Which Carb for my set up

[SUPERSTOCKRACER]

With proper carb tuning the edelbrock or carter will outperform any holley imo. I just switched back from holley 770's to my edelbrock 800's and picked up ,25
So I disagree with a lot of whats said about edelbrocks.,
I have them on most my cars and I don't do too bad.

 

[73Runner4spd]

With proper carb tuning the edelbrock or carter will outperform any holley imo. I just switched back from holley 770's to my edelbrock 800's and picked up ,25
So I disagree with a lot of whats said about edelbrocks.,
I have them on most my cars and I don't do too bad.

Pretty impressive set up! that looks sick.

 

[65 Plymouth Satellite 426]

After Years Of Using Carter AFB's And Thermo Quads, I Have Had It With Replacement Built Edelbrocks! No More! Vic Needs To Stick With Building Heads And Intakes!

 

[73Runner4spd]

what do you run now?

After Years Of Using Carter AFB's And Thermo Quads, I Have Had It With Replacement Built Edelbrocks! No More! Vic Needs To Stick With Building Heads And Intakes!

 

[RustyRatRod]

On your carburetor. There's certainly room for improvement. Carter knew this when they came out with the AVS as an improvement over the AFB. Look at where the secondary vacuum door location on each carburetor. On your 750 AFB, the door is below the boosters. The AVS improved this design by relocating the secondary air door above the boosters, so they are regulated by the secondary air door all of the time. This created a more smooth transition into the secondaries and generally smoother secondary operation. So I agree with rumblefish about the AVS. It's a great carburetor.

Don't put a double pumper on that car unless you want to slow it down terribly. Double pumpers are for manual trans cars and auto cars with loose converters and 4 and up series gears. The extra pump of fuel while opening the secondaries will slow your car down, not speed it up.

IMO, I don't think that cam change will make enough difference to warrent all of the labor involved. You have a camshaft that's IMO too big. With no other modifications, simply installing 915 heads probably brings compression up to 9.1 if you are lucky. So with that in mind, I think this is a better choice than the 484 or the Whiplash:

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=716&sb=2

It has a longer exhaust duration, so you will still have some bump, but the duration @ .050 is less and it is ground on a 110, not a 108. The 110 will give it a little better street manners and also bump the bottom end torque up and flatten the torque curve out more. Generally, 108 ground cams are more peaky with the torque curve and sacrifice a little bottom end for peak torque. With a street car you want the opposite.

 

[73Runner4spd]

On your carburetor. There's certainly room for improvement. Carter knew this when they came out with the AVS as an improvement over the AFB. Look at where the secondary vacuum door location on each carburetor. On your 750 AFB, the door is below the boosters. The AVS improved this design by relocating the secondary air door above the boosters, so they are regulated by the secondary air door all of the time. This created a more smooth transition into the secondaries and generally smoother secondary operation. So I agree with rumblefish about the AVS. It's a great carburetor.

Don't put a double pumper on that car unless you want to slow it down terribly. Double pumpers are for manual trans cars and auto cars with loose converters and 4 and up series gears. The extra pump of fuel while opening the secondaries will slow your car down, not speed it up.

IMO, I don't think that cam change will make enough difference to warrent all of the labor involved. You have a camshaft that's IMO too big. With no other modifications, simply installing 915 heads probably brings compression up to 9.1 if you are lucky. So with that in mind, I think this is a better choice than the 484 or the Whiplash:

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=716&sb=2

It has a longer exhaust duration, so you will still have some bump, but the duration @ .050 is less and it is ground on a 110, not a 108. The 110 will give it a little better street manners and also bump the bottom end torque up and flatten the torque curve out more. Generally, 108 ground cams are more peaky with the torque curve and sacrifice a little bottom end for peak torque. With a street car you want the opposite.

I just put my 3.91s the other day and that woke it up a bit, makes the take off transition much better, it has absolutely no clutch chatter now, compared to the 3.55's I just found receipts for my car the other day, the engine was honed, and the stock pistons re ringed, in 2006. I just did a compression test and it varied between 100 psi, and 120 psi. Per jug with the purple cam and the 915 heads. The heads were also freshened up and had a 5 angle valve job, ( I thought anything passed a 3 angle was pointless but idk) in 2006. You think that cylinder pressure would collaborate well with the cam you recommended? Also I am running an edelbrock dp4b intake, msd coil, and I am thinking about switching to a 6al box (not to gain hp or anything, just to make it a better driver with the addition of a limiter) Also I have a saginaw style power steering pump to replace my federal pump. Is it just plug and play? when it comes to swapping the p/s setup? (I know I need the corresponding pullies as well)
Thanks Rusty. Your the man

 

[RustyRatRod]

I think that 484 cam is the reason compression pressure is low, BUT you need to understand cranking pressure really doesn't mean much. It's nice to see strong numbers, but like everything else, there's a bell shaped curve. Compression pressure goes up with RPM to a peak and then falls off. This is easily followed in a HP and TQ graph or chart. Compression pressure will closely follow. So while 100 is somewhat low, I would not look for anything much over 175 on a street car. I am sure the cam I recommended will raise cranking pressure, but by how much, I don't know. I am also really not sure cranking pressure is an accurate measure of anything anyway, since it does change with RPM. Not sure I would worry about cranking pressure anyway, since you have a 400 with stock pistons. There's not a lot you can do other than kinda maximize what's there. The pistons are so far in the hole, you may never see 170 plus, I don't know. But as I said, I think there's room for improvement. Whether it's worth the labor for a cam change is ultimately up to you. Good luck and keep us posted.

 

[747mopar]

Yeah the guy said he added the choke kit. What is your engine set up? I think it may be a little too much for my current set up. Im running an edelbrock 1407 It isn't to snappy though

It was on a "please excuse me" Chevy 400 SB, the motor was not stock somewhere around 450hp but ran great with it. The one thing that really determines what cfm you need other than Cubes is RPM, that motor and my current motor where built to run up to 6,500 rpm, if your not going to spin it that fast then like Bud pointed out a 650 cfm will do. I don't know what your plans are down the road but even a mild build like Edelbrock Performer RPM kit is made to build power into the 6,000 range.

 

[rumblefish360]

The differences between the two pumps is one pulley is pressed on and the other has a key way. The attaching hardware might be an issue, IDK. It is on my '73 Cuda.

 

[73Runner4spd]

Thanks guys, Yeah, Rusty I have realized that it is a a pretty negligible think to have high cranking pressure, as the band would vary throughout the rpm range, and I can tell you that my car loves higher rpms. I have all of the mounting brackets with the saginaw pump I thought one was mounted further, back I could be wrong. Thanks, 747 I've pulled my car into 6500 territory before, it pulled hard right before it, and started to fall flat around 6500.

 

[RustyRatRod]

Regardless of whether you choose the one I recommended or not, I really think a cam with smaller duration numbers will actually make your power go up and come further down in the RPM range, if that makes sense.

 

[73Runner4spd]

That makes sense, that's exactly how the gentleman at Hughes explained it, he said I would notice a lot more low end grunt than the cam that is in there now. I think the whiplash if I remember correctly has a lot tighter duration than the purple cam as well

 

[Dennis H]

850. Mighty Demon.

 

[muscle72]

I know this a old thread if you put a 750 speed demon on a 383 with a 292 high extreme energy comp cam,would that carb work with that cam?

 

[383man]

Myself I like the Holley double pumper carbs. If money is tight just the basic 750 or 850 DP Holley will do a great job. You can spend more money and get the Holley HP carb or one of the other knock-off carbs like the Demon or Pro Form but it will cost more money and I can say my basic 850 Holley DP ran as good as the 950 Pro Form did on my car. You can spend the extra money for a specialty carb but for the average set up a basic Double Pumper has always worked very good for me. Ron

 

[muscle72]

Myself I like the Holley double pumper carbs. If money is tight just the basic 750 or 850 DP Holley will do a great job. You can spend more money and get the Holley HP carb or one of the other knock-off carbs like the Demon or Pro Form but it will cost more money and I can say my basic 850 Holley DP ran as good as the 950 Pro Form did on my car. You can spend the extra money for a specialty carb but for the average set up a basic Double Pumper has always worked very good for me. Ron

Oh ok l see do have a 770 street avenger holley carb

 

[440 Charger]

Hey guys, its getting nicer up here in the northeast so I figured I would put some coin into my old bird. I am in the process of rebuilding a set of 3.91's to replace my 3.55's. I would also like to pick a different carb with the advice of you guys. My set up is a stock bottom end 73 400 with steel crank a set of 915 heads and the 284 484 purple cam. It has a dual plane intake on it currently, however I do have a single plane torquer that I just powder coated for myself. On top currently is an edelbrock 1407 750. I am wondering if switching to a pro form, demon, or holley would benefit me in any way. I was looking at the holley 4150, a speed demon 750, and a proform 67200. All 750s. Im just not sure if any of these would give me better performance over the edelbrock with my current cam and rear end. This is in a 73 b body 4 speed car with soon to be 3.91's. Also once I get the brackets and pulleys to delete my a/c I may decide to put a different cam in it, maybe one of the hughes whiplash cams as I feel that my current cam bleeds off too much cylinder pressure on an already low compression engine. The specs are .229-.242 .518 .518 at 107 lsa.

You already know you have to play a bit

 

[muscle72]

Myself I like the Holley double pumper carbs. If money is tight just the basic 750 or 850 DP Holley will do a great job. You can spend more money and get the Holley HP carb or one of the other knock-off carbs like the Demon or Pro Form but it will cost more money and I can say my basic 850 Holley DP ran as good as the 950 Pro Form did on my car. You can spend the extra money for a specialty carb but for the average set up a basic Double Pumper has always worked very good for me. Ron

I just sold my 850 speed demon for a 750 speed demon.l got really deal from a member on here