Camshaft 4-7 Swaps: What's the Reason?

[@GreenShogun]

I think we need an engine masters episode testing just this!!

[@TheDavidFreiburger]

Yup, I’m doing that

[@RichardMLowe]

@@TheDavidFreiburger so basically you can do a 4 Cylinder Swap A thought: Take a 1-8-4-3-6-5-7-2 motor and swap it all the way around 1-6 6-1 5-8 8-5 4-7 7-4 3-2 2-3 Wonder how that'll run/idle Companion swap the motor

[@RichardMLowe]

@@TheDavidFreiburger Oh 1 other thing: Use the same pistons intake (do a new ring replacement and have the heads cleaned up (no new heads just clean up what you have) #RoadkillStyle

[@eformance]

@@RichardMLowe it's already been done in boats. (it makes the engine turn the opposite direction so twin screws counter rotate)

[@RichardMLowe]

@@eformance kinda like how a Blower/Supercharger works ✌️

[@ecorey45]

Id watch a podcast series of david freiburger , steve dulcich and steve magnante just talking about automotive history and hotrodder history because everytime i watch there videos i learn something new

[@TexasRebel83]

So happy to see you on KZbin David!

[@myemailaddress93]

Dude, I am now almost 40 years old and Freiburger has been teaching me badass Street Machine knowledge since high school! You're awesome man!!

[@thomasking4136]

David, you know this, now you know I know this. Articulate and understandable presentation. Well done.

[@hpower8311]

Glad you did the follow up!

[@AB-80X]

Here's a suggestion to Engine Masters. Test four pattern cams vs. traditional cams. Two cams that are essentially the same, but one with the new four pattern setup. Run both cams in a single plane Brodix setup, but with both carb and EFI. So basically the following. Run 1: Dual pattern cam with carb on a Brodix single plane manifold. Run 2: Dual pattern cam with MPI on the same type of Brodix single plane manifold. Run 3: Four pattern cam with carb on the Brodix SP. Run 4: Four pattern cam with MPI on the Brodix SP. Those Brodix manifolds have bosses that makes it possible to drill and tap for injectors. Would be great to see a test showing whether or not there's something to gain from both carb and MPI ATB

[@BlindBatG34]

I always dig your content even though I'm more of an import guy. I bought the shirt for my buddy who's a dyed in the wool SBC guy. You know the Camaro, 350, insky cam, camel hump heads, hei, dubble pumper, 'merica variety.

[@DrTittieSprinkles]

Do he got a tree fiddy wit 2-oh-2 camel humps, a 3/4 race cam, and a Holley dubble pumper in front of a Mucie rock crusher and Lincoln locker'd 12 bolt?

[@dirtyworkzracing2747]

@@DrTittieSprinkles 😂😭🤣😅

[@dickjohnson4268]

A most prodigious shirt. If it were a FORD, you'd have to have about 7 shirts. If it is the firing order of an 18 cylinder Wright, you'd have to have at least two overcoats for each dash model.

[@cfmechanic]

When I ordered my cam comp asked if I wanted at the time I didn't know any better and told em to keep it standard for simplicity in the future

[@finnroen2334]

In old engines two cylinders, side-by-side on one bank fire 90 degrees apart at the back of the engine where the cooling is not so good. Newer firing orders moves these cylinders to the front for better cooling. Cylinder to cylinder AFR is also something that should be talked more about.

[@larney37]

I know you are involved in a million things, but man I wish you had a podcast!

[@johnbecay6887]

Building my latest Pontiac 455 street strip motor i investigated putting a solid flat tappet 4-7 swap cam in it. I found, much to my chagrin, that only hydraulic rollers with a 4/7 swap are available for Pontiacs.

[@stevie..d..pontiactransamm1215]

GREAT VIDEO, I LOVE THE 4,7,/4,7,2,3 SWAP ON A EXTERNALLY BALANCED SBC 400 ENGINE.

[@patrickrodig5667]

I know this is an old video......but.......I have a carburetor / hot rod shop and I do a lot of street & bracket style engines. Since the 80's from time to time I'd get a Chevy engine both small & big that had damage to #7 piston, rings or bearings....and sometimes a bent rod. No other cylinder was damaged eliminating a tuning issue in general. In every case the customer had his plug wire wires tied together or at best, 5 & 7 touching or crossed over each other. I only saw this with very high output ignition systems and fairly high compression. If the #5 & #7 crossfire, you're firing #7 45 degrees early. A recipe for damage. Back then I was working for a Speed Shop and could call any perf mfg and get in the back door at will. I had long talks with a Comp Cams & a Crane rep. Both told me the only reason for the 4 - 7 swap was to avoid the internal engine damage. The Comp Cams guy said Reher Morrison & Sheppard came up with this idea and once somebody else saw it, it became common. I've used 4 - 7 swap cams using the identical grind in a freshen up at the customers request and never was there an ET or MPH change we could attribute to the swap. In all of them, the engine had a very slight difference in the idle sound and less noticeable with open headers.

[@TheDavidFreiburger]

Interesting, thanks for taking the time to share that. I’ve never heard the crossfire theory, even after speaking with Reher-Morrison years ago.

[@dylansutliff8642]

I was so mad you didn't say why lmao. Thanks for the update.

[@necrofool]

I have actually been wondering why since your last episode. Thanks for clearing that up!

[@UnityMotorSportsGarage]

The Ford 351. The original firing order swap... The LS engine has the same firing order as the Windsor if looking at the cylinders.. Engine Masters DYNO test!!!!

[@7REDDRACO7]

yay Freiburger! as far as i am concerned your the one that made the truth of the essences, you are hot rodding and tech a great writer and tester and you always want to get to brass and it always prevails for us the readers subscribers viewers this is what the new earth is al about, you won't have to go to college because the real world testing and learning is done just there in it! its about free technology and free learning and communicating it all thats what i do . everybody loves youns just not crazy about the corporate you know how that gets, but i do not blame you for working hard alright person. bless you my teacher, bless you.

[@matthewmillar3804]

That's very interesting. I didn't expect it would make more power. Thanks David!

[@electric7487]

Today, Caterpillar 3508's still follow the old SBC firing order. Ford used to use both the 4-7 and 2-3 swaps on their Modular V8's, but recently got rid of the 2-3 swap. Now, their 5.0 Coyote, 5.2 Predator, and 7.3 Godzilla engines follow the 4-7 swap, which is, interestingly, the same firing order as the old Flathead V8's. The 6.7 Powerstrokes use both swaps. And finally, the L5P Duramax follows only the 4-7 swap. And to top it off, some MTU V8 engines do a 5-8 swap which is almost unheard of in the car world.

[@mike_aglione1132]

Don’t worry. I just swap the spark plugs around. Tons more power and it’s waaaay easier than a cam swap!!

[@marioherrera3060]

Love to see you on KZbin again you explain everything easily and persice

[@mattmiksch3587]

Thanks David Freiburger

[@tylersgoatinsurance7081]

Makes sense! Nice work on the video David!

[@naughtyponyracing]

Totally golden stuff to know!

[@panagiotis1519]

Nice video, thank for the explanation. Been wondering about it for some time!

[@danieldimitri6133]

Well at least he didn't sight the old 5-7 pair. I'd agree that would make sense on a front throttlebody efi engine where having a 90 degree pair near the throttle body could help feed the trailing cylinder. But for a manifold with induction in the center you just move the 90degree pair to 4-2 or 3-1 and it all has similar proximity to the air source. I guess it can be an interaction over multiple cylinders but I've never seen a decisive analysis.

[@mikeeagle2653]

Switching the 4-7 also stop cranks from breaking on high hp big blocks. A customer of ours kept breaking cranks on a big block Chevy alter and we swapped 4-7 and never broke a crank again and picked up power

[@robertmetz1912]

I would love to see you have a cam ground to fire the paired cylinders simultaneously, similar to the “Big Bang” 4 cylinders. Spilt wires for the plugs and skipping distributor cap posts. May not run smooth, but it would be interesting content.

[@Bodgemiester]

Hi David, UTG just threw down the gauntlet to you guys. Are you man enough to take the challenge!

[@danieldimitri6133]

@David Freiburger can we see a Dyno test with the air flow meter installed so we can see if there is a slight boost in air flow or a (slight) boost in brake specific air consumption. It might be fun to see if it helps a nitrous engine more Than otherwise.

[@caseyjones3684]

Thank You for the clarification.Good Stuff

[@ourgarage183]

Great more things to try for the fun of it. I think the LS sounds smoother.

[@kevinnobody3052]

I thought it was also discussed that swapping 4 and 7 was to keep 5 and 7 from firing in succession to cut some heat build up of the block between 5 and 7. Yes- no?

[@kevinmatthiesen8961]

I always thought that it was to stop crossfire between 5 and 7 because there in succession of the firing order.

[@stacyyealock6779]

Also 5 and 7 are fighting each other for air/fuel mixture.. does create a heat difference firing side by side.. slightly. Thanks for the water crossover, helps 7 or be (Not so good) if not for that. Only my opinion... Seen it done, scratched my head wondering why 25yrs ago, I think it made more than 3-4hp.

[@kevinphallus]

I graduated from HS and college with Darin Morgan’s brother.

[@christj7073]

You are so flipping smart, a real role model to us car guys, thank you for sharing your infinite knowledge!

[@dylanzrim1011]

Christ J boy howdy is this the worst messiah complex I’ve seen

[@fzj8022]

I can't remember which one, but I believe there's a common problem with certain Duramax motors where the snap at the front of the crank shaft and that's due to the firing order putting uneven stress on the crank shaft

[@doughopkinsjr]

Been testing the 4 7 swap for years. Unless you're over 550 ci we haven't seen a benefit. Speaking for a drag racing engine. We have changed out the intakes after making 4 7 swap and a tunnel ram made more hp mid to high range where a single plane and dual plain didnt make any difference.

[@johnbecay6887]

Doug Hopkins good info, thanks for sharing...

[@cerneysmallengines]

Can we also get an engine masters episode of just easy ways to squeeze hp out of engines. Different oil viscosity, different muffler locations.

[@bff1316]

Exhaust holes, shapes, pipe & headers, restrictors or not, height of carb, single or two plane, multiple carbs, mathematics and physics courses, and the list goes on. Kind of like fishing, not professional, the more you know the better your catch. If you are good, everybody is catching carp and pan fry and you are bring in bass.

[@hotrodray6802]

David, when are you going to do a back to back Dyno test on crankshaft dampers (harmonic balancers)? Somebody punished a test about 25 yrs ago. Remember the short/long rod test and the iron/alum identical head tests?? Back then we talked about dampers.

[@Snowmirage6453]

Thank you! I immediately thought... Wait... Did I miss him explain why? Lol

[@highoctain113]

That shirt is bad ass!!! I want one... and I'm a 6 cylinder diesel guy... jus sayin

[@brianglade848]

Be cool if you had a t-shirt that says "after a duck hunt I crave a breakfast sandwich and a coffee spiked with Makers Mark"....

[@chibimentor]

Clean Pimp award 2020

[@kingks3302]

A very Joe Dirt's dad attitude 😆 it just does!!!

[@travispeoples]

Thanks

[@walkerpayne7019]

Your garage is worth more than everything I own combined and that includes the house

[@nathanmayo1918]

Bill Compton is a vampire.

[@jeffparris8387]

David, I love everything you've done both in print and digital media. Anchoring your ship to MotorTrend on Demand has been HORRIBLE though!!!!!! In the midst of Covid19 and needing to cancel my subscription at least temporarily I had to search a deep deep dive to figure out how to do it. And it's so dishonest on MotorTrend's part to make the process difficult to the point I think they figure we'll just go, "well, I couldn't figure it out. guess I'll just keep it going" Most, like 99.7% of the content on MotorTrend on Demand is total GARBAGE! I have to search to find Freiburger, Finnegan and Dulcich (and accomplices) content. That SHIT that's been on Discovery....... we didn't want to see it when it was new. We don't want to see it NOW!!! When Covid19 is over I might be back. I hang on every freakin' show y'all launch (the FFD crew). But I'm pissed right now. Just go off on your own. Kick corporate to the curb. I watch Finnegan's Garage. Just do what he's doing. Even when the audio sucks

[@hotrodray6802]

So that the "modern firing order" of the LS engines us like the 351w and 5.0 HO FORDs. (Real Ford guys knew that decades ago)

[@BruceLee-xn3nn]

LS motor bottom end looks alot like the old ford fe motors from the 60s.

[@thehandlesticks66]

"if it ain't broke"

[@iqinsanity]

It take a very little amount of work to bolt LS heads on a sbf, and the LS uses the Cleveland deck height. They literally took every good idea Ford had and added tilted cylinder heads.

[@10thScaleGarage]

Is that a Traxxas E-revo with a BMW body on it?

[@TheDavidFreiburger]

Yup

[@johnwoodworth248]

So if I wore my T-shirt inside out would the firing order now be for a marine Application firing order running backwards ? Or lol

[@DiscoFang]

john woodworth ... down under in Australia & New Zealand.

[@red7fifty]

Inside out, and backwards....what's it fit?

[@elektro3000]

Just watched your previous video and I was wondering why you left that out!

[@dbelflower6793]

If your ever stranded at that shell gas staion again off fwy 99 in the valley let me know! Roadkill was cool as shit

[@LongPeter]

Would sound be another potential reason? Maybe you want the parts availability and knowledge base of an LS in your project but don't want it to sound like a Commodore.

[@peanutbutter2597]

And with a camshaft that matches with to whole intake and airflow systems

[@janisjanis6633]

When is roadkill garage coming back and is it coming back?

[@terrypickette118]

Thank You

[@MrDetroit1701]

I want that shirt!

[@NA-sd1fo]

I wonder if that more even bearing load of the LS firing order contributes at all to how much boost they can handle stock.

[@chuckfarley5415]

Just makes more sense. 18/18

[@Connor4x4]

Doesn't matter what firing order any newer ford engine uses, seeing as they still misfire on at least 2 cylinders all the time

[@TheBridgesboys]

The guy that created the ls engine copied the 351 almost exactly that’s why the ls heads with very little modification can fit a 351

[@nickreynolds5786]

I have a roadkill or roadkill garage truck that would be perfect for you to make an episode on

[@overkillaudioinc]

oh good, i was wondering

[@blownaway4371]

But, is there a dramatic sound difference?

[@hojnikb]

Kind of dumb idea, but related to cams; could one for lets say efficiency's sake, make an atkinson style camshaft for engines like that ? To my understanding, atkinson cycle trades power for better efficiency and seems to be commonly used on hybrid cars?

[@pylertyler]

Been wondering if there could be an episode on reverse split pattern cams. More intake duration and lift than exhaust.

[@ClumsyCars]

Cool story.

[@sethbarnes7608]

My caddy 429 has the 18726543 firing order😁😁

[@dirk013adfa]

1-5-4-2-6-3-7-8 for life....

[@SAMSTRECKER]

Nice eRevo

[@pizzandoughnutspage7817]

Would 3hp on top make that much difference? On a street car definitely not, and especially if it costs extra to get the cam ground as such.

[@wyattwoodard9801]

I have a 1980 Plymouth volare with a 360 in it. The 360 came out of a 73 dodge truck. The power steering pump pulley is bent really bad and I have been trying to find a replacement but I cant find one. Do You know were I could find one or what other replacement there could be for it .

[@leonbell9653]

Would that work for a second Gen lt1 engine with the optispark?

[@spccaldwellbretw.2701]

what about the distributor

[@bronsonc5.9]

Hey David quick question. On engine masters episode were to put 150 shot of Nitrous in a 305, after those bolt on upgrades to the 305 what did the compression ratio come up to??

[@charlesware3698]

Have you guys ever worked with the 8.1 .. ? Chevys big block new version.

[@bbdog10]

But does this work on the throttle Body injection motors? 89 to 98 tbi motors

[@bretth3224]

If you swapped an LS firing order to the older firing order would it make it sound like an old school v8?

[@kermets]

Hay David, I thought GM also change the LS firing order because the old style was firing 5 then 7 which caused more heat in the high HP iron blocks firing two cylinders next to each other...... or it a wives tail ? cheers Brett

[@johnbecay6887]

kermets i've heard the same thing, even in older engines. swapping the 4 7 still leaves 2 cylinders paired in the block and the firing order, changing 5/7 pair for the 2/4 pair, but, the 2/4 pair is closer to the coolant inlet from the radiator and thus receives cooler coolant. as a result the 2/4 pair run cooler than the 5/7 pair and you experience less detonation. thanks, Brett

[@jesussaves6348]

I have a rebuilt 351C with 2v heads that I know nothing about and I can't seem to get it running right. Can I swap the firing on different cylinders to see if it will run better?

[@mcmillanbs43]

Ooooh!

[@Rook00]

What ever happened to the roadkill ford ranchero

[@arnoudjanschut]

And you just changes the leads from the distributor to the spark plug, too?

[@jasontruman1215]

Arnoud Jan Schut yes it has to match the camshaft.

[@ericingram7864]

Are the old Pioneer Champion series subs still in those boxes??

[@martinholmes3499]

"Fart-Burger"

[@VintageMoparnut]

David can you or anybody on here help me with my timing on my mildly build 318? I dont expect any body to show up at my home just walk me through the detailed steps to time and fine tune my engine ? I have nobody in my area to help me including automotive shops

[@eformance]

Chris Craft did a 6-5-7-2 1-8-4-3 swap on the 327 in some of their boats...

[@Stainlessslayer]

So minimal benefit for a guy like me with your "ultimate average sbc"

[@socalltd]

Hey Dave . . I have a 71 raodrunner 1/25 mpc ertl model kit that i would like to pass along to you. . its not assembled and in its original box. I'm in n the San Gabriel Valley. .

[@Panhead49EL]

Do they sound different? Could you swap an LS to the old firing order?

[@dylanzrim1011]

Panhead49EL dunno. Yes. Although you’d be best switching to flatplane, far better balance than even the 4/7 2/3 swap

[@dylanzrim1011]

Would require a full build though

[@danieldimitri6133]

People say they sound different but all orders have banks with the same uneven pattern. If all the header tubes have the same length they shouldn't be any different other than maybe when it tends to misfire.

[@chevy6794]

Roadkill garage? Is there more episodes coming to motor trend on demand? Hasn’t been since dec 2?

[@pgtmr2713]

Why not swap 1 6 or 8 5? Bit of a rabbit hole isn't it

[@elyeli6250]

so this wouldnt work in newer vehicles unless it was reprogrammed as such?

[@MsPokemonsoulsilver]

if your planning on using efi then yes you would need to tune for this and change firing order within the PCM/ECM or even upgrade to an aftermaket engine controller. but if you switch it over to a carburator and get rid of your pcm then you could do this to a new engine.

[@dukenukeum3d650]

Do u half to have that cam to do the swap or can u just do it anyway jw

[@cfmechanic]

Where do I get this shirt

[@danielmazurek7559]

Are there any cam grinders in the US that grind 4 7 swap camshafts for big block mopar engines? I have not been able to find any!

[@HemiJoel]

Daniel, try LSM cams in Michigan

[@frankm8533]

So what can I do with 4.8 that's about to go in my 80s shortbed. Trying get some power but not redo the whole engine.

[@kstricl]

Practically anything. Look up Richard Holdener on KZbin and Sloppy Mechanics on facebook (Richard has also contributed quite a bit to the sloppy group, and has also been on Engine Masters several times) for lots of ideas. The 4.Great pretty much responds favorably to anything that increases airflow (cam and headers are), before you get around to doing anything with the heads. Mind you, this is just me following along, and not my own experience, so do your research.

[@BlindBatG34]

What kstricl said. In a couple recent videos Richard recommended a decent cam, valve springs and possibly shaving the head for more compression was worth about 100hp for the little 4.8.