>> OK, THIS IS WHAT HAPPENS WHEN WORK IS REALLY SLOW AND I HAVE TOO MANY STOOPID IDEAS RUNNING THRU MY HEAD <<

Let's suspend reality for the moment and proceed under the assumption that the dyno results from three (3) different dynos referenced below can be compared without needing to apply "fudge factors". What I'm trying to cover here is not intended to be based on the absolute #s, but point out the trends and findings that I believe can be gleaned from the information. Also, it's NOT a way to bad-mouth OR praise one selection of parts over another, but to highlight the design implications of certain of parts choices.


So, what's going thru my mind here?

1. Lower flowing heads with better velocity can peform as well as -- or better than -- higher flowing heads with less velocity... IF used with the appropriate application

2. Impressive flow #s won't help as much for limited-displacement applications that aren't able to take full advantage of the head's potential

3. It's a balancing act of optimizing what you have (or are required to use) and minimizing the compromises that go along with it

4. Be careful what you wish for

5. The numbers on the dyno may not translate to the numbers on the ET slip... or, at least, not the way you were expecting them to


What got me thinking about this?
1. The recent dyno session of my new combination, which is a 452 RB w/ standard-port E Victor heads and my first time using a solid roller w/ a street/strip car

2. My review & analysis of the 2008 Mopar Muscle Engine Challenge where the engines were limited to stock-stroke 440-based builds, required to use Indy SR heads, and run on Rockett-brand 93 octane fuel. There was a wide range of outcomes as far as final parts combinations and dyno results, but I saw some of the same performance characteristics with almost all the builds.
- http://www.hotrod.com/articles/mopp-0910-2008-amsoil-mopar-muscle-engine-challenge-wrapup and the invdividual articles that were written about each entry

3. An article I read about the Kaase P51 BBF heads for the 429-460 platform when these heads were introduced around 2007. That test used OOB P51 heads on a basic 460 performance rebuild w/ an aggressive -- although not especially big duration -- solid roller, and made close to 700 HP on pump gas and about 600 torque.
- http://www.hotrod.com/articles/0707phr-p51-cylinder-heads/


Keep in mind that my understanding is that all of these builds, irrespective of brand, were "supposed" to be targeted to what I'll call "real-world serious street/strip applications" that were expected to get by on pump fuel if required, although a blend of race fuel might be needed on track day.

>> NEXT >>

General observations & opinions from 2008 Mopar Muscle Engine Challenge:

1. All the legit competitors in the 2008 Mopar Muscle Engine Challenge used MW-sized ported versions of the spec Indy SR head. Some started out using ICH's 295 CNC program and at least one used MCH's CNC program. It's probably fair to say those were at least 355+ CFM heads, depending upon any additional work done. Most used MW-sized single-plane intakes (ICH RB and Edelbrock Super Victor) and two entries used ICH's tunnel ram intake. The cams, when the specs were provided, ranged from 260 to 276+ at .050" and most builders used 1.7 rockers to get the lift well over .700".

2. The dyno tests were run from 3000 to 7000 RPM and, not unexpectedly IMO, every one of those MW-head 440s had a big freakin' dip in the torque curve around 4000 RPM. The engine with the smallest cam listed that also used one of the tunnel ram setups actually had one of the biggest holes in the torque curve. None of them hit their torque peaks below 5500+, and only one actually got close to, or exceeded, 600 lbs-ft. That was the 750+ HP ICH build with the offset heads, custom T&D rocker setup, and a 276/280 at .050" cam. Yeah, it was the HP and torque King, but peak torque was almost 6000 RPM and it probably hadn't even maxed out on HP at the 7000 limit from the look of the dyno chart (still climbing).

3. One of the single-plane Dominator combinations made about 735 HP at 7000, 585 torque at 5500 and, oh yeah, they didn't provide their cam specs. Im' guessing... pretty bleepin' big. A more "mild" single-plane Dominator combination made almost 700 HP, but only 560-something torque at around 5600, and used a 270/280-ish at .050" cam.

Anybody see the obvious (to me, at least) pattern?
- 450-ish cubes
- Octane-limited CR
- MW ports
- Big dips in the torque curves right at the bottom of the range of where I'd expect a typical street/strip 440 needs the converter to stall
- Big HP at high RPM at the expense of the rest of the torque curve

>> NEXT >>

More 2008 Mopar Muscle Engine Challenge results...

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What about the Kaase P51 466?

IMO, P51s are way better heads than any of the Indy-headed combinations in the MM Challenge: Kaase claims almost 400 CFM OOB, has a more oval-shaped intake port that is better for the velocity gradient in the port and results in less fuel drop-out, definitely has a better chamber design w/ canted valves, and the chamber's more centrally-located over the bore to reduce shrouding. This design is also more detonation-resistent, since the P51 build has 12.0:1 CR and was still able to pull solid #s on "real" pump gas.

Kaase stuffed an aggressive (not really "streetable" lobes IMO) 256/262 at 0.050" x 0.761"/0.743" roller in it and put an Edelbrock Victor with an 1150 CFM 4500-series carb on it. The cool stuff is that it made almost the same HP and torque on pump swill as it did on 100 oct race fuel, and it made 597 lbs-ft at only 4900 RPM and 687 HP at 6700 RPM on pump. And there was no "hole" in the torque curve across the 3000 to 7000 RPM dyno pull.


Sooo... going back to my opening statement "Let's suspend reality for the moment and proceed under the assumption that the dyno results from three (3) different dynos... can be compared", then consider why my 11.5:1, "small-block sized" standard-port 350 CFM head, 266 at .050" x .670" endurance-type solid roller, 4150-carbed RB 452:
- Had a broader torque curve than everything above except the Kaase 466, and out-grunted the Kaase 466 below 4000
- Made more torque than everything except the insane ICH 750+ HP combination
- Had a torque peak at a lower RPM than everthing except the Kaase 466, about 500 RPM lower than any MW-head combination in the MM Engine Challenge
- Made comparable HP to the Kaase 466 when used w/ the 2" spacer, and was less than 10 HP down with a 1" spacer... and this was testing 1.52" v downleg and 1.59" v annular 4150 carbs, rather than a Dominator
- Actually idles well at 1200 RPM and won't eat valve springs in the first 1000 miles on the street
- Can get away with a dual-purpose 4500-stall converter, even though it would probably 60-ft better with a 5000+ stall

FWIW, the Kaase 466 was tested at Westech in CA, the MM Engine Challenge was held at COMP Cams in TN, and my results came from dyno testing w/ Porter Racing Heads in VT. I know that the results from that dyno in Vermont correlate quite accurately to the in-car results, so I have faith in at least one of them.

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Again, back (almost) to the top where I listed...

1. Lower flowing heads with better velocity can peform as well as -- or better than -- higher flowing heads with less velocity... IF used with the appropriate application

2. Impressive flow #s won't help as much for limited-displacement applications that aren't able to take full advantage of the head's potential

>> I think it's reasonable to believe that all of the MW-port heads in the MM Engine Challenge flowed at least as much as, and likely more than, my standard-port heads, and there's no doubt that Kaase's P51 heads flow 20-40 CFM more across virtually the entire lift curve. Yet... I don't think in either the MM Engine Challenge or the Ford 466 build that the heads used were being utilized to their full potential. Stick the Kaase P51s on a 500++ engine and the HP #s jump waaay up over this test.


3. It's a balancing act of optimizing what you have (or are required to use) and minimizing the compromises that go along with it

>> Cam profile vs spring load required vs durability vs RPM vs... whatever you want to add here


4. Be careful what you wish for

>> I got a 750 HP 440 pump gas engine!!! Uh... did I mention I need to use a 6K-stall 8" converter on the street so it can get outta of its own way at the track?


5. The numbers on the dyno may not translate to the numbers on the ET slip... or, at least, not the way you were expecting them to

>> I picked up 40 HP with my new heads and cam!!! And because my torque curve is lower everywhere except the last 500 RPM below peak HP, the car may actually not ET any better unless I change converters and/or gearing cuz the power has shifted up the RPM curve.

I have nothing to add. Lol

I agree on the velocity thing 100%. Hughes Engines used to advertise their head porting that way yrs back. Dom uses ported Rpm heads on a 470 and i use E MW heads on a 511. Doms engine makes more power than my 511. Compression is not much different between the 2. I think my 511 combo may make more power with RPM heads.

I think I agree with all of that. What I've seen from my own testing is that I can keep moving the peak HP number up by getting more aggressive with intake porting, cam specs, etc., but the peak numbers are only changing for the last 1000 rpm. So the car might not be any faster with a 750 hp engine than a 700 hp engine, especially if you aren't shifting it right at the redline all the way down the track and running it out the back door.

As Andy pointed out, engine dyno tests are not always a good indication on how those motors will perform in the car
The torque converter, exhaust system and every other part on the car contributes to the in car feelings
One of my old pump gas Duster(that I traded to 9second Phil) with a mild 360 motor and 4 speed ran mid 14.40 at LACR with 3.55 gears and slicks, we swap the third member to a set of 4.89 and the car felt way faster on the street, at the track it might have pickup .2 ET and maybe 1/2 MPH
My other bracket Duster picked up .8 ET and 7 MPH by changing the carb. from 600 DP on a Eddy TM7 intake to a 1050 Holley Dominator carb. and Mopar M1 4500 single plane intake manifold with no other changes
Theory is one thing , real world results are different
I should add, put that motor in the car and go drive it and flog that rascal a bunch Have fun

I like the idea of usable horsepower and torque. That’s what the standard port does for you especially when your driving a street/strip heavy automatic car. Velocity, Velocity and let there be more velocity

Picking a cylinder head based on the rpm range of the lower half of each gear makes the most sense to me, which falls right in line with what you are pointing to, Brad. Once another car has a length on you out of the gate, it takes a big top end charge to overcome it, if you even can!

[quote=BradH

So, what's going thru my mind here?

1. Lower flowing heads with better velocity can peform as well as -- or better than -- higher flowing heads with less velocity... IF used with the appropriate application Here's where you can get tripped up---higher flow equals higher velocity. You need to look at discharge co-efficient for a better view.

2. Impressive flow #s won't help as much for limited-displacement applications that aren't able to take full advantage of the head's potential Of course not. A more accurate statement would be RPM limited

3. It's a balancing act of optimizing what you have (or are required to use) and minimizing the compromises that go along with it 100% agree

4. Be careful what you wish for Don't fall into the bigger is better trap

5. The numbers on the dyno may not translate to the numbers on the ET slip... or, at least, not the way you were expecting them to See #4


What got me thinking about this?
1. The recent dyno session of my new combination, which is a 452 RB w/ standard-port E Victor heads and my first time using a solid roller w/ a street/strip car

2. My review & analysis of the 2008 Mopar Muscle Engine Challenge where the engines were limited to stock-stroke 440-based builds, required to use Indy SR heads, and run on Rockett-brand 93 octane fuel. There was a wide range of outcomes as far as final parts combinations and dyno results, but I saw some of the same performance characteristics with almost all the builds.
- http://www.hotrod.com/articles/mopp-0910-2008-amsoil-mopar-muscle-engine-challenge-wrapup and the invdividual articles that were written about each entry

3. An article I read about the Kaase P51 BBF heads for the 429-460 platform when these heads were introduced around 2007. That test used OOB P51 heads on a basic 460 performance rebuild w/ an aggressive -- although not especially big duration -- solid roller, and made close to 700 HP on pump gas and about 600 torque.
- http://www.hotrod.com/articles/0707phr-p51-cylinder-heads/


Keep in mind that my understanding is that all of these builds, irrespective of brand, were "supposed" to be targeted to what I'll call "real-world serious street/strip applications" that were expected to get by on pump fuel if required, although a blend of race fuel might be needed on track day.

>> NEXT >>

J.Rob

A few of my own thoughts.

Kaase's P51 heads are excellent and not just because of the flow. They don't flow anywhere near 400 unless you test @ 10" and convert up. However the flow @ .400" is remarkable--I believe 325-330 cfm IIRC. It is the chamber and how it is positioned (which you pointed out) which belies its true flow capability. What is baffling about them is the massive stall they suffer from @ .550" and up. I've tested 3 different sets and they all exhibit the same trend. Is there something more to this?

Those curves you put up are all indicative of a large port volume AND the wrong header design. My 2013 466 Pro-comp Victor deal had the same trend until we added something like 24" of collector with a .5" reduction in diameter along the way. This knocked out most of that dip. However this is pretty much a Band-Aid to a high flow port that is too large for the application. Min CSA of these heads were exactly 3.125" as calculated by Solidworks.

Learning from this I used a 2.85" CSA on my 2014 EMC 439.9 ci (440) effort. These Victors were dowel shifted, angle milled, guides moved in X and Y and angle changed. Flow was 353 cf. with a 2.19" valve. Torque was impressive 535 tq @ 3000, off the brake zero dip was observed and a peak of 630 was observed. If I could do it again I would make the port even smaller. That engine was easily 100pts better than my 2013 effort. J.Rob

After my 2016 EMC build 469 ci SPEC build using RPM heads I have determined some eye opening results. The SPEC rules that year mandated the use of Edelbrocks RPM heads and no welding or epoxy whatsoever was allowed so this limited us to a stock offset rocker. We were also required to use the stem size and head diameter of the valves that Edelbrock states. This meant 2.14/1.81" and that was it. The cylinder heads were ported hastily and a peak of 298-299 cfm was my first and last result--meaning I didn't agonize at all--they were what they were and that is all. I made a best of 592 ft/lbs @ 3500 rpm ZERO dip and 653 ft/lbs @ 4800 rpm with 680 hp @ 6100-6300 rpm IIRC. This build really makes me question the Victors when used with a standard port opening, I mean if you are required to use a big .650" offset rocker then why the heck would you NOT open the port to gain more CSA?

What this means to me is--On your engine Brad, the Victors are a waste. You could have gotten where you are with regular old RPM,s. I've said it before and I'll say it again--I don't know why Edelbrock would even offer them in a standard port. IMO selecting standard port Victors and not targeting BIG power--800-900HP is a dichotomy. Victors should be used only by masochists and those that are hoping for well into the 800+hp range. J.Rob

IMO, if you replaced Brads Victor heads with a set of 300cfm RPM heads, milled for equal compression, and left everything else the same, the motor would have made way less power.

Additionally, in "engine contest" trim, there would certainly be some more power available from that combo.
More aggressive cam, more rigid rocker arms, ported intake manifold, gas ported pistons, lower tension ring pack, 4500 carb on an HVH SS/adapter...... It easily would have made solidly over 700hp.

When the RPM heads first came out I built a 448 that was very comparable to Brads 452(same cr, similar cam).
I ported the heads to flow in the 300cfm range, and tested them on the motor with a few different intake and carb combos.
At that point, the best intake/carb combo i tried was the Weiand TR with 2 x 650 Demon carbs on it. That made around 595tq and not quite 640hp.
The next closest single carb test was around 625hp, with a similar drop in tq.

Brads Victor combo made 684hp/605tq with an old school HP950 Holley on it(1.375 venturi), which resulted in the motor using 20cfm less air than when the bigger carbs were being run.
Had the bigger carbs been better optimized for the motor, I have to believe some benefit could have been gleaned from that extra 20cfm of air.

With the current crop of std port offerings available, for me the real litmus test would be how much difference in power there would be if you pulled the Victors off Brads motor and plopped a set of ootb TF240's on it.
If it made within 10-15hp of the Victors, then that would be a good argument against the viability of the std port version of those heads, at least at that power level.
It would be a fun test.

The nuts and bolts of this particular test is that Brad replaced his ported std port Stage 6's and flat tappet cam with the std port Victors and a roller cam and picked up 20ft/lbs and 60hp.

There are a few things I don't really care for in how the Victors are made, but I'd say the biggest "problem" with the std port version for me is the they are cast with the bowls .300 smaller in diameter than they should be.
If they had the bowls sized correctly to begin with(sort of like the original version was), then I would feel better about recommending them for the hot street applications where a high flowing std port head can work.

As they are now though, they're too labor intensive to be cost effective.

I wouldn't mind doing a "low effort" type job with some Pro Comp "Victors" at some point though(since those don't have the ridiculously undersized bowls).

Mine may be considered max ported base on Pettis and George Koopals opinions but no flow #`s since I was in a hurry to assemble and the flow bench was tied up. I know that on a chassis dyno years ago it was still makin power to 7000 where I stopped and went home and on the street, it's a beast to me anyhow w/a new best hopefully very soon..........I plan on a max wedge build next year and a bigger cam..............

My first 400 block stroker motor made 612 HP at 5500 RPM and 644 Ft. lbs. torque at 4500 RPM, that was with 9.25 to 1 compression using a set of mildly ported 906 heads (flowed 266 at 28.0 inches at .700 lift on Pettis 600 Super flow bench) with 2.14 intake and 1.81 ex. valves. Comp Cams solid roller custom ground for Benschoff racing (SP?) in WI. the testing was done on Vrbansic Bros. (Ontario, CA) DTS engine dyno in 2003 or 2004, CRS We tested three different sets of six pack carbs and multiple air cleaners combination. the best results are posted where with the stock air cleaner base with no air cleaner and a set of the Holley mechanical carbs with stock jetting, the worst results where with a set of replacement Holley 1971 440 automatic carbs with stock jetting that bogged horribly when open but still made 605 HP at 5400 RPM
I put the motor in my Duster and took it to Woodburn drag strip in October of 2005 after we moved to Oregon, it ran a best of 10.69 at 124. MPH.
I swapped the heads that winter to a set of MCH CNC ported Eddy RPM heads that flowed 319 CFM at .700 on MCH flow bench and flowed 310 CFM on Pettis bench at .700 lift with 28 inches of water on his Super Flow bench Both sets of heads had 84 CC so the motor ended up having the same compression ratio and a different set of 1.6 rockers, I took the CAT 1.6 ratio rockers off(they where wearing the shafts out nmaking metal ) and put a set of Harland sharp 1.65 ratio on the Eddy heads, those two changes ended up making the car go 10.49 at 126 MPH
I ended up changing a lot of other things on the motor including the cranks shaft increasing the stroke .050 to make the same pistons and rods end up with 10.29 to 1 compression ratio and increased the C.I. from 511 to 517, that change made the car go 10.30s ET at 127.+ MPH
The last change was going to a set of Indy SR M.W. size ports not CNC ported with a Indy 400-3 intake with a Wilson manifold 1.5 inch reversion spacer with a 19x3.0 inch air cleaner instead of the stock type six pack air cleaner with two K&N six pack elements on it. I ended up using several different Holley 1050 CFM Dominator carbs on the motor that ended up with a best ET of 9.993 at 134.+ MPH through the 3.0 inch exhaust with the 16x3.0 inch tall paper air cleaner element on using 91 octane non ethanol pump swill, the car weighed 3450 Lbs. with me in it.
I had a lot of fun and learned a bunch from that car and different engine combinations I did try a set of 440-1 heads with 2.25 intake valves that where CNC ported by MCH, on the DTS engine dyno in Klamath Falls OR they made 50 HP more on my Duster motor with the same compression ratio, those heads flowed 30 CFM more at .700 (370 CFM)than the SR heads did on the same bench
I would of loved to try a set of B1 heads that flowed over 400 CFM with that short block making less than 11.0 to 1 compression
My message is results on the dyno compared to at the track may or may not make what you think it should, go test that motor Brad in the car

David vizard has a theory and is developing some software for calculating port energy. Which talks about a lot of the issues in your post. Lot of discussion on the speedtalk forum

https://www.pistonheads.com/gassing/topic.asp?t=1096171

Where drivability (I define as off idle to <WOT) throttle torque is important (and for most dual purpose cars it's way more important than most will admit) having a slightly undersized higher velocity port will be more responsive and fun to drive. At the track and with the optimal gearing (critically important) a larger port will et quicker, though driving it around on the street it will feel more sluggish or will be far more dependent on stall/flash....which means pretty inefficient if only in terms of how it's mainly going to be used.

Brad do you have Steve Dulcich's hp/tq graph from his 2003 EM 470/Chapman or our own EM Stage VI high velocity/epoxied MW entry? I don't think those had much if/any perceivable dip, but 470's hit a little quicker and harder on a dyno than a 440 of the same peak power. I think a big part of the strategy for EM is the fixed rate of acceleration in 100R's/sec against WOT standardized testing. I think guys like Kaase and Bischoff figured out very early that tight lobe centers combined with early ICL's get the motors a harder dyno "hit" and perhaps help the combo carry momentum...like 'pedaling downhill' of sorts. in other words the gains in torque below the peak more than offset perhaps losing a couple up top, the motors are obviously much more "lift dependant" from peak torque to peak power because the durations have to be kept relatively short to achieve mid range velocity at the slower RPM/piston speeds.

On the street or at the strip with a high stall converter or a clutch that 3500-4000 won't have much bearing with the right converter, but velocity has a TON to do with responsiveness. My approach has always been on a big 500" motor it shouldn't need to be so converter dependent to get to the sweet spot, so I'm a huge fan of velocity. But of course my philosophy for dual purpose cars is more likened to a road-race shortblock with killer heads for the best (or near best) of both worlds. My 517 Chapman design was based a lot on what I learned from Steve's 470 motor and discussions with Dwayne and Dan Costello....and it's the flattest/broadest torque and fastest revving wedge I've ever built...by a mile.

No dyno graph, but for those who are interested, here are some of the details of Steve's 470. Lots of clever techniques involved and some smart planning.

Peak HP: 752@ 6,500 rpm
Peak TQ: 641.9@ 5,500 rpm
Avg. HP: 547
Avg. TQ: 598.8

Dulcich 470" 2003 Engine Masters info link a

Dulcich 470 Engine Masters info link b

.034-inch quench clearance,
12.7:1
Ohio Crankshaft forged steel 3.90-inch stroke
TCI Rattler balancer 7.2" diameter
Manley connecting rods
Ross Pistons
Harland Sharp 1.7 rockers

Comp MM lobe Solid flat tappet cam
259@.050 single pattern
108 LSA - 102.5 intake centerline

Indy 383-13 intake
Tapered 4150-4500 HVH spacer adapter
Barry Grant King Demon RS carb
TTI 2"-2-1/8" step headers

Chapman CNC Victor Heads, 285cc

INTAKE VALVE EXHAUST VALVE

0.050 -36 cfm - 0.050 -30 cfm
0.100 -73 cfm - 0.100 -60 cfm
0.200 -148 cfm - 0.200 -107 cfm
0.300 -214 cfm - 0.300 -158 cfm
0.400 -270 cfm - 0.400 -210 cfm
0.500 -308 cfm - 0.500 -232 cfm
0.600 -332 cfm - 0.600 -250 cfm
0.700 -350 cfm - 0.700 -265 cfm
0.800 -385 cfm - 0.800 -278 cfm

Thanks Brent,

I see the flow numbers on the intakes are POST Tear-down for his EM 285CC heads, which are lower than his as new bench set in the magazine.

The Chapman 285s from Steves bench (Mopar Muscle May 2004 Issue) were:

.100---77
.200---151
.300---220
.400---283
.500---330
.600---364
.700---375

Dwayne (Fast68Plymouth) flowed my actual set of 285s for Moparts and they were pretty close to this, If I remember right (at the time ) he only used a 10" flowbench so the bigger (>.600 lifts) were maybe a little low compared to being measured on a 28". Here they are from the tech archives:


Lift" I/E

.100 72.5/58.2
.200 153.7/118.6
.300 224.3/178.2
.400 285.2/218.2
.500 329.6/232.8
.600 361.9/245.1
.650 368.1/249.9
.700 364/253.1
.750 364/254.7
.800 364/256.3

At the time we were commenting that although they flowed very close to a well ported set of -1's, they do so with a far smaller CC intake port, so they acheive the flows with much higher velocity (which for a street car equates to responsivenness and torque)

I would not have used those springs with those rockers on that 2016 EMC build.

In general most folks always opt for biggest port--highest flow numbers they can find and afford
That is exactly why AFR sells so many sets of ( chevy and ford )heads for about the highest price on the market Biggest valves--highest flow numbers
yet many engines that are built with them would be far better drivers and much more fun with smaller port runner volume
Folks always want a street car that runs like a dragster
They sell fake boobs but not man parts because guys would all have to push a wheel barrow to walk around
Head sales people know this simple fact and profit greatly from it

My conclusion is an easy to build cheapo 500CI big block with almost any head will make 570 HP easy as pie and be the most awesome fun most have ever had and often when combined with the right gear. converter/ intake/ carb combo out run many that sport much more HP and if it does not--WHO CARES? Because no matter how much HP you have or how much $$$ you throw at it thirty other guys can wax your behind so ??????????

If you want to go fast attend one of the dragster or funny car deals--pay a couple thou and on day two make a 200 MPH pass--then you are done for least amount possible

Dwayne I think you and I are on the same page almost all of the time, however I don't think you realize just how underperforming the Victors really are. I don't want to de-rail this thread further with more of their shortcomings (install height, etc....)

In short I view the RPM's especially the 75cc version, and TF 240 as the same in power potential. The only difference is the TF's come fully CNC'd. If Edelbrock was smart they would offer their 75cc version fully CNC'c with a GOOD design at the same price point as TF and with their marketing and distribution TF probably would not sell too many. Edelbrock could then market their NOW JUNK Victor line with revised valve locations and angles with only a large port version CNC'd for serious efforts and probably demolish Indy's sales.

Sorry Brad, not meaning to derail your thread, the question you posed is a very viable one. A large port in this style of head CAN be crutched with headers, aggressive cam, increased static comp, wrong timing curve, etc..... However when these are missed a giant hole in the power curve often shows up.

To sum up: How much more power are the standard port Victors worth over another standard port RPM or TF240? 100hp? nope, 75hp? nope, 50hp? probably not even. ROI @ less than 50hp? Not there for me. J.Rob

I remember several years ago talking to David Vizard (who lives here in Charlotte) and one thing we both agree on is that Velocity AND Flow are critical to maximizing torque and horsepower, particularly when you consider the slight 'supercharging' or "packing' force that occurs when the intake valve is still open while the piston is coming back up the cylinder after passing BDC. If you still fill the hole as the swept volume is Decreasing...well that my friends is where the magic really happens in terms of high RPM power output. Too small or too low a velocity ports can't achieve this.

To me the ultimate street/strip BBW head might be the Chapman MW ports combined with the TF chamber and plug placement.

And of course "real world" torque is also as much dependent on intake flow as it is the port itself, To me looking at just the port is kinda moot, you have to consider the whole intake tract from the plenum to the valve, again too big is a low/mid torque/response killer, too small is a high RPM HP killer (choke point). But the intake alone has a huge impact on how a motor is going to hit on the dyno or on the street. The intake has to outflow the port or really the flowbench numbers for the port itself are kinda moot. And lets not even go into how the fuel mass in suspension passes through the port. at 12.5 A/F ratio on a 360 cfm port flow you are flowing roughly (air and fuel obviously have different flow cooefficients) a rate of 28.8 CFM of solid fuel (which displaces/subtracts from the same volume of bench Air flow). To me port flow in a poppet valve engine needs to be viewed as a Window (opening and shutting over a fixed time) which is the average sum/mean flow from all the effective lift points....peak flow is only one point of measure.

Sorry guys...my second cup of coffe was kicking in, don't mean to ramble!

This Victor thing has been beat to death for 3-4 years. The manufacturer is well aware of the negative posts. This is getting a little silly and unproductive at this point.

Here is a chart from my last round of 470 testing. This is with the Trick Flow 270 heads and the 264/268 roller cam. Flat top pistons, unleaded premium gas, Dominator carb, locked timing curve. There might be a hole in the torque curve below 4000 but from 4000 up it looks pretty smooth. With this engine we don't pull it below 4000 so I'm not sure what the torque curve looks like down there. Might not be a ton of torque down low since the cam is pretty big for the compression ratio.

Sorry guys, I was just going by the thread title, I didn't think the discussion was limited to the merits of the Victor, or TF, or Chapmans or whatever...I didn't think anything I was saying or bringing up for consideration would be considered going "off topic"...was I???

Finding the neal ideal balance of flow (for power) and Velocity (for torque and drivability...at least in a dual purpose street/strip application) for a given displacement and weight/gearing....well that should always be the goal...right? for Drag racing it gets at least a bit simpler.

BTW, Dom's 470 is definately one of the most impressive Eddy RPM combos I've ever seen or heard about, and he's probably getting about as much out of a set of them as there is to have for sure.

Actually I was thinking (and judging from the caliber of respected participants) that this was one of the more interesting threads in the past several months.

Jesse, I guess we look at the Victors through different eyes.
It seems like unless you take them “to the max”, and bolt them onto a similar type of short block, to get every last possible hp out of them, then they aren’t worth using.

I see them differently.
Again, “if” they had the bowls sized correctly(or using the Pro Comp head)it wouldn’t take any more time for me to port them into the 340cfm range than it would to port an RPM to 300.

They aren’t that much more money, you get away from the valley pan gasket, and the chambers are better.
If you bought TF240’s and used the recommended HS rockers for the TF heads, or something like T&D’s......then the cost difference of the rockers is diminished considerably.
Like I said previously, the big hurdle in using them for me is the way the bowls are cast.
One thing I do like about them is they are a true std port head. Not a MW head with a reduced port opening at the flange.
If, in your words, flow is velocity......then at 350cfm from a true std port head.......they should be pretty good.
IMO, if they made 30hp more than a set of CNC RPM heads on the same motor, same cam, same compression.......I’d be fine with that.
I don’t feel like I need to make 800hp out of them to have them be worthwhile.

With regards to Brads combo, there is no way the two cams used in his motor would be 50hp apart......with either set of heads. Maybe 1/2 that.
As for whether or not his stage 6’s could have been improved today......that wasn’t really part of your original argument. You said your 298-299cfm RPM heads would have made the same power as the Victors.
If that’s the case, then the Stage 6’s would also be just as good, since they flowed a little more than 300, and have a better chamber(although those heads required way more work to be made usable than the Victors).

Also, at 350cfm @.700 Victors have a better discharge coefficient than the RPM’s at 300, or the TF’s at 325(what they flow on my bench).
A 251cc MCH CNC ported RPM flows 315@.700 on my bench.

If the flow doesn’t matter, and the c/d doesn’t make any difference........we might as well stop testing heads, since the numbers must not have any bearing on power output.

Until someone does “the test”, it’s all just speculation.

It’s easy.......don’t like ‘em? Don’t use ‘em.........plenty of other choices.

As for the carbs.......couldn’t disagree more.
I tried my HP950 on his motor as a point of reference to gauge how well the other carbs were doing their job. It’s by no means my best carb, yet was basically as good as the others we tried.


You totally lost me here.
By that logic I guess I could have put a 650 on it and made the same power with even less flow through the motor.

I’m confident that had I run the motor with my ported annular 850(which flows about 40cfm more than the HP950) it would have made 8-10 more HP........and picked up most of the lost 20cfm.

I feel the same way and because I have firsthand experience with this build numerous times I was sharing my thoughts on the whys and hows. Nothing more, nothing less. J.rob

J.Rob

I’ll only add this.....

Brads motor made the most HP of any std port motor I’ve tested.
It wasn’t the biggest, didn’t have the biggest cam, or the most compression.......but it did have the highest flowing heads.



That’s exactly what happened when we did it with the stage 6 heads.


You mean the $54 per head?



Well......IMO, you did indirectly.
Your position is that your 299cfm heads that flow 50cfm less than the ported Victors, that also have a lower c/d.......would make the same power on Brads short block.
That certainly seems like you’re saying to disregard the c/d and fairly substantial flow differential.

Maybe it’s my lack of knowledge of the platform for the low expectations of what I was looking for out of the Victor heads.........but they performed as I thought they would on Brads motor.

The best stock stroke RPM headed motor I’ve tested(which as it turns out had 300cfm intake ports) was an RB 451 with a tall filled block, Ross dome pistons(13:1cr), aluminum rods, ported Victor intake with a blended HVH SS 4500/4150 spacer/adapter, Pro Systems 1050 Dominator, 272@.050 flat tappet cam, .650 lift with 1.6 rockers, big box style pan.......and that motor made 652hp and about 570tq........and I was pretty happy with that too.

I like the Engine Masters stuff but think it has gotten too specific to dyno racing.
Hot Rod makes it seem these engines can be run on pump gas. They specify a spec 93 octane Race fuel, That is not the same as pump 93 octane swill.

My motor is a old Engine Masters motor and I have never used anything but 93 octane pump gas in it. Has run fine for 5 years.

No problem. It was NOT intended to be a brand-specific promo or bash thread, as I did state originally. That it took on that sort of flavor... well, it is what it is. Hey, "Let it roll..."


Thanks. I was really hoping it would generate some interest and add some value, given what I believe this forum is intended primarily to be.

It seems to me that a too big of port thing is not as important as it seems at first glance, a stone stock 392 CID GEN III hemi runs great at 2000 RPM with huge ports, next time you drive one with a 6spd try lugging it at low RPM, seems to run just fine, as a matter of fact the eagle 5.7 has almost as big of ports with even less displacement and make plenty of TQ down low and has great throttle response once the DBW crap is tuned right.

Wet flow dynamics is more than just high velocity. These modern engines work so well because the engineers work on improving all aspects like flow, swirl, velocity, cam timing, runner length, ex flow, chamber shape, spark plug placement (find a way to get the plug in the richest mixture part of the chamber), cool intake air (hint... the manifold is a lot more important in keeping the charge cool before entering the chamber than the part the air filter is hiding in).

Bottom line is you can still make big TQ with big efficent ports but you can not make big HP with little ports no matter how "efficent" they are. I got a set of modern cylinder head CNC 302 casting heads and velocity is incredible but even jeff said he had a hard time making 500 hp with em but TQ was great. You just got to find a balance that works for you.

HRD - I don't think that's an apples-to-apples comparison. How's a 426 N/A Drag Pak with a 270+ at .050" cam pull at 2000 RPM under a load? And how would it behave if it was also retro-fitted with a carb and old-tech mechanical-advance ignition?

Do you follow Brad's posts on here?

Brads Victors were less work than his stage 6's(well, pretty much any non-Chapman stage 6's)......and no more time or labor intensive than a set of 280cfm 906's.

Your talking dry flow VS wet.. 2 different worlds
I love the power in my 416 W2.. its injected
with multi port injection.. it was less power with
the carb on the street.. but I did make some changes
so its not 100% the same... I did go with a smaller
cam for one thing

The original question was port size vs aplication, this is a very exagerated example of really big ports in both size and flow for the CID but still makes plenty of TQ in the aplication and velocity will be really low at lower RPM yet it works. If you heard of someone putting heavily ported W2s (similar flow to an eagle but smaller cross section) but on a stock 340 short block you would think they were crazy and going to kill there streetability but the Gen III engine seems to defy old school logic. All I am saying is you can not just say you need velocity more than flow, there is a lot more to it and some of the old hard fast theory no longer seems to hold up. Now we have a 485 hp SAE Net 392 with plenty of low end TQ.

True, as it is w/ the GM LS7 "stuff". But what works using current tech doesn't always apply -- much less retro-fit -- to the old sh!t most of us are building on here.

What do you consider " big HP?" Modified eliminator guys were running in the 9's, under 300 cubic inches, and with stock head castings. and that was 40 years ago.

When you discuss the old days in Modified eliminator you have to remember that all those drivers let the clutch out at 8000 + RPM with either 6.17, 5.86 or maybe as tall as 5.57 with a 3.25 low gear and shifted them between 8500 up to 9800 RPM, NO torque what so dang ever
They idle at 1500 + RPM, those motors flat scream from when the top bulb came on until they let off on the other end, none of those motors ran in gear below 2500 RPM until they stuck the clutch in to reverse directions or were shutting the motor off

That was my point. Those cars made big HP, from little cubes, and a production head, with not very large ports( compared to what is available in the aftermarket today).

The smaller the motor the more sensitive it is to port size at WOT below peak torque RPM
Did you ever drive a 351 Cleveland powered Mustang or Torino? Talk about port size being over sized for the application They where dogs to me below 5000 RPM

Glad the cleavland was brought up, it is about 2.9 square inch and the eagle 5.7 is about 3.0 sq inch. One is good at making TQ and one sucks both are good at making HP but one is better.

Nice analysis and research, good reading and food for thought as ever.

Is there a timeframe for the ol' E body to come back out with the new bullet in it?

Any changes anticipated to better accommodate the motor?

Put port injection and a fast burn chamber that only needs 25 degrees of timing on the Cleveland and I think the torque gap disappears.

Kevin

Comparing old to new is a bit moot, New motors have either port or dirct chamber fuel injection, the manifold and port only have to move AIR and not carry fuel in suspension. Put a carb manifold on a modern hemi in a 4400 pound car nd watch the torque plummet at low/medium piston speeds.

The cleveland in smaller 2V form still needed a long skinny intake manifold runner just ot make decent torque, and the 4V was a bit soft on the bottom end unless you had steep gears, you basically had a smallblock with a 427 Chevy size intake port , they used to sell port stuffer sheetmetal plates to pick up the velocity in the Cleveland heads which blocked the lower third of the port....but Clevelands still make really stout 408+ " short rod stroker motors.

I had a 351C 4V in my '56 F-100 pickup when I was in high school. No idea how much torque it made but I'm lucky I'm still alive. I'd drive that truck on a two line highway over to visit a girlfriend and I would pass 5 or 6 cars at a time. Just punch it from 55 and it would bury the speedo in nothing flat. 100+ mph in a '56 F-100 with drum brakes and a straight axle was not the smartest thing to do. But I was only 17 and didn't know any better! I don't recall any flat spot in the torque curve.......

Newer engines also have variable runner length intake manifolds, this is an OLD Harley engine I built, this is a 94 inch Harley, very old design with heads I ported on the large side for cid, it is also EFI, the blue run on the dyno is with a 8 inch long individual runner length, very gutless down low, the red line is with 22 inch runners, everything else is the same, tie both these power bands together with a Variable runner set up & you will have something that has power all over the place with a HUGE intake port on the cyl head. this is only for a 2 cyl, X the results by 4 for an 8 cyl

When your 17 yrs old and ten feet tall, bullet proof and Superman nothing bothers you does it
It never bother me when I was that way

Look at the flow out of the box though, the Hemi head flows ~50 CFM more at .300 (190 vs 240) and ~60 CFM more at .600. (270 vs 330).

The yamaha r600 has something simular to what you found. The velocity stacks electronically lift off the carbs at a certain rpm for better top end power. Best of both worlds. That 600 red lines at 18000 rpm. If we could just do this with our motors we would really have something.

So do most of the gen3 Hemi's, Active Intake Control

only the trucks have active runners and only on 09 up

Thanks.

2018... or my family will find me swinging by a rope tied around my neck on New Years Eve 2019

Replaced the 8.75" with a Strange S-60, and the S-60 has CalTrac's reinforced spring perches to take the hit off the line better

Went back to 22" front spring segments from the SS-spec 20" while staying w/ CalTracs and their mono-leaf springs

Switched from 8" to 10" rims to help spread the footprint of the 275/60R15 drag radials; also going with M&H radial "skinnies" up front that will lower the ride height of the car a tad

The Drag-Pack inspired hood mod gives me room for an air cleaner and at least some amount (1/2" or maybe 1") of carb spacer; I wasn't even sure the standard T/A scoop would fit a 3" air cleaner with the Victor heads & a tall intake like a Victor or Trick Flow

Maybe some other things that don't come to mind at the moment...

Probably need better rear dampers than my old Rancho 5-ways; a nice DA would help getting the rear suspension dialed in

6.4 SRT's have the active intake as well. Guys swap them over to Eagle engines and control them with an RPM switch, apparently 4400 RPM is the sweet spot