SINGLE PLANE VS DUAL PLANE, WHICH INTAKE OFFERS THE BEST AF DISTRIBUTION? FULL DYNO RESULTS! 

That's downright scary. I wonder if it would be better on the old small block firing order vs the LS one. LS pattern is regarded as a little better for power and smoothness, but maybe there's a reason the engineers chose the old pattern back in the day when fueling was a bit less precise. If the LS pattern is indeed a little worse in this regard, that might explain why GM monitors it so closely. A lot of people don't know this, but most, maybe all, GM LS/new LT engines monitor individual cylinder air fuel ratios, even with just one O2 sensor per bank. The sensor and ECM is sensitive enough to detect A/F variations between cylinder pulses and too much variation will set DTCs P219A (Fuel Trim Cylinder Balance Bank 1) or P219B (Fuel Trim Cylinder Balance Bank 2). With just one sensor per bank, the ECM doesn't know which cylinder is causing the variation, but it still knows if one of them is off beyond a certain threshold and will set a check engine lamp with one of these codes depending on the bank it detects the problem on. And it doesn't take much. Seen a lot of this code on seemingly perfectly running engines. I've personally never seen another engine family where the OE does this.

I spend a lot of time looking at, and talking about firing sequence as opposed to firing order. In my opinion, what you are seeing is a combination of cylinder robbing during the induction stroke, and differences in cylinder scavenging during the exhaust stroke. Because of this, when I port intake manifolds, I bias the porting based on firing sequence, and if I'm making an exhaust, I never use equal length primary pipes, because I'm trying to equalise the pulse in the collector, not having 2 pulses arrive on top of each other, then a big gap. Good stuff Richard. Really looking forward to the next instalment

That's why I have EGTs on every cylinder. Also you can tune the carb jetting in the lean holes a little bit. At least to get to the safe zone. Also you can port the intake in ways to better equalize the flow to a particular cylinder. I've been there and done that (just using spark plug readings 30 years ago.)

Love seeing the a/f ratio differences of individual cylinders vs dp/sp intakes. Great stuff, i cant wait to see blow thru setup next. Could you do duel 4 barrel carbs also? Great channel.

At a pro stock team I woked at in the late 90's, we had to stagger the jetting by eight numbers to get the O2's evened out on the dyno. This was with symmetrical port DRCE 2 heads. The GM engineer said this was typical from what he had seen at other teams. He also said he had finished a week of testing at a pro stock truck team running 18 degree chevy heads (siamese runners); and they ended up staggering jetting seventeen (!) numbers to even out O2 readings.

A properly ported manifold can be key to a build. A lot of guys get an imported intake for cheap and optimize it for the price of a domestic as cast manifold.

One of your best videos, Richard. I tune for the leanest cylinders to be on the safe side. The A/F comparison between intakes is great info. Thanks man! 👍

Before I left for NNN 2023 I installed new Accel C-cut spark plugs in the 1997 C2500 454 Gen6 engine. Used Accels had 15k miles on them nice even Burn patterns on porcelain tips. Was impressed no Porting any by me pure bone stock.

I really like these type of tests 👍

Cool video..I have always used a open single plane type plastic carburator 2 inch spacer on both single/ Dual plane intake manifolds..Helps with vapor lock/ Fuel temp with a 800cfm Q-jet......

Really good stuff! Diving back into your channel and really digging the content lately

nice test. thank you

Thank you for covering this. I assume the pulls were WOT, imagine the fuel distribution at part throttle with angled throttle blades in the airstream. This is the reason I usually advise people to skip right over throttle body injection and go straight to port injection.

The blow through that could make in better or worse based on design. The shape of blow through hats vary pretty significantly between different manufacturers, and it would be hard to know what a “good” shape would be to improve the issue without testing multiple.

Right on

Obviously, stacks!

I love your information, thank you. How do you keep your engine [your body] running healthy? diet and exercise?

Hello Everyone!

Like to see this test with nailhead/holden firing order

1 & 7 are the front and rear on drivers side. Just goes to show that modern day FI w/an injector at each cylinder is more efficient and IMO wiser to use.

Boost will help distribution.

Ls7 motor i had done saw a 22hp and almost the same tq increase going from a edelbrock super vic to a CID. BR7 liked the CID

Be interesting to test on a 454 Gen 4, Gen 5 454 and Gen6 454. Big Block Chevy has 2 good intake ports and 2 bad intake ports per cylinder head in Racing Porting world. Mine runs hard and butter smooth at idle.

we used to read plugs and individual egt wish we had had 02 we used popsicle sticks xrams were tough

LOVE IT! I remember asking this question! Thank you! You are THE man! One more question, what about an throttle body efi unit? Do you think it would aid in distribution?

It's also worth noting that it might not be just an intake problem. Or at least I've seen evidence that the cylinder to cylinder torque production varies by a LOT driven by the exhaust design. Mostly because of blowdown interference.

I'd like to see how much better something like a Parker funnelweb intake would do with distribution.

I noticed that it was 7 and 1 both times, was wondering if that was a result of firering order and whether stagered jetting could alleviate some of the leanness without richenung the entire enigine too much. Great vid, very interesting.

Richard, this is really interesting. I really appreciate your insightful video, yet again. This kind of begs the question, why would anyone use a carburetor when you can fix this problem using FI?

Richard, I’d love if you could test the Edelbrock Pro Flo 4, specially in the Ford 302. Thank you.

Two things. First..try a Ford product firing order difference. Second, is there a preventative AFR number to get some added safety? Jump the secondary jets a few? Us street guys need to know if our afr targets are hurting us.

tunnel ram for the win.

Makes me curious about a tunnel ram intake.

Do you think the lean cylinders is a product of the intake design and/or firing order. I would to see the same test on a port layout like a SBC and see the individual AFRs cylinder to cylinder.

ebay sellers have started importing these 2 manifolds without branding for 175-200 bucks on both i currently have a the dual plain on a blowthrough 5.3 and has run fine but for hood space alone i wanted to get the single since its almost 2 inches shorter than the dual

I think with certain engine platforms and coresponding cylinder head designs afr balancing within each individual cylinder can be acheivable with a dual quad intake or ITB's. No real difference than port injection other than better control over precise fuel metering at all rpm ranges due to electonic control. Sure there will be some minor differences due to differences in individual cylinders like ring sealing, valve sealing, dynamic compression differences, cam grind tolerances, etc., but once each cylinder has its own dedicated throttle to control and refine or tune the end result should be balanced between them. Just my 2 cents worth.

I think the issue can ony be solved by cylinder head and intake Porting Richard Holdener. Not so much after hige CSA for 100+ Hp gains but to even out Cylinder Airflow and wetflow. Complex topic Indeed.

Now do it with a hi ram ! 😊 !

Has anyone added injector bungs to a dual plane LS intake in order to make a broader torque curve? No one seems to sell that configuration.

Which cylinders were going lean? Wet flow will be worse.

Is it due to a runner with additional airflow, less fuel, or both?

wish edelbrock would offer the dual plane in a fuel injected version .. torque with the old school look without using the truck intake

So what's making cylinder number 1 run much leaner than the rest

I've wondered about larger cross section for lean ports. I've looked at Buick 455 factory manifolds noticing those manifolds are huge in cross section. Never seen a dual plane manifold that large. Just thinking.

Mercruiser staggered jets may be 2 to 4 different jets, and in the carter's they used air directors and staggered jets

Can you please do a collaboration with Project Farm. That is all! Love your content!

Great test- Thanks! Could a simpler/cheaper messurement be made with a (cheap laser) temp measurement on the individual exh manifold pipes? Is cyl 1 & 7 often the most starving cylinders?

Always wondered why when the auto world made the transition to EFI, there weren't o2 sensors for each individual cylinder, as there were injectors placed for each individual cylinder?? Seems if your goal is optimization, that would have been the logical step, right.

Lean Mixtures do NOT kill cylinders or motors. Cylinder TEMPERATURE does.

even with efi it can still be 1-2 point variation but i expected carbs to be more consistent than efi

Love these tests ! Question, if you are running headers that don't have any O2 sensors in them, could you use a thermal gun to find the cooler/hotter cylinders ? Thanks in advance.

Would be interesting to test the dual plane with an open spacer for comparison

4-7 switch?

Is it possible to run 2 separate ecus on a 8 cylinder fuel injection motor with 4 02 sensors to monitor and regulate the efi system for maximum efficiency??? 🤔🤔 of course some wires will be spliced together inputs .. outputs would vary also.. could it be not a fuel issue but a air tunnel issue... I think by changing port size or inserting a restricted adapter in the lean cylinders might get less air and maybe more gas... to make that cylinder run same as rest..

Sefi for the win.

Richard... If you happen to see this... Could you please tell me which colors on the single plane intake graft, go to what cylinders ? It would help me in my research greatly... Thanks

I wonder if this has to do with each cylinder having a different flow rate/flow characteristics based on the head design and header flow concentration and o2 sensor location. Just a few thoughts.

Richard.. can i ask what car/truck u have... And ofcource engine? Supercharger? Cam?.. Nice vids... Just never stop making 💪 Greetings from Finland

Hey mate, looking for advice on a cam for a 350 sbc. It has standard flat tappet heads, new 4 barrel 600 holley on an edelbrock street performer. And new hei dissy. Also block hugger headers and 2.5 exhaust. Im after a cam that doesnt compromise torque and has a nice idle to it, any suggestions? Its a 66 impala. I want to make more power but not lose drivability down low

How does adding spacers under the carb affect distribution? I've always heard open spacer for dual plane helps distribution... but does it?

Would be really interesting to try to jet each 4bbl hole to fix it. Would jetting a corner up help?

How would these results go if you tried the Aces Throttle Body injection to compensate for the AFR adjustments?

How about a real world AFR measurement at part throttle between 1,600 to 2,500 rpm. Were an engine spends the majority of it's time.

Do sbc intake manifolds have the same issue? I am putting an old LT1 in my wife's 240z with a T56 but planned on shooting a little N2O for when she has a bad day. But I guess I will keep away from the bottle so that it doesn't do that.

So recommendation is read the plugs along with the O2 sensors?

Would stager jetting have an effect on the AFR for each cylinder? Also for those of us who don't have the ability to check each cylinder for AFR can we tune using exhaust gas or header temperature in conjunction with AFR?

What was the AFR on cylinders 4 and 6 with the single plane manifold?

I tried a single plane holy street dominator on my 400 Pontiac. It lost lots of torque below about 3000-3500rpm it sucked for the street. With gears more cam and higher stall speed I’m sure it would work ok but I had none of those things

That's why u have to read the plugs.

So at what number is AFR considered lean? Guess it's a lot less than stoich

Where's the other two cylinders traces ? and if you number them we may see what causes the dual plane unevenness.

Part 2 out yet?

With a solid cam, is it possible to adjust this with valve lash? Or am I way off?

Do equal length runners help?

Would port injection help with this issue?

i need to bring your blow thru carb back.. 😉

Look behind you! There a funny looking bald guy sneaking up back there around 9 minutes in

Dual carbs

I just watched your AFR video. Those lean cylinders would keep me awake at night. I wonder if a TBI would fare better than a carb? As I understand it, a TBI tries to throw the same amount of fuel in every cylinder, but vacuum pulling on the venturi of a carb will be a little different for each induction stroke. I put a TBI of a SP manifold on a Pontiac because other test I read about suggest TBI prefer SP manifold over DP. However, I call BS, all I need do is look at your manifold test and focus on Tq under 5000RPM. Still, all said and done, how do we fatten up that one cylinder? I'd try fooling around with a turtle, but with low optimism.

wow this is unexpected! another argument for going with a rich AFR.

When you say fuel injection make sure you make it clear you mean port fuel, not throttle body. Throttle body is a total waste of time, money, and effort. Still has a wet intake, for one thing.

120° LSA? Why? That will prevent the headers from doing anything useful. Heck it shouldn't even exist.

That thing needed to rev higher

good grief... Looks like going to EFI is the smart thing to use

Single plane it's the adjacent runner openings into the plenum with intake valve opening overlap that miss out. 3 robs 1 and 8 robs 7. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-uVw3GyTfHlE.html

Interesting but, you should rehearse the dialogue first. For someone like me who depends on the cc, It frustrating, to say the least. Mark

On much smaller engines that I get to work on, 13.2-13.4 AFR is normally where the best power is. In all honesty there has to be a better inlet manifold available than what was tested. Realistically either of those is unusable.

Too lean, too long, too bad. Priceless.

Sure looks like an intake gasket leak on the single plane

And this is why you run multiport injection...

Can you say PORT VELOCITY??.......all of that yadda was just summed up. Street cars, dual plane...circle track WFO, single. And I'll say ALL of the lore of the Hemi is complete BS....ALL of the pro-stock Mopars ran wedge engines.....period.

Take away: don't run carburetors.

I see talking about green screen on live worked you got pic up there @Richard Holdner

EDELBROCK = a few red faces I bet.