Edelbrock/Carter carb tuning help

[Tahiti350]

I need help dialing in my carb for the new manifold (haven't messed with the Edelbrock/Carter much). I went from an old style Torquer to the Performer RPM, and now I'm way lean on top. Bottom and mid range feel better, but once the secondaries tip in it starts missing and occasionally pops out the carb . Couldn't get it to pull past 4k rpm on the big prop, 14x21+ S/S, and only to 4,800 on the 14 1/2x19 aluminum.
The rest of the setup is: mostly stock 350 Chev, mild rv type cam, OSO water manifolds running thru the drive, HEI and a 1" open spacer between carb and intake.
This set-up, with the Torquer, ran to 5,400-5,600 with the big prop 2 years ago, I never got it out last summer (work sucks). Any ideas from the carb guru's??
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[HP350SC]

No guru here, just basics. :) Check for intake leak, spray carb. cleaner around carb. base, and ports on manifold and see if idle raises. How is your valvetrain? Correct carb. gasket?Intake valve maybe? If you are sure it's the carb, buy their jet/spring kit which comes with the booklet on how to tune. They are very simple carbs. to make changes on, can be done on the water. Set accelerator pump linkage to longest throw and/or get the biggest accelerator pump they sell. That will cure your off idle stumble. They also sell a larger needle and seat which can't hurt. Good luck.

[HP350SC]

5600 with a "recreational vehicle" cam? :wink:

[Moneypitt]

It could be laying down due to fuel starvation. What fuel pressure are you maintaining, and have you checked the float levels in the carb. I was given 2 of those carbs by BradP, and although they worked from the begining better than what I had, I had to raise the floats quite a bit to bring them to the suggested setting. These carbs were virtually new, just shelve time, and I also replaced the pumps. The accelerator pump is for transistion into the main jets/mettering rods, and would have nothing to do with WOT into the secondaries....One more thing, buy Edelbrock parts for the carb. .......MP

[HP350SC]

His other post in Sandbar said he had an off-idle stumble, that's why I mentioned the accel pump :)

[Moneypitt]

What is the history of this carb?? New, used, really used, sat for awhile, etc.....MP

[Tahiti350]

Carb was on the boat when I bought it about 5 years ago, and has always run fine. The boat did sit last year, but was pulled out of the carport and run a couple of times prior to changing the intake and ran fine. After I changed the intake last sumer it seemed to break up a little when I tipped in the secondaries, but since that was just on the hose, I waited until I could get it in the water and push it with a load. It did about what I expected.
HP350SC,
not sure what cam is in it, and with thru the drive exhaust it's hard to tell how much lope, but it will pull 14-15 " of vacumn at idle at 900. Not a huge cam, that's why I said RV-type cam.

[HP350SC]

Was that open spacer on there before? Just wondering if it's compatible with carb. base.
You are on the right track, backfire through carb. is lean. Get the spring/needle/jet kit if you determine carb is problem, and try diff. settings.
Just messin' with you on the cam. :D

[HP350SC]

Water in fuel can cause similar problems as well. Spend time on diagnosis.

[Tahiti350]

Fuel was fresh today, ran out of fuel while warming up at the house, but had the miss before refueling. The spacer was on the Torquer. Used new gaskets both sides. Will have to try the carb cleaner leak test first, but checked everything close going together. No vacumn hoses except the PVC valve, so that's not is. May put a Holley on it and take it back out tomorrow and see what that does. That would tell me if it was the carb or something else. Was going to try this today, but fogot to put a plug in teh 1/2" vacmn port on the back.
Thanks for the info on E-brock, will pick up a tuning kit. and will post what I find out as I go.

[Sleek-Jet]

There is also a set of jets for the secondary's as well. When you pull the top of the carb off, you can see them in the back of the fuel "bowls". There is no meter rod for the secondary jets. The book the Edlebrock puts out lists which jets to put in to fatten or lean the secondaries.
If you don't have that book, let me know what carb you have, and I can copy the pages and fax them to you if you want. Sorry, I don't have access to a scanner, or I'd PDF them. Or, I have a couple extras laying around (I think), I can drop one in the mail if you would like.

[Tahiti350]

Sleek-jet, you have a p.m. There's the piece I was trying to figure out, how they altered the secondary side metering. I am used to Q-Jet's, and know how to dial in with the jets and metering rods they have, but could not see how the E-brock secondary was set up, and didn't want to pull it apart just to see.
Decided not to try the Holley after all, once I found out is was a 450 CFM Economiser. Had never seen one before, thought it was just a cool little Q-jet replacement. Nothing cool about a 450 CFM 4 BBL when I still have several 500 CFM 2 Bbl's from my circle track days. Might need to track down the guy who "borrowed" my 750 DP and jet set 3 years ago after his burnt (backfired and melted down). He needed a carb for "a week or two" and then would bring it back.
What sucks is the fact I have an easy dozen Q-jets, including a couple of fresh rebuilds, but can't try them on the boat, as they don't work well going backwards at high speed. Found that out the hard way during a "specialty" race, 25 laps on a 1/2 mile high bank in REVERSE!!!! When I would get on it out of the corner the fuel moved away from the jets and secondary wells. Leaned out and burnt a piston during that Heat race, and couldn't make the call for the "normal" main event. Had several others who couldn't make the call either. Why would I do somehting that dumb?? Not many heat races with $500 to win, and you had to run the heat to be in the main, which was $1000 to win, $750 for second, etc. They never tried it again, go figure.
Oh, well enough rambling. Thanks for the help ya'all. Will results after I get it dialed in.

[Sleek-Jet]

I'll check my PM's, but I also did a little surfing last night and Edelbrock has all the tuning stuff on their website. :D Here's the link: http://www.edelbrock.com/automotive/eps_intro.html
Don't wory about pulling the top of the carb off. Just undo the accel. pump linkage, the choke linkage (if you have one) and pull the fuel line. Remove the 9 screws and pop the top off. All the fuel is below the gasket, you don't have to worry about fuel leaks. It's also a good idea to check the float levels and such while you've got the top off.
There are little baffels in the bowls and the secondary jets are just aft of the baffels.

[Moneypitt]

And the fuel pressure is............??????????

[Fiat48]

And the fuel pressure is............??????????
My thoughts exactly.

[Tahiti350]

Okay, I can take a hint, I will go fire it up and check fuel press. Maybe it is time for a new fuel filter, since I haven't changed it since I've owned it, but it ran fine with the Torquer.

[malcolm]

Maybe I've never seen this setup before, but your engine sits backwards?
I tried an Edelbrock carb for a couple weekends, wouldn't run for shit! I had no secondaries. It would die out like I turned the key off. I finally put my old trusty Q-jet back on and life was good again. The only reason I came up with later, was the weighted air valves in the secondaries weren't opening. :confused:

[Tahiti350]

Malcom,
The motor sits normal for a stern drive, but the carb is backwards due to the throttle cable routing, it runs down teh right side of the boat and up behind the motor. Might have to see if it will re-route so I can turn the carb around, but the intake manifold is square bore and won't accept a Q-jet. I would have to drop down to a standard Performer for that.
Wasn't able to mess with the boat on Saturday, went out shopping for computer memory, and ended up with a new tower, also. See "How do you post pic's on Hot Boat" thread in Sandbar. This old POS computer has been kicking my a$$. Planning on running the boat today, and checking fuel press.

[Sir Psycho Sexy]

When you replaced your intake, are you sure you dropped the distributer back in on the right tooth. All of your symtoms sound like A timing problem, or A bad vaccum leak.

[Moneypitt]

The fuel pressure must be read at WOT for a while. Idle pressure means nothing, WOT till it lays down, THEN look at the pressure...........MP

[malcolm]

I think I'd do whatever I had to, to get that carb on there the right way. Does it at least sit on a wedge to tip the front side (of the carb) up?
Where have you been taking the boat to run it?

[Tahiti350]

Sir P.S..
I've double checked for vacumn leaks, and yes, the distributor is in right. I've chased that circle about 3 times. a vacumn leak should show under any condition, including idle (higher vacumn than at WOT).
Moneypitt,
It lays down immediately on tipping the secondaries in (everytime), but if I roll back slightly (back to just the primaries) it runs smooth, strong, and clean. You can feel it rough up at the transition point, like the secondaries aren't getting fuel. If the press was low, or there was a flow problem it should take a second to rough up, and should also take a second to recover afterwards. Not real keen on making a run to check fuel press after the oil pressure going away last time out, that's why I haven't checked it yet.
Malcomn,
I plan to look and see if I can re-route the throttle cable. It has always worked fine the way it was set up, until the maniofold swap. Switching it around will be easy if the cable is long enough. Still won't be able to try a Q-jet as the Performer RPM is a square bore manifold.
But all the above might become a moot point as I am seriously considering swapping in my Pontiac 400. Just need to find some exhaust manifolds,and build a front mount adapter for the OMC trim system, and want to build a rail mount for the whole thing.

[sleekcraft76]

take the top off and pull the secondary float out and remove the needle and seat "the one farthest away from the fuel inlet" their is a small filter screen attached to the top of the seat .it's probaly pluged up. "been their done that"!!!

[Sleek-Jet]

Did you ever get that book Tahiti??? I sent it last week sometime.

[1978 Rogers]

Gary I have an spacer that matches a Q-jet to a regular squarebore. Do you want it?

[Tahiti350]

Did you ever get that book Tahiti??? I sent it last week sometime.
Sorry,
Thought I sent a pm to you to let you know I got it.., Many thanks.
Still haven't got back to the boat, too many other projects, and the wife always wanting me in the house, in the garage, out behind the garage :jawdrop: :supp: :D . Anyways, trying to get back to it this week.

[Tahiti350]

take the top off and pull the secondary float out and remove the needle and seat "the one farthest away from the fuel inlet" their is a small filter screen attached to the top of the seat .it's probaly pluged up. "been their done that"!!!
Bingo, This sounds like the piece of info I was looking for. I know it's not getting, or not getting enough, fuel, this would explain it!! :) I'm working on the boat Sunday afternoon, don't really care about the game, so no loss. :crossx:
Will let everyone know what I find.

[sleekcraft76]

hope it will work out for you