Today on Unity Motorsports Garage we dive into a basic entry guide to running Dual Quads both low rise and tunnel ram setups. Special Thanks to David Vizard for wealth of knowledge and teaching me through the years!
Excellent. Vizard's documented guidance even helped me with my Triumph TR cylinder head work. I also built a 5.0 Mustang with a 650 Holley that got over 30 MPG on the highway with a B-W T-5.
That is awesome stuff! Please subscribe as you will see more of more good stuff coming up.. David and I will probably be doing a live chat coming up here in the near future. Andy
Tunnel ram tuning article from years gone by advised; lots of timing in quickly, and a big accelerator pump shot. On a BB jet boat, double pumpers are best. Vacuum secondary carbs can be used if you change the 30cc acc. pumps to 50cc, tune your pump cam, and use a light secondary opening spring. Drag racing about the same.
Freekin' Great Video! this should be required viewing for all multi-carb planning & installation. Can't click the Like Button enough times man. Thank You, and I will be recommending this Vid to everyone that asks me about our Tunnel Ram & Multi Carb setups, because I can't say it better brother.
Thanks for Watching and kind words... I will have a part 2 coming in a week or so... Covering more in depth stuff regarding jetting and how to go about it.. Andy
There is nothing like that sound of a Tri-Power! You can hear that sweet sound on the chassis dyno videos that I have posted on Casper where the camera is above the carbs! Andy
Andy. I surprised myself watching this. I cant believe that the exact intake setup i got a shout out from you. And now with you explaining the science behind it a bit i feel really good about my choice. Thanks man!
Always enjoy your videos, I'm working on a few different Mustangs at work. It's really cool to finally get my hands into some Ford stuff. I couldn't help but feel like a badass in the 69 fastback lol!
Big thumbs up! Great info and love your Holley circuit mods video! Seems like those mods might apply to a single carb setup possibly. Thank you and Dave so much for sharing your time and knowledge with us mere mortals...;).
Yes sir !Uncle Tony , rich @precision transmission and you . Are the only 3 people. I hear and value your guys information. ! Ty for the videos and knowledge!
Thanks for coming over... I'm going to be doing a part 2 coming up.. getting more in depth on carb specific things but you can see some vids I have done in my Tunnel Ram playlist on here.. Thanks again! Love your channel too, the two lane blacktop car AWESOME Andy
@@UnityMotorSportsGarage yeah ill be going back for sure! I mostly fit the "looks cool" category. Gotta work on my dual quad tuning skills haha. Thanks again man.
Great video. I built a small block Chevy 427 stroker. I ran a fabricated aluminum tunnel ram with twin 500 cfm edelbrock avs2 carbs. With a lityle tuning, It dynos at 548 hp and 547 ft lbs of torque. I used a 1 to 1 linkage, it runs like it's fuel injected. Thanks for the tips.
I just picked up an Edelbrock TR5 tunnel ram for my 318 project. The top is the open plenum tall style. The plan is to put 2 Edelbrock 500 CFM AVS2 carbs on it. I will be running progressive linkage using the rear carb as the primary. I think that I can still keep low end torque and good fuel economy this way.
Great video. Doing my own 273 with an offy DQ. Using an Eddy 1406 as primary(rear). Homemade progressive linkage and trans kickdown. Unfortunately couldnt use an oem throttle cable and had to go Lokar. Thanks again!
Another great video Andy. I actually have your mentors book and use it occasionally. I like my Holley carbs and I’m not a big fan of the Edelbrocks. I prefer my double pumpers and my 4 speed😬. Looking forward to the next video 👍
Thank you for the kind words! Part 2 will be coming up here in the next week or so! I have ran Edelbrocks with success but I'm like you.. I'm a Holley guy that loves Center Squirters and Double Pumpers Stay tuned! Andy
Tim, you will LOVE it! Thanks for checking it out... Im going to do a part 2 in a week or so and get more in detail about the tuning aspects. I cant wait to hear and see that Pro/Stock build run... I wish that there was a true vintage Pro/Stock class to run... I would find me a Maverick and do it in a minute! Andy
@@UnityMotorSportsGarage I have a sub that wants to give me a 79 Fairmount, for a build. Think I am going to take him up on it. That would be a cool pro stock build for sure
@@DragBoss351Cleveland Everyone here needs to check out the Drag Boss channel here on RU-vid if you love Ford's... More specific Cleveland's Tim is the MAN.... Just saying...
Thanks for covering this, love your content, here and with DV. Sorry about the $5000. I know I'm kinda late to the Unity game but this shit doesn't get old. Cheers from Calgary
Thanks for coming over! Hopefully Tony and I will be doing more stuff together here in the near future... The bad part is he lives about 6hrs away.. Andy
I use to run a single 700 dual line double pumper street dom intake 305 58cc head 350 small block stock piston rod an crank comp cam extream energy 1600-5800 rpm band cam advanced 6 degrees in a 80 k10 with 35-12.50 340 gear 4 speed and tuned the 700 Holley myself put the and the effort like you said I know I was around 22 mpg and higher as I kept jetting and power valves acc spay jets and cam and what time they gave the most amont offfuel and had no hesatation it ran on 92 the best I tried higher and lower no better I jetted till the plugs were powder gray then went back up two sizes then they were a dark gray but no black and no black smoke out the pipes ! Been fooling with GM since I was about 8 years old I know hard to believe but my dad and when he was at work my mom would come get me at the mec garage at the end of the road were we lived he worked for GM but had a little retirement thing like we know you just can’t stop or quit right we’ll he taught me carb and always didn’t like most any of them but I learned that most Quadra jets pump way to much fuel in the motor at the wrong time so black sky out the pipes there is your gas mileage he would say wasting fuel is the number one thing on bad gas milage I found myself with some time and collecting all kinda hollys playing with them all kinda set ups I always wanted just a little big for what I was doing I could always say holly is the closest thing to fuel injection you can get ! There’s nothing in a carb more tunable that has a way or you can change something and make it better ! Hey hollys a good girl you just have to know what she wants and make her happy and at the end of the track she’ll make you happy ! Great vids man I like it the great thing is I’m learning some things I didn’t know !
Got a question that kinda splits this video with the Glyptal video. You talked about how important it was to keep heat out of the intake. Have you thought about painting the bottom of the intake with Glyptal, for a little more insulation?
I have watched a bunch of your stuff and thanks for all your help .... Hopefully you can help me out with an issue I have. I bought a T Bucket that has a 1980 350 chevy ... mild cam, roller rocker, and 4 bolt main, dual 390 cfm holly on a tunnel ram... I know nothing about the lower half. When I got the car, it would run ... but gas would run out the headers . My neighbor knows hollys but not so much about duals on a tunnel ram. Both cars are 4150's ...390 cfm .... before they had 6.5 power valves, 57 jets, and 110 needle .... after rebuild ..... we put in 4.5 power valve, 50 jets, and 97 needle ...... after adjustment ... car will idle just fine, idle in gear, drive in a slow to medium acceleration to any speed .... but if you try and give it a quick throttle .... it will stumble once ( like cut off ) ....almost like it is starving for gas .... or getting too much .... after the single stumble .... it takes off like a bat out of hell ... Hoping you can give me some direction ... Thanks .... Have had a bunch of people telling me to ditch the tunnel ram .... but it looks too cool ..
You need to up the accelerator pump squirter.. what you are feeling is a massive lean spot.. if by doing this, and it helps but doesn't solve the issue altogether you will need to replace the 30cc accelerator pumps out for 50cc pumps.. Hope this helps! Andy
Hi Andy , another great video . A quick question brother - What different carbs , sizes , vac / mech and brands have you tryed on casper over the years , and how are you getting on with mixed up boss ? Cheers and Have a great day Andy .
David, I will get into in the next video that will be coming up next week... needless to say I have tried many different things over the years... Some worked and Many didn't! LOL Thanks for watching and I will keep them coming.. Andy
On an old school Jet Boat with 350-500 CI , the tunnel ram is a go-to item. Jet boats are typically in the 3000-5500 RPM range. I thought most cast tunnel rams give up power down low and gain up top above 6500. I guess a huge stroker motor would not matter but should the smaller engines stick with a dual plane intake?
General, the cast tunnel rams to me fall between the dual plane and single plane designs. You have 8 equal length long runners which really boost mid range torque production. The tunnel rams carry the top end out futher due to a complete clear line of sight to the back of the valve... To me its the perfect mix but you have to be willing to have a whole in the hood most of the time! Thanks for Watching Andy
I have a 1963 mark 3 Zephyr, 302 Ford, Turbo Thrust Offenhauser tunnel ram, dual 600 vacuum secondary Holley's and bug catcher. It was running kind of ok, but then won't even start. Fuel is getting to the float bowls but nothing squirting into the pots.
I'm running a 496ci big block Chevy, with Brodix BB2 heads, 10.5 to 1 pistons and a 720 solid roller cam and a weiand 1985 tunnel ram. I'd like to try a pair of Edelbrock AVS2 650cfm carbs. I'm located about 600 feet above sea level, got any tuning advise or instructions that will make jetting easier?
running two 450s on a clifford 2x4. pulled 383 HP 418.7 Tq ,60 over 292 inline 6 4 speed wide M21,430 Dana just best of best scheider cam solid ,Grind Number: 280-88F Intake Duration (gross): 280 Exhaust Duration (gross): 288 Intake Duration (.050”): 240 Exhaust Duration (.050”): 246 Intake Valve Lift*: .507" Exhaust Valve Lift*: .525" Lobe Separation: 108 Intake Valve Lash: .016" Exhaust Valve Lash: .016" RPM Range: 3200-7000 *Based on 1.75 Rocker Arm Ratio 194/174/ valves 600 springs. in went into this no budget,im 64 doing this all mine life , wanted to do something different. I taped the heater lines to go through the intake to heat it up ,First pull was with a MAN-A-FRE 3 X2 DIRECT INJECTION .ALL 3 CARBS INDEPENDENT, 1 CARB FEED 2 CYLINDERS, NO PLENUM AND ALL HAVE IDLE CIRCUITS,ORANGE THROTTLE CAM JETS ARE LOW 60S 5 LBS fuel pressure,one of the 2 bbls cracked at the base on the dyno, good thing I had the complete 2X4 set up.I have bolted on dual quads on SBC,BBC, AND A USED 1050 DOMINATOR ON A STOCK LS6 . tunnel rams AND DUAL 4s on mild small blocks and many different intakes , no issues since the 70s .I Never had issues every car was immediate response and fast, 11.66 3960 LBS ,tHE BLOCK WAS TOTALLY DONE, 60 OVER ,100th off the deck, 100th off the head Im mixing sunoco 110 blue with 94 , sunuso says they are compatible and you should have around 103.5 octane more than enough after 48 years at it , to much octane wont make you faster , GM Say 103 for a 69 ZL1 so 103 should be fine ,but the car feels lazy and loads up it was beyer with the orage cams than the white .jetting was stock but richer or leaner hurt it .The motor feels strong and you can feel the potential and it will turn over 6500 !!!!! EASY But loads up and feels like its drowning IDK????ALSO DRILLED OUT THE REAR PLATE TAPPED IT FOR A JET MAYBE 60-62 I THINK
Question…. When you mount dual 4150’s side saddle on a Weiand TR (with spacers on top/ under each carb for linkage clearance), and my jets are 74 primary/ 84 secondary, and 4.5 power valves- will one bank of the engine tend to get a richer mixture vs the opposite bank due to the difference in jetting from primary to secondary on both carbs? “One barrel to one cylinder” statement made me wonder? The jets and power valves are from the factory the way they shipped the Brawlers to me….. have no idea of even where to go jet and power valve wise, on this 496 bbc stroker, big cam, 10.5:1- in a jet boat…… just getting started on learning what to do from here…… Thank you in advance!!!!!!
When you buy Aluminum heads I want to get the best hp out of the heads do you still have to do the bowl and blending and porting I'm ether going to build a fe or 460 to go in my 68 Mercury parklane
I built a 545 stroker with a tunnel ram. 11:1 compression. Im still trying to determine carb size. Any suggestions on carb size? The truck is street/strip. Running 373 gear with 4000 stall.Thanks!
Hi Andy, great video brother. I have a firebird 75 with a 455 engine and i planning to install a dual quad to it, note that the engine is stock, can i just install it with the carbs without modify the engine for that?? Sorry for my question im just a beginner.. thanks
great video, what size carb and booster do you recommend for a .30 over 350 with a 6-71 blower? I am glad I watched your video, I didn't realize the loss of CFM. I was planning on running 2 Holley 450s, but am thinking bigger now.
Yeah with a blower.. 450's would be a huge restriction since the blower capacity is much greater that what can be drawn through those small carbs.... If it were me I would run 750's on it.. with the 750's most of them have downlegs already in them.. so depending on how much cam and what the rest of the combo is.. roots superchargers are sensitive to restrictions above the entry of the blower..
@@UnityMotorSportsGarage id have to find the spec card for the cam, a typical blower cam for a street car. Low compression rartio. Thanks for the info.
Hi Andy, just watched part 2 over on utg and are you able to draw on paper each step of modification to the 660 center squirts please, as in what hole to drill with drill size and what size tap and grub screw and what size hole in the grub screws. I have a 440 stroked to 472 that i will run either a M1 tunnel ram or Edelbrock STR crossram with 660's, working on stealth heads at the moment so have not picked a cam yet. Thanks mate. Australia.
Hi Andy do you think a fella could manage to get similar low down throttle response with a ram as a dual plane single or no chance? Cheers from Australia love the vids
Might have asked this here already but i have a buddy with a tunnel ram with 2 vacuum secondary carbs with mechanical linkage & vacuum pods removed & no secondary pump shot . The car runs fine & i don't see how it doesn't have a lean spot or even a bog ?
I would guess that either the carbs are really small and or the car is very light and it could be just passing through the bog so fast you really cant feel it... All I can say is that I have never been that lucky... I have tried it and FAILED! LOL Andy
Awesome video thanks. For a street car would you recommend a high rise or low. I’m wondering if I’ll loose throttle response. I was thinking low rise intake with 1 inch spacers. I’m building a 496 4 speed in a car
What manifold are you thinking of running? with a 496 you shouldnt be lacking in the torque dept! lol.... What is the rest of your motor combo if you dont mind me asking? Andy
Unity MotorSports Garage it’s a gen 6 454 Budget build to keep it simple. But hears a few options I was considering. With the zz502 roller cam and valve train / a little port matching and exhaust work and spring upgrade with MSD 6AL I was thinking 496 with twin carb tunnel ram or keep it a 454 and go 454 twin turbo with stock intake With 496 i like the simplicity of setting up the fuel and its a lot cheaper. I wasn’t sure if I would loose throttle response and street performance on a high ram. But I like the high ram because it looks like will open the motor up in the Rs The 454 turbo build I got off of Richard Holder junk yard build. He did twin turbo on holly efi and 80 pound injectors gave 1000 hp. With that you need a big fuel system, injectors, efi, gt45 turbos .
Sorry I just seen this post... You will lose a small amount of low end torque but not as much as you would with a big single plane... From my experience everytime I put a Ram on a engine the owner Loves it... On a 496 torque won't be a issue.. Andy
Thanks Dave. I just got a 93 f350 4x4 last week got the motor running good running motor. So I want to get the stroker kit 557 for 1300 from eagle and rehone the cylinders and give her a bath. But there's a problem I found out that what restricts the 460 is the heads on the exhaust. There's a massive intake. So I think if I do a lot lot of grinding and open the exhaust and run a good rv came with a duel plain intake I'll be good
I'm going to preface this by saying that I am new to dual quads. If my information is wrong, please correct me. A couple of questions: 1) When you talk about linkages, you mention that a progressive linkage on a intake with a common plenum is a bad idea because only half of the engine will get proper air/fuel. Wouldn't the same problem happen with a dual plane as well? Or do both sets of primaries open at the same time? 2) Is there a book/video that focuses more on setting up and tuning Edelbrock/Carter dual quad setups? Thanks! -James
There are a few differences.. the plenum volume is so much smaller on a low rise dual plane intake dual quad intake and being a dual plane each side of the carb feeds four cylinders... You can run a 1:1 on a low rise setup but you would get better low speed driveability with a progressive style linkage... Because most of the time at small throttle opening it would act almost like a single four barrel dual plane... I hope this helps answer your question.. Thanks for Watching Andy
Very good video Andy. Perhaps you can help me out. I’ve got a 499ci low deck Mopar in a 78 ClubCab D150 that I’m running a Edelbrock Victor intake and 950 double pumper on. It’s a pump gas build with Indy 440-1 heads with no porting just flash cleaned up in ports solid lift compcam I can’t remember the specifics of it 3500 8” converter motor made 556hp on engine dyno. Run strong but after watching this video I’m wondering if I might gain more from a Dual quad set up.
Thanks Jimmy for the kind words.. Dual Quads will make more power when tuned right. It also depends on the manifold choice too... Because not all Dual Quad manifolds are created equal.. on my 393w when I dyno'ed it it made 575hp @ 6500 and 540 lbft at 5100! We did some testing I had a Edelbrock Vic jr intake with a 830cfm DP and it made 537hp and 501lbft.. the best part was the tunnel ram made more power and torque from beginning of the pull 3500 to 6500.. What manifold are thinking of going with? Andy
@@UnityMotorSportsGarage I really don’t know what intake just yet. The engine has a lot of miles on it so I’m thinking of going through it. I don’t street drive it anymore so head porting and upping the compression along with more cam are in the works. I found the cam card its a baby solid roller from Crane 246/254 @.050 .543 .561 on a 112 LSA with 108 ICL. I’ll probably go with Comp on the new cam.
If you swap the cam.. going to a 108 lsa will give you another 35-45lbft more torque in the mid range. I love tunnel rams.. but I know not everyone likes having to cut a hole in their hood.. I really like the Rpm Air gap dual Quad setups but you can only run Carter style carbs... The low rise single plane dual quad manifolds give away alot of torque down low because of the short runner length.. they run good up top though
What about tunnel rams and cams that have a lot of overlap? I'm having problems with my SBC, tunnel ram and my Holley 390's. Having a off idle stumble an occasional backfire thru the carbs. Any ideas would be greatly appreciated.
That is from a lean condition.. you will need to increase the squirter size... If that doesn't quite cure it then you will have to upgrade to 50cc Accelerator pumps.. hope this helps what size squirters do you currently have?
Sorry for the long winded post but I have some findings you may be interested in. I am a qualified mechanic so tend to notice things that I've screwed up. I also like towing with dual quads. I had a dual quad 440 that I towed with a bit. I towed a tandem trailer with a car on it or a tandem trailer with a two seat fiberglass glider in it. Be a bit careful with compression. I towed many many miles of country driving with this car. I found if comp is anywhere over about 9:1 if you pull the motor down in rpm - like going up a hill and the revs are between say 2000rpm and 2500 but the motor still responsive in that gear and you hit the gas to compensate for a hill and the secondaries open (I had edelbrock AFBs) my motor would start knocking bad. I quickly realized this is why gas truck engines have low comp. Even those Dodge V10s in trucks have low comp. It all becomes apparent. Compression in gas engines and towing heavy loads isn't a good combo. It is likely that my cam LSA was too tight for towing exacerbating the situation by building cylinder pressure adding to the detonation. It had a Mopar Purple Stripe hydraulic cam of fairly moderate specs but it did have a lumpy idle - it was no good. A low comp gas engine with a towing cam and 2x AVS carbs with 1:1 linkage on the primaries (so no progressive) and careful jetting and accelerator pump tuning could be ideal in say a 440 with a 500" stroker crank in it and about 8:1 comp with aluminum heads to heat soak the chambers a bit. Not too much timing either - can always add more if you need it LOL. If new build use single layer steel shim head gasket (~.018") at say 9:1 comp and if it rattles use a thick head gasket (+.040") to lower the comp. Plan the engine build around this as a tuning aid if you're going the new build route. Engine builder can sort that part of it all out if you relay the idea. My current dual quad tow vehicle. I now have a new OEM roller block 350 Chevy in a Toyota FJ40 4x4 that I use for towing stuff and it has an Offy cross ram with dual quad TBIs and it still rattles even with a towing cam - but I have an out - I can lower the comp via the head gasket method. It is brand new build and the comp is currently 9.2:1 but I can lower it into the 8.5 - 8.7:1 range. I got my machine shop to sort it all out by telling him what I wanted to do and if it rattled and how I proposed to lower it (all based on my 440 experience). It was all worked out in advance by my machinist and he milled pistons and heads to get it all to 9.2:1 based on the thin steel shim gasket. My new 350 doesn't rattle anything like my 440 did but it still does rattle a bit. The 440 was terrible esp on hot days, but my Toyota/dual quad Offy/350 is still too untested to pull it to pieces yet. I might be able to tune it out with plug heat ranges and a dizzy recurve. I even fitted an expensive Milodon single idler gear drive to my dual quad roller cam 350 tow truck so I could very easily play with cam timing. No it doesn't whine - it is totally silent gear drive when installed as per the instructions. If you're using a secondhand 440 motorhome engine then that would be ideal esp if it has the tapered plug heads. Dual quad on that could work really well as a tow engine. Whatever you do, don't up the damn comp rofl...
I'm currently running rpm air gap with edelbrock avs2 800 cfm on my 454 with 600 lift cam if I got a tunnel ram could I just get one more carb to match the one I have and run 2 avs2 800s?
And my carb is electric choke and I see a used carb for sale same as mine with electric choke is it possible to run 2 carbs both with electric chokes on a tunnel ram would it affect how it runs? When it's running chokes are open so I don't see why it won't work lol just will look funny running 2 carbs with electric chokes ? Let me know if that is possible pls?
I retained all of the 1:1 linkage on the street. I decided to use the 660's on the street to show that it is just like any other Holley carb.. it can be tuned to do the job and get good mileage in the process! The next challenge I'm going after is to do the same with a pair of 1050 Dominators on MIXED UP BOSS.. Stay tuned Andy
Tuning dual quads it too complicated for my tiny brain and physically impossible for me so I'm replacing my dual Edelbrock Carbs for dual Holley Super Sniper Efi because I have confidence that I'll be able to make adjustments after some time learning.
You will be basically making the same changes with EFI as you would do tuning carbs.. To me the Carb vs EFI is Analog vs Digital type deal... coming up when I did i cut my teeth on the 5.0 mustang EFI system and went from there... I like EFI but i really Love carbs and once I learned how to manipulate each circuit of the carb I was able then to use my wideband o2 sensors to get the same results as EFI... one thing hard to beat with EFI... The cold start! Thanks for watching and please subscribe as I have some cool stuff coming up... Andy
Not really.. because of distribution issues, now there is a caveat to that if you have a large downward tapered Plenum they work really well. Most of those designs are sheet metal style intakes. Hope that helps Andy
@@UnityMotorSportsGarage Thanks, I am determined to get this to work well. I can have a new plenum made or modify the old plenum. But I just can't find much info on it. And the info I do find is really not based on much. Do you have any suggestions about making a plenum or suggestions where to look?
Thanks for the kind words, but since David had brain surgery he has had a hard time conveying his thoughts sometimes... He is getting better but it has been a slow process. Andy
Edelbrock messed up when they captured a Rochester Quadra puke on their manifolds. Holley is what real Hot Rodder want. Nobody winning at the drag strip wins with Edelbrock Quadra pukes on their car. Avoid Edelbrock dual quad manifolds. Resale sucks on them too. Just sayin.
I wish you would not use the dual quad lingo so much..say 2/4s say anything just stop saying dual quad...Nobody I know used that terminology.. ..and Nobody I know puts 2/4s on a stock motor Nobody...so let's move away from the 600cfm card discussion ...and as far as car shows and seeing a car with a tunnel ram yes they usually have 2 /4s on top.
