Need different carb for street on 408

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aengineguy

aengineguy

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Please help me choose a new different carb. Problem is that I have a Holley 750 HP, which has no choke and it takes about 3 starts to get it warmed enough to keep it running good. After about 2 minutes its fine and I am very happy with it. I would like to stay with the performance, mainly street at this time. I am pondering a Holley 870 Street Avenger (vacuum secondaries and choke), but don't want to serious diminish the instant response I have now, i.e. vacuum secondaries. Here are my specs....

Thanks for your input!!

1971 Dart Swinger with 408
Edelbrock Magnum Heads fully CNC ported by Hughes, 2.08" intakes, milled back to 58cc chambers. Around 300 cfm @ .600 lift
10.65 static compression
Hughes Solid Camshaft
Intake Lift .610
Exhaust Lift .614
Intake Duration @ .050 valve lift 252
Exhaust Duration @ .050 valve lift 256
106 degrees Lobe separation angle
Port matched Edelbrock Air gap Intake
750 HP Holley double pump Carb
TTI Industries 1 7/8 Headers
TTI Industries 3" dual exhaust with X pipe to the rear bumper
Mallory Magnetic Breakerless #42 Distributor
Mallory Hyfire 6AL Capacitive Discharge box with rev. limiter
Edelbrock 160 GPH pump
-8 AN lines to regulator and -6 AN to carb
John Cope built HD904 Torqueflight
Manual Shift Reverse Pattern
Kolene steels
Red Alto Clutches
PTC 3600 rpm torque converter
Moser 8 3/4 nodular center section with Richmond 4.10's and Moser Alloy axles
Should weigh around 3100-3200 with me
 
Wow, that is one hell of a street engine. My 408 is a little bit milder than your''s and I'm running a Pro Systems Pro Series XE, based on Holley HP Series Carb. I love the performance of the carb so I just live with the short warm up time. But my 408 has an LD-340 intake and 4-speed so it's easier to deal with the warm up.

Here's a link to the Holley 850 Street Strip Carb, List#0-4781S, this may be closer to your needs, but that's just my opinion only.
http://www.holley.com/0-4781S.asp

Or you can shop around the Holley web site: http://www.holley.com/division/Holley.asp#1

I'm happy with the Holley because I know how to tune them, but I'm sure there will be different opinions from others.
 
Thanks Demon,

Yup, this thing is a beast. With the big bump stick, the idle sound is incredible, and so is the performance. Zero hesitation, Zero traction! I have been a Holley dude for over 40 years and have had the 4781's and so forth, but they are spendy, guess I was trying to save a couple of $$. Thanks for your input, may just consider the 850!
 
I have a question for you. Since you have the 750 on it now and love it all to death minus the warm up issues, why not run the 770 avenger?

I say this because you said you don't want to seriously diminish the instant response that you now have.
 
so the 750 HP you have now has no choke? Has the choke tower been milled off, or is the choke simply not hooked up? Why not stick with the same carb, if your car runs good with it, and get a choke back on it, even if it means replacing the main body for one with a choke? You can find main bodys on ebay pretty cheap.
 
Rumble, that is an option. I thought I had run across others running the 870's on their 408's and had good luck. With either of the vac sec carbs, will probably have to play with the secondary springs. Will consider.....Thanks!
 
Thanks fanofpetty,

The 750HP is made without a choke or horn at all. I still want to keep the 750HP for whenever I get this thing to the track since I have rejetted and put different power valves in it.
 
oh ok, thats exactly what I am doing.....I have a 750 HP for the track (no choke), and I run a 770 street avenger on the street. I do love the street avenger.
 
So what is wrong with having to use your foot to keep the engine running while it gets warmed up enough to sustain idle? With that combo those 2 minutes should be plenty of enjoyment as you get ready to hit the street.

I was playing with using thinner oil in my 416 as I suspect that is the reason it didn't like idling when first fired up.
 
I see no issues with what you're claiming. Most have to do this anyways. Why waste the money?
 
airwoofer said:
So what is wrong with having to use your foot to keep the engine running while it gets warmed up enough to sustain idle? With that combo those 2 minutes should be plenty of enjoyment as you get ready to hit the street.

I was playing with using thinner oil in my 416 as I suspect that is the reason it didn't like idling when first fired up.
Click to expand...

x2
 
It won't run like it does now with a vac sec carb on it.

If you like the way it runs after it's warmed up, accept the fact you have to use your foot as the choke to keep it running for those 2-3 minutes.
 
Thanks guys.....

I guess I just am not wild about running the thing at around 2200-2500 when it first fires. Anything below that and for that first couple of minutes it quits. My garage is part of the house and I like to move it out pretty quickly so as not to fume it up. I like the unburnt hydrocarbons, but the little redhead is not too keen on it. Also, I kind of live in a neighborhood that is really not too conducive to 500+hp cars throttling up and down, for any period of time.......THEY JUST DON'T GET IT! ...and yes I do have full dual 3" sewer pipes to the bumper. I would like to live about 1 mile from everyone......but that won't happen, at least for a while.
 
I'm sure you drive this every day. Your neighbors need to be more tolerant, 2-3 minutes out of the day, REALLY? I'm sure you aren't out there warming up at 2am. I bet the UPS delivery trucks really tick them off.

Wonder if they wouldn't mind so much if it was a Ferrari or Lambo warming up. sheesh.
 
I hear ya Cracked....

When I broke in the cam, I went around and talked to my closest neighbors and told them that I was going to be making some noise for a while, just didn't want to piss someone off. Some of the guys, said do it whenever you want, music to my ears.......then some said, well ok. THEY JUST DON'T GET IT!

Like you said.......sheesh!
 
i know just what your talking about. i live in a upper middle class, blue collar neighborhood. you would think that people would be able to handle a little bit of noise. **** my neighbor has 6 kids all less than 16 yrs old and 4 dogs. they are always kicking and screaming and she gives me the stink eye everytime i fire up my dart.
 
aengineguy said:
I hear ya Cracked....

When I broke in the cam, I went around and talked to my closest neighbors and told them that I was going to be making some noise for a while, just didn't want to piss someone off. Some of the guys, said do it whenever you want, music to my ears.......then some said, well ok. THEY JUST DON'T GET IT!

Like you said.......sheesh!
Click to expand...

You sound like me. That's good about letting them know regarding cam break in. It's not something you normally do every day.

I let my neighbors know if there is anything I'm doing that needs addressing, let me know. Got sick kids and I'm beating the snot of and grinding metal, tell me, I'll shut it down. Always another day. All you can do is be considerate and hope for reciprocity.

If they already know you have the car, I wouldn't be one bit concerned with warming it up. If they call the police, so what. Be cool with the PD, tell them you are warming the car up on high idle and it last 2 or so minutes. I always throw out the Ferrari/Lambo thing and how they likely wouldn't mind if it was one of those cars. Usually gets a chuckle. Most of the time the PD will tell the complainer you are doing nothing wrong and please don't call again about this issue.
 
Fst73_360 said:
I see no issues with what you're claiming. Most have to do this any ways. Why waste the money?
Click to expand...

airwoofer said:
So what is wrong with having to use your foot to keep the engine running while it gets warmed up enough to sustain idle? With that combo those 2 minutes should be plenty of enjoyment as you get ready to hit the street.
Click to expand...

crackedback said:
It won't run like it does now with a vac sec carb on it.

If you like the way it runs after it's warmed up, accept the fact you have to use your foot as the choke to keep it running for those 2-3 minutes.
Click to expand...
FST-73, his money to waste or not waste. Why bring that up like your his dad? Saying most do it anyway doesn't make it right or desirable for him as well help solve the problem. If he feels like spending the money, so be it. You go horde your money and worry not about everybody else's.

Airwoofer, I think it just a Convenience issue. Turn key and walk away, or not. Maybe just sit and relax the foot and talk instead of tickling the pedal as needed. Hot Rod or not, it is nice just to turn a key and let it run on it's own.

Cracked, I think your 100% right on this.

My question to you all present here is;

Do you think that my 770 Avenger thought was OK?
 
Heres a question on top of his question. I have always wondered if a two step box could be used for this. Fire it up and throw a little advance at it so it idles up till it gets warm,then dial it back where you want it and go. Would this work.
 
rumblefish360 said:
FST-73, his money to waste or not waste. Why bring that up like your his dad? Saying most do it anyway doesn't make it right or desirable for him as well help solve the problem. If he feels like spending the money, so be it. You go horde your money and worry not about everybody else's.

Airwoofer, I think it just a Convenience issue. Turn key and walk away, or not. Maybe just sit and relax the foot and talk instead of tickling the pedal as needed. Hot Rod or not, it is nice just to turn a key and let it run on it's own.

Cracked, I think your 100% right on this.

My question to you all present here is;

Do you think that my 770 Avenger thought was OK?
Click to expand...

When you come to a "Public Forum" and ask for "opinions," I am pretty sure I am allowed to do that. For you to come in and make a big issue out of it makes no sense at all. Who's acting like someones father now, which you're not even close to being in anyway shape or form. Now you have just made this go completely sideways when it could have been fine. I am sure there are hundreds of threads on here where people come in and say "don't wast your money" for things like headers or going with one thing over something they already have like from one intake to another. Maybe YOU should have realized that I was trying to help and not "be his father," :banghead:
 
ya I totally feel you on all points. I dont run chokes on my car and go through that same thing every time gets kinda old for me also
 
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