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Carb Cunundrum

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Randar35
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Carb Cunundrum

Post by Randar35 » Mon Feb 18, 2008 7:26 pm

OK...So here we have it. New and ready to roll into the 59 Connie...One GM Small Block 350. Top to bottom rebuild. Done right. Have two Carbs to choose from. One Edelbrock performer 1410 and one 1409. 750 cfm and 600 cfm respectively. Some folks are telling me that the 750 is just too much for the small block chevy. Stuck as to which one to lead with. I can get the 750 tuned for the motor but that is about $150 bucks on top of the $$$'s shelled out for the carb.

Just interested in any ideas.

Thanks for the help

~R~

PS...Depending on which one goes on...Will be listing the other on here for sale.

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57 chris
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Post by 57 chris » Mon Feb 18, 2008 8:04 pm

Hi Randall,
I found that the 1409 (600 cfm) was the right combination for my small block that was box stock. If you have done any internal mods to your engine such as intake, exhaust, heads or bore and/or stroke you might be able to go up to the 750 but if not I think you will have trouble with too much carburator.

Craig
1957 18' SeaSkiff #SK 18675 "Knot Sure!"
1958 18' SeaSkiff #SK18722 "Wreckreation"

Past projects: 1972 19' Lancer with 307 Volvo drive-Great Blue, 1968 23' Lancer Offshore with 283 Volvo drive-Narwahl
1988 FourWinns 245 Vista - Blue Ayes.

It's good to have wood!

Sundowner
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Post by Sundowner » Sat Mar 08, 2008 10:16 pm

What kind of adapter plate did you find to use with the 1409 and keep the 12% wedge plate.
I have two boats both with 283's .One has a rebuilt WCFB and ons came with the edlebrock 1409. I could not identify the adapter on it.

Thanks,

Alan

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Commander38
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Post by Commander38 » Sun Mar 09, 2008 5:22 am

Stick with the 600. It's kind of like taking Tylenol for pain. Anything over the prescribed amount is simply wasted and "exited" unused. Same applies here with one exception. Unburned fuel is ALOT more expensive than unused Tylenol :D
Lee H. Dahlen
Glassic Boatworks
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Paul P
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Antique & classic boaters, stay AWAY from the 750 CFM ca

Post by Paul P » Sun Mar 09, 2008 11:09 am

I hope you didn't put a 750 on that small block, and I hope nobody puts a 750 on anything as big as a 427 either, because it's simply too much carb for the rpm we're turning in boats.

It is a common event, to have boat guys talking to car guys about boat issues. The two don't mix very well, because the entire car motor culture is based upon high rpm for performance, and boats are based upon torque and lugging abililty over the long haul.

The 427 Ford is a perfect example. In street tune it was conservatively rated at 425-hp and everyone but the insurance companies seemed to know the true power was up around 450, perhaps more in certain motors. The factory redline was set at 6000 rpm. Imagine today, being sold a big block motor with an approved max rpm of 6000? Those motors were sold with dual carb capabilities because at that high of an rpm they were pumping a huge quantity of air through those 425 cubic inches (yes, the 427 is actually 425 cubes).

Now in marine form (4000 rpm max, rarely seen for any appreciable amount of time), the 300-hp 427 is actually a bit over carbed at the 625 CFM Carter CC chose. The Edelbrock 600 is a great swap and many of we Commander owners running these motors have made the swap with very good results when our old Carters are worn beyond repair.

A comparable story is appropriate for the small block motors. A 750 on a small motor turning only 4000 is going to simply kill it early. Pistons, rings, and bores will take a beating. Valve stems may take a beating too. Fuel economy will be poor. The Edelbrock 600 may be a little too much carb for the marine small block, but it is the smallest carb available for people (like me) who want to upgrade from something that is way beyond repair, and stay with the Carter AFB look. The new Edelbrock is basically a clone of the Carter AFB, easy to work on, very good reliability and performance too.

I'm running one now on a small block 327F. My particular motor has an automotive block installed due to previous owner freeze damage, so it has 8.5:1 compression rather than 8.0:1 on the stock F motor. The results have been very good so far, great performance, no smell of fuel fumes, exhaust looks reasonably clean after a run.

The 750 marine carbs have no place on anything other than a big block drag or jet boat producing mega power. If the formulas show the big 427 Ford spinning at 4000 CFM can't use all of what a 600 has to give, that tells you a smaller motor sure doesn't need a 750.


Here's a photo of an old spare carb off a 283H I used to get my 327F running, along side the new Edelbrock 600. The old carb worked, but the new one worked a LOT better. This is aboard my 1966 2o' fiberglass Sea Skiff restoration project.
Image

The linkage will fit up nicely, but the fuel inlet may be a little tricky. Edelbrock sells a banjo fitting that allows you to utilize a marine rated fuel hose, but naturally it would be better to use the flared copper lines.
Image


From someone who's done it with his own hands!
PROOF IS IN THE PUDDING !! 8)
Image

Image


So many boats.........so little time.....but what a way to go!!!! :lol:

Regards,

Happy boating!

Paul
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

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Commander38
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Post by Commander38 » Sun Mar 09, 2008 12:03 pm

Make sure those copper lines are seamless copper, and of course, watch out for setting up yourself for galvanic corrosion with more than one metal, especially where you "clamp" it down during the run along the stringers and engines. Most modern builders are using A1 or A1 CG rated hose, or seamless steel lines.

To each their own preference, and that's a good thing but of course, be safe
Lee H. Dahlen
Glassic Boatworks
704-287-3914

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Commander38
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Post by Commander38 » Sun Mar 09, 2008 12:04 pm

That should have read A1 or A2 hose.
Lee H. Dahlen
Glassic Boatworks
704-287-3914

Wood Commander
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Post by Wood Commander » Sun Mar 09, 2008 1:38 pm

Paul, how do you feel about the 750 CFM Quadrajets or the earlier Rochester 4 jets? Many of the 283 and 327 F's came with the 4 jets from the factory, but I don't know their CFM rating.
I know that Quadrajets aren't original, but I like them. I recently got one that somebody had installed on my CC 307 Q. It's a Mercruiser carb so it's a marine version, and I will probably rebuild it and use it. I'm going to be using an aftermarket manifold anyway so I am not concerned about originality.
What I like about the Q- jet is that when you are just cruising, your only running on the front two barrels which are actually smaller than the two barrels on a two barrel carb (or other 4 barrel carbs), so it's pretty effecient. If you can stay out of the secondaries, they are fairly frugal. Q- jets over the years have gotten kind of a bad rap for all out performance as compared to a Holly or Carter (now Edelbrock, as is the Q- jet). But I run 'em in hot rods and have run them in plastic boats that aren't all out track machines and I think that they run very well. I even liked the performance and fuel efficiency of the old 4- jet (all four barrels, venturies, are the same size)on my old CC 283 F.
Bret

1953 35' Commander "Adonis III"

1970 23' lancer project

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Paul P
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Post by Paul P » Sun Mar 09, 2008 6:45 pm

I wouldn't put any 750 CFM carb on a boat motor unless it was a 400 hp or higher, jet boat, drag boat, or some other go-fast boat. No need for it. The only Holly I have here on the ranch is on a 366 GM C-60 farm truck, and it's vac secondaries and not a double pumper.

The Carters came on all the CC small blocks to my knowledge. They're simple and you can run on two bbl with one of those just as easily as you can with a Holly. I don't know the CFM rating for the small CC motors, but you are never going to use all of what a 600 anything has to offer in one. The only use of a big carb on a small block is if it's turning high rpm and producing lots of (racing) horsepower.

Personally, I'd stick with the Carter (or Edelbrock clone). They are VERY SIMPLE to work on.

BTW, in case anyone is wondering why I bought a 1409, here is why. I took one look into the old carb that showed up on my project boat and decided life was too short to be out on the lake on a sweltering hot day having to deal with THIS, ha!

The new Edelbrock 1409 in the photo is a dead ringer for the old Carter, and if you really want, you can change out the jets to tune it to your particular whim. I'm using mine out of the box with good results.



Image

Image

Holly makes a great carb, I'm sure their marine carb will work fine, but be careful not to go up beyond a 600, becuase even with that, you have more carb than the motor is going to be able to put to use. A big carb does NOT mean you're going to get more power. Too big, and all you get is more wear, poor running conditions and bad fuel economy.

Regards,

Paul
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

Wood Commander
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Post by Wood Commander » Sun Mar 09, 2008 7:39 pm

My 1968 19' Chris Craft Lancer with a 283 F(FLV- Left Hand, Volvo outdrive designation) and both engines, a pair of 327 F's (F and FL) out of an early- to mid- 1960's Constellation, have/had the early Rochester 4 - jet carbs.
Bret

1953 35' Commander "Adonis III"

1970 23' lancer project

Wood Commander
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Post by Wood Commander » Sun Mar 09, 2008 7:41 pm

In my previous post it should have said that I also recently bought the pair of cruiser engines with the 4- jet carbs.
Bret

1953 35' Commander "Adonis III"

1970 23' lancer project

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Paul P
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Post by Paul P » Mon Mar 10, 2008 10:16 am

Looking over the charts this morning, I see there are some versions of the 283, for instance, from THE SAME YEAR, that use either the Carter or Rochester carb.

It seems that most V8 motors came with the Carter, including all the 431 Lincolns and all the 427 Fords. Rochesters seem to be the exception, used on the 1962 283 (Carters also on that model in '62), and the 1967 307. In reality, they (Chris Craft) may have pulled carbs from the shelf as their stock would dictate, and it may not have really made a difference to them (or the performance). In looking through the listings that are available, mostly from people providing repair kits for carbs, there is more reference to the Carter than the Rochester (the latter also used on 4 and 6 cylinder motors). As long as they fit the intake, had 4 barrels, had linkage that would hook up quickly, and provide the desired power rating, I am not sure anyone (other than the buying agent) would really care.

If you can find any additional info on why CC used these carbs as they did, please let us know. It is just one more obscure forensic issue we're trying to understand "40 or 50 years later" :-)

Regards,

Paul


Wood Commander wrote:My 1968 19' Chris Craft Lancer with a 283 F(FLV- Left Hand, Volvo outdrive designation) and both engines, a pair of 327 F's (F and FL) out of an early- to mid- 1960's Constellation, have/had the early Rochester 4 - jet carbs.
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

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campjer
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Post by campjer » Mon Aug 04, 2008 8:37 pm

Hi all - to continue on this post... the Edelbrock 1409 - is this "Good to go" out of the box onto a small block Chev (283)? I've been checking it out and after dealing with what you see in the photos below, I'm really tempted to pick 2 up.

In addition to the above - do I require a wedge plate at all? Currently there are none on either one of my engines (did they come with a 12% originally?). Both intake manifold are, as best as I know - completely original (no mods or customizing).

I've just completed the 1st half of my 1st trip on my Connie (covering about 150 nautical miles in 2 weeks). Throughout that trip I've been dead in the middle of L.Ontario in a severe storm (8' waves - thanks Coast Guard!), gone dead in the Murray Channel once again near Picton, Ontario and today outside of Kingston, Ontario. I'm 200% convinced it is all due to the carbs (hard starting, running rich = fouling plugs, carbon builds and subsequent manual carbon blow outs every 45 minutes to keep the cylinders clean). I'm really tired of messing with them (after 3 rebuilds, 4 plug changes and 2 swaps to have 1 running engine on the voyage).

These pics were from my first rebuilds. Notice the beautiful quality of the gas that was in my tanks (issue since resolved):

Image

Image

Image

Image
Cheers,
Jeremy Campbell

Current Projects:
'61 32' Connie
'61 45' Connie (RIP)
'50 42' DCFB

Wet Dreams:
'61 57' Connie

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campjer
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Post by campjer » Mon Aug 04, 2008 10:47 pm

Wow - sorry for the size of the images in the previous post!

One last question in regards to the Edelbrock 1409. How is the clearance on these with and without the wedge? My air breather bolts right now are as high as a carb can possibly sit before I run into hatch issues.

Thanks in advance.
Cheers,
Jeremy Campbell

Current Projects:
'61 32' Connie
'61 45' Connie (RIP)
'50 42' DCFB

Wet Dreams:
'61 57' Connie

toma
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carb conunndrum

Post by toma » Wed Aug 06, 2008 5:08 pm

as i recall chris craft used two different carb/manifold combinations on 283 flywheel forward installations. on engine box confifurations they used a stock chevrolet cast iron intake manifold with a carter wcfb carb. on flush deck models requiring some height restrictions a specially cast low profile aluminum intake manifold with a rochester 4gc carb.iworked on both 50 years ago and salt water are up the aluminum manifolds.

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Paul P
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Post by Paul P » Wed Aug 06, 2008 5:36 pm

my old flywheel forward 283 (now 327) in the 1956 17' Sportsman has the wedge, and the flywheel aft 327F does not, but soon will because a friend recommended it. For the few bucks (Glenwood marine hardware catalog) http://glen-l.com/inboard-hdw/hdw-index.html I guess I'm going to add one just to keep the floats from getting too much on an angle. It makes more of a difference in a smaller boat that likes to put it's nose to the sky under certain rpm, than it does in a cruiser that normally likes to run flat regardless of power (such as a 38' Commander, which has NO need for trim tabs).

Regards,

Paul
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

toma
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Post by toma » Wed Aug 06, 2008 9:03 pm

Oops meant to say ate up the aluminum manifolds at the rear corners. currently own a 1947 19 ft red&white racing runabout with a mb engine, and a 26ft 1958 continental with twin mcl engines.

Wood Commander
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Post by Wood Commander » Thu Aug 07, 2008 12:06 am

A 26' 1958 Continental with twin MCl's? Excellent! Waaaayyy cool!
Bret

1953 35' Commander "Adonis III"

1970 23' lancer project

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campjer
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Post by campjer » Thu Aug 07, 2008 10:01 pm

Well I've succumbed... an Edel 1409 is on order and I should have it no later than Tuesday. This "should" (hopefully, fingers/toes/legs/arms crossed) fix my issue on at least my starboard engine. If it does - I'll grab another for my port.

New Question.

My starboard engine (rebuilt, previous post) - is running richer than Bill Gates (carb I know). But what would cause a cylinder to fill up with gas? I noticed this today when I spent hours trying to move slips for the Poker Run up here. Couldn't start after firing fine then not taking an idle. Cleaned all my plugs. I have 3 cylinders towards the stern that get wet - 2 of them REALLY WET. Pulled the plug - grounded it near the block to test spark - which I have. But when the engine cycled, it through several ounces of gas out of the cylinder.

Would this also be carb related? Are my floats so messed up that they're just flooding out and the cylinders that are on the decline of the engine slope eat it up?

Sincerely,

Ready to LAW rocket my carbs off my manifolds.

(Plus side is I have the #1 dock space for the biggest Poker Run in N.America and the marina has sympathy! :) )
Cheers,
Jeremy Campbell

Current Projects:
'61 32' Connie
'61 45' Connie (RIP)
'50 42' DCFB

Wet Dreams:
'61 57' Connie

Jessica
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Re: Carb Cunundrum

Post by Jessica » Tue Mar 23, 2021 7:28 pm

These posts are fairly old, and not sure how this buzz works... however, I just purchased a 1964 CC Super Sport, 327-F with a Carter AFB carburetor that leaks around the base. I suspect it is a gasket, and have purchased new ones to repair. But I was wondering about carburetor wedges. They seem to make sense regarding internal float performance, etc. Does anyone know if these wedges are recommended, how many degrees of tilt are advisable, and where to get one to fit this manifold/carb. Thanks for any help anyone can offer. Best wishes.

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