelbrock they are way easier to set up and once set up you just leave it alone and run it. I have had great luck with carter and edelbrock carbs.
I agree.. Those Edelbrocks are known to be good to go right out of the box. I installed a 750cfm Edelbrock Marine carb (1410?) in my old boat that was solid, a true plug and play carb.. I'm not saying they're better than Holleys, just might be easier to tune.

[rrrr]

I agree.. Those Edelbrocks are known to be good to go right out of the box. I installed a 750cfm Edelbrock Marine carb (1410?) in my old boat that was solid, a true plug and play carb.. I'm not saying they're better than Holleys, just might be easier to tune.
The Mercruiser carb is a Weber....but it's identical to the Edelbrock 1410, which is identical to an AFB.
Edelbrock has a good tuning book available for download from their website. You can tune it easily, and you'll learn something new while doing it.
You prolly need to change the secondary vacuum spring. It's easy. Also, look at the Edelbrock book for some baseline rod and jet combos. The parts are cheap.
Square-bore AFB style carbs are good stuff....that's why Merc put 'em on a jillion big blocks.

[DUCKY]

Most all the AFB style carbs are awesome on an application that doesn't require a lot of accelerator pump shot. They are smooth, easy to tune, and virtually leak free. That Mercruiser carb of yours could have either been made by Weber or Merc themselves (MerCarb) and is probably an 825cfm if it came off a 502.
From a strictly mathmatical standpoint,a 460ci engine requires a minimum of 730cfm at 5500rpm and 100% VE. When you put into the equation things like camshaft duration and overlap, that size motor only "needs" a 650 to run, but it wouldn't make any horsepower.
Anything in the 750-850cfm range would be the right choice for your motor, and if I were buying a carb, I would purchase a Holley simply because I have more experience fine tuning them. Since you already have this Mercruiser carb, I would bolt it on and use the hell out if it! If it's in good repair, you shouldn't have to do more than set the idle speed and mixture screws as they come setup a little fat from the factory, and you are putting it on a jet (Jetboats like a little more fuel, especially off idle, which is why they like double pumpers so well) and the fact that your smaller motor has far better exhaust than did the 502. Good Luck!

[Dominator Scott]

You obviously have a clogged up Edelbrock. They are very simple in design. Like i said. Give it a good cleaning and it will run fine. Send it to me and i'll do it for you.
Normally I would agree 100%. But I have 2 of these Edelbrock carbs and they both are doing the same thing. Secondaries are not opening. I have had a few of these Edelbrock carbs over the years and have always had good luck with them in the past. That is why I am just baffled over this issue. That is the nice thing about a Holley double pumper,there is no guessing as to if the secondaries are opening or not. :)
On a positive note, a member of Speedwake.com that I associate with often is sending me a Holley 800double pumper to try and has offered to sell it to me at a very fair price. So I will try the 750 Holley and then the 800 and see which performes better. If they give the same performance then I will go with the 800 simply because of the price.

[DUCKY]

Although the AFB style carbs (most) have mechanical secondaries, they also have weighted air valves above the secondaries. You will not get them to open with your face over the carb, revving the motor with no load on it (which is really stupid BTW, unless you don't like your eyebrows) All you have to do is make sure that those air valves move freely with your finger, and rest assured that they will open when the motor needs them to. These air valves are the main reason that these carbs offer such linear throttle response right out of the box.

[Dominator Scott]

Although the AFB style carbs (most) have mechanical secondaries, they also have weighted air valves above the secondaries. You will not get them to open with your face over the carb, revving the motor with no load on it (which is really stupid BTW, unless you don't like your eyebrows) All you have to do is make sure that those air valves move freely with your finger, and rest assured that they will open when the motor needs them to. These air valves are the main reason that these carbs offer such linear throttle response right out of the box.
If you are referring to the upper set of butterflies,I have already checked them and they move freely with nothing obstructing them what so ever. For some reason I am not pulling the vacuum that is needed to engage the secondaries.

[Taylorman]

If you are referring to the upper set of butterflies,I have already checked them and they move freely with nothing obstructing them what so ever. For some reason I am not pulling the vacuum that is needed to engage the secondaries.
How do you know they are not opening? Are you looking down the carb when the secondaries are open with the engine running? If you are giving it enough throttle to open the secondaries, they are opening cause they are mechanical like a Holley DP.
Normally I would agree 100%. But I have 2 of these Edelbrock carbs and they both are doing the same thing. Secondaries are not opening. I have had a few of these Edelbrock carbs over the years and have always had good luck with them in the past. That is why I am just baffled over this issue.
I just can't believe that you are having the same problem on both carbs. Take that butterfly out and run it like that. I have run my edelbrock without it before and did not notice any difference in my boat. I doubt that those butterfly's do anything in a boat. A car is a different story but a boat rev's fast so i doubt it makes any difference.

[Dominator Scott]

How do you know they are not opening? Are you looking down the carb when the secondaries are open with the engine running? If you are giving it enough throttle to open the secondaries, they are opening cause they are mechanical like a Holley DP.
I just can't believe that you are having the same problem on both carbs. Take that butterfly out and run it like that. I have run my edelbrock without it before and did not notice any difference in my boat. I doubt that those butterfly's do anything in a boat. A car is a different story but a boat rev's fast so i doubt it makes any difference.
The same problem with both barbs surprised me too. I am trying it again with the Holley to see if the problem goes away. If it doesn't than there is another issue that I will have to track down. I will update everyone tomorrow.

[boatgonewild]

I have a big block chevy pushing 500 horses, when i got it it had a 650 holley, great out of the hole , faulters about 3200 to 4000 once secondarys kicked in carb would pin me , almost like a passing gear in a car .
Since then have put 8000 eldy on , feels like a miny bike trottle.
That a perfect water ski carb. New battle plan 750 holley, tuned by the gods.
650 holley would take the 800 eldy in a heart beat.

[Dominator Scott]

Well last night was a total failure. It was only 50 degrees outside and this Barry Grant/Holley has no choke so trying to keep it running at the dock was a joke since there isn't a neutral on this thing to speak of. Eventually she was so loaded up that she wouldn't clean herself out even when we secured it back on the trailer and only backed her in far enough so the jet could draw water and tried revving her up. So I loaded her on the trailer and picked up some spark plugs on the way home. I also stepped up the heat range a notch on the spark plugs to compensate for the cooler temps and we will try it again tonight.

[Dominator Scott]

Well I found the running fat problem with the Holley. The needle and seat was stuck on the seconday side and it was dumping the fuel. Clened it out and all is good. I am sea trialing it tonight after work. :rollside: