You don't have to apologize for cost of book.

Would love to see this test with dual planes

I got my book in today. Its worth the money.

Eric, Thank you for your extensive time testing all of these products. You are doing a fantastic service to all of us out here. Trying to do an objective analysis and assessment. Keep up all of your hard work.

Thank you for your knowledge 💪🏽 🙏 USA 🇺🇸 USA 🇺🇸

Looks like the inside of the Edelbrock plenum has bigger protruding fins thus the plenum is smaller increasing velocity helping out the smaller 2bbl carb. Just my guess. Thanks for sharing! Love these test. I had a 77 camaro with a 2bbl eons ago. Car ran pretty good for what it was.

2 bbl carbs are rated at 3.0 in Hg, 4 bbl carbs are rated at 1.5 in Hg, so comparing the two numbers isn't quite accurate unless you convert. Multiply the 2 bbl number by 0.707 if you want to compare to a 4bbl. I raced nascar for a couple of decades and remember using the same engine in two different classes by just changing from 4412 2 bbl to 830 cfm spec 4 bbl. HP change on the dyno was about 90 hp with a 355. Also, using the slotted adapter plate for the 4412 was worth a few hp, but you really needed to back-to-back pulls to see what worked best on each intake. Also, "accidentally" leaving out a vacuum plug in the intake on the 2bbl intake was good for 10 hp, and using a balsa wood adapter was worth even more, if legal.

Thanks for sharing, hope your boy is still killing it with his Swimming, all the best to you and your loved ones

Hey Eric if possible can you test a dual plane edelbrock 2701 to a wiend 7547 dualplane to see wich one out performs for us imca 2 barrel class cars.

I think this book is a fantastic idea. Research far more expensive to figure out than look up.

I would give 10HP @ 6500 for 10ft/lb @ 4500 anytime on a Saturday night special claimer. 2bbl CT engines are very sensitive to bore/rod/stroke ratios vs cam overlap and centerline. Changing rods from 5.7 to 6in requires reduced overlap. Economy classes require stock exhaust manifolds which messes with intake flow. Too many variables in possible combinations to get much specific information on your limited tests. Don't let people talk you in to extensive combos, test as you can and let others make inferences as they will.

There’s an interesting carburetor I’d like to see tested. The 6425 Holley 2 barrel 650 cfm. There are some full house Frankenstein versions that are available through the aftermarket with larger throttle blades installed that flow north of 800 cfm.

My favorite manifold for my 327 stock car was a dual plane Weiand, I'd bet it's still good.

4bbl are rated at 1.5 inches Hg, 2bbls @ 3 inches. I can't believe I know something about flow that Eric didn't know!

looks like its the 2925 to 6100rpm then the Hurricane after that even though the flow numbers for the 2925 ar better ??? Would love to see the 2bbl tested on a Vic Jr as well as the Performer RPM ! I like the HVH Super Sucker but would like to see the 2bbl adaptor you r using ? Keep Up The Great Work !!!

If you take the 2-barrel rating at 3-inHg and multiply it’s CFM rating by .707 then you get the CFM at 1.5-inHg…..that “500cfm” 2-barrel should flow about 353-CFM at the same depression as the 4-barrel…..you can calculate what depression it was at on engine by doing other math if you use the airflow meter on the dyno.

Love the 4412 b Holley

I am building a 1959 283 Chevy for the street it is .o60 over with the 601 gm high output 305 truck heads with 1.84 intake valves it does have a 446 lift cam I'm wondering what intake and carb to run .....my thoughts are the Edelbrock eps with avs2 650

Starting to guess that a longer runner with less taper "might" improve average numbers with the 2bbl?

Very interesting bout the 2 barrel carb test. Bet an RPM Airgap dual plane would bet them all 😮

For being a carburetor company Holley never made very good intake manifolds. And don't get me started on their naming scheme! A Street Dominator from the '70s might be single plane but in the '80s they change things up and the Street Dominator is now dual plane. And how many names has their 1970 Z-28 clone intake had?

On my street and strip 327 2 bolt main block small block Chevy solid.roller combo, with the hurricane intake, and out of the box Calflow 200cc 64cc 2.02 intake 1.6" exhaust valves (measured 196cc 65cc) ( China copy heads of the AFR 195cc enforcer, all copy's of the Dart Pro-1. 200cc 64cc. ran best with my 4150 flange 950 double pumper carb.

Eric, Looking at the 4 intakes, it appears the Edelbrock has the thinnest dividers. That's the only difference I noticed. Maybe that's what made the Edelbrock perform better with the two-barrel. BTW, I would like to see the Holley port matched and ported then bolted to a set of your prepped Dragon Slayers on the dyno mule. Maybe it will perform then. Maybe the stock heads aren't working it out enough. Who knows! Thanks for another great video!

Manufacturers usually cast those ports with a taper at the head flange to aid in port matching. But don't tell anyone about that.

Eric, it is interesting that the holley strip dominator doesn't do as well as the others. I have one that I ported about 10 years ago. I can send it to ya for testing if ya send it back when you're done. I will pay for shipping. Let me know. Thanks for all the info. Good job!!!

4 to 2 barrel, 1 for 1 loss, 3 cylinders are pulling on the carb at the same time. Doesn't relate to flowing a single port. where its 2.2ish HP for 1 cfm.

The reason the Edelbrock made way more torque on the bottom and the Hurricane made such hood high RPM horsepower is due to the air fuel ratios. The trick to making huge power with 2 barrels is to get the lower RPM range good and rich like normal (12.0-12.5) and as lean as possible on the top end (14.0 ish) Take a look at the Edelbrock afr and coincidentally it’s right around 12.5 to 13.0 in the low rpm area but the Hurricane is leaner in this range. Also in the high RPM range where the Hurricane is better it is around 14.0 which is leaner than the Edelbrock in that range. It all makes sense in the twisted world of 2 barrel motors 😉 BTW with proper carb tuning on both I’d expect the Hurricane to just edge out the Edelbrock Super Victor on most of the run and elsewhere be equal.

So what's up with the spacer (?) In the thermostat housing in the intake? I've never seen that before.

Some people will argue that the upper rpm power is all thats important on a circle track engine (6000 and up), but they forget the start and restarts...the edelbrock will kill then ;)

Air speed. Gets more air in the cylinder.

Very cool testing so my question is since the hurricane passed the elderbrock 6100 and above what if the engine that revs about 7500 or almost 8000 for what I am about to do would it be better to run the hurricane than the elderbrock I need to ask my buddy how much rpm we come off the corner because I swear the wingless spec Sprints we don't slow down to much on the big tracks at least. But what are your thoughts on what is I run a engine that is a way higher rpm would the hurricane be a better option if we run 7500 or another 8000 peak

What two barrel carb and adaptor were used in the testing?

Ya know, the Holley design looks different than the top three manifolds. The Holley looks taller vs the ports. So the question is, how deep is the plenum vs the three others.

$38 is a bargain for the value you get.

I don't recall but, are you also dynoing everything again with a set of high flow heads to see the difference? Thanks

How about flowing a four barrel and two barrel carb?

Tks were they all lean and did you rejet?

Usless information if you have to run a dual plane manifold.