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Carburetor size question #423519 07/29/09 11:59 PM 07/29/09 11:59 PM
Joined: Feb 2009 Posts: 10 East Bay Area B Bladeruner69 OP member
Bladeruner69 OP member B Joined: Feb 2009 Posts: 10 East Bay Area	Hey guys, while my soon to be 496 stroker is at the machine shop, I am trying to gather to parts to complete so that I can finish it and drop it in when they are done with it. I would like a solid flat cam with something like 250/259 degrees duration @.050. This will be going in my '69 B-body with 4.10 gears. It will be mostly a hot street car with an occasional 1/4 mile run. My question is what carb would you recommend for this set up(Performer RPM) intake. I have been looking at the Holley 950hp but think that it might be a little race oriented and it has mechanical secondaries. The Street Avenger 870 would seem to be more of the correct type of carb but I dont know if it flows enought for an engine of that size. What are your thoughts? Also how about a cam recommendation. The car currently has a 727 trans but i am trying to finance a 5 speed manual.

Re: Carburetor size question [Re: Bladeruner69] #423520 07/30/09 12:11 AM 07/30/09 12:11 AM
Joined: Aug 2006 Posts: 1,609 Southern Cal Noblewk top fuel
Noblewk top fuel Joined: Aug 2006 Posts: 1,609 Southern Cal	Wow!!! Thats a lot of Gear for that Cam!!!! I'd be looking at a 3.55 rear Gear with about a 2200 Stall Converter. But an 870 will be plenty, you don't want to run mechanical secondaries with the auto.... Last edited by Noblewk; 07/30/09 12:22 AM.

Re: Carburetor size question [Re: Bladeruner69] #423521 07/30/09 12:17 AM 07/30/09 12:17 AM
Joined: Feb 2003 Posts: 21,318 Manitoba, Canada DaytonaTurbo Too Many Posts
DaytonaTurbo Too Many Posts Joined: Feb 2003 Posts: 21,318 Manitoba, Canada	I like a choke on a street car to make for easy starting, being able to fire and go without babying the pedal. For that reason I would go with either a 870 street avenger or a 850 double pumper. But it comes down to how high do you want to rev the motor? If you only want to rev to 6-6.5k one of the above carbs would be enough, anything higher than that and I think for flow you'll be in race carb territory. With a 500" engine and 4.10 gears you won't have a problem running mech secondaries so long as they're tuned decent. For cams, lunati makes a solid flat cam #60342 251/259@050, 566/586 lift on a 110lsa if that's the duration/lift you had in mind.

Re: Carburetor size question [Re: Bladeruner69] #423522 07/30/09 05:28 PM 07/30/09 05:28 PM
Joined: Nov 2006 Posts: 1,460 oklahoma F forphorty pro stock
forphorty pro stock F Joined: Nov 2006 Posts: 1,460 oklahoma	mechanical secondaries for sure. The 950HP is supposed to be a very versatile carb( havent owned one myself). It doesnt have a choke, but depending on where you live you might not miss it. I would choose a 3.55 gear over a 4.10, much more enjoyable on the highway and i dont think the ET will suffer a bit. A 10 inch, 3000-3500 convertor would be about right i think. If you dont have a convertor yet, call one of the good convertor companies and give them all your specs so they can recommend something.

Re: Carburetor size question [Re: forphorty] #423523 07/30/09 09:01 PM 07/30/09 09:01 PM
Joined: Apr 2007 Posts: 1,261 ILL mark7171 pro stock
mark7171 pro stock Joined: Apr 2007 Posts: 1,261 ILL	3500 stall feels like a 3500 stall, not for the street. I have built driven cars for 20+ yrs. a solid monster cammed 496 " with 4.10's makes that crappiest street driver possible. Finacing a transmission...Maybe quit while your a head.

Re: Carburetor size question [Re: mark7171] #423524 07/31/09 07:40 PM 07/31/09 07:40 PM
Joined: Nov 2006 Posts: 1,460 oklahoma F forphorty pro stock
forphorty pro stock F Joined: Nov 2006 Posts: 1,460 oklahoma	Quote: 3500 stall feels like a 3500 stall, not for the street. I have built driven cars for 20+ yrs. a solid monster cammed 496 " with 4.10's makes that crappiest street driver possible. Finacing a transmission...Maybe quit while your a head. 3500 stall convertors are fine on the street. I have run 3500+ stall on a street car for 15 years. Gets driven alot. No problems. No problems for lots of other Moparts members either. Currently i have a 9 1/2 Dynamic that flashes to 4500. I will admit that my current convertor might be at the upper limit of what most people would want in a street car. Even so, it is street driven regularly. Been in the car for about 7 years and thousands of miles.

Re: Carburetor size question [Re: forphorty] #423525 07/31/09 08:51 PM 07/31/09 08:51 PM
Joined: Aug 2006 Posts: 1,609 Southern Cal Noblewk top fuel
Noblewk top fuel Joined: Aug 2006 Posts: 1,609 Southern Cal	Quote: Quote: 3500 stall feels like a 3500 stall, not for the street. I have built driven cars for 20+ yrs. a solid monster cammed 496 " with 4.10's makes that crappiest street driver possible. Finacing a transmission...Maybe quit while your a head. 3500 stall convertors are fine on the street. I have run 3500+ stall on a street car for 15 years. Gets driven alot. No problems. No problems for lots of other Moparts members either. Currently i have a 9 1/2 Dynamic that flashes to 4500. I will admit that my current convertor might be at the upper limit of what most people would want in a street car. Even so, it is street driven regularly. Been in the car for about 7 years and thousands of miles. on the way a 3500 Stall converter works, I have one in my Dart and it is fine for street use. What I don't agree with is a 3500 Stall and 4.11 gears with this combo. He is running a 250/259 degrees duration @.050 Cam.... The 496" with that cam is going to be a Torque Monster, you need to control the power by utilizing a 2000 to 2500 Stall and no higher then 3:55 gear. If he was running a 290 to 310 duration I would have to agree with the 3500 to 4000 and a 4:11 Gear but that is not what he has. As far as Carb 870 will be plenty since I doubt that this engine will be run much past 5500 RPMS even at the track. 66 Dart GT, 402 11.18:109 Best 63 1/2 Galaxie 500XL 406 4Speed 13.20:103 Best 2000 Ram 2005 Durango Hemi.

Re: Carburetor size question [Re: Noblewk] #423526 07/31/09 10:15 PM 07/31/09 10:15 PM
Joined: Aug 2005 Posts: 11,543 chicagoland,usa B buildanother I Live Here
buildanother I Live Here B Joined: Aug 2005 Posts: 11,543 chicagoland,usa	That's alot of duration and will work great and need at least 3000 stall, maybe not so much gear. My 500" had the 525 lift 305 adv comp and worked great with 355's and 10 ta converter. 11.20 et.

Re: Carburetor size question [Re: buildanother] #423527 07/31/09 10:28 PM 07/31/09 10:28 PM
Joined: Aug 2006 Posts: 1,609 Southern Cal Noblewk top fuel
Noblewk top fuel Joined: Aug 2006 Posts: 1,609 Southern Cal	Quote: That's alot of duration and will work great and need at least 3000 stall, maybe not so much gear. My 500" had the 525 lift 305 adv comp and worked great with 355's and 10 ta converter. 11.20 et. I don't agree that 250/259 @50 is alot of duration, but it will move the torque band up 1500 Rpms. You have a 305@50 and yes that motor will like a converter around 3000 to 3500. Yes his profile is higher then stock (195 to 205@50) but stock converters were kicking in fully at 1500 to 1800. He has move the torque band up about 750 to 1000 RPMS with that cam. a 3500 stall converter would move the car but he would be well into his torque band at that point. 66 Dart GT, 402 11.18:109 Best 63 1/2 Galaxie 500XL 406 4Speed 13.20:103 Best 2000 Ram 2005 Durango Hemi.

Re: Carburetor size question [Re: Noblewk] #423528 07/31/09 10:38 PM 07/31/09 10:38 PM
Joined: Aug 2005 Posts: 11,543 chicagoland,usa B buildanother I Live Here
buildanother I Live Here B Joined: Aug 2005 Posts: 11,543 chicagoland,usa	The "305" cam I speak of has 253 degrees at .050 int and exhaust. It was quite a rough idle even with the decent amount of cubes. I was happy with the converter choice. Now have the ptc 9.5 with same combo, works great.

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