PowerTec 10 EP 11Hi-Torque Tunnel-Ram Mods

[@jayramirez3646]

Anxiously awaiting your spacer video!

[@vincentenk4449]

Same here!

[@manitoublack]

Come for the mid 90's video editing. Stay for the wealth of knowledge

[@alhailalhail8645]

Awesome information. Proved to me why experience is the most important and 99% of the new cfd designed intake manifolds dont take into consideration the cylinder robbing. Excellent superb video 👌👏

[@sgtrock6213]

Nothing quite like watching a Master practice his craft....thank you for sharing your knowledge.....

[@groomlake51]

A lot of racing roots blown applications like the single 4&7 swap because the blower front loads the manifold. Allowing them to stagger the compression less in the front holes. Blown Fuel engines with the 4,7 3’2 swap beat the crap out of #3 for some reason. Most guys run it .030”-.040” lowered down the bore.

[@user-dx4br5gd1r]

I have subscribed to your channel as I do find it helpful. You're covering many things that most don't know or understand. I do wish that you would have included resonate harmonic pulses and how they influence the port length and the percentage of potential filling of the cylinders at specific rpm ranges. You're offering a great deal of information and I'd love to see even more in depth information being shared to those that share your passion of physics.

[@vincentenk4449]

Thank you Mr. Vizard! Wish I was one of your class room students! And younger! LOL!

[@shaneshane1379]

Sir, you just defined something I did in the early 90s but I never put any science to it. I had a 350 Chevy with lt1 head that I spent many hours porting. It had a big nice comp solid cam and 12 to 1 pistons. The engine ran very good and I was always tweeking and tuning to get more out of it. One problem I always had was no 2 spark plugs was brown and not burning clean as the other. I knew I had power waiting if I could get that cylinder to flow. My intake was the old holley strip dominator single plain. I ended up beveling the entry edges to the port runners and the little engine had a tenth better et. Not focusing on more of what I did that helped, I simply realized the intake was a that needed opened. Then I scored a TRXY1 tunnel ram and two 660s with linkages. This was the beginning of a 19 year old kids lifetime love of engine building and heads up racing. I have used several of your books as well as smokeys books in my early years. I'm also proud to say my eyes and ears are still open. Thank you sir.

[@napolionbonipart3558]

I can't forget my 1st launch when switching to a tunnel ram and 660 holleys on my 468 I kept waiting for the front end to come back down! Super fun but inconsistent for bracket racing.

[@cjbert6790]

I’ve been altering port inlet sizes on single plane intake manifolds for years based on careful spark plug readings. It does seem to improve engine performance within a few percent. The way David does it on the flow bench is good.

[@jpfreeman3906]

Thank you Mr. Vizard for sharing your irreplaceable and awesome knowledge!

[@DragBoss351Cleveland]

David always love hearing your experience, and explanations, thanks for teaching me. I love the 5 flow benches, and lunch story.

[@marvingvx1]

Hi DragBoss, good to see your name in there once again. Take care! DV

[@DragBoss351Cleveland]

@@marvingvx1 you blew me away with the 4 7 swap, is that why they stagger jet sometimes without it. Great info, Darin Morgan and I talk at length on flow dynamics. appreciate you giving back,

[@riclambert4291]

Love this channel!! Love the way David spells it all out

[@ricardawessel438]

Great siecince and lots of testing ! And every seriös learn from . (-180 dge crank Fans outside ) thank you ,David for great Help !!

[@rickhowd6093]

I’ve learned a lot from you I bought lotta your books helped me build motors Rick from Michigan

[@DougsterWolverineGarage]

Another Michigander agrees! Good quality tech for sure!

[@mikecondoluci53]

IM SO GLAD YOU MADE THIS VIDEO BECAUSE IM BUILDING A SMALL BLOCK CHEVY WITH A 4-7 SWAP AND A TUNNEL RAM THANKS AGAIN

[@stevehammel2939]

Very interesting, Thanks David

[@peggyparrow2059]

Love your videos!

[@performancenaveia7821]

*very good teacher many details know a lot*

[@thomasmcglinchey2024]

Very well explained . The only criticism that I have coming from ireland that I dont see many v8s . I am more experienced with 4 cylinder engines like ford cvh or zvh . Ford n/a yb cosworth. Some uk engine builder like roy millington etc

[@marvingvx1]

Tom, did quite a bit of consulting work for Mountune back in the day when the Cosworth YB was all the rage.

[@thomasmcglinchey2024]

@@marvingvx1 thanks David am a big fan have some of your books I use them as a bible. A power tec ten on a semi hemi cvh head would be nice. I am working on one at the minute. Exhaust port is all wrong need to weld it up. Thanks for your reply

[@ronhodgkinson7683]

Perfect timing David. I am installing a tunnel ram on my Chevy 383. Keep up your great tips.

[@rayowens4355]

Thanks David. Your videos are excellent. I recently modified a Dodge kegger manifold with good results. But after seeing this video , i think i will do another one. Almost free power!

[@haydenspence6952]

Why dont you put a wall/divider between 4&2 so the air cant be robbed between cylenders?

[@johnnycu]

Sorry for your loss Dave.

[@markcarter78]

Great information. Thanks Mr David

[@dondagy9109]

Incredible information as always.

[@geoffcrabbe4323]

The Horse Power BOSS....Super job David....

[@brentonk461]

I ticked the like box, but I must mention here that, I believe, that there is nothing wrong with the standard firing order. if i were going to change the firing order, the 4/7 swap, would not be my choice.

[@black_sheep_fab9411]

Would be interesting to see smoke being pulled through those before and after. I know that's no comparison to the chaos of a running engine but would be neat to see.

[@pmd7771969]

We used to separate the ports with a divider wall of aluminum back in the 80s. Bv

[@jackflash538]

ELIPTICAL(protractor shape) shaped divider set into epoxy from top to bottom of the divider wall entrance between runners #5 & #7, then drilled out on the top edge of the ELIPTICAL divider extension & into the factory divider wall for appropriate sized brass machine screws??? I figured someone had already done it & you proved my hunch. Did your modification have any negatives regarding flow to cylinder #7?

[@joedozier3422]

Awesome, video and very good information. thanks for sharing

[@trentm7964]

Thanks David!

[@hondatech5000]

Thank you David thank you internet

[@richardgutteridge2127]

Condolences for your loss .

[@maxlacugnato442]

incredible amount of R and D data in such a short time.... Thank you David

[@josephnubile1970]

Fantastic video, you are the Man when it comes to Making Horsepower. I have alot of your books and it is so nice to share some time with you even though its virtual. Thank you for the Knowledge.

[@ridgerunnerperformance-jas5418]

Always informative. Thanks for your efforts.

[@edwardchascsa4191]

I've had great luck with modified spacers. Can't wait for that one.

[@stephendennis7871]

You are Leading the way as usual David and well explained.

[@StephenGiovi]

David: Thank you for the information on the tunnel ram manifold. I've been conceptualizing my path for achieving a balance in fuel delivery for the intake manifold in general w/o the 7 to 4 cam shaft split. I was told, and I hope the information is correct, that the richest to leanest cylinders running are #1, #3, and #6 on a SBC. I see that there is truth as your porting example will express. The only difference is the #4 cylinder which should be changed for the #3 cylinder....I hope this is correct. I'm going to give your recommendations a try. See ya!

[@Val_Killmore]

great knowledge as always

[@DURRIESVISION]

Thank you David for your wealth of knowledge and very informative presentation. Will help me alot with a f future tunnel rammed 350 chev gasser project. Look forward to your spacer video and future explanations. Cheers

[@MasterWitchDoctor]

He was something back in 1965 - 75 and maybe as late as 1980. His knowledge of engines is as obsolete as the small block Chevy is. None of any of this applies to an LS engine so why bother? In 1984 I was making 52 PSI at the intake valve on a 1985 GPz 750 turbo. In a time Terry Vance and Bob Carpenter were running 8.20s on their 1260cc Pro Stock Suzuki's and George Bryce was running 8.0 on a 1425cc pro comp Suzuki GS1100s I was running 7.70s on an 810cc street bike. It was the fastest street bike in the world according to several motorcycle magazines. Bill Hahn and Bo O'brochta were only .500 faster than my street bike on their top fuel funny bikes. I never got to finish that project because I got hurt in a wreck that took years to recover from. I'd love to hear David tell me why I could explode a turbocharger in 3rd gear because it was spinning so high the oil wouldnt lubricate the bearing. I had Terry Kiser put a 3 stage Torrington bearing in it which meant I could now shift from 3rd gear to 4th gear before it exploded. FYI in 3rd gear the bike ran a low 9 second et at 145 mph after it came apart. in 4th gear it ran a low 8 second et after it exploded. My point here is I was against guys a lot smarter than David Vizard who were doing a whole lot more with a whole lot less and I beat them so bad its not funny. I hardly think anything Davids ever built could run with a motorcycle I built 37 years ago.

[@bobg3034]

What if you welded a divider plate between 2 and 4?

[@dondotterer24]

I couldn't believe that I was on live chat with Richard holder .i told him to ask DV about tthe 5 and 7 cylinders on a small block Chevy and how you can port the intake manifold to help balance the flow he said I don't need to call DV because because it's not going to work because the intake runners are intake runners.

[@stephenmitchell3569]

Holder is very good over all and forever learning. I have dyno the swap special Howard cam order my spec. On a big block chevy 540 c.i. in the mid 80s. The gain was 91 hp to as low as 64 hp. With altitude/temp effect the most. E.T./mph and two other dyno used with 4021 feet difference but ran still on dyno with 47 degree temp difference. This was 13.28 to 1 fuel alcohol twin carbs, MSD, 7000 RPM. Plus O-ring block copper head gaskets...belt driven vacuum pump, other tricks like crank scraper.

[@stephenmitchell3569]

Check Steve Morrison videos on BBC swap twin turbo 3000 hp twin turbo. Think did same on Cleetus engine that just won this psdt week. Drove 800 miles and ran 6.99 /210 mph without turn up the engine even close to it's build. Check I may be almost wrong...70 yrs old watching and comparing note! After seeing .... Well the last of several videos I ordered the 540 power adder from BluePrint with couple filters and oil for two oil changes price was a bit over $14,000. Yep tax is a killer! Wish you the best and if your ever in Georgia north of Atlanta yell let you be my guest and I have a fun firearms collects I own my own range steel targets and great country cooking near by. I furnish everything for free. Plus you get look photos and time slips covering decades.

[@jamestupper5599]

Love your videos, and that you leave the bloopers in. Can't stop laughing at 3:55 bananafold. 👍

[@patrickmoore1017]

Fantastic

[@crittercraig9445]

Great video David Thank you for sharing your knowledge. Hope you are having a good one. Take Care

[@thomashodges6104]

Hi Dave Vary good info on port flow and firing order can effect flow, On Ford's small Windsor engines. The have the 3 7 swap on the HO motors. Cylinders across from each other.

[@jayramirez3646]

Wow cant believe how much I just learned thanks

[@mikedeal8659]

Thanks

[@bruceleroybell8139]

Love these videos Dave. Wish i could attend your classes.

[@richardgutteridge2127]

Thank you this a awesome!

[@bcbloc02]

A few percent here and there adds up to a whole lot in the end.

[@johnparrish9215]

Sir, could you do a video on or recommend a book about proper Epoxy work on the manifold and intake ports?

[@marvingvx1]

it's on my list to do John. If your a subscriber you will be notified.

[@TurboMinicom]

@@marvingvx1 looking forward to that one.

[@shoominati23]

Devcon is decent stuff

[@vortecturbo]

Love it David. Thank you!

[@ts302]

Thank you Mr. Vizard!

[@loafbred]

Since I first took an interest in single plane intakes (early '70's), I've wondered if anyone has ever tried placing fine steel wires across the length of the plenum (staggered, two or so levels deep) to possibly help atomize the fuel droplets.

[@BuzzLOLOL]

Screens and such can sometimes help low RPMs power, but anything you add increases the laminations of the flow and turbulence and hurts high RPMs power...

[@garyvaughan7748]

Thanks!

[@marvingvx1]

Gary, the kids will love guys like you for sure. DV

[@xxdabroxx]

I'd love to see a single plane intake ported by you something like an Edelbrock Super Victor, particularly a SBC design.

[@blairberg1081]

Ive got a tunnel ram on my 302 and its got a slight miss on number 5. New headers on all primarys turned blue apart from number 5. After it heats up it runs smoother. But firing order starts as 1,5 and those ports are right next to each other

[@johnelliott7375]

If I only had the muscle memory of those hands from the years of knowledge and experience, great day to you Mr. Visard! The practical experience and knowledge of him is priceless.

[@richardbrickner1688]

David, could you please build a Chrysler 225 Slant Six?

[@anvilsvs]

That would be the most widely used ram manifold ever put into series production.

[@MsKatjie]

Ok listerned to the vid further. Jumping the gun!

[@troymecey]

Unfortunately, I have the Edelbrock Street Ram. I would appreciate your thoughts on it. Thanks

[@michaelvanaalst9204]

Great information

[@TheProchargedmopar]

👍

[@richardoliver1303]

Excellent

[@kbommer64]

Would this same principle work with a crossram manifold? Have an Edelbrock crossram manifold from the 70's for BB Mopar in the build plan using throttle body injection.

[@oratiolibre1673]

The cross ram looks cool and works pretty well, see Engine Masters episode.

[@robmoore68601]

Love your videos and data, been following for a long time and helped a ton. Better than backyard or Monday morning mechanics around here locally. Recently read articles again talking about carbs and getting the right size the first time. But, what formula do you use for a tunnel ram? I know that 2 450 Holley's aren't giving me 900 CFM. I've got a 421 SBC Dart SHP, radical Solid roller cam ,275 intake duration 285 ext. Duration 650 lift int.645ext.lift 108 lobe celebration Herbert cams, 4800 stall, 3:73 gears. Weiand single plain tunnel ram. Will run mechanical secondaries, no choke housing, but what carbs should I choose from? 850's 750's 650's

[@grapeknutz]

WOW!!!!

[@drewsharpe7484]

Have you looked at a Holley Lo Ram? They actually have a large cast In “trumpet” to guide airflow

[@tonypierce5661]

Awesome video

[@laytonturpin864]

What, or which of these mods help or hurt a tunnel ram used in an Enderle “Bug Catcher” mechanical injection system, with a 7070 Victor Ram? I’m running this on a 440 cid SBC. It runs 5.902 @ 116.1 MPH, 1/8th mile, on methanol, 73 Pontiac Ventura, 3,260 lbs, including driver.

[@brianalbrecht4423]

Thank u David....great video....can u make the same changes to the runners in 5 & 7 that u did to 2 & 4...? That way u dont have to change the firing order......will that work...? That way it saves u from swaping out the cam...just thought I would ask...thank u again for taking the time to make this informative video....!

[@Hitman-ds1ei]

What about using Holden v8 firing order 12784563 then there is no cylinder next to each other in sequence

[@MsKatjie]

Few would know what such is!

[@DaveMcLain]

But they are across the intake from one another is that any better?

[@BuzzLOLOL]

Looks vastly worse than SBC firing order for a tunnel ram... maybe better for a dual plane...

[@arthurking6549]

3 &1 argue

[@arturos.3973]

Like

[@boharris8179]

I've meant to ask. Is the red tunnel ram that is in the background of your videos the one illustrated in your book Horsepower Secrets: Intake Manifolds?? Will the same concept help a single plane? Without the 4-7 swap would you wanna do this on the 5-7 pair?

[@ashforrest5408]

Hi David… Question do you sell the top plate you show in the video for the Holley Stealthram ? Or have drawings/cad designs for it ? Cheers Ashley from New Zealand.

[@garymathews4042]

can the carb mount plate be altered to even out flow on all intake ports ? moving the carb opening forward or back ? how would a LS engine firing order work with a Tunnel ram intake ?

[@4speed3pedals]

David, great series and I thank you for uploading these videos. It should be called a publication but, I am not a lawyer. My qustion is: What are your thought on the Chevrolet (Winters) low profile crossram. I hear Smokey Yunick had a hand it the development, if not for GM that possibly Edelbrock. I have the Offenhauser version I will be uising with 2 500 cfm Holley carbs on a 352 Chevy (400 bnlock with 327 stroke). I don't really expect an answer as it would take volumes. Wondering if you ever investigated the use of the low profile crossram vs the tunnel ram.

[@spambeanie2]

An oval port tunnel ram ported to rectangle Port big block Chevy

[@stephenmitchell3569]

Ooops Forgot to say Special Thanks from an old Gear head that used Slide Ruler and dyno decades ago.

[@Anarchy-Is-Liberty]

David, I'm going to be using the Weiand 925-1981 oval port tunnel ram on my engine (460ci bbc) with 781 heads, would this same idea hold true for that intake?

[@stephenmitchell3569]

Me Too..lol! For 540 BBC delivery in weeks now after 3 month wait..

[@jimdouglasgregory]

Can you please share the dyno information on the three different manifolds for a small block Chevrolet. I've been searching trying to find a comparison between an Edelbrock tr1y style Street tunnel ram and the Victor ram like you were working on. Thanks and keep it up

[@richardoliver1303]

Holden V8 firing order has 1 and 3 next to each other??????

[@MsKatjie]

I don't get it. After the 4,7 swap, there still is a " robbing event"?

[@dondotterer24]

I would like to see this mod.on a SBC single plane.I would like to modify the The Team G intake like you did adding the extensions on the deviders and the 2" spacer in one of your books.Will it be good on lets say a 421 cid street car around 570 HP. Also curious about the what you found out years ago when you tested the Holley Duntov intake the had the extra runner to help with the 5 and 7 runners. Thanks for all your help all the years. You have saved me alot of time and money. Thanks for the great video.

[@derranged28]

What are your thoughts on extrude honing? Have you ever tried it?

[@marvingvx1]

Yes -it does increase flow and some OE manufactures have successfully used it - however the finish is not conducive to good wet flow so only a port injected system can be used to side-step this issue. DV

[@carportshenanigans5918]

Interesting video...I’ve always bell-mouthed the ports equally on Ford efi 5.0’s when I cut open the plenum for porting. In the 5.0HO and 351w firing order, cylinders 3/7, 2/6, 4/8 compete for air in the stock type long runner intake....my question is: would the principles from this video still apply to a much longer runner, in which the air coming into the plenum has to make a U-turn before entering the ports?

[@marvingvx1]

Tell you what Mr. Carport sir, you have just initiated a video on this very subject. If you are a subscriber you will get a notification but don't look for said deal just yet. DV

[@carportshenanigans5918]

Sounds great, I am a subscriber, and I look forward to each new video that comes out. For what it’s worth, I’m about to purchase a flowbench and valve grinding equipment so I can dive into the deep end of porting and have qualitative results for my work.

[@oksblue]

Nice video

[@jimdude4464]

Grandfather knowledge of biblical pretorians🚗🙏🏽

[@peggyparrow2059]

Will down leg boosters work better on a tunnel ram ??

[@SinsBird]

This channel is dead for now, find his other channel here: www.youtube.com/@DavidVizard

[@sixsec636]

Where's the spacer on tunnelram episode

[@vinshanestrickland4179]

Where when and how to get in a class of yours david

[@marvingvx1]

Go to davidvizardperformanceseminars.com

[@citizendick6087]

What about a non 4,7 swap?

[@laytonturpin6957]

Does this apply to mechanical injection? Namely Enderle? It uses an Edelbrock VictorRam. It looks like the one you’re modifying now. Thanks a million in advance!

[@BuzzLOLOL]

Air flow is the key... the rest of the system is just trying to keep the A/F ratio correct at all times...

[@jeffcarpenter396]

There is something not quite right with the 4 and 7 swap cams you see slot of cranks break at 5 and 6 journals

[@BuzzLOLOL]

After the swap there are still cylinders robbing cylinders... wonder if an even better swap is possible?

[@saddletramp7215]

Awesome! Can't help but wonder if this would also apply to a BBC?

[@marvingvx1]

Yes it does!!!

[@saddletramp7215]

@@marvingvx1 Great and thanks for sharing your knowledge. : )

[@tonypierce5661]

Were is your porting school at.

[@gothicpagan.666]

Making a silk purse out of a pigs ear springs to mind. That designe must be very subceptible to cam duration and overlap?

[@marvingvx1]

Do I hear a hint of disapproval in your comment? Lets take a simple look at what was delivered here. For about 5-6 hours work and zero cost I have shown how to take a relatively cheap (as apposed to sheet metal stuff) cast intake and add about 25 hp and a similar number of lbs/ft to what ever your typical hot 383(585-600 hp before) delivers. Since it has a tendency to reduce any air and fuel distribution problems there are no cam issues that have to be 'fixed'.

[@gothicpagan.666]

@@marvingvx1No not disapproval (who am I to think such a thing). Having 8 branches into a plenum fed by 2x4 barrel carbs seems like a missed opportunity. The spacer plate test is going to be fascinating, does any of them separate out the individual carb. barrels to match the manifold runners? Time will tell, Thanks in advance🙂

[@marvingvx1]

@@gothicpagan.666 You are more than welcome sir. DV

[@jeffwooton7138]

When will we get to see LS stuff?

[@dynodaze5824]

A 4-7 swap is just changing the port "stealing" from 5/7 to 2/4.

[@antaresanthony8205]

I think the 4/7 swap reduces 6 & 5 stealing from 7.

[@LS-mw6lc]

Knife edge 2 to reduce stealing from 4, 7 from 5 same issue.