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Carb for a street/strip stroked 440

dammstrate

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The care in my avatar came with a stroked and 30 over 440, about 500ci. Supposedly "mildly" worked heads, no I don't know what exact kind. 10.5:1 CR, but a pretty hefty cam: 590 intake lift 318 duration, 609 exhaust lift 324 curation, with a 112 lob seperation. It has a holley 850 double pumper, which I despise. Would an 800cfm AVS2 be enough carb for this combination?
 
The 800 AVS will certainly work but may lose some HP to the 850. Both need to be tuned to be optimal.

What makes you hate the 850?
 
To put it bluntly, that's a huge cam for the street. More like a 5000- 75000 bracket cam. The best match would be a 950+ quick fuel Q series .
IMO
 
My thoughts are that an Ede avs carb will not have enough idle circuit capacity to provide satisfactory lower speed street manners……with that cam.

Holley makes a lot of “850’s”, some would be better suited for a combo like that than others.

In my mind(and new ones are prohibitively expensive these days) the old school traditional 850 double pumper, number 4781, would be a good fit.
(It would need to be one equipped with 4 corner idle, but they’ve had that for like 30 years now.)
In all fairness, I haven’t put a new one of those on an engine since like 2005.

That being said, I agree the cam is on the rowdy side if decent street manners are on the priority list.
Any idea what the duration @.050 numbers are?
I’d expect that combo to be pretty fussy about having the timing curve set up pretty short.

If it hasn’t been done in a while, I’d suggest re-gasketing the carb.

Edit- I guess if I had to buy something new, I’d probably lean towards a Street Brawler 850.

Edit 2- cam specs look like a Crower 318FDP, but on a 112lsa
 
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I agree....if it's going to be on the street, your carb is too big and so is the cam unless you plan on being a total street hell raiser......
 
I know I'll get pushback, but a holley terminator would allow you to store multiple tunes depending on where and how you are driving. With that cam and depending on rear gears, that's what I'd do. And yes this would involve fuel system changes but my experience with carb tune management, real street and strip usage, pushed me to EFI.
 
My thoughts are that an Ede avs carb will not have enough idle circuit capacity to provide satisfactory lower speed street manners……with that cam.

Holley makes a lot of “850’s”, some would be better suited for a combo like that than others.

In my mind(and new ones are prohibitively expensive these days) the old school traditional 850 double pumper, number 4781, would be a good fit.
(It would need to be one equipped with 4 corner idle, but they’ve had that for like 30 years now.)
In all fairness, I haven’t put a new one of those on an engine since like 2005.

That being said, I agree the cam is on the rowdy side if decent street manners are on the priority list.
Any idea what the duration @.050 numbers are?
I’d expect that combo to be pretty fussy about having the timing curve set up pretty short.

If it hasn’t been done in a while, I’d suggest re-gasketing the carb.

Edit- I guess if I had to buy something new, I’d probably lean towards a Street Brawler 850.

Edit 2- cam specs look like a Crower 318FDP, but on a 112lsa
Yes current carb is a 4781. Yes, that is the cam from Crower. Not shure why the previous owner chose it (I wouldn't have gone so hot), but that's what I have to work with.
 
Yes current carb is a 4781. Yes, that is the cam from Crower. Not shure why the previous owner chose it (I wouldn't have gone so hot), but that's what I have to work with.
Why do you say the AVS will not have the idle curcuit capacity not enough vacuum with that cam?
 
The 800 AVS will certainly work but may lose some HP to the 850. Both need to be tuned to be optimal.

What makes you hate the 850?
Yes, I know the cam makes this not really a street engine, the DP throws too much gas off idle and as such has to be tuned carefully or it will not be smooth.
 
To put it bluntly, that's a huge cam for the street. More like a 5000- 75000 bracket cam. The best match would be a 950+ quick fuel Q series .
IMO
Agree about the cam, but that's what it came with. I doubt I would ever race it, just want a street beast to fool around with, and take to car shows, it has a top flight resto on the body and interior.
 
The 800 AVS will certainly work but may lose some HP to the 850. Both need to be tuned to be optimal.

What makes you hate the 850?
What the hell is going on here? This shows up on an Amazon search, what's the dealio with the first one? Looks wrong and no way should a new car be only $179.

1757879937071.png
 
It's a Chinese knock-off, the internet is full of them. Notice in the description it says " for Edelbrock Thunder Series".
This will be the legal loophole to avoid any accusations of false advertising or copyright.

DO NOT BUY. There's plenty of reviews on youtube. Everything will look similar but be slightly different. Tuning nightmare.
 
Agree about the cam, but that's what it came with. I doubt I would ever race it, just want a street beast to fool around with, and take to car shows, it has a top flight resto on the body and interior.
Then why not change the cam ? And the carb while you're at it. I've "de-cammed" engines for streetable purposes.
 
has to be tuned carefully or it will not be smooth.

Some of this will come down to how “smooth” it has to be(personal preference)………but imo, a cam that’s 271/277@.050 isn’t going to provide what I would consider “smooth” low speed operation.
Something with 20-25* less duration would go a long ways towards smoothing out the low speed manners.
 
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Why do you say the AVS will not have the idle curcuit capacity not enough vacuum with that cam?
My experience has been that cams with that much duration don’t play well with carbs that have street calibrated low speed circuits…….and “two corner” idle.
 
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