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Discussion Starter #1
Been reading up on carbs a little and wondering if a Holley double pumper would be fun to try out on my car or if it'd be overkill.

Here's my setup:

383 stroker
9.5:1 compression
234/238 @ .050" w/ .539 lift w/ 112lsa cam (full roller)
RPM Airgap intake
Edelbrock 800 AVS carb
Pertronix HEI ignition
TH350 trans, shift kit, 2200 stall
3.73 posi
3400 lbs w/ me in car

Typically drive the car on the street on weekends/summertime and take to the track a few times each summer to make some passes (maybe 10 passes a year).

Based on everything I've read it seems like I would need vacuum secondaries. Yet I see/hear all the time people switching to a double pumper and loving how their car runs/responds with it. I know that mileage would suffer if I stepped into it a lot, but seeing how I only drive the car occasionally on weekends/summertime thats not too big of a deal.

I always read about how Holleys outperform Edelbrocks and stuff, but I've always stuck with Edelbrocks on my car and have had good luck with them. Just wondering if I'm really leaving that much on the table running the Edelbrock 800 AVS vs a 750 DP or other version of Holley carb (i.e. 770 SA, 750 VA, etc)

Car has run a best of 12.66 @ 110.8 mph in 2,242 ft DA with a sad 2.02 60 ft time due to low stall speed. Looking to get a 3500 stall for next year if funds allow to get my 60 ft time down. Car did not bog or spin off the line, just lazy.

Anyone else out there switch to a DP and love it or was it a disaster? Would love to hear your stories. I've never run a Holley style carb before but am willing to try it out if it would be beneficial.
 

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gas mileage will go down dramatically around town, but the performance will go up...

i took off my 750dbl-pmpr and installed a VS carb and the performance dropped a little but my fuel mileage almost doubled...
 

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Discussion Starter #4
Yeah I think you're right, the car really needs the appropriate converter more than a different carb.

I always hear stories of people dropping two tenths or more by switching to a double pumper over a vacuum secondary at the track. Any of you guys experience this firsthand on your car or no?

But the car is mainly a street car, so I guess I should be sticking with a vacuum secondary style carb anyway.
 

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I run a double pump on my car with an auto trans, and it does suck up the fuel more than the vac sec. I am going to put one of my 780 3310-1 carbs back on it when its back from paint. I don't plan on taking it to track that much anymore, and the fuel savings will help.
 

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Discussion Starter #6
Does your car run significantly better with the DP on it over the VS or is the difference negligible?

I'm sure cruising around on the street and drinking extra gas when you dont need to does get old after a while.

I finally got my carb tuned pretty good (outside of my occasional stalling issue at stops) and I got some really good mpgs out of it taking it to work and back the other day. As long as you dont step into it too bad its actually pretty good.

Unfortunately, until I get this one issue worked out its looking like a new carb may be in my future. But we'll see.

Sounds to me like I should be sticking to a VS carb since I use it on the street primarily. Would be fun to swap on a DP carb at the track after a pass with a VS carb and see the difference that same day/same track, etc.
 

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Does your car run significantly better with the DP on it over the VS or is the difference negligible?

I'm sure cruising around on the street and drinking extra gas when you dont need to does get old after a while.

I finally got my carb tuned pretty good (outside of my occasional stalling issue at stops) and I got some really good mpgs out of it taking it to work and back the other day. As long as you dont step into it too bad its actually pretty good.

Unfortunately, until I get this one issue worked out its looking like a new carb may be in my future. But we'll see.

Sounds to me like I should be sticking to a VS carb since I use it on the street primarily. Would be fun to swap on a DP carb at the track after a pass with a VS carb and see the difference that same day/same track, etc.
I feel like it pulls harder with the double pumper when I mash the go pedal, but I use to take it to the track 3 days a week back then.
 

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I use a double pumper and love it. I mean how good is your gas mileage now anyways? I know I didn't build my car for gas mileage. I built mine for abuse and having fun so I wanted to get all I can out of it performance wise so I went with a DP. jmo

Did you get your stalling issues squared away?
 

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Discussion Starter #9
Haha thats true. For as much as I drive the car mpgs really dont matter. Its a weekend car that I drive in nice weather and take to the track a few times a year.

Nope, still stalling out. Thought I had it fixed. Drove it to work Wednesday, drove it there, to lunch, and then back home with no problems. Parked it in the street for a bit at home, went to move it an hour later to pull it in the garage, started stalling out again in gear. Did it three times before I got into the yard. Looked down the carb, throttle blades wet again with fuel.

Called Edelbrock, he said to lower the floats from 7/16" to 1/2". I've had the carb apart a few times now to make adjustments and every time it just seems to get worse.

I've had good luck with them in the past, but Im definitely having some bad luck now. Maybe I just goofed something up, the carb runs pretty good other than that.

I'm wondering if a Quickfuel or Prosystems carb is overkill for my car or if I should just stick with an off the shelf type carb. I'm going to try and get this one to work first, but if I cant get it to work soon, I'm ready to try something else.
 

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With the carbs you mentioned and even with a holley. I personally think you will be able to get a little more out of your car than the eddy.

7/16 is smaller than 1/2 right? Doesn't make sense. I personally would lower the floats to much on purpose to see what happens.

My friend has a VS 750 holley and when we cruise his car and he floors it he says to me there are secondaries opening up, hear them, and it seems to me they open up really late compared to DP. And he has his car dialed in to the "T"

Compare to the DP its just go, go, go.

Sounds to me like your needle and seat are dirty.

I took the old needle out and would do the test where you put the needle horizontal and slowly move it to vertical and see if it was sticking and to me it seemed ok, but I still put a new one in and bingo. I would turn the car and go look at the carb and fuel would be dumping in the 2ndaries.
 

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Discussion Starter #12
1 am is nothing, after I went to bed around 1:30, my daughter woke up and she wouldnt fall asleep totally until around 3 am. Changed her diaper and held her for a bit and she was asleep. So I'm operating on a few hours of sleep today, but thats just how it goes sometimes, no big deal.

Thats what everyone else says. I like the Eddy because I'm comfortable with it and have used them before, but now that I'm having problems, I'm about ready to try out something else.

1/2" will actually lower the floats more since it is the distance from the top of the float to the top of the airhorn. The closer they are, the more fuel in the bowls, the further they are, the less fuel in the bowls.

Could be dirt in the carb. It doesnt flood out completely though. When I shut the car off, there is no fuel coming out of the boosters, its like it much just dribble over enough while running to stall it out in gear or something.

I checked mine for movement as well and they both moved freely just fine. Its possible there is some crap in the little screens in front of them though, or maybe in the float bowls themselves.

Whatever it is, its really screwy. The car starts up really easy, runs good, drove it to work and back with no issues, but then it started doing it again at home. Its just frustrating because I thought I had fixed it, but it appears its still an issue. I'm not that good at diagnosing things either, I can bolt things on but far from a great mechanic.

Anyway, its not the end of the world, I'll figure it out, thats just how these cars are sometimes, always something.
 

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I have a 750DP on a similar setup to yours.

zz4 with fastburn heads
air gap
750 DP
Lunati 60122 cam
Duration @ .050 (Int/Exh): 231/239
Gross Valve Lift (Int/Exh): .535/.550
LSA/ICL: 110/106
Valve Lash (Int/Exh): Hyd/Hyd
RPM Range: 2400-6200
Stall 2000 TH350
rear end 3:90's

With the stall that is in the car and the amount of vacuum produced tuning is rough.

The DP likes having a stall, it has a small hesitation while it waits to build RPM"s. It runs like an animal from 3000 RPM + getting to 3000 is another story. When we were tuning it we dis connected the rear squirters and the car was much more responsive on the streets.

By putting a DP on your car with your limited stall you're not going to gain much if anything you're going to be spending hours trying to dial in the Holley.

Id put a 3000 or 3500 stall in and see how the edelbrock responds. Also if I had to do it again I would order a custom carb from Pro etc.
 

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Discussion Starter #14
Thanks for the input! Sounds like a double pumper might not be a good idea for my current setup then.

I get about 16" of vacuum in park and around 10-11" in gear. This is running vacuum advance at manifold to bring it in at idle. Without that I'm sure it'd be a little lower (running 10* of vacuum advance).

The car definitely needs a better converter to be optimal. Most converter companies I called recommended anywhere from 3200-3800 in a 10" converter.

However, both my dad and my wife have been trying to get me to splurge for a new front disc brake conversion next year instead of the converter. I have manual drum brakes all around and it doesnt stop all that well. It does ok for what it is, but it would be nice (and safer) to have some better brakes. Now that my daughter is getting a little older, in the next year or two I might be able to take her for rides in the car, and would rather have better brakes than a better converter.

So the converter idea may have to wait a year or two now. If it were just a drag car I'd do the converter and double pumper and call it a day, but its 95% street and I like to drive it around so that may have to be on hold for a while.

I think the issue I'm having is a flooding issue at idle. The throttle blades should NOT be wet after shutdown, especially if its been idling in gear for a while. I never see fuel dribbling in after I shut it down, but maybe its doing that while its running.

I've lowered the float levels to 7/16", and my needle and seat assemblies looked nice and clean when I checked them. Its possible the fuel is boiling over in the bowls. I used to run a 1" spacer but now just run the 1/4" heat insulator gasket. I never have issues with vapor lock, car restarts immediately after stalling, but fuel just seems to keep getting in there at idle.

I'm leaning towards:

1.) Fuel pressure too high (maybe need to lower it to 4 or 5 psi from 5.5 psi)
2.) Pinhole in one of the floats (haven't checked this yet)
3.) Dirt in carb somewhere (its only two years old though)
4.) Fuel pump is acting up

I'm going to see what I can do with the current carb since I've already got it and stuff, but if I can eliminate this stalling crap then I think I'd be pretty happy for a while.
 

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Your listing! (rare in most cases)

Take the advise and do the brakes. The brake upgrade on my 70 has been and still is the best investment ever on my car. And everyone I do installs, no one has ever regretted spending the money for the safety.

Do to popular internet scuttle butt the Holley is a great carb. Yes, your leaving performance on the table with the Eddy.

Mileage can easy be matched or even better with a Holley. 95% of the time Holley right out of the box is good.

The DP illusion is the same as the Rochester WOOOOOP! It feels good, but your not going anywhere, your just making noise. (Don't get me wrong, when everything is right, the DP can with correct vehicle setup be the more HP.)

The Holley 3310 750VS secondary carb did not make the top 10 performance parts of all time by accident. It is a very affordable carb with great results. And Holley offers them NEW at a very economical price.

http://www.summitracing.com/parts/HLY-0-3310C/

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this is a 406 on Dyno 750VS 3310C compared to a 750DP Carb.
When installed in the vehicle it took a converter change to make it work in the car. And fuel mileage dumped! I mean dumped hideous 10 mpg.
the car worked perfect with the VS with the 2200 stall.

So be careful what you wish for. :yes:



 

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Discussion Starter #16
Thanks for the input! Yes I think its time I finally stop spending money on making the car faster and spend some money on making it safer. I never gave a crap when I was younger, but now that I'm older and have kids and would like to take the kids for a ride now and then, it only makes sense.

Any particular front disc brake conversion kits that stand out from the rest? I have little to no knowledge on them. I'll definitely do my own research soon, just wondering your thoughts for now.

Gotcha on the DP and Q-jet sounds. I'd rather just get up and go than make a bunch of noise.

I've always run Eddy style carbs in the past because my engines were normally stock or close to stock, which they run awesome on those engines. Now that my car is a little more modified, I"m wondering how much I'm leaving on the table with the current Eddy carb.

I'll take a look at the Holley 3310C online. I wouldnt mind doing a carb swap next year just for fun to see what kind of difference I end up getting at the track and on the street with the Eddy vs Holley carbs.

Do the Holley Street Avenger carbs seem good at all or no? I was looking at the 770 cfm version just for fun, some guys seem to really like them, while others seem to have bad luck with them. There is also a new one out called the Ultra Street Avenger, but its quite a bit more (around $500 or so).

I was at Milan Dragway this weekend for the NMCA Nationals. Walked around in the pits, talked to quite a few guys, what they were running, what carb they ran, how they liked it, etc. Almost everyone there had a Holley or Quickfuel (the guys running in the 12.0 class anyway). Not one Edelbrock on there that I saw.

Of course my car is primarily a street car, but I see quite a few street cars with Holleys as well. I think I'm to the point now where I'm ready to experiment with something else, so I'll check the Holley 750 VS out. Maybe I'll bolt one of those one later this year before I run it again to see what it does to my ET.
 

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Discussion Starter #17
Al,

Can you get a 3310 with an electric choke or no? I looked around on Summit for a while but it looks like they're all manual chokes.

I've got an electric choke right now which is great, would like to keep that if possible. I'm sure Holley has some sort of add-on, just wondering if you can get them brand new like that or not.

I have an old Holley at my parent's house sitting on my old 307 engine, wonder what model that one is? It ran like crap on my stock 307, was probably too big for the engine and may have been old and needed a rebuild. Probably better off just getting a brand new one though.
 

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Avenger series carb is a great carb.

They will have electric choke, dual jet plates, and secondary vacuum chamber with easy change spring access.

The 3310, yes they have a electric choke kit. Price it out. The avenger, you get more for the money. It's all on your budget.


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I use RightStuff brakes kits now. I did in the past use MPbrakes.

Right Stuff has excellent customer service and the kit is complete right down to the carter keys. And priced very reasonable. Quality kit.
www.getdiscbrakes.com

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95% of carb problems are something else and 75% of the time is a timing curve issue!

FYI
Al
 

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Discussion Starter #20
I was checking out the 770 cfm Street Avenger, looks like a nice carb. I notice they have a regular Street Avenger for around $400 and then an Ultra Street Avenger for around $500. Didn't really understand what the differences were between the two though. Both seem like they'd be a good fit.

I'll have to check into the RightStuff brakes, sounds good. It would be nice to have decent brakes in that car after all these years of driving around with manual drums all around, haha!

I think I have a carb problem with my current carb as the throttle blades are wet after it stalls out in gear sometimes when warmed up. Seems like fuel is getting in there somehow. I've tried lowering the float levels, checked the needles and seats, adjusted the idle mixture to max vacuum, made sure fuel psi was correct, etc. Still stalls out in gear sometimes at lights, etc. I'm running 16 initial with 16 mechanical all in by 2800 RPM with 10 vac advance on top of that hooked to manifold. The car runs great outside of that stupid problem. Running short on time this week, hope to look at it some more this weekend. We'll see.

I'll have to check into the other Holley carb too. I went by my parents today and picked up my old carb, turns out its an 1850-3. Not sure what that is, I'll have to look it up. Its pretty ancient looking though, would need a complete rebuild before even attempting to use it again. Figured it might be good for me to look at how things are setup on a Holley since I'm only familiar with Edelbrock carbs.
 
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