[glhx]

planning on running a (580 cfm total) dual 2 bbl set up. this will need a strong vacuum signal to work well and from what my buddy says...i should run the sp2p manifold . he says i will get better mileage, more low end torque, and will have a power band from idle to 4000 rpm. i cruise it and usually never go fast

the car has 2.76:1 gears and a stock 1976 low compression 318 engine
late 60's a body

[cobalt327]

Originally Posted by glhx

planning on running a (580 cfm total) dual 2 bbl set up. this will need a strong vacuum signal to work well and from what my buddy says...i should run the sp2p manifold . he says i will get better mileage, more low end torque, and will have a power band from idle to 4000 rpm. i cruise it and usually never go fast

the car has 2.76:1 gears and a stock 1976 low compression 318 engine
late 60's a body

Interesting...

How are you plumbing the carbs, as in what type adapter to do the 2, 2-bbl's through the 4-bbl. intake?

Are you going to use progressive linkage?

Any thoughts on the idle circuit and such?

But AFA the intake itself, it would be as good a choice as any for velocity, I would think. And that's helped by your rather low RPM ceiling. There was a "Streetmaster" intake that kind of fits w/what you're doing.

I don't know but what the good old Performer intake might not be just as good as either of those obsolete intakes...

[ap72]

dual 2bbls? Sounds like you're more concerned with looks than performance so I would just use whichever intake you think looks the coolest.

[glhx]

you are right about the looks over performance....not much kick to the 318...i was told the performer doesnt pull enough vacuum. if i bumped up the cam to a stock 340 cam and ran some 360 heads that flow more i could go with the performer and may do so in the future.....but this old vintage intake is a high velocity intake with really small runners (smaller than stock) but moves the air a lot faster....and .......it's just different...as is a dual 2 1973 carters (with metering rods) on a muscle car. i will go with a progressive set up....trying to now figure out the idle circuit....in concept if i used all 4 idle screws, i question.....will this act like a holley 4 corner idle set up. or i can shut the back one off and just use the front primary carb for the idle. dont know what to do for the squirters. thought about removing the accelerator pump to the back carb and just use jets back there. going to run 2 carter bbd's or rochester 2g's. the carters would be harder to tune with the metering rods but would run better and have a smoother fuel curve. i hate to but i will have to use a carb spacer. vintage speed sells an adapter for a 4 to 2x2 set up for $85. Then the matter is just figuring out a custom linkage and trying to get it to work

if you can find a 318 street master let me know.....i think it's a better intake. the weiand 3000 is as well

[cobalt327]

Originally Posted by glhx

you are right about the looks over performance

I wouldn't let that worry me- at least your not doing something as insane as an individual runner deal. lol

The 2G has good support, I'd probably lean (he haw) towards those.

If I were doing this, I'd want to at least try to use the 'secondary' carb as if it were one of the end carbs on some trip set-ups, w/closed off idle circuit and tuned to run similar to the secondary side of a 4-bbl. This should work fine, unless you find you have some sort of unforeseen fuel distribution problems that can't be dealt with.

Unless you want to fab up the linkage from scratch, just get a cheap-o (they're ALL high, though...) triple 2-bbl progressive linkage and use what you need of it for your 2x2 set-up.

[glhx]

i will check into the linkage and look at the 2g as an option. i already have a brand new bbd. maybe both...1 bbd and 1 2g

[cobalt327]

Originally Posted by glhx

maybe both...1 bbd and 1 2g

Yeah... well, I wouldn't NOT use the Carter- especially if you already have a new one.

AFA one of each... I dunno... lol

[Hippie]

I have an SP2P on the 9.0 to 1 318 in my '86 D150. It has a 727 and 2.94 gears. The engine is internally stock except for a .020" overbore, a 6619 600 Holley and 1-5/8" headers. Performance off idle to 4,000 is decent for a big old barge with tall gears but when you hit 4,000 that is it, period. Gas mileage........ we don't mention gas mileage and my truck in the same breath.

[glhx]

gas mileage. let's talk gas mileage here. what are you gettin hippie? do you like this manifold or would you rather have a performer? in your opinion.....hands down...is this the best manifold for a dual 2 barrel carb set up with a dead stock 1976 smog 318 with smog pistons and 273:1 gears?

[ap72]

Originally Posted by glhx

gas mileage. let's talk gas mileage here. what are you gettin hippie? do you like this manifold or would you rather have a performer? in your opinion.....hands down...is this the best manifold for a dual 2 barrel carb set up with a dead stock 1976 smog 318 with smog pistons and 273:1 gears?

The stock intake usally is bet for milage out of a stock engie...

[Mertz]

If you want to try something different, the carbs for a Corvair are already set up for one as a primary and one as a secondary. My 140 has 2 primary carbs and 2 secondary. That solves the idle circuit issue. Linkage is progressive.

[cobalt327]

Originally Posted by Mertz

If you want to try something different, the carbs for a Corvair are already set up for one as a primary and one as a secondary. My 140 has 2 primary carbs and 2 secondary. That solves the idle circuit issue. Linkage is progressive.

Are those 1-bbls? If so, he'd need about 8 of them for a 350- but that would look bad!!

[Mertz]

Yea they are one barrels. I was thinking he could build a 2 to one manifold and use 4 carbs. That would be cool.

[Hippie]

Originally Posted by glhx

gas mileage. let's talk gas mileage here. what are you gettin hippie? do you like this manifold or would you rather have a performer? in your opinion.....hands down...is this the best manifold for a dual 2 barrel carb set up with a dead stock 1976 smog 318 with smog pistons and 273:1 gears?

The SP2P was on the truck when it came to me. The best I can pull is 10.5 on a good day but there aren't a lot of "good" days. Mostly it's around 9.5 but they didn't get much better than 11-13 new. This truck was royally cobbled up when I got it and I still don't have everything up to snuff although the engine only has 15,000 on it. I did the rebuild for the PO a couple years ago and ended up with the truck as payment for an unrelated debt. It got 7 MPG when I started. I'm going to replace the 6619 Holley with a 450 spreadbore when the weather warms up and eventually sell it to make room for my C10 project. I think if the engine was in a nice little Dart it would do much better and would probably be pretty quick stoplight to stoplight. I'd say if you already have an SP2P it would do the job but I wouldn't go out looking for one.

[glhx]

ok....so for a 2x2 set up. 2 carters or 2gc rochesters. 1976 stock smog motor.....2:76 gears.......stock cam. i will run an adapter plate for the 2x2 to 4 barrel adapter. what manifold should i run...i have a 2 barrel manifold now.