CUSTOM INTAKES--BUILT NOT BOUGHT

[@MegaScott]

Back When I was a crew chief on an old six cylinder Asphalt Modified, Slant Six Chrysler, We made our own intake by using 2x2 square tubing about two feet long with an aftermarket 4bbl intake bolted to that. my goodness, tons of torque! Also I made a custom 904 push button shifted trans with no torque converter, It had a ball valve controlling the trans pump pressure. Super low inertia for lightening quick acceleration off the turns!

[@gibbsey9579]

Caterpillar forklifts used the same idea on their transmissions, when the "clutch" was depressed oil pressure was bled progressively back into the transmission. They still had a torque converter though.

[@muskyelondragon]

Rich, your vids are solid freaking gold brother. Priceless!

[@richardholdener1727]

Glad you like them!

[@garyderian4350]

It appears that other resonances, such as plenum volume Helmholz resonance is occurring here. Perhaps attaching the ram tubes in a 180 degree fashion to have equal pulsing in each plenum will provide different or better results. Also connecting the two plenums with a valve will allow different tuning.

[@mazcatii]

Look at the mazda factory racing lemans winning 787b 4 rotor. Adjustable intake runners depending on revs, beautiful engineering 👌👏👏👏

[@richardholdener1727]

yes-and early F1 motor had same thing

[@Karpo1986]

@@richardholdener1727 Alfa Romeo and Lancia had variable induction in their road cars in the 90's, although they had only two different runner lenghts.

[@robertokandal]

@@Karpo1986 In 1960 already existed that,,,

[@JETZcorp]

Some 2-strokes did the same with their exhausts to change the tuned-length of the expansion chambers. Some jet skis even had variable water injection in the exhaust to change the temperature, which changed the local speed of sound (!!) inside the pipes to alter the powerband.

[@9psi]

Have you ever done a similar test but vaying the runner diameter by dropping in sleeves?

[@richardholdener1727]

not with drop in sleeves but good idea

[@alloyspeed1889]

I was thinking the same thing.

[@ChevetteWiz]

@@richardholdener1727 Radius entry and/or increasing the runner diameter helps gain power back with long runner intake manifolds, but not always.

[@dug8531]

I tested a method similar to this on an old motorcycle once. Slid velocity stacks up and down on the top side of carbs only(downdraft style). Long=low end short= top end

[@sorryociffer]

@@dug8531 I have a set of these for my V twin Aprilia... vacuum operated.

[@madmod]

Even with you going into detail explaining how runner length affects power, youve still got people leaving those comments that manifolds won't lose 60+ ft lbs of torque just from runner length despite having hard data right in front of them.

[@Crysmatic]

you pick the combo that has the most area under the curve in the intended rpm range. It would have been nice to list the exact runner length.

[@BustedWalletGarage]

I think it was the “High And Mighty” Ramchargers of the early 1960’s used radiator hose as the intake runners with a huge metal box as the plenum. Some pictures the runners would be so long the carbs were almost above the roofline. Those cars had some cartoonish exhaust too.

[@donellmuniz590]

I saw it run on tv, and the megaphone exhaust give it the howl from Hell!! It absolutely BELLOWED!

[@donellmuniz590]

The Ramchargers (all young Chrysler engineers, like Tom Hoover) basically invented the tunnel ram, and used this knowledge to design the Sonoramic Commando (lol) long ram intakes, as well as the Max Wedge cross rams.

[@xmo552]

Those cartoonish exhaust were tuned also

[@albertgaspar627]

you are right, and they used hose so they could keep cutting it shorter and shorter until the quarter mile times increased, and they knew what the last best runner length was. They needed that plenum because unless you use a sequesial port injection, every time the intake valve closes, the air/fuel mix runs back up the runner. If there's a shared plenum, the air fuel mix goes to another cylinder. but with individual runners and no shared plenum, the result is a hazy fog of atomized fuel hanging over the top if you've ever seen a mechanical fuel injector setup idle in the pits. Bruce Crower took it a step further, using different length caliopes on his injectors.

[@xmo552]

@@albertgaspar627 Another reason for the plenum is to keep air speed from siphoning the fuel up and out of the carb while moving foward. Look at early drag cars and Bonneville cars. I almost caught my car on fire while test driving and tuning while on the freeway with no air cleaner and no hood. 🔥😂👎 You should see later header designs, like what Smokey Yunick did. Or, the crazy-cool 180 degree and 360 degree headers. That's the tuning I like to read about.

[@RadDadisRad]

I saw a rotary with electronic slides that got shorter at higher rpm and were long at idle. The slide length was set to rpm and throttle opening percentage.

[@mchristr]

For engine geeks this is something we've wondered about. How does this apply to a boosted engine? Should the runners/volume stay relatively small while the boost does the work?

[@carlhilliard8846]

I would love to see this also.

[@williamkillingsworth2619]

Runner length will have a similar effect on the power curve n/a or boosted. short runner high/ long runner low. Boost pressure is just a measure of resistance. It depends on what’s causing the”most” resistance, again its dependent on you combination of parts, as to whats going to change. Runner area matters, the less area in the runner means more velocity for the same mass of air(how big is the straw), which is beneficial at low engine speed, The velocity helps charge the cylinder at low rpm. But this can begin to be restrictive at higher rpm. Think about valve opening time and how that shortens as engine RPM increases. The more RPM increases the less time you have to shove air into the engine. So a short larger runner with a good sized plenum, is what you want for high rpm turbo power. Do you want a easy way to experience this go get a bunch of straws like a coffee straw and something you can suck a milkshake through and play around with blowing different fluids through them, Air is a fluid. Mazdas 787B 4 rotor race car for 1991lemans season had adjustable intake runner lenghs. The only vehicle I’m aware of with the moving intake manifold. Check it out There is no one size fits all answer, but boost pressure is just a measure of resistance in your system at a specified CFM and rpm. Over all air flow is what u wana pay attention to.

[@johnparrish9215]

Every turbo engine he puts on the dyno he runs NA first, you will see that the curves mirror each other in shape. Just look up his other videos.

[@richardholdener1727]

same under boost

[@oldleatherhandsfriends4053]

@@williamkillingsworth2619 fluids don't compress

[@timothybayliss6680]

I am surprised that you don't have a 3d printer yet. Lots of even hobby printers will push .065 nylon trimmer line that you can find with glass or Aramid fibre. The benefits of having a printed intake is you can have proper runner taper and gives you so much more freedom in packaging.

[@DodgyBrothersEngineering]

or make sections that screw on for quick changes.

[@richardholdener1727]

I have some 3D printed intakes too-the problem is usually heat

[@AP-vv1yu]

Damn Richard always comes out swinging with knowledge! 🔥🔥🔥🔥

[@okjd159]

My father wrote his Masters Thesis about this exact problem in 1951. I have a pdf copy if you have a place I could upload it to.

[@richardprice5978]

Did he hang out with the the ramchagers/work for Chrysler corporation of gmc ?? If so thank you ☺️ to your dad as most of the information that I’ve learned is from older hot roders and dodge explaining how the 1950-70’s max wedge 🧀 engines 30” inch long runners work

[@jordanwaughtal7649]

I can upload it to my server. Email it to me. [e-mail]

[@donellmuniz590]

That was a forward thinking young man in 1951! Most cars on the road at that time still ran flatheads of one kind or another, the only overheads were the Caddy, Olds, and Hemis, all brand new then. I think on the flatheads, the block itself was such a choke point, the manifold would hardly matter.

[@jlda1887]

I'd kill to read that thesis...

[@okjd159]

@@jlda1887 Do you have a throw away email, I could send it.

[@evillancer4580]

any tests on runner area/ diameter or a tapered runner?

[@richardholdener1727]

taper is harder to do-but made easier with 3D printing

[@richardprice5978]

Does the angles of entry on the runners from the cross ram intake planning to the intake of the cylinder head port make a big difference or not really?? ( like having it go straight in like most stack injection vs 2 or 3 90* bends or a U mandrel bend in and out of the cylinder flanges to the intake plenum and of course everything is port matched because obviously that makes turbulence which I don’t think 🤔 ever works to your advantage to make higher hp or torque ) The reason im asking questions is I’m planning on making a variable length runner with flaps ( 🤔 of trying to have 2 to 3 different stages so I have lowered end , middle and higher end torque by folding the runners on top of each other ( 🥖 like kneading bread dough or making candy 🍬 ) with stepper motors ( my Version of vanos and or Gm’s DBW Throttlebody ) ( still will work with other ways like toggle switches or vacuum/boost canisters but the general setup is way different from mine ) controlling too open up a different set of intake runners ) inside like the ford SHO v6 aluminium intake that some people Polish up. mixed with the 1960’s max wedge 🧀 mopar engines longer 30” runner intake / Nelson racing engines / Edelbrock intake Cross ram with a built in super chiller running a/c cooling at @ -10 f maximum capacity ( R744 instead of R12 refrigerant ) ( might never see it though and be wishful thinking 💭 that I get sub 0 f cooling on a 60+ F day and actually need M100 spray as antifreeze on the HX air side ( water side already has automotive antifreeze in it, 1-3 gallon total loop sizing with different 5~G main water to air loop to shed most of the boost heat way away from the front of the intake but after the low mounted turbos ) with higher humidity if at all🤷🏻‍♂️ We see ) it’s for my 440/426 hemi block platform was working on a b deck but it’s dead 💀 and this one is easier to build into a foe hemi it’s a or hot rod and NASCAR trick you might know about Richard. That cobra 🐍 intake picture you chose for the thumb nail is one funny 😂😂😂 looking part as I genuinely laugh at loud and thought 💭 what the hell are you up to now Richard after watching the video Look 👀 like it works but it’s goofy 🙃 cartoonish as all get out never seen anyone running one like that in my lifetime the closest thing I’ve seen is high and Mighty ramchagers/stack intakes but that’s straight up or in a cross ram folded flat with the ground not 120~* pointed out wards ( and obviously not across ram ) and 2-4 feet up from the rest of the engine. Would having variable exhaust runners work the same way as the intake side of the engine system?? I can’t get it to work on the project engine I’m working on right now with the turbos but maybe some one smarter than me in the future can or this will be helpful information for me and others in the future as I know that there’s a difference between log and longer fixed runner length exhaust as in the other videos of yours Richard and on the internet/real life information available to me and others

[@sam_s_]

What would happen if every other cylinder had an intake runner and header that was turned for bottom end power and the other half of the cyclenders were tuned for top end power? Would you get the best of both worlds? I always wondered the same thing with 2 strokes. What would happen if you took a Banshee and had one cyclender ported for bottom end and put on a bottim end expansion chamber. Then port and pipe the other cyclender as a top end screamer. It would be cool to see.

[@richardholdener1727]

I did that test with the Fast adj intake on the big LS3 intake test

[@guidoheeling1179]

ferrari actually has an ajustable intake length on the LaFerrari, that tech is already banned from formula one before they got tu use is, the new gmc 3.0L inline 6 diesel also has variable runner length intakes.

[@ReubenHorner]

Most vw engines seem to have flaps that block one intake port per cylinder I think. Acts similar to variable runner length

[@michaelangelo8001]

@@ReubenHorner So do those 4.6 Lincoln engines.

[@julienboucaron9780]

@@ReubenHorner Those flaps changes the swirl/tumble of the air entering the cylinder for lean combustion. Those flaps are removed in high performance engines.

[@Torquemonster440]

My 2018 Tundra has automatic adjustable runners , that vary according to load and RPM. Cool stuff.

[@GrimReaper528777]

@@julienboucaron9780 the tumble flaps also prevent super knock during high load low rpm situations like from cruising on the highway and having to go up a hill in the highest gear of the transmission. Most of the time my calibrator will have the tumble flaps just stay open from about 1900 rpms to redline. Plus they help with cold start up because the air swirl causes the fuel to mix better.

[@lb9gta307]

I recently watched a similar test with an ITB 4AGE. You could hear when the harmonics were working and when they weren't. He also tested straight, 45* bend, and 90* bend trumpets of a similar length to see if that cost power (it did) as well as different opening styles. All real interesting stuff.

[@gurjindersingh199]

Garage4age ? I love that guy (no homo)

[@kissmyaskew9844]

This guy tests a lot of variables, it's cool stuff.

[@GUEST-qw4te]

Mr. Holdener..Thank you for actually listening about testing differing lengths and general tpi mods. I posted on another video with suggestions in regards to this.. The fact that you actually did it, just blows me away... It also shows the wave resonance effects something fierce on that first one...just remember Everything in a tpi system is tunable.

[@xmo552]

Everything in everything is tunable

[@manitoublack]

Talk about seeing reflected waves in the power curve. Oh and this is exactly why OEM's have sold many intake manifolds with dual length runners. Long for the low end torque, then swaps over to a short runner as the RPM rise. Mostly on 4 and 6 cylinders. Why settle, when you can have both ;)

[@GrimReaper528777]

My V8 Audi S4 has that as well. Even seen three stage/runner length intake manifolds on the older timing belt V8 Audi engines. Pretty sure that the older Lamborghini Murcielago 6.2 liter V12 had a three stage intake manifold too.

[@greggreg6975]

Almost all new cars have some form of variable intakes.

[@donellmuniz590]

That and VVT have completely changed the game. EFI did too, but these things build on that. No wonder modern engines have such a wide powerband and a flat torque curve! If Comp or Isky or Crane were to develop a retrofit VVT system for old-school V8s, sportsman racing and hot rodding would never be the same. And honestly, a simple, rudimentary system could be devised with a variable cam gear, incorporating a clutch or spring with electronic control, based on load data.

[@MLFranklin]

Excellent work here. I would have loved to do this experiment back when I taught engine lab back at U of MN. This is a perfect example of the concepts taught in the classic IC engine textbook by Taylor & Taylor decades ago. I'm so glad you chose to show it here. Hardcore fundamental stuff. We all love Engine Masters, but the knowledgeable engine guys like your channel just a bit better.

[@ryanmalin]

Now you got me looking at intake manifolds going "whaowaahowowowohm"

[@donellmuniz590]

This just proves what Mopar knew 60 years ago, when they designed the long ram manifolds for big blocks in big heavy cars, and short runner cross rams for their Super Stock drag cars. No secret, for an old goat like me, lol.

[@rileydrabek6795]

This was awesome! You should test the working man's mods or the hs budget stuff like throttle body spacers, muffler delete, or change to duals and "cai" (but you did that)!

[@madmod]

Im really going to need to buy a couple of your books.

[@albertgaspar627]

Focus first on the exhaust system--get something that really clears out the combustion chamber, since you can't burn that exhaust twice. That in itself will create a "Draw" on the intake, and if you tune that to make torque at what RPM you will run, then the ram effect almost acts like "boost"

[@Justls1v8parts]

Just found this awesome love the indepth knowledge for me long Runners suits my car and my needs more tourqe

[@chriscatarcio9933]

I can't wate for the 4,3 Chevy tests .....my edrbrock pef. Is a let down. But l got a good T.I.G....PORTING THE HEADS NOW.. I DID THE INTAKE TO. GONA RUN STOCK CAM TO GET A BASELINE. U TEST STOCK AT 200 HP. SO IL SEE WHAT HAP. MY MACH SHOP GOT A CHAS..DINO.... ASK DAN CHEZOM.

[@jayallen408]

This is pretty disappointing I've been wanting to put an old Cobra motor in my 97 Grand Marquis. Barely getting 400hp looks like I'll have to go with a 4-cylinder Honda K swap

[@madmod]

That 13 inch runner was definitely going back up. Goes to show B heads with the right induction don't do bad for peak power when optemized.

[@kevinmcneeely7277]

A Volvo redblock would be great. i look at this as my 2.3 is 1/2 of this v8 but our heads diffently not as good. But I thiink same concept applies.

[@teamvoxracing2192]

I'd LOVE to see this test on a 4.3 v6 there's only 2 different intakes available, dual plane vortec, or dual plane non vortec. Unless you can find one of the old nascar intakes. I'd be interested in seeing what gains a single plane would have on my little nitrous 4.3

[@DefenistrationAlley]

I'm almost done with an EFI-converted Edelbrock #2114 intake on the 4.3 in my '97 s10 and I'm excited to test it out. I don't think the good Vortec heads have any other intake available. They call this intake a "dual plane" but the runners are definitely set up different than a v8 dual plane, it just has the left and right bank divided at the plenum. I'm pretty sure Richard did a video recently using this intake with a later model 4.3, carbureted of course. I'd personally love to see a "big bang" test with EFI and turbo boost on a stock bottom end and see what it can take if tuned properly.

[@DefenistrationAlley]

PS what a cool project for a 4.3! Subscribed.

[@teamvoxracing2192]

@@DefenistrationAlley awesome thanks!! I subscribed back 🙂

[@joelstatosky1817]

Hello fellow 850i owners. How are all those cylinders, I'm assume you did preventative maintenance so your car is running reliably. So now you want some more power without boosting, and you cant find a cheap manifold because you have a v12? Same here bro, same here.

[@donellmuniz590]

If I was to build my own rat rod (someday!), and hood clearance won't be an issue (no hood!), I'd build the longest manifold I could, and the longest-tubed headers. Cuz I'd be doing burnouts and street cruising, not racing. Besides, it's also about what looks cool.

[@Marc_Wolfe]

Now DIY something like the Isuzu used on the 6VD1 engine (like 2001 Rodeo). Vacuum solenoid for secondary throttles. even if secondaries stick open, it doesn't run away.

[@mcqueenfanman]

Someone should build a tpi system for the GM torquers, the Buick, Olds, & Pontiac 455s.

[@Prestiged_peck]

Why go to when you can just add injector ports for a sequential system? Or just go with a Holley sniper electric carburetor

[@mcqueenfanman]

@@Prestiged_peck I don't know but maybe a tpi type intake on those old 455s might work well. I remember Hot Rod did build ups on all of those engines about 20 years ago, they said that some of them were at the maximum measured torque just as the dyno run was beginning. They were probably making more but it wasn't measured. A tpi intake would enhance that even more. Don't worry, no one is going to make a tpi intake for them.

[@MrChooch84]

Would love to see this performed again with a tapering diameter runners, different shape runners, or a hydroformed running thatr has a surface like a golf ball, just to see if CFM increases... I love the content! Can you do a Volvo Redblock? B230? :)

[@crazyDIYguy]

I always target that low end grunt, I don't really drive in the super high revs. Longer runners all the way 👍

[@Ricky-manic]

Should make a supercharger intake for a GM 3.9L V6 not alot of intakes for that not like the 3.8L V6

[@johnparrish9215]

Mr. Holdener, with a long runner intake manifold, if you were to move the injectors further up stream would the engine enjoy the benefits of Charge Cooling or does this effect happen mainly in the plenum with carbs??

[@michaelangelo8001]

It works.

[@richardholdener1727]

Hint-did you see the injector bungs in the top of the plenum? There were lots of tests run with these!

[@ts302]

@@richardholdener1727 future video?

[@cajunroadwarrior]

Ford actually had a dual runner length manifold on their V6 engines. It was a complex manifold with a trapdoor. By default the engine would be set at the long runners and as soon as the engine crept up in RPM the little trap door would flip to the short runners at high RPM. It wasn't a very reliable system.

[@tartus4916]

until ford perfected it with the 1989 ford taurus sho, 3.0L DOHC.

[@PoppaSnipe]

@@tartus4916 That would be Yamaha that perfected it. The whole engine in the Ford Taurus SHO 89-91

[@The_R-n-I_Guy]

I only street drive my car and I never rev very high, so I guess a long runner would be best for me

[@richardprice5978]

Most of my stuff stays below 4 grand RPMs 80% of the time even if it can rev to 6-8 grand before hitting redline and the new RB v8 stroker ( 4.5 crank stock 4.25 bore ) mopar engine I’m putting together isn’t setup for HP as diesel like torque curves are good enough and modern 6 or 7 manual transmission and rear end gearing work so well together and is more realistically useable day to day

[@ChevetteWiz]

This brings back memories of my old Formula SAE college days. Back then, I thought intakes were all about flow numbers, but then I realized the importance of Heimholtz Resonance on how to tune the intake plenum, runner length and diameter, and radii. Air flow is fluid like and sound waves/resonance affects the flow of the air going into the engine. Think of it this way, if you had a subwoofer up against a draining kitchen sink, the water doesn't flow as fast as with no sound.

[@fokjohnpainkiller]

Any book you recommend on intake design?

[@OgamiItto70]

@@fokjohnpainkiller Scientific Design of Intake and Exhaust Systems by Phillip H. Smith. Also The Design and Tuning of Competition Engines by the same author. You can get some of the same information from David Vizard's How To Build Horsepower in a less dry format. (This is no exhaustive [no pun intended] list, just a few to get you started. Amazon or your local library would be a resource to try for more.)

[@AndyFromm]

Build & test a long tube equal length collector like header.. (edit: as intakes, equal length long tube intake header with collector and no plenum.)

[@richardholdener1727]

I've built lots of adj headers too

[@AndyFromm]

@@richardholdener1727 i meant for on the intake side, sorry for not being clearer.

[@GrimReaper528777]

@@AndyFromm I want to do that on my cars. Basically the custom intake manifold will be headers in reverse to suck in the air more effectively.

[@erenzoscroggins8056]

Just gotta love Rich... His Info is always helpful and valuable💪🏾💪🏾💪🏾 what's crazy is I personally know a guy out here in AZ with a 1929 "something car" with 2 long custom intakes that sit on each side of the 350 sbc with edlebrock carbs on top.. I can and will prove it if needed... But great Info Dog

[@michaelblacktree]

When I saw the thumbnail, I immediately thought "Starship Enterprise". 😛

[@richardholdener1727]

Engage

[@michaelblacktree]

"Mr Sulu, plot a course for Gapplebees, maximum warp."

[@robhudson6133]

Great video Richard How much do find plenum volume to effect power I've always seen best results when air flow is even to all cylinders not always an tubular plenum design Thankyou as always

[@richardholdener1727]

take a look at the Kegalodon video

[@charliekeel3264]

This is why I have a Hilborn 8 stack EFI on my street car,, great video well done !!!

[@martinherrington4885]

I would really like to see you mess around with an old caddilac 500 motor and do a mild to wild build up on it and then finish it up with a big bang on it

[@donellmuniz590]

Me too!

[@minimanadam]

The cobra motors DID have adjustable intake runners . It sat under the manifold and would open at 2500 rpm

[@richardholdener1727]

are you talking about IMRC plates?

[@TheRetarp]

Too bad the factory manifolds weren't tested with their adjustable runner lengths enabled. Would be neat to see if there would be more torque way down low at 3000-3500rpm.

[@richardholdener1727]

they just have IMRC plates-no change in runner length-but those help

[@shadowopsairman1583]

The 2nd and 3rd intake were better, the 3rd had gains across the board

[@franksdg125]

The factory intake with plates would be adjusting through the rpm range. By removing them it eliminated that but wouldn't they adjust to rpm/load

[@4_700Melnikov]

Hi, would be interested to know how long runnes can be when power start drops down in middle rpm, were is the limit when runners is to long Thanks for the videos, it's very nice👍

[@ze_german2921]

What about throttle response? Do short runners increase it, like ITB’s? I heard have very light internals does the same thing.

[@richardholdener1727]

short runner don't increase throttle response

[@donaldconnolly220]

you built your manifolde as separate left and right manifolds...build with oposit mixed left and right sides....and a common plenum

[@richardholdener1727]

we ran it joined and not joined-all various lengths. Adjustable rules

[@icesecurity]

I like having torque on the lower end for street racing, light to light, took all my smog stuff , larger fuel injectors, chip and tune, larger modified exhaust, cold air intake, on my 1986 Corvette, scary torque monster with the long runner length, don't need high speed dangerous stuff.

[@NOSLEEPATALL]

Any trying the IMRC to change from one to 2 runners to optimize the lower end torque curve with the longer/shorter tests?

[@horizoninabucket]

Please, some time, play with adding ports between the two plenums. i.e. One connecting the two in the middle, and one connecting the two at the end (which could eventually be open/closed by the ECU at different RPM ranges) i.e. Like Mazda's KL motor (i.e. the V6 used in the mid 90's Ford Probe). Would love to see the gains actually quantified.

[@richardholdener1727]

I did that

[@davidcunningham00]

I like the 2nd intake runner, sure you dont have all the top end power but that bottom with some on top is a really good setup

[@georgeedellstein9133]

I worked in a Chevrolet dealership in 1968 thru 1972, and remember the dealer's son ordering a 1969 Camaro Z28, and with it a staggered dual quad CanAm intake manifold. I would assume that the way the intake was made, the plenum was probably open which would lead to high rev. capability. Have you ever played with one of these?

[@richardholdener1727]

I have not run the factory cross ram intake

[@michelcote]

Pick the one that has the most area under the curve

[@redactedrider7606]

I saw a intake made out of a fire extinguisher lol

[@danmyers9372]

Back in the 70’s a buddy of mine made his own sheet metal tunnel ram intake manifold for the 350 Chev in his mid engine sand rail. He used like 1 1/4 or 1 1/2” tubing running up to a square(ish) plenum. It totally didn’t work. The fuel just ponded in the plenum under the carb.

[@danmyers9372]

The runners on his manifold were around 12” long (or slightly more) as I recall.

[@lawrenceveinotte]

if you were going to make a tunnel ram for a small block chevy, 327, stock 461 heads, around a .500 lift cam running a 2g tri power carb setup, what dia. tube would you choose, its for a 35 ford pick up hot rod, thanks

[@richardholdener1727]

easy to test-squish a 2-inch or 1 3/4 inch section of tubing over a 461 head port and see what fits best

[@Fljeff7]

I liked the adjustable runner intake on the early mid 90s L35 4.3 very efficient and effective

[@CRUSHFACTORPC]

Imagine an Intake that allows the perfect length per specific RPM that's is a constant variable length intake say every 50 RPM max torque at any given RPM.

[@richardholdener1727]

do a search for bmw variable intake or F1 intakes when they allowed them to be movable

[@marknelson3511]

Richard I know it would be a pain but I’d love to see you take the data you just learned and build a variable length manifold that optimize both top and bottom. It would make a great vid!

[@independentassesor2630]

That was done years ago with a For 250 Cross flow engine. Was quite impressive. It was controlled by small electric motors increasing the runner length up top with the rpm from 3000 rpm onwards. The torque was very impressive

[@zacharyohare6029]

Pretty much what many factory intakes do, but obviously size/space restricted. Would definitely be useful to have both options though. Going road racing, pop on the stacks and run with it. Then putting around, swap em out.

[@donellmuniz590]

When you think of the engine as an air pump and a complete system, you have to measure from the carb/tb blades all the way to the exhaust exit, wherever that may be (uncorked at least). So the same principles work on headers. Long runner intakes need longer tube headers, short runners need shorter header tubes. One wont work best without the other. I dont quite understand the terms and physics involved, but I understand results.

[@xmo552]

If you want to learn, study up on fluid dynamics and tuning flow.

[@donellmuniz590]

@@xmo552 I probably should've done that 30 years ago, back when I still read books. Nowadays, if I cant absorb and understand content within 10 minutes, I move on, lol.

[@xmo552]

@@donellmuniz590 Yuuuuuup. Well, try a KZbin vid. 👍

[@antonisautos8704]

Hey Richard, I know this isn't a LS video but I have some questions I hope you could test or answer. I'm actually looking to use my gen 3 6.0 LQ4 in my yukon 2500 as a tow rig... well I actually do that now but I need to get as much low end HP/TQ as possible and was wondering if you could do some testing on what works and what doesn't?

[@richardholdener1727]

we have-even designed some new stuff (don't tell anyone)

[@MrVeteranMan]

@RichardHoldener, what is the tallest spacer you have ever put under a carb? 12-36" testing would be awesome!

[@richardholdener1727]

I think Freiburger stacked them-not sure how high

[@cj15941]

This is really awesome! I’ve got a 3.0/3.5 liter Nissan V6 being built and will be running individual throttle bodies. Been trying to figure out how I’m going to figure out the “right” length for the runners up to the throttle body(s), and then length of trumpet out away from throttle body(s). My question is,, Would a guy see the same type of changes with my set up or would the butterfly being closer to the head affect it differently? Have you ever done any dyno tests on runner and trumpet length differences with ITB systems?

[@richardholdener1727]

runner length still works the same regardless of where the throttles are

[@vlasi4x417]

Would have the sin wave changed much if the two banks were balanced between themselves? balanced at or just after the throttle bodies v's the rear? Looking at the photo it looks like the two banks are separated.

[@richardholdener1727]

we ran joined and not joined, with different lengths of air intake, different injector positions-I only covered the runner length

[@busij44]

Half the cylinders long runners, half short runners.....best of both worlds, right? Lol.

[@richardholdener1727]

I did that when I ran the LS3 intake test with the Fast adj intake

[@OxBlitzkriegxO]

where does the 96-98 modded short runner intake fall in all of this? its been a common mod more decades now, sad to see it missed out on here. i believe the hot ticket is to remove 1.5" from the stock runners. thoughts on where that intake would fit in all this?

[@richardholdener1727]

We did that on the 96 motor too-did lots of testing on it

[@terrycarter8929]

Can you list the different runner lengths so we can decide which is best for what we want? I want to build a dual quad tunnel ram for one of these engines for a Model A build.

[@richardholdener1727]

I don't have the exact measurements

[@samstewart4807]

hmm why dont your runners have any taper?

[@approachingtarget.4503]

Car craft did this test on a bbc with a mech. Fi system. Found that 13" from valve face to air opening of the stack. Made the most for cinder ramming. This was for individual runners. On a 98 honda vfr 800. The do use a two length running intake. The tall stacks would lift out of the shorter ones at about 10000rpm. A very noticeable change from 10000 up to 15,500. This test doesnt take into account the shared plenum or amount of volume a plenum has on the effect. The first graft showed a very erratic graph line. As the runners got shorter...they leveled off. When you get to the dodge magnum dog house intake. You will find ne of the best designs for runner length and volume. Another amazing pc is the wiend dual tunnel ram.

[@allenhoward9379]

Thanks for using ford engines in this video!

[@Phil-rs5wl]

Should try to run shorter runner in the back and increase height as you get towards the throttle body. On equal length runners with the throttle body at the front the rear runner is over twice as long as the first one.

[@richardholdener1727]

The plenum is not runner length

[@jamesetyrrell13]

How about 2 intakes..a right and a left with 2 throttle bodies..and then check the runner lengths

[@richardholdener1727]

these had two plenums and two throttle bodies

[@bighowardshsn]

I have an idea. Have throttle body on long runner and a 2nd throttle closer to intake manifold to open at high rpm

[@thejues3919]

Like a 6 pack or triple quad so u could drive on one and then when u get ur foot into it it opens up

[@kurtkimmerly5898]

Have you seen a Ford SPI 3.8 engine before?

[@kevinjohnson9372]

Is that ford 3.8 the one with imrc wear it's a 12 runner system 6long 6 short? They did em on 4.6s too

[@jackrabbit7389]

It’s been done

[@Daytonaman675]

Sliding runners typically do much better but are a fucking nightmare to setup

[@Brock_Landers]

So I remember back in the day my dad rented a Lincoln Mark VIII and it had the 4.6 4 valve and it was pretty damn fast. I also drove one of the OBS Ford Lightnings with a 351 and while it was pretty quick, it wasn't anywhere near as fast as the newer body style Lightning with the 5.4 supercharged. I used to race a modified 2000 Lightning and I had a 1992 Acura Integra with a custom built turbo kit using an old Garrett T3 from a Dodge Daytona 2.2 and it was ALOT of fun. It made 308 whp, but it also didn't weigh much, so it was pretty closely matched to the Lightning on paper. The Lightning came stock with 360 HP, but he had a custom tune, a bigger supercharger pulley, I/H/E, and some slight bolt ons, so he was making around 500 whp, and on the street we were always close, but he would always pull away from me. It was always alot of fun though and we became friends, but I always wanted a Lightning...or a Mark VIII.

[@TractorWrangler01]

I wonder what would happen if your intake runners were larger by the carb and narrowed down to the intake port size so you would get more and more velocity as the RPM increased while still maintaining the pressure effect of a short runner down low. Would you get a smoother less erratic torque and HP curve with less loss on the botton without sacrificing top end power?

[@micmalone6722]

I think you just had a million dollar idea. If you can figure out how to do an adjustable runner while you are going through the power band that would be awesome!

[@richardholdener1727]

lots out there already doing it

[@melbrooks5816]

pretty sure Yamaha had constantly variable intake lengths on some of their performance motorbikes. They also did a lot of intake/head work for other car companies

[@ryanmalin]

But how? I dont think its possible.

[@garyhowe88]

@@ryanmalin it's easily possible, was a hill climb car here in the uk that had it.

[@DodgyBrothersEngineering]

@@ryanmalin Ford in Australia did it on their production line 6 cylinder cars for a few years.

[@garyhowe88]

@@DodgyBrothersEngineering continuous? Or just two stages?

[@DodgyBrothersEngineering]

@@garyhowe88 I'm not a Ford fan, so I know they did it but never really went too deeply into it. I was told it was continuous but I suspect it was just two stage. I can't see it being fully adjustable. It was quite a while ago, like 20 years ago.

[@ralfbond258]

sheet steel & sheet aluminum alloy make great DIY intake manifolds..

[@donellmuniz590]

Back in the 50s, the Crower U-fab was just two long tubes and two intake "adapters", for lack of a better word. The runners were just hoses that you cut to length and clamped down!

[@guidoheeling1179]

this is awsome!!! this is something i always wondered

[@glenmcfarlane599]

Richard, we've seen a consistent theme with runner length and relative power. As a rule of thumb, is there a typical length that you would class as long, and same for short runner length? And is this measurement the effective length from the back of the valve?

[@GrimReaper528777]

Everything is probably specific to the engine.

[@richardprice5978]

Grumpy bill Jenkins wrote about it and posted to the internet somewhere ( brain 🧠 fart 💨 ) but be forewarned it’s long but filled out with really useful information. It had one entire section dedicated to port and head design and a different one for valve train design and setup and after all he figure out how to keep up with much bigger engines than his for awhile

[@fatherfirefighter7751]

Where can I find the video of the 4.6 4v intake manifold shootout?

[@richardholdener1727]

I have not posted it yet

[@dwnrety1]

Hi Richard, I understand this is an older video now but I have a kind of odd question that I dont see anyone else asking.. What about variable intake runner length, in a different sense - using different length runners per cylinder. I've been kicking around the idea of making my own prototype intake manifold for an LS swap and I got the idea to alternate runner lengths. So 1: long, 8: short, 7: long, 2: short etc. etc. So theres 2 long and 2 short on each side of the engine. Have you ever tested an intake like this or do you have any kind insight as to how something like this might perform or affect engine life?

[@richardholdener1727]

I TESTED THAT ON THE FAST ADJ INTAKE-TO SIMULATE THE SINGLE PLANE-NO MAGIC

[@dwnrety1]

@@richardholdener1727 interesting. I'll have to check that video out when I get home from work. I'm excited to see which end of the spectrum that favored. Do you have any videos on the effects of 4-2-1 headers? I've seen that style on other applications, especially 4 cylinder engines but in my admittedly limited research I haven't noticed anything like that with the long tube style for the LS engines.

[@jimhertel5125]

Highest average wins

[@RobertMacNeil-t7c]

what would happen with indiviual throttle bodies?

[@richardholdener1727]

nothing would change if the intake design was the same except you added 8 throttle bodies

[@secularsunshine9036]

*Let the Sunshine In...*

[@srdjanstanacev3886]

do it work on diesel?

[@donellmuniz590]

Please explain "sine wave". I know this brings us into pulses, laminar flow, helmholz resonators, etc, ALL terms that I read but don't really comprehend.

[@TheNumbers400]

I like the "belt driven" intakes the most :D

[@GIGABACHI]

🤣 HAH! That was awesome, here's your well deserved 👍🏻.

[@andyharman3022]

I prefer the gas-driven intakes.

[@TheNumbers400]

@@andyharman3022 having both is better :D

[@shadowopsairman1583]

Just use a 4.6 intake...

[@baloneyjusticecheezedog]

I feel like the thing you should be doing with this is doing profiles on a bunch of different engines see if you can find some kind of data correlation. I also be interested to see what does the intake runner diameter do to your numbers... It seems like you never really explain this in the video... so I am wondering if after it clears the size of the valves, does it not make sense to make it bigger or what not.. Whatever the case, this might be a good fallow up content video, even if the topic is short.

[@halldorra]

GM did experiment with this in the Opel Omega Lotus headed 3.0 six in 1986,they used a variable runner length manifold

[@richardholdener1727]

Did they use it on the Carlton?

[@halldorra]

@@richardholdener1727 Hi yes it was actually a 3.6 and it was called Opel Omega in Germany,Vauxhall Lotus Carlton in UK,it was a popular joyriders car next to the Xr4 Turbo Ford Sierra

[@P71ScrewHead]

it all depends on the cam being used, that 262 is a stage 1 comp cams, right?? I'm going stage 2 on my 2v 09 P71.. Hey, i'm going to put titanium retainers on my car, its completely stock, have you ever dyno tested power gains in doing just that mod?? i'm hopefully going to record it n upload it on here for my 2v Panther loving ppl to see n maybe they'd like to do it as well, not one video have i seen of any person doing this mod to their engine (4.6L 2v) so i'm doing it.. That's a mod that'll give increases in both hp n trq at all rpms n even more rev-ability..

[@richardholdener1727]

titanium retainers? with stock springs and cams? It won't change by 1 hp

[@P71ScrewHead]

@@richardholdener1727 well, i'll soon find out..lol Springs n cams will come after, but 1st i want to have documented dyno results after every mod cuz too many times ppl change 2 or 3 parts n say they made x amount of hp but do they know what part made how much, most certainly they dont.. Plus many claim some mods make 0 hp (cai, tb/plenum, shorty headers, etc) so i'm going to let the dyno results speak for themselves instead of repeating other ppl's opinion.. ;)