We are all no doubt aware of the best performance inlet manifolds avaiable for BBC powered Vettes and that 99% of these will require a hood scoop of some description to clear the carb/airfilter - or use an L88 hi-rise type hood. Other than perhaps some of the rarer OEM 'inlets' my understanding it that it only leaves Edelbrocks (rather ancient design) Torker 11 and perhaps some of the versions with the angled carb 'pad') that are able to fit under a stock BB/LT1 hood.
When I first bought my L36 powered '68 nearly 25 years ago the two things I initially did was fit a set of headers and then an Edelbrock Torker 11 'O' with a Holley 750 DP.
Did that give any extra performance? - other than perhaps some increased torque in the 2500 - 3500 band, no - not really?
Moving forward to the current day I'm using Edelbrocks Performer RPM Air Gap with (perhaps oversized) Proform 950 DP on my 489.
With its Brodix Racerite 'small' oval port heads it developed 570 hp @ 5850rpm and 606ft/lb tq @ 3850rpm at the flywheel on the dyno. Max usuable rpm is 6200.....it dosen't really want to 'breathe' past this point. That it fine. It has a nice wide torque spread with 463 ft/lbs @ 2450 rpm.

My question to you knowledgable fella's - if I was to source another Torker 11 'O' (to enable refitting of the OEM BB/LT1 hood).........what effect could I expect this to have on the HP/Torque in total and the engines power band (given that the Torker is single plane and the engine capacity is higher). Is there much that can be done with the Torker to improve airflow?

 

I'd consider the Holley Strip Dominator single plain intake - fits a BB hood w/o modification. Much better intake than the old Torker II

 

Single planes usually help with the top end as it has a single open area and short straight runners which tend to not help low end torque but will increase the upper end horsepower. Im running a stock tripower intake that is low profile, very short runners, oval port, and is dual plane and I for one, dont have any complaints about it. Im running about 535hp and and just over that for torque. I dont think you will have and issue with your current HP and Tq. If you are racing then you will want to reconsider everything but You arent going to be running a low deck intake or oval ports

If you want to port it you can port match it and clean up the runners . port match it and bring the port match about two inches into the runner. Then at the plenum, sharpen the divider walls and bring that shape back into the runners. you want to make it so the flow of the mixture is drawn in easily and isnt fighting a blunt wall at the end of the dividers or a step into the heads. A shelf or wall will disrupt flow enough to push the flow from the wall into the center of the flow which slows it down ....I did it to a small block tarantula intake with EFi and it was much better afterwards.

 

These are pics I found online as examples of what I would do







This how I have done it to other intakes


You would want the thin ones thinner and to a point, not like a knife though. And the flat round ones pointed like a bow of a boat

The blue would be smoothed to a rounder shape. Again the broad faces would be more pronounced so the flow doesn't get "stuck" there like running into a flat wall

 

I've seen some dyno testing on this one on hyd roller 540's and it does pretty well. A buddy has on on his 540 going in a C2, but we've only run it on the test stand...not on the road yet.

But it's hard to beat an Air Gap at that level.


Brodix Cylinder Heads HV 2016 Brodix Cylinder Heads Dual Plane Intake Manifolds | Summit Racing

JIM

 

Thanks Jim - it was only when reminding myself of the Performer RPM Air Gaps advertised power band (1,500-6,500 RPM range) - with my oval port heads - flat tappet cam - street use......that perhaps I'm better off where I am? - someone mentioned a Holley Strip Dominator single plane but power band is shown as 3500 - 8500 rpm.......mine won't go better than 6200 rpm. Perhaps I should search for someone who has done some of the Torker 11 divider grinding?

 

Strip Dominator is an excellent manifold. I ran one for years on my 427.

Here's a really good older article that might tell you exactly what you're looking for...they test intakes and the Torker II is one of them

Hydraulic Versus Solid Versus Roller Tappet: Which Will Have…The Lash Word? (motortrend.com)


JIM

 

Roscoe, here are my BBC intake notes that I have collected over the years:



DDawson is running a 502 with the stock BB hood and a 569 intake. I put one on my 454 for the same reason, the hood.
I felt it was worth it, I like that hood so much more.
Anything taller is a problem with that hood.

The ports are really large and although they twist down & up there is only some HP loss, maybe 20 HP, or less, vs an L88 intake. It is a low rise. Some ports are dead flat, and some go down & then back up. The carb flange is below the top of the valve covers. I am told the loss is all above 5000 anyway, and a taller L88 height intake on a C3 needs the L88 hood. Other sources say all the dual planes test about the same for HP.

There is a Nascar level head porting place in N.C. that I talked to about it, they guaranteed me they could add 30HP on my size street cam, by porting it.
I'll dig up their info if you need it, and I can find it.

It is an R-port intake. Most that have dyno'd it say it works well even on O-port heads, the port mismatch does not hurt it as much on the dyno as the myths say it should. I guess the large ports make up for some of that. And your Brodix O-port heads are pretty big oval head anyway, bigger than OEM ones.

Your HP dyno curve seems much like mine, yours is just 50 bigger all around with your 489 vs my 454. Guess I have a "baby" big-block. LOL

 

Here is the intake & my conversation info:
Wilson Manifolds, FL (not NC) ph: 954-771-6216
569 intake, porting +30HP, & TQ everywhere, $1450
tapered 1" spacer +28HP, should fit the hood if mill the intake 1/2"

I forgot about the tapered spacer comments until I looked up my notes.

There is a guy online that runs this (modified) intake and a stock BB hood on his 71, with 850HP worth of 589 inch engine. Runs 9.70s.
I guess that intake doesn't hold him back very much.
https://www.motortrend.com/features/...imate-sleeper/

I am still running the ancient L88 heads. So between new AFR heads and the intake mods, I am leaving ~100HP on the table, I could be at ~600
Oh heck, I gotta stop the dive into the rabbit hole somewhere!
And I would just break more IRS parts anyway.
But I know where to find it if I feel I ever need it.

But I did drop $4k for the TKX with it's overdrive. I figure I will use that much more often than WOT redline shifts!
I would not have a liscense very long if I use redline very much.
And I am trying not to turn this into a track only weapon, like my last car was.

 

Thanks for info' Leigh - all very interesting and informative - much appreciated!

 

If it was my Vette I would make it run the the best and most most responsive for the least amount of money. 950 CFM and only lower 6000 rpm needs to be addressed to get instant on throttle. I'm very PRO annular boosters. Great fuel atomization and because they are physically blocking more air flow than say a down leg booster it cuts the total carb CFM. I could never get my Demon carb to have that instant on throttle so I had a race carb shop do all the flow testing and air bleed work and then on to a dyno test mule engine.

The second thing the race carb shop gave me was the 4 hole wood thermal spacer. The extra 1/2 inch gives more signal to the boosters and increases the distance to where the fuel has to make a 90 degree turn. The other thermal bennefit of the fuel running cooler.

The head ports determine the intake manifold type. My 427 had such big head ports that i had to go to the biggest single plane manifold made. To clear the hood I went to install a 2 X 14 inch open element with a K&N filter top.

Leigh1322, I was driving my vette a few hundred miles yesterday and I ran it through the gears a few times and I was thinking when I had my foot on the floor in 3 and 4th gear that sure wished that I had like an extra 150 hp to get up into the 800 range!

 

Yeah I get it!
It's an age old problem:
"I could use a few more HP"
LOL

 

I am running a ported Holley Strip Dominator on my 660 hp 502. The Holley is one of the few manifolds that have the back to front slope similar to the stock 163 manifold. It fits perfectly with an L88 Hood, but I can also tell you that the stock L88 drop base air cleaner does not leave much room for airflow above the carb. I modified my L88 hood to get a 4 inch air filter in there and picked up 20 horsepower over the stock L88 set up. Instead of fastening the L88 air box to the hood, I riveted the air cleaner base to the air box and am using it as a cold air box fully sealed from any underhood air. Works great.

 

That's an interesting 'observation' (the 'slope' of the carb mounting pad). I recall this was of concern when I ran the Torker 11/Holly combo with the stock engine. Using the Torker in the Vette meant that the carb 'leant forward' effectively and setting float levels was a bit of guess-work. Now, all these years later on a 'level' carb mount (on a Performer RPM) even with a 2" filter the underhood clearance using the L88 type hood is limited to 3/8"........but that is right at the front of the filter.........so yes, I guess at the 'cost' of not having a level carb means improved clearance for certain carb/inlet manifold combinations.......interesting! - BTW I did eventually install an angled 'wedge' shaped spacer on top of the inlet manifold to level-up the carb.

 

Generally engines are mounted OEM with the rear lower.

So those older forward angle intakes brought the carburetor back to level. Another thought about down angle carburetors was for drag racing. It helped keep fuel on the rear bowls jets.

The bowl fuel level effects the air fuel ratio. So it doesn't matter if the front bowl is different than the rear as long as the level is consistent. I'm referring to modern duel fuel feed 4 barrels.

The best practice is for only like 5 psi fuel log pressures and larger diameter needles and seats. So when the floats open low pressure and big flow keeps non aireated fuel in the bowls

 

FWIW there is a post on the Chevelle forum from 3/12/2010 by Mark Jones about a guy that had to have the Torker 2 on the 468 he was building him due to hood clearance. Mark said that he figured the engine was down about 20hp & 20tq vs the Air Gap but was relieved that the engine still made 608hp & 590tq. you can easily find the post on the forum with a google search.
Pat