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

WHICH INTAKE OFFERS THE BEST AIR/FUEL DISTRIBUTION? HOW CAN A MOTOR GET HURT WITH A PERFECT TUNE? WILL MY MOTOR BE OKAY IF THE AF METER SAYS IT IS SAFE? HOW TO TUNE AN LS! CARBURETED AIR/FUEL DISTRIBUTION. SINGLE PLANE VS DUAL PLANE, WHICH INTAKE MAKES THE MOST POWER AND TORQUE? CHECK OUT THIS VIDEO WHERE I COMPARED A SINGLE-PLANE EDELBROCK VIC JR. TO A DUAL-PLANE, EDELBROCK PERFORMER RPM INTAKE FOR POWER AND AIR/FUEL DISTRIBUTION. BOTH INTAKES WERE RUN WITH 8 OXYGEN SENSORS, 1 IN EACH OF THE PRIMARY PIPES OF THE HEADERS TO MONITOR THE AF RATIO IN EACH CYLINDER. JUST BECAUSE THE AF METER IN YOUR EXHAUST SHOWS A SAFE MIXTURE (AN AVERAGE OF THE 4 CYLINDERS), DOESN'T MEAN THE MIXTURE IS SAFE IN EACH CYLINDER.

[jmans]

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.

[stickman-]

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.)

[mattg]

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.

[theshed]

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

[bryanmaloney]

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.

[josephtravers]

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! 👍

[brracing]

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.

[anthonyrowland]

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.

[tonybernheim]

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

[ricksshop]

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.

[ericschumacher]

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.

[earth]

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

[dannytravis]

Makes me curious about a tunnel ram intake.

[mattmorrison]

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

[Jim_Lawrence]

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

[blainesnider]

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

[brracing]

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.

[wydopnthrtl]

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.

[Dannymclovin]

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

[ninjahawg]

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.