SBC intake question for the experts

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statsystems
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Re: SBC intake question for the experts

Post by statsystems »

Carnut1 wrote: Thu Jun 21, 2018 8:08 am
statsystems wrote: Wed Jun 20, 2018 4:43 pm I don't know how you guys do it, but why is it I've been ditching dual plane intakes for decades and not lost power or made the car undrivable. Never had a complaint about no bottom end or none of that.

Surely, Chevrolet could be so stupid as to do what you suggest.
Stats, as with everything it is in the combo. Weight, gear, converter, tire size, compression, cam. I think the cross over rpm is 3500-4000 rpm, if you start making real power over this single plane all the way. I have done detailed experiments on intakes, vic jr, on roller 383 in 5800 lb truck with stock converter and 3.73 gears. Pulled great over 3500 rpm, couldn't chirp the 33' tires from a stop. Same combo dual plane and instant tire smoke. A high winding 306 Ford ran better with a dual plane because it needed the torque boost in the mid range and still pulled to 6800 rpm. Still a 3000 lb ride with tko-600 and 3.73 gears. We had plans to upgrade to hotter heads and a single plane to up the rpm and lower the E.T. but never happened. Thanks, Charlie

Well just make shit up as you go then. Who is talking about a tow rig? Are you buying the engine in the OP and drop that in your tow rig? If so, that's on the idiot consumer.

As for all the leg humping on dual plane intakes I can tell you the cross over ISNT nearly as high as you think. It never is. IDGAF what the dyno says (much like a flow bench at times) because in the car, the dual plane has been slower every time I tested it. And that's not just once.

I suspect the problem is some of you can't tune. That's the only option.


BTW, if your asses are so sensitive, so supple, so accurate as to see 20 pounds of torque at part throttle you should be calling some real race teams. Because your asses certainly are more accurate and sensitive then a time slip or lap time.
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Re: SBC intake question for the experts

Post by novadude »

CGT wrote: Thu Jun 21, 2018 11:54 am OP. That manifold runs good, not overly big for a single plane. Same manifold that's on my special needs project.
Thanks. It still seems to me like it would be a bit much for 208 @ .050" duration and 350 ci, HOWEVER, I have no experience with this intake. Just looking at the rest of the engine spec (a good engine for a street rod or tow rig), it seemed like an unconventional choice. I got curious as to "why?" when there are good dual plane options in the Chevrolet performance catalog. 3 pages of speculation tells me I'm not the only one who doesn't understand why they did what they did. LOL :wink: :lol:
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Re: SBC intake question for the experts

Post by statsystems »

novadude wrote: Thu Jun 21, 2018 12:56 pm
CGT wrote: Thu Jun 21, 2018 11:54 am OP. That manifold runs good, not overly big for a single plane. Same manifold that's on my special needs project.
Thanks. It still seems to me like it would be a bit much for 208 @ .050" duration and 350 ci, HOWEVER, I have no experience with this intake. Just looking at the rest of the engine spec (a good engine for a street rod or tow rig), it seemed like an unconventional choice. I got curious as to "why?" when there are good dual plane options in the Chevrolet performance catalog. 3 pages of speculation tells me I'm not the only one who doesn't understand why they did what they did. LOL :wink: :lol:


I'll give you a hint as to why. Because a dyno, like the tool that it is, has limitations. Just like a flow bench. I don't care what the dyno says about low speed torque. IMO, the dyno doesn't measure it very good. And certainly, most commercial dynos do not measure the ability to RPM.
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Re: SBC intake question for the experts

Post by Carnut1 »

statsystems wrote: Thu Jun 21, 2018 12:40 pm
Carnut1 wrote: Thu Jun 21, 2018 8:08 am
statsystems wrote: Wed Jun 20, 2018 4:43 pm I don't know how you guys do it, but why is it I've been ditching dual plane intakes for decades and not lost power or made the car undrivable. Never had a complaint about no bottom end or none of that.

Surely, Chevrolet could be so stupid as to do what you suggest.
Stats, as with everything it is in the combo. Weight, gear, converter, tire size, compression, cam. I think the cross over rpm is 3500-4000 rpm, if you start making real power over this single plane all the way. I have done detailed experiments on intakes, vic jr, on roller 383 in 5800 lb truck with stock converter and 3.73 gears. Pulled great over 3500 rpm, couldn't chirp the 33' tires from a stop. Same combo dual plane and instant tire smoke. A high winding 306 Ford ran better with a dual plane because it needed the torque boost in the mid range and still pulled to 6800 rpm. Still a 3000 lb ride with tko-600 and 3.73 gears. We had plans to upgrade to hotter heads and a single plane to up the rpm and lower the E.T. but never happened. Thanks, Charlie

Well just make shit up as you go then. Who is talking about a tow rig? Are you buying the engine in the OP and drop that in your tow rig? If so, that's on the idiot consumer.

As for all the leg humping on dual plane intakes I can tell you the cross over ISNT nearly as high as you think. It never is. IDGAF what the dyno says (much like a flow bench at times) because in the car, the dual plane has been slower every time I tested it. And that's not just once.

I suspect the problem is some of you can't tune. That's the only option.


BTW, if your asses are so sensitive, so supple, so accurate as to see 20 pounds of torque at part throttle you should be calling some real race teams. Because your asses certainly are more accurate and sensitive then a time slip or lap time.
Stats, not sure how it is considered making shit up if my example was very similar to the op mill. 350 208 cam single plane. Mine was 383 206 cam with single plane. Yes it was in a truck, not sure how that matters.
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Re: SBC intake question for the experts

Post by novadude »

statsystems wrote: Thu Jun 21, 2018 1:27 pm
novadude wrote: Thu Jun 21, 2018 12:56 pm
CGT wrote: Thu Jun 21, 2018 11:54 am OP. That manifold runs good, not overly big for a single plane. Same manifold that's on my special needs project.
Thanks. It still seems to me like it would be a bit much for 208 @ .050" duration and 350 ci, HOWEVER, I have no experience with this intake. Just looking at the rest of the engine spec (a good engine for a street rod or tow rig), it seemed like an unconventional choice. I got curious as to "why?" when there are good dual plane options in the Chevrolet performance catalog. 3 pages of speculation tells me I'm not the only one who doesn't understand why they did what they did. LOL :wink: :lol:


I'll give you a hint as to why. Because a dyno, like the tool that it is, has limitations. Just like a flow bench. I don't care what the dyno says about low speed torque. IMO, the dyno doesn't measure it very good. And certainly, most commercial dynos do not measure the ability to RPM.

Not sure what you mean by "ability to RPM"? A dyno can certainly show the WOT power curve, right?

A dyno also does nothing to measure part throttle, which is where this particular crate engine is likely to spend most of it's time. I'd be more curious to see how a dual plane vs single plane affects part throttle mixture quality and distribution. My feeble mind believes that the dual plane might have a bit of an edge when it comes to part-throttle efficiency, but I have no data to back it up.
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Re: SBC intake question for the experts

Post by paulzig »

novadude wrote: Thu Jun 21, 2018 12:56 pm 3 pages of speculation tells me I'm not the only one who doesn't understand why they did what they did. LOL :wink: :lol:
If one was to speculate:

Open the induction system up so there is less restriction, then use 208° intake / 221° exhaust cam 112LSA, less duration on the intake lobe, early IVC for the 9.7 compression to make the Torkz, then earlier EVO to help it pull up the top end. Smooth idle, less noise and vibration compromise for different end use..
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Re: SBC intake question for the experts

Post by 77cruiser »

Maybe it needs a blower & 6 Qjetz, or something. :P
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Re: SBC intake question for the experts

Post by Frankshaft »

statsystems wrote: Thu Jun 21, 2018 12:40 pm
Carnut1 wrote: Thu Jun 21, 2018 8:08 am
statsystems wrote: Wed Jun 20, 2018 4:43 pm I don't know how you guys do it, but why is it I've been ditching dual plane intakes for decades and not lost power or made the car undrivable. Never had a complaint about no bottom end or none of that.

Surely, Chevrolet could be so stupid as to do what you suggest.
Stats, as with everything it is in the combo. Weight, gear, converter, tire size, compression, cam. I think the cross over rpm is 3500-4000 rpm, if you start making real power over this single plane all the way. I have done detailed experiments on intakes, vic jr, on roller 383 in 5800 lb truck with stock converter and 3.73 gears. Pulled great over 3500 rpm, couldn't chirp the 33' tires from a stop. Same combo dual plane and instant tire smoke. A high winding 306 Ford ran better with a dual plane because it needed the torque boost in the mid range and still pulled to 6800 rpm. Still a 3000 lb ride with tko-600 and 3.73 gears. We had plans to upgrade to hotter heads and a single plane to up the rpm and lower the E.T. but never happened. Thanks, Charlie

Well just make shit up as you go then. Who is talking about a tow rig? Are you buying the engine in the OP and drop that in your tow rig? If so, that's on the idiot consumer.

As for all the leg humping on dual plane intakes I can tell you the cross over ISNT nearly as high as you think. It never is. IDGAF what the dyno says (much like a flow bench at times) because in the car, the dual plane has been slower every time I tested it. And that's not just once.

I suspect the problem is some of you can't tune. That's the only option.


BTW, if your asses are so sensitive, so supple, so accurate as to see 20 pounds of torque at part throttle you should be calling some real race teams. Because your asses certainly are more accurate and sensitive then a time slip or lap time.
Butt dyno simulation maybe? It's connected via usb port. When you run a sim, it vibrates a pad your sitting on in the chair. It vibrates harder or softer based on how much tq it makes at various rpm. Calling Stan, I just gave you an idea for a new project. I bet you would sell a ton of em too. Then you can update it with some virtual reality goggles, and guys wouldn't have to leave their house. :mrgreen:

In all seriousness, How many people mash the gas off idle when they are towing? I don't know, everytime I have towed anything, I EASE into the throttle off idle from a stop. Then as everything settles in, you roll into the throttle harder. That is usually in that 3500 rpm range and above, when your trying to accelerate to speed, your above that point, and that is where the power really needs to be. If you want low rpm, off idle power, buy a diesel.

My assumption, is they tested it. They used the single plane because it was better. Also, it will fit under more hoods. I often use single plane intakes like team G or Victor Jr for that reason. The stock hood will shut. With a Air gap, or tall dual plane, it won't. Guys that want their stock hoods, have little choice. Maybe that was another reason for it.
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Re: SBC intake question for the experts

Post by cjperformance »

^^^ exactly.
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Re: SBC intake question for the experts

Post by groberts101 »

Same shit different day. Dual planes are for pussies. That manifolds absolutely perfect for a small cam and taller gears in a heavier street ride! If you don't believe me ask all the guys who put single planes, 850 double pumpers, and big headers with 3" duals on their old low compression Camaro's of yesteryear. And nobody really truly needs extra carb signal or wider torque spreads.. just add more gear and they're always faster! Only tow trucks need low rpm torque. :lol:

I could take the induction off that marketing fluff piece.. put a BIGGER CAM.. BIGGER CARB.. decently designed air-gap.. maybe add a spacer.. and beat it up everywhere from start to finish. Much crisper transient throttle response driving around town too. :wink:
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Re: SBC intake question for the experts

Post by Warp Speed »

groberts101 wrote: Sat Jun 23, 2018 7:16 pm Same shit different day. Dual planes are for pussies. That manifolds absolutely perfect for a small cam and taller gears in a heavier street ride! If you don't believe me ask all the guys who put single planes, 850 double pumpers, and big headers with 3" duals on their old low compression Camaro's of yesteryear. And nobody really truly needs extra carb signal or wider torque spreads.. just add more gear and they're always faster! Only tow trucks need low rpm torque. :lol:

I could take the induction off that marketing fluff piece.. put a BIGGER CAM.. BIGGER CARB.. decently designed air-gap.. maybe add a spacer.. and beat it up everywhere from start to finish. Much crisper transient throttle response driving around town too. :wink:
You could argue that the same results, and maybe even better could be achieved with the single plane and a "BIGGER CAM.. BIGGER CARB". The throttle response/transient stuff is all related to tune up! :wink:
You bust on the "yesteryear" methods, but it seems you are hung up in them too, just maybe a few years past what you mentioned!
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Re: SBC intake question for the experts

Post by groberts101 »

Warp Speed wrote: Sun Jun 24, 2018 8:12 am
groberts101 wrote: Sat Jun 23, 2018 7:16 pm Same shit different day. Dual planes are for pussies. That manifolds absolutely perfect for a small cam and taller gears in a heavier street ride! If you don't believe me ask all the guys who put single planes, 850 double pumpers, and big headers with 3" duals on their old low compression Camaro's of yesteryear. And nobody really truly needs extra carb signal or wider torque spreads.. just add more gear and they're always faster! Only tow trucks need low rpm torque. :lol:

I could take the induction off that marketing fluff piece.. put a BIGGER CAM.. BIGGER CARB.. decently designed air-gap.. maybe add a spacer.. and beat it up everywhere from start to finish. Much crisper transient throttle response driving around town too. :wink:
You could argue that the same results, and maybe even better could be achieved with the single plane and a "BIGGER CAM.. BIGGER CARB". The throttle response/transient stuff is all related to tune up! :wink:
You bust on the "yesteryear" methods, but it seems you are hung up in them too, just maybe a few years past what you mentioned!
:lol: .. like a boss. You know your tuning skilz are top notch when they can defy the laws of physics. Probably needs a bigger cylinder head for more flowZ too!

I keep forgetting the race guys mantra.. "the camshaft and induction ain't too big.. the converters too tight and those gears are just too damned tall"!
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Re: SBC intake question for the experts

Post by Warp Speed »

groberts101 wrote: Sun Jun 24, 2018 8:51 am
Warp Speed wrote: Sun Jun 24, 2018 8:12 am
groberts101 wrote: Sat Jun 23, 2018 7:16 pm Same shit different day. Dual planes are for pussies. That manifolds absolutely perfect for a small cam and taller gears in a heavier street ride! If you don't believe me ask all the guys who put single planes, 850 double pumpers, and big headers with 3" duals on their old low compression Camaro's of yesteryear. And nobody really truly needs extra carb signal or wider torque spreads.. just add more gear and they're always faster! Only tow trucks need low rpm torque. :lol:

I could take the induction off that marketing fluff piece.. put a BIGGER CAM.. BIGGER CARB.. decently designed air-gap.. maybe add a spacer.. and beat it up everywhere from start to finish. Much crisper transient throttle response driving around town too. :wink:
You could argue that the same results, and maybe even better could be achieved with the single plane and a "BIGGER CAM.. BIGGER CARB". The throttle response/transient stuff is all related to tune up! :wink:
You bust on the "yesteryear" methods, but it seems you are hung up in them too, just maybe a few years past what you mentioned!
:lol: .. like a boss. You know your tuning skilz are top notch when they can defy the laws of physics. Probably needs a bigger cylinder head for more flowZ too!

I keep forgetting the race guys mantra.. "the camshaft and induction ain't too big.. the converters too tight and those gears are just too damned tall"!
Lost in the 90s! #-o
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Re: SBC intake question for the experts

Post by groberts101 »

Yeah.. most street rodders and entry level guys looking for dumbed down 9.7:1 crate motors usually are content with 90's tech and power levels. If that's the way you have me pegged then so be it but you couldn't be further from the truth because I cut, grind, modify, and weld most everything of my own. Hell, even my little lowly 302 mule motor is far beyond most guys race motor from a tech and modification standpoint. Cut manifolds, port welding, coatings, bigger lifters, handbuilt headers.. far from average and just how I do. Plus.. I can actually tune my junk to make things come together.

And regardless of decade being discussed.. the physics involved comparing duals to single remains a constant. Runner size and length changes will only tweak final results so much. All about carb signal dude.
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Re: SBC intake question for the experts

Post by Frankshaft »

groberts101 wrote: Sun Jun 24, 2018 9:40 am Yeah.. most street rodders and entry level guys looking for dumbed down 9.7:1 crate motors usually are content with 90's tech and power levels. If that's the way you have me pegged then so be it but you couldn't be further from the truth because I cut, grind, modify, and weld most everything of my own. Hell, even my little lowly 302 mule motor is far beyond most guys race motor from a tech and modification standpoint. Cut manifolds, port welding, coatings, bigger lifters, handbuilt headers.. far from average and just how I do. Plus.. I can actually tune my junk to make things come together.

And regardless of decade being discussed.. the physics involved comparing duals to single remains a constant. Runner size and length changes will only tweak final results so much. All about carb signal dude.
Have you used one of the "new" carbs from one of the good carb guys? They are so much better than the "old" stuff its crazy. They truly work unbelievably well. Idle, throttle response, power, fuel usage, etc. They turn a 289-314 at .050 cam into something almost tame. Idle at 800 rpm for an hour if you wanted without loading up, coughing, bogging, flooding, etc. Absolutely INSTANT throttle response, that is literally better than efi. Like idling at 800 rpm, wack the throttle, it INSTANTLY is at 7000 rpm, and INSTANTLY idling again at 800 rpm. We are talking 2.4 to 2.8 inch throttle blades, with venturis sized to match, BIG. Keep in mind, a H.P. 1250 Holley dominator has a 2.08 throttle blade. The drivability is borderline amazing. On an intake that is big enough to drive a bus through. One of the 4150 versions are even better. They aren't cheap, but, they absolutely work. The right amount of fuel at the right time, makes up for A LOT. In a lot of cases, that is the issue.

I have one question for you Groberts, why a 302? Why not a 347 or a 363. And just tell everyone its a 302. Not to be a smartass, just curious.
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