4150 Holley swap for 1409 Edelbrock on 454 PCM

[Sdc77]

Hi everyone !
I finally did a swap of my old Holley (4160 with vaccum secondary and secondary metering plate). As it has a bad idle, with black smoke and unburnt fuel coming from the exhaust, sparkplugs are black, and mixture screws are tightened at maximum. Hesitation at acceleration as well.

The Edelbrock 1409 started good, just had to tune the idle screw to go to 800rpm.
I put a fuel pressure regulator with a gauge. Initial setup was 4.5 PSI (the factory mecanical fuel pump gives 6.5 PSI), power pump at 2nd hole.
I run at 300ft over sea level, use 90 aki octane gasoline with 10% ethanol (E95 E10 as we name it here).

The idle is ok but as I push the accelerator slowly, it hesitate, sometimes it stalls, and has no power until I go on secondaries. At 20mph it keeps the speed ok.
When I push accelerator quick, it backfires from the carburetor and stalls !
I tried the 3 holes on the pump : 1st it "paffffff" from the carb and stalls, 2nd it "paffff" and keep running if I go slowly, 3rd it stalls.
Went to 5.5 psi on the fuel regulator : no change.
Ignition setup is 8°BTDC @ idle 800rpm (as mentioned in the 454 PCM manual)

The floats are tuned the right way with 7/16 drill bit (I had to ask for new floats to the ebay dealer as the carburetor came with leaking used floats !), ah did I miss the fact that it's a remanufactured carburetor, actually a #9909 from National Carburetors.

It seems that the primary system is too lean for this engine, am I right ?

Is there a difference if the floats are set higher ?

Maybe the mettering rod spring is not strong enough for this displacement engine causing too lean mixture with the 454 intake vaccum ?

National Carburetors propose the kit#1488
On the Edelbrock forum, they propose to go to 10°BTDC

Do you guys have any recommendation for my setup ?

Regards

[michael hunter]

Rebuild the OE Holley and stop trying to change the system with an unknown product.

[Sdc77]

Unknown product !!! Edelbrock !? Come on guys, any inspiration ?
Don't forget that we don't have same Relationship on fuel consumption here. It's twice the price than in the USA. If I can save 30% fuel with an intelligent carburetor, it's tons of money saved at the end of the season.
The Edelbrock has a Metering rod system that saves fuel when no big load is required by reducing the fuel mixture.

Anyway, I already rebuilt the Holley, and still no good performance.

[Wulphie]

I have never seen a Edelbrock carb on a boat but it sounds like an accelerator pump problem, not even sure that they use one but that is what your description sounds like.

You already have the Edelbrock so it is a little late, but the Mercruiser Quadrajet works very well on a 454.

[michael hunter]

By unknown I meant that the carb you have was never made for your Supra . Is it even a marine carb? When the engineers at PCM built your drive train they chose the Holley for a reason . I am a X GM tech and have worked on hundreds of Rochester carbs I know them well but in my boats I stick with Holley. I guess I'm too old and not smart enough to re engineer the boat you might be smarter and younger. I don't believe any carb will give you a 30 % increase in fuel economy. INO if you are looking for fuel economy you bought the wrong boat.

[Sdc77]

Quadrajet was my first thought, but it's a spread bore carb, and Holley/Edelbrock are square bore, means it's a direct fit replacement. A Q-jet needs a square bore/spread bore plate to fit. Many forums says that Q-Jet are difficult to get properly tuned.

Michael, no offence to you, I just try to get a better mileage. Holley was THE solution maybe because they are the simplest carbs to rebuild and they don't need many adjustments, like the metering rod we find in the Edelbrock.
Notice that my Holley doesn't have a spring on the vaccum secondary diaphragm, I don't know why. It has 1 bowl leaking, an unadjustable metering plate on secondary, useless mixture screws, hesitation on accelerations, black smoke, black spark plugs etc.

The 1409 is a marine carb. It's a 600cfm, and some people here already have it on a 454, with no issue. Mine is remanufactured and came with dead floats. I maybe should ship it back to the dealer, but as I'm in France, it will cost me more than finding why it doesn't run the way it should.

Actually my tired Holley drinks 30L/hour at wakeboard speed : 20MPH @ 2200rpm. Some here reports 18L/hour with the same configuration/boat/engine. It's 40% better. Even if I see an economy of 7-8L/hour, it's 400L less per year and 600€ economy (basing on 50h/year).

[michael hunter]

My experience with any store bought rebuilt carb has not been good. When they tear down the carbs they combine all the parts from many carbs together so you don't get the same parts put together again. When I was a GM dealer tech and I learned that every part that is used is there for a reason . As soon as you start changing things you may unknowingly effect something else. I think my brother put it best '' For every action there is a reaction'' It looks to me you changed a bad carb with a different bad carb . At this point I think you should just order a new carb or get a professional involved.

[wotan2525]

There is no such thing as a "bad carb."

There is a dirty carb and there is a broken carb and there is a carb that has the wrong pieces in it, or a carb that is tuned incorrectly.....

I have a 1409 on my 454 and it performs flawlessly. The previous owner is the one that bolted it on (to save gas) and I have no idea if it was straight out of the box or if he messed with it. I've never done anything to it except run gas through it. The edelbrock is easy to rebuild with a kit, but I'm not convinced that your problem is carb related.

Backfiring and paffffff sounds (to me at least) sound like timing problems. Edelbrock have good documents on their website as far as tuning -- but if the boat won't even run, you aren't quite to the tuning stage yet. Are you sure your distributor is on the right tooth on the oil pump? Are you sure that your spark plug wires are in the correct order? Are you sure your distributor is in good shape?

[Sdc77]

Hi Wotan, I was expecting your feeling on it, as I know you run the same carburetor.
I agreed about a bad or at least a badly tuned carb for another badly tuned carb.
Believe me I regret to didn't buy a new one but a remanufactured. But understand me, it was half the price of a brand new one.

I should ask for a refund and send it back to USA. Or maybe try to sold it here in France. I don't know yet, have to think about it.

The ignition seems ok. It's not factory, it's an electronic one. I will probably go for a new HV ignition distributor with new wires for next season, it will be a good start for a good tune of the carburetor.

[michael hunter]

For every good running modified engine there is a hundred good running stock engines. What I am saying is now that you have strayed from the original components you cant get any useful information here because your engine is no longer stock . You will have to keep trying things until you get it working. Wotan lucked out and didn't have any problem yet. But even he cant help much with your problem.

[wotan2525]

Mine is due for a rebuild. It takes a few more cranks to get it to fire when it's cold and it tends to flood once in a while. If I have the time to tear into it this fall I will take you photos and try to help you identify what parts are inside of mine.

[cadunkle]

Nothing wrong with an Edelbrock. I don't care for them and you'll leave some power on the table vs a Holley but just like any carb it should run fine when tuned to suit the engine.

To the OP, you need a larger accelerator pump shot. First verify you're getting a good shot. With engine off look down carb venturis and work the throttle, you should see a stream of fuel come out of the accelerator pump discharge nozzles immediately when you begin to open the throttle and continue as you open it more. If the shot is weak or inconsistent you may need to replace the accelerator pump. On an edelbrock it's typically a small cup on a plunger, you can replace the whole shebang or just the rubber cup. If the shot only begins after moving the throttle a bit you need to adjust the linkage so it begins squirting fuel immediately when touching the throttle. If all that looks goo you need a larger shot, the holes in the accelerator pump arm closest to the pump plunger/main body should give the largest shot of fuel, try that one. If that doesn't help then you need larger accelerator pump discharge nozzles. Not sure how they are sized on an Edelbrock but go up a few sizes since it's stalling and not just stumbling.

[Sdc77]

Thanks for answers guys. I will first open the carb and check if the jets, metering rods and Accelerator pump are the good ones on the original 1409; As the carburetor is a remenufactured one, came with dead floats, and came polished ! The 1409 should be shiny silver treated. I Wonder if it's a 1406 with a marine sticker on it. It could explain why it's too lean on accelerations. The 1409 should have bigger jets/metering rods and a power pump with bigger discharge. I will check it tomorrow and let you know.

Anyway, I still Wonder if I keep it or sold it. Pros and cons ?

1409 Edel : I like the fact that it is a mecanical secondary. I know when I'm on secondaries and drink alot of fuel.
I like the metering rod system that reduces fuel consumption when there is no big load
I don't like the fact that it is not working actually on the factory configuration

4160 (not 4150 as mentioned in the thread title) Holley : I like the fact that it works ! lol
But : it's leaking, there is a missing spring in the secondary, it burns tons of fuel, and burns it bad regarding the smoke, smell and sparkplugs looking
I don't like the metering plate on the secondary, making it impossible to tune.
I don't know what to think about a vacuum secondary VS a mecanical ?

[michael hunter]

Sounds like your Holley has a blown power valve or a leaking float? As I said before when they rebuild the carbs they do a bunch of that model at the same time . They just combine all the parts clean them and put them together . You never get the same parts combination as the original. There is no way to know if its even the correct carb for your boat?

[Sdc77]

Hey Guys, I didn't find time yet to open the carb, but I find a photo I took when the floats were leaking, to send to the carb dealer, and look what I found :

http://sdch2o.free.fr/perso/bateau/supra/1409-01.JPG

The Accelerator pump on the left of the picture is blue. It should be Brown on the 1409 : http://www.summitracing.com/int/parts/edl-1471/overview/

The blue one is for cars application.
I will open it soon, and I'm almost sure that it's a 1406 (for cars) with a marine sticker on it, a 3/8 in. inverted flare fuel inlet fitting, and no ported and full time vacuum ports.

I will try to figure out what is the most inexpensive solution between send it back to the dealer or trying to put back together the good parts in it.

http://sdch2o.free.fr/perso/bateau/supra/1409-02.JPG

[michael hunter]

Is that a temporary fuel inlet ? rubber hose is a big nono on any application especially on a boat.

[SUPRA_ALLEGRO_LANE]

Is that because of the Heat?

[michael hunter]

No its because of the possibility of leaks . Rubber hose is easily cut by sharp components, pulleys, belts and can also be burned by hot engine parts. NO manufacture of marine engines will use rubber hose on an engine.

[Sdc77]

It's not temporary, we don't have US cost guard here, we can do what we want on our engines. I had to cut the factory fuel inlet, on Holleys it's on the front of the carb, on Eldelbroks it's on the right side. Then connected a rubber hose, as It's like that on almost every car's engine.
I always open the engine compartment before I start the engine, to evaporate fuel vapors, to check everything and to listen to what my engine has to say. There is no fuel leak.

The 2 PVC hoses were temporary. I have now a PVC port on the front on the carb (like on Holleys), and I can put back the flame arrestor where the second PVC is connected. I could'nt fit it directly on the Edelbrock, it needed a spacer of 0.75''. So I ordered the spacer, the port, a fuel pressure regulator + gauge.

[michael hunter]

This is a typical armature attempt to try and outdo the engineers that made it. There is a reason for every part on your boat . If they could get by with rubber hose they would if the Edelbrock was overall a superior carb then why didn't they use it? Your workmanship is poor in this country we would call you a hack. And then you try to justify your dangerous modifications by saying there are no rules to comply with. Its too bad there is nobody there to guide you . In the end you will have a worthless POS that nobody can fix.

[haugy]

It's not temporary, we don't have US cost guard here, we can do what we want on our engines.

I know you're limited by what you can get for parts over there, but just because you can bypass or rig something up, doesn't mean you should. You are creating a very dangerous situation for yourself and any passengers you bring aboard. I know you are good at creating things on a whim with things you have laying around, but when it comes to fuel systems on an enclosed engine hatch, you can't take shortcuts with parts.

As Michael is trying to tell you, you need to get the right parts to make it run well, and get the right components to keep it safe as well. I don't want to see a post from you one day with a picture of the center of your boat all burnt up from fire.

Pull that carb off as it doesn't look like a Marine Carb at all, no overflow tubes going into the carb. And get a good marine grade carb.

[Sdc77]

Guys, no offence to anybody, I will just explain my point of view.
I use this boat every day or so, doing wakeboarding.
I will not reinvent the whell, I just try to improve my entire setup (tower, hifi, engine etc.), because I like it. I like to make things going better than factory. Ok I'm probably wrong with the remanufactured 1409 Edelbrock (maybe a new one would worked just perfect without issue).
I choose it because I read alot about it and it looked to save gas.

I'm not a "like factory" man, I dream of a 67 convertible Mustang, I probably will get one in few years and be sure I will modify many things on it (breaking system, engine, interior etc.)

I got this boat and I love it. It has already been modified by it's previous owner : There is an electronic ignition from mercruiser, a front crank water pump, car battery (I had one more, still car's).

I'm ok there is a risk with the rubber hose on carb, but, I have no belt on this side of the engine, because of the crank water pump. I've done it few times on other boats because the solid hose was leaking, never had any issue. I will check for a new one on the Holley and one for the Edelbrock, but if I can't find it, I will leave it this way, as it works just fine, and every car is this way.

The Holley is back in place since the first day I was not happy with the Edelbrock. I will buy a rebuild kit and a spring for the vacuum device. I'm also planning to put a spacer between exhaust manifolds with a oxygen sensor + O2 gauge to can perfectly tune the Holley.

Marine parts are twice the price of car parts, and difficult to get here, so I put as much car parts I can. I put marine parts when it's really needed, like marine carb, marine speakers, every other hifi parts are from cars. It's now 3 years without issue. Idem for my car's batteries.

The solid hose will probably cost me something like 50$, I just try to find a cheaper solution, keeping in mind safety and good performances.

I will end this season this way and will let you know what I decide this winter regarding carburetors on my boat.

Thanks again for your help and advices guys

[lively]

http://i1189.photobucket.com/albums/z433/lively86/Mobile%20Uploads/2014-05/6115FC00-F8DD-4E0D-BD84-D8B97EA2FE94_zps1q65xrqk.jpg (http://s1189.photobucket.com/user/lively86/media/Mobile%20Uploads/2014-05/6115FC00-F8DD-4E0D-BD84-D8B97EA2FE94_zps1q65xrqk.jpg.html)
That's a 650 cfm edlebrock marine carb , bolted up and adjusted the idle and that was it . Make sure your CFM is correct , to big of a carb the engine will load up . Too less it will run too lean . Both would cause your issues . But please don't run auto carb on inboard with closed hood . Jet boats and open engine bay style boat would be ok but your asking to seriously hurt yourself or someone else with those vapors . Do you have auto plug wires ? If you do start it at night and watch the fireworks against your block and other grounds . May not happen now but why take the risk .

My two cents .


Happy boating

Sent from my iPhone using Tapatalk

[Sdc77]

Thanks for advises lively.
I'm also happy to see that I'm not the only one running a rubber hose to the carburetor ...
Some here have good results with the #1409 600cfm on the 454 with no issue.
My carburetor is actually a marine one, but remanufactured. Means as mentionned by Michael hunter that it has been rebuilt with average parts, including car parts, as the Accelerator pump.

I just put the carb for sale on our Craigslist. Will see if it goes. If it does, I will properly rebuild the Holley and try an oxygen sensor system to tune it the most efficient I can.

I don't know if the spark wires are automotive or not. Assuming yes, I never saw any spark Under the Hood.

[lively]

You needed a 650 for the 454 , not enough fuel , I broke my hard line from pump to carb . Although once I get a flaring tool I'll go get some brake line and bend it and make a new one . The edlebrock works great with my setup . And I just got tired of messing with my holley and keeping it from leaking from secondaries . But I later found a cracked booster so replacing was a good choice . Good luck


Sent from my iPhone using Tapatalk

[Zim]

I got this boat and I love it. It has already been modified by it's previous owner : There is an electronic ignition from mercruiser, a front crank water pump, car battery (I had one more, still car's).

I'm ok there is a risk with the rubber hose on carb, but, I have no belt on this side of the engine, because of the crank water pump. I've done it few times on other boats because the solid hose was leaking, never had any issue. I will check for a new one on the Holley and one for the Edelbrock, but if I can't find it, I will leave it this way, as it works just fine, and every car is this way.

The Holley is back in place since the first day I was not happy with the Edelbrock. I will buy a rebuild kit and a spring for the vacuum device. I'm also planning to put a spacer between exhaust manifolds with a oxygen sensor + O2 gauge to can perfectly tune the Holley.

Marine parts are twice the price of car parts, and difficult to get here, so I put as much car parts I can. I put marine parts when it's really needed, like marine carb, marine speakers, every other hifi parts are from cars. It's now 3 years without issue. Idem for my car's batteries.

The solid hose will probably cost me something like 50$, I just try to find a cheaper solution, keeping in mind safety and good performances.



That's great and all that you like to modify your boat, but you need to do it safely, or don't do it. Cars are very different than boats, because in a car, the engine is housed in steel with a firewall between you and any combustion that could happen. You still see cars on the side of the road with their engines on fire due to bad parts. Just because most cars are this way, doesn't mean they're immune to the dangers associated with fuel leaks and vapors.

Boats, on the other hand, are made of fiberglass. Fiberglass is like a fire's best friend. Boats go up in flames in a matter of seconds in the fire catches the right parts. That's the reason the US Coast guard mandates fuel system safety the way they do. They don't do it to make it a pain in the ass to get parts, they do it because it lowers the risk of death.

As for opening your engine cover, that's great and all, but if you don't have a blower in there just opening the hatch isn't going to do anything. Gas vapors are heavier than air... this means they don't escape when you open the hatch because they sit in the bottom of your bilge. This is why a blower is placed low in your bilge area, to suck the gasses out that fall low in the bilge.

To be completely honest, if you're not willing to spend 50 bucks on a fuel line that prevents your entire boat from going up in flames, then you need to prioritize a bit. Spend the money on parts that save your life, not on audio equipment with stainless screws that prevent corrosion.

[cadunkle]

This is a typical armature attempt to try and outdo the engineers that made it. There is a reason for every part on your boat . If they could get by with rubber hose they would if the Edelbrock was overall a superior carb then why didn't they use it? Your workmanship is poor in this country we would call you a hack. And then you try to justify your dangerous modifications by saying there are no rules to comply with. Its too bad there is nobody there to guide you . In the end you will have a worthless POS that nobody can fix.

As for using an Edelbrock carb and the whole engineering bit... That's nonsense, plenty of marine engines have used AFB style carbs over the years. They are not my personal preference but technically they can meter fuel more accurately than a Holely as they are capable of variable enrichment based on load vs Holley on/off enrichment. Minimal if any gain in a boat IMO because the load is always high, not as moderate or variable as in an automotive application.

As for the rubber hose, bad idea on the pressure side. Just pick up a length of preflared brake line and bend to fit. Cheap and easy and then no worries about leaks or fires. Rubber works in a pinch but I wouldn't be comfortable running it long term. Too risky, especially considering hard line is so cheap and easy.

[Sdc77]

Hi guys. I just sold the Edelbrock. I will rebuild the Holley this winter and of course a new solid fuel line ...