Barring any new "challenge" pops up that is a bleepin' show-stopper to my trip to VT this weekend, the next incarnation of The MoPig's engine will be flogged on Dwayne Porter's dyno this Saturday.

Everybody loves a good "Guess they dyno results!" thread, so I'll put out all the details for you to come up w/ your #s.

>>>>>>>>>>

I. I'm working off the same 440 + .060" (452) short block as before, but...
- It's got a fresh hone, and I changed from Total Seal "Gapless Top" rings to conventional rings gapped at .020" top / .024" second
- The ring pack also changed to use a Napier 2nd ring, and the oil rings have a little less tension than the last "standard" tension set... 16-18# vs 20-22#, IIRC
- I've made a few tweaks to improve oil control (Milodon "Street Hemi" style w/ windage tray, added a crank scraper, and had some additional oil-return baffles welded in the pan)
- New Eagle 4340 crank, instead of my old OEM piece
- BHJ SFI balancer that I sent back to BHJ to "rebuild" before putting it back into service
- After break-in, it'll have 10w40 in it, whereas I used to run 20w50


II. The heads are standard-port Edelbrock Victors that Dwayne Porter finished for me.
- The heads were originally used by Brian at IMM for a 400 build-up, but he pulled them off after dynoing that combination and I ended up buying them some years later
- I had Hughes do their CNC chamber work
- Dwayne did the porting and a touch-up to Brian's valve job
- Avg CSA is 2.76" and Min CSA is 2.65" (presuming I did the measurements & calcs correctly)

Flow results (because EVERYBODY knows that flow #s tell you EXACTLY how much power an engine is going to make, right? )

INTAKE -
0.100 -- 75
0.200 -- 151
0.300 -- 220
0.400 -- 280
0.500 -- 326
0.550 -- 338
0.600 -- 346
0.650 -- 350
0.700 -- 355

EXHAUST --- w/ 2" pipe added
0.100 -- 55
0.200 -- 116
0.300 -- 155
0.400 -- 194
0.500 -- 211 -- 238
0.550 -- 222 -- 249
0.600 -- 231 -- 259
0.650 -- 237 -- 267
0.700 -- 243 -- 274

Oh, the chambers are smaller than my old Stage VIs, which has bumped up the CR from about 10.8 to just under 11.5. We'll be using pump 93 E10 w/ a blend of race fuel to increase the octane some.


III. Cam specs

Oh, boy... my first venture into solid roller territory , whereas I used to run solid flat-tappet cams.

Dwayne recommended a COMP RX roller, a moderately aggressive endurance lobe which he's said has been very successful for his customers looking for decent valve train life when running a solid roller. Since mine is a limited-use dual-purpose application, we didn't want to go w/ a "spring killer".

As measured in my block w/ .800"-wheel lifters:
@ .020" - 300
@ .050" - 266
@ .100" - 233
@ .200" - 184
@ .300" - 134
@ .400" - 68

Lobe lift -- .434"
Net measured lift after lash w/ 600# open spring loads: ~.655"
LSA -------- 108 installed on 104 ICL
Lash ------- .018" hot

Other valve train stuff:
- B.A.M. "Pro Series" roller lifters running in bronze-bushed lifter bores w/ oil-feed holes
- Smith Bros. adjusting screws & 3/8" x .120"-wall pushrods
- Hughes Engines rocker arms
- RAS rocker shafts
- PAC 1243 springs w/ 240#s at 1.90" installed height, ~ 600#s open
- Pro Gear double-roller timing set w/ 9-position crank gear


IV. Induction

Carb... See my other post w/ the options being considered for testing.

Intake... It was originally going to be a modified Edelbrock Victor 440 with the same plenum mods as I've done before w/ good results, but I ended up w/ a Trick Flow intake to try out
- The Trick Flow isn't 100% out-of-the-box, but the work I did to it was only some basic plenum & runner casting cleanup (not even port matched), and making sure any spacers wouldn't have a ledge sticking out from the carb mounting pad interfering w/ the fuel/air mix outta the carb
- I've got various 1/2" and 1" spacers (open, "Super Sucker") to try out, even though I may not be able to use a 1"-tall spacer as installed in the car


V. Exhaust

On the dyno, Hooker 2" Super Comps w/ 3.5" x 18" collector extensions

FWIW, on the car, TTI 2" with an X-pipe about 20" after the collectors and a full 3" exhaust system thru tailpipes to the back bumper. My TTIs don't fit Dwayne's dyno setup, and Hooker 2" Super Comps don't fit an E-body w/ an RB & heads with raised exhaust ports (at least not w/o significant mods).


VI. Misc "stuff"

Well... that's everything I can pull up for background info for this post.

Oh, the rules: (Rules???)
1. Ya' gotta give both the peak HP and torque, AND the peak RPMs for each... just to make it a little more interesting.

2. Give one set of #s for the baseline carb as described in the other post, and one set for whatever you think "the best" of the other carbs tested makes.

NO, I don't know what that carb will be at this point, so it's up to you to think about what you see as potential improvements -- if any -- from the different carbs listed in the other thread.


VII. "Winners!"

1. The person who gets the closest using the baseline carb and a 1/2" open spacer (since I know that size spacer will fit in the car)

2. The person who gets the closest using "the best" carb TBD (that's "To Be Determined" for anyone not familiar w/ the term) and whatever spacer works best with it

Prize?
=> Uhhhh.... maybe I can find a cool t-shirt or something to send to the two folks who get closest. Maybe a gift certificate to a commonly-used parts supplier?

Seriously, I do want to give something here to "incentive-ize" the challenge...

Oh, the restrictions: (Restrictions???)
1. If I blow it up on the dyno before getting a full set of GOOD data, ya' get NOTHING... except the opportunity to listen to me complain about blowing up my sh!t after all these years waiting to get it back together.

2. Ummmm... yeah, that's the only one that comes to mind at the moment


If everything goes according to plan, I'll have my data by late Saturday, but won't likely be able to post it up until either late Sunday after getting home, or possibly not until Monday.

base line carb 656 hp @ 6500 , 609 tq @ 5000

best carb 678 hp @ 6600, 617 tq @ 5000

BL 665@6800. TQ 580@5200
Best 681@6800 TQ 595@5200

Base HP 675@6100 TQ 600@5150
Best HP 700@6300 TQ 615@5200

So far, I hope I win, for your sake.
P.S. Don't blow up.

I'm gonna say.......solidly under 1000..... but also solidly over 400

Prize update: Each winner gets a $25 Summit Gift Card.

As much $$$ as I've spent to get to this point, what's another $50 to make it more interesting to others!

Carry on...

What type of dyno will be used.

SuperFlow 901(?), but I don't remember if Dwayne said the software package has been upgraded since when I was there 10++ years ago.

To get a sense for how "happy" it is or isn't, the old version of this same engine made about 610 HP and pushed my 3750# car & driver to mid 10s at 126 MPH in full street trim. The track is close to sea level, so the #s do reflect that.

Base line 661 HP @ 6300, 612 TQ @ 5100
Best 685 HP @ 6600, 618 TQ @ 5200

Base, 681 HP @ 6500, 644 TQ @ 5000
Best, 704 HP @ 6600, 648 TQ @ 5000

If that was through mufflers,the 610 number is probably pretty close. I have a 901 but the dyno cell isn't finished yet. I want to accurately calibrate it and get the engine from my race car on it so I can have some reference factors for the engines I build.

Just don't let Dwayne reach under the console.....

Yep: 610 HP & 570 torque on the dyno with open headers and my mechanical water pump; full 3" TTI x-pipe system to the rear bumper thru Dynomax Ultraflows, plus ailternator drag... I figured about a 4% loss as installed in the car.

646 hp @ 6300 rpm
596 tq @ 5000 rpm with baseline carb

651 hp @ 6300 rpm
599 tq @ 5000 rpm with better carb

Your 3.5" collectors are large for the app that's why the conservative TQ #'s. Assuming water temp and air temp are "normal" and not super cool. Good luck this should be interesting. J.Rob

630 hp and 570 tq as baseline
660 hp @ 6700, 588 tq @ 5100 with.. carb 5 after reading Mark W reply lol. Good luck! I'm looking forward to the results.

I know what slow progress is like. I almost got my 446 together after 11 years ofsaving and hoarding

639 HP @ 6400 and 589 ft lbs @ 4900 baseline

657 HP @ 6400 and 599 ft lbs @ 5000 with the best carb

EDIT:

BASE 669@6750 TQ 590@5250
BEST 689@6850 TQ 600@5250

Not good at this but I'll say;

640 hp and 650 tq but sure would love to see a comparison w/an adapter and Dommy just for giggles...........

I'd think it would make 700 hp. You have better heads than my 470 and more compression. Your cam is similar to mine. Your headers aren't as good as mine but that shouldn't be more than 10 hp. Not sure about your oil pan, might not be as good as mine but maybe only 5 or 10 hp. My intake manifold is better than yours and I have a few more inches but it should all even out at around 700 hp with a correction factor of 1.00.

for the fun I like your baseline carb Demon RS next pick would be the Holley ultra hp/xp

688hp 652 torque on the demon baseline carb

705hp 667 torque on the Holley ultra

you mentioned 93 octane fuel my engine program shows that it needs more octane, at least 105

And if you have time it shows that it might like the cam installed heads up at 108, instead of advanced to 104.

The ramp rate the dyno guy pulls the engine at will affect the HP numbers as well. I used 600rpm per second ramp rate for the pull.

A few tid bits.....

Water temp will be in the 160's for all the testing.
Weather is supposed to be pretty nice this weekend, so air temps would be mid-60's/70's.
The dyno exhaust isn't really "open".
There are 5" pipes coming off the collectors going through the wall, where they attach to tractor trailer mufflers.
Testing will be done at a 300rpm/sec rate.

Provided everything is still going smoothly at the end of the session, we'll take the "best" carb/spacer combo and make a cold water "bonzai" pull to try for "the big number"....... But we won't use that run for "scoring"
How low I can get the water temp will depend on how many runs we have made up to that point, and what the temp of the water in the storage tank has gotten up to......... But I'd expect to be able to get it down into the 110-120deg range.

The cooler temp is usually worth something...... But not always.
I think it would be on this motor though.

How many gallons is the water tank.

FWIW, I'd LIKE to post what I THINK it'll make, and what I HOPE that it makes... but I won't.

First, I don't want to influence anyone's predictions.

Second, if it's an underachiever and doesn't make nearly what I think it should... well, that's for me to think over afterwards.

Good luck ! A Day at the PRH dyno cell is loads of fun and a real learning experience.

Baseline WAG ; 645hp@6900/605tq@5200

Best pull : 658hp@7100/617tq@5400

750 zillion hp @ 7200 thousand billion rpm and 650 gazillion tq @ 5000 trillion million billion rpm!!!!!!!

There's always an optimist around somewhere!

Y'all have fun with this. Unless something goes t!ts-up between now and Saturday night, this is my last post on this thread until I have some results to show.

Lots of good guesses so far........ And a pretty big spread from high to low, so I'm sure someone will be pretty close.

690 hp 6300 590 tq 5300 base
703 hp 6300 595 tq 5300 best

FYI if he is using the latest version of windyn, it has an inertia correction factor, if set right, the sweep rate will not mater, 600 rpm vs 300 rpm vs step will lay right over the top of each other.

Explanation: the inertia correction factor is used to correct for the loss of torque as you accelerate the engine internals and related dyno equipment that is connected to the crankshaft. Without this correction you will get different torque reading @ each sweep rate.


Joe

680Hp@ 6700 and 610Tq@ 5500 base carb.
695Hp@ 6800 and 615Tq@ 5700 best carb.

Base carb 665Hp@ 6850 590Tq@ 5200

Best carb 680Hp@ 6950 600Tq@ 5300

Peak torque cannot and will not occur at that RPM with the engine specs listed. If it does-dyno is screwy. J.Rob

Don't forget to shoot some video with your cell phone.

The big dyno day was yesterday.
I told Brad I wouldn't post up any numbers.......but I can say the motor ran well, and we made I think it was 28 pulls without any "incidents".

I'll also reveal that we tried the "cold water" pulls with two different carbs and got nothing out of that either time.
The cooler temps thickened up the oil enough(8-10psi higher oil pressure) to offset any gains from having the heads and intake cooler......so it was a wash.
In hindsight, I probably should have tried a run with "lowered" water temps, instead of the relatively cold temps I tried it at(105-110).

He's driving back home today........so I'd think there should be some results posted tonight.

I run all of my dyno pulls with 180 degree water temp these days. I used to try and run cooler but eventually just decided it was easier to run everything at 180. I usually try to get the oil to 180 also but it tends to vary more. Sometimes the first pull is at 150 oil temp and then after a few back to back pulls it will get up into the 200 range.

Glad to hear it ran good. 28 pulls in a day is a lot of work, especially if you are swapping parts and then trying to get the engine pulled down and ready for the road.

I had a really mild 505 on the dyno last week.......the cold water test on that was a 14tq/8hp gain.

I've seen it change the numbers on a 700-800HP BBC by about 25hp.

Just depends on what it is.

Greetings from I-81 south of Scranton, PA. Mike ("THESHAKERPROJECT") is driving, so I'll try to post some results from my phone.

Baseline Race Demon 1.42" v, 1/2" open spacers, 34* timing
- 654.5 at 6100, 594 at 4900
- Air-fuel ratio getting progressively richer across 3500 - 7200 test range, even after opening the MABs

Can you post a couple tq# from 3k rpm?THX!

QFT 1.52" v with BLP downleg boosters, 38* timing, 1" Super Sucker spacer
- 677.7 at 6800, 603.3 at 5100
- gained power with each additional 2* advance
- too lean with starting 80/90 jets; ended up with 88/98
- part throttle not great

QFT 1.59" v annular, 38* timing, 1" Super Sucker
- 678.0 at 6800, 606.8 at 5100
- going rich above 6700
- part throttle even fatter than the 1.52 downleg

QFT 1.52 downleg, 38*, 2" Super Sucker
- 684.2 at 6800, 606.2 at 5000
- the "Big Number Run" although I would not be able to use a 2" spacer with an air cleaner, even with my raised T/A scoop

I am very surprised it liked 38* timing.

We ended up putting 5 different carbs on the motor, and all were briefly tested for part throttle operation.
At a variety of low loads(35-80-ish hp), at a variety of rpm's(2200-3200), looking at A/F ratios being displayed from the flow turbines and a Daytona Sensors wide band showed that none of the 5 had what either of us considered "acceptable" part throttle operation...... with the best of them being in the low-12's, and some in the 11.0-11.2 range.
They worked perfectly well to use on a "race car", but wouldn't be the hot ticket on the street(in their current configuration).

I can't believe I'm going to say this........but........this is an example of a good argument for EFI.

The pulls were started at 3500.

Once we started to get it dialed in, the tq at 3500 was a little over 500.

Things didn't really start to happen until it was closer to 4K.

Thank you for all of your results!

You did better than I thought on HP but I was fairly close on my TQ guess. IFR and PVCR circuits are always too big it seems for part throttle operation. Good job Brad and Dwayne and thankyou for sharing this. Brad your big block is going to feel like a supersized small block with this power and RPM. J.Rob

my 440 liked the same 38/39. my 505 is 35 iirc
a function of efficiency
Well done Brad and Dwayne , good to see the results

Tex

Yep, Holley carbs are almost always rich in the mid-range. On the dyno you can crutch it by turning the idle screws in since you don't usually need the idle circuit on the dyno. On a street car it needs to be sorted out. On the dyno we typically use the idle screws to get the mid-range cleaned up and then use the main jets for WOT. It takes way too much time to mess with the PVCRs during testing. Besides, it all changes once the engine goes in the car so no reason to mess with the carb twice.

And I agree with your EFI comment. Once you start tuning EFI engines you'll wonder why people waste their time with carbs!

Why do you say that? Just because nobody had time to fix a part throttle lean issue? An EFI system with a lean part throttle concern is still going to need calibration also. 5 minutes booting up a laptop or 5 minutes changing a bleed. I had someone drive over their laptop on a test day. Guess how much data we got that day?

Still about 2 hours out from home & Mike's driving again.

Miscellaneous comments...

I wasn't expecting it to want that much ignition advance. My Stage VIs' sweet spot was 35, which is why we started out about there. But we weren't seeing the results until bumping it up; 36 was better than 34, but 38 was better yet.

The Race Demon fuel curve made no sense given what I'd seen before. We went from .026 MABs to .028, but it wasn't much change. At that point we yanked it off and started testing other carbs.

Things that ended up NOT like I'd expected:
- More torque by about 20 #s... and the peak RPM wasn't really any different than where it was for the old combination

- Harder to get "big" HP numbers, and I'd been HOPING we might be closer to 700, although Dwayne & I agreed it "should" make 670+ before it was tested

- Peak HP RPM... thought it would be around 6500... didn't think the small CSA heads and moderate cam would keep pulling that high

- NONE of the carbs were really "right", even after some tweaking

- The 1.52 downleg needed WAY more jet than I thought it should; we also appear to have maxed out fuel flow capacity of the metering blocks used, since adding more secondary jet stopped much in secondary fuel flow increases before we got to the 98s

- Enough of the carb stuff I saw didn't make sense to me that I ended up stealing Quick Fuel's tune (as much as I knew, at least) for the 1.59 v annular rather than use what I'd intended

The part-throttle was rich on all of them, not lean, and really out of normal range in at least one case.

It was a loooong day. Met Dwayne a the dyno at 8:00 AM, last pull was close to 7:30 PM. Then time to break it all down, etc.

Thanks.

Funny you mention the small block thing. Since I seem to be one of the few BB people who still run a stock stroke, I've been thinking of my engine as more of a stroker SB... with a really heavy bob weight.

What did i win?


Stopping in Hazleton for some Senapes Pitza would have been a nice prize

And not just a little rich either........some were way way rich with light loads simulating highway driving.
Under those conditions, the main circuit is already flowing plenty of fuel,........and you're not going to lean out the mixture by 3.5 points by tweaking an air bleed.

All the carbs had a tendency to richen up throughout the run(both the turbines and O2 agreed).......some worse than others.



And, as I recall, it seemed to have the flattest fuel curve.

I haven't done the reviews of all the predictions to see who is closest to the two categories... but yours looked pretty good when you first posted them.

I'm still typing this stuff on my phone while on the drive home. I'll try to figure out who gets the Summit gift card(s) as soon as possible, but it may not be until tomorrow.

this might be why some of the carb tuners talk about all the newer bodies such as QFT and the variants need transfer slot restrictors in the bodies?

I'm sure that would help with the part throttle.

Transfer slot restrictions alone won't correct this type of driveability issue, although they may be one the things changed as part of the fix.

Dude! Still about 30 minutes from home... at least we're in the right state now.

Brad,

Thanks for sharing your results. How much HP did you gain with each 2* of timing? Did you only test the baseline carb at 34* timing? I wondering how close the baseline carb would have been with 38* timing and the 1" spacer, and whether your original carb is the best solution for a street car?

Do you think if you had the time to sort it out, you could have made some emulsion changes to clean up the middle?

Keep in mind the wot a/f ratios were fairly decent on both the QFT carbs when they made their best runs.
So, whatever you do to lean out the part throttle cruise, you're trying to do something that changes that part of the carbs operation by around 3 points......and have essentially zero affect on wot operation.

There are smarter guys with carbs than me, but I have a feeling it's easier said than done.

The QFT 1.52 carb had the least offensive part throttle cruise operation when it was first bolted on.......low/mid-12's, with the 80/90 jets.
However, with that set up, the motor didn't take a load real well, and I aborted the run about 800rpm into it when I saw the a/f ratios weren't getting out of the 15's.

Once the jetting was increased to get the wot a/f ratios in line, and the power up......which ended up being 88/98....... then the part throttle cruise was down at the bottom of the 11's.

The Demon had the next best part throttle operation, low-12's, and had the best throttle response.
IMO, this carb is probably the best candidate of what we ran to be tweaked to get decent part throttle operation for street use.
The down side of this carb as we ran it was, it had the biggest change in wot a/f operation from the bottom of the run to the top........it really richened up at the top end.

Running a power valve on both sides helps on the dyno but might not work at the track.

Re timing...
- One comparison between 34 and 38 using the same carb & spacer picked up 15 HP and almost 8 lbs-feet at their respective peaks.

- Going from 34 to 36 on a different carb & spacer combination picked up 13+ HP, but only about 1.5 lbs-feet; from 36 to 38 didn't pick up any HP (actually lost 2 at peak), but the engine got into the 670s 100 RPM sooner & stayed above 670 for 100 RPM later, and picked up 3.5 lbs-feet.

- No, never tried the Race Demon with the Super Sucker and more ignition advance. I'll need to spend more time on it when the car is running again to see what it does.

Thanks BH/DP for posting.

This (WOT fuel curve, cruise) mirrors my past results.

Did you look at the boosters at cruise RPM and the A/R befor the booster started flowing? Mine was fat before they were flowing and not flowing much at the lower RPM. The IFR did matter. My testing was in the 2000 to 2500 range.

Do you believe that if you did track testing under similar conditions, and based on et and mph, you would have come up with the same hierarchy?

Do you believe that cruise numbers in the 12s will truly cruise poorly on the street.

Finally,based on what an O2 sensor is really measuring, and how low the fuel flow/air flow measurements are (relative to their span) how robust do you thing the cruise A/F numbers are?

Thanks

My scoring methodology is to add the differences in estimated HP and torque from the actual results for each category. If there is a tie, then the same approach based upon RPM differences would be the deciding factors.

Winners:
- Baseline test - RAMM
- Best test - 572B1

FWIW, 572B1 was also 2nd in Baseline, and Triple Threat was 2nd in Best with a score only 1 point behind 572B1!

Being that the winners are both outside the USA (Canada and Australia, respectively), I'll need to ask Summit how I can award the Gift Cards if mailing them is an issue... primarily a concern for 572B1. Would both of you please PM me your mailing addresses? Thanks - Brad

Since this is a street car, were you running a PCV valve? Then tend to lean out the low to mid-range without having much affect up top.



Joe

Brad and Dwayne.. This has been a great thread! Very informative. Get that thing into the car!

Russ, on the carbs where the part throttle cruise was in the low 12's, the motor was running smoothly enough where I don't think it would drive bad at all.

I've had quite a few years and plenty of examples to look at, and when they come off the dyno like this, and get put right into the car without getting the part throttle a/f ratios into a more favorable range....... The trend does seem to suggest that the instrumentation isn't lying.
Those motors end up getting abnormally poor fuel mileage, plugs that are always dark, and sometimes even gassy smelling oil.

I had a really mild 505 on the dyno about a week ago.
It had a Holley 850vs on it.
Jets 80/88, part throttle operation very crisp and clean in the low-14's, WOT in the 12's & 13's.
No tendancy to get "fat" at any throttle or load setting.
That carb was a good match for that motor.

Good reading. Thanks for sharing your work!

I actually came here wanting to talk about carbs a bit, but after reading this, it seems it might be a bad time to ask questions

I would be very pleased with those hp figures on a stock stroke motor with that comp, that would put my 3200# car solidly into the 9's The timing aspect suprised me as well.
Mick

My 512 likes a lot of timing as well. It actually runs the fastest by leaving the starting line at 42 degrees and then I retard it at 5,000rpm 4 degrees to 36. An engine needs what fuel it does no matter how you feed it, cab or EFI. A well set up carb I understand makes more power doe to the cooling effect of the fuel vaporizing in the intake. But getting a carb RIGHT requires a lot of effort, drill airbleeds, power valve restrictions etc. The main advantage to EFI in my opinion is you do all your work an a lap top and if you screw up it is easy to go back to what works. On a card sometimes your changes are hard to undo.

Did you guys mess w/the emulsion cos you can change the mixture quite easily in the range needed buy the location and sizes.........

That's what I was getting at. My thinking was adding some bleed in a middle hole, or if there was already a bleed there, open it up a bit.

Am I thinking on the correct lines?

Congrats on a great build Brad. It will "haul the mail" as they would say back in the day
What will your car weigh when ready? We have a little time for "guess your ET" !

Exactly what I've done on the street w/interesting results and yes, adding bigger or smaller not necessarily more changes things pretty quickly and so do the hi-speed bleeds............The richness imo has a LOT to do w/a healthy bigish motor sucking through small venturi's/boosters makin em go rich and I see it all the time on my car and if they put a real carb on that beast(1050 dommy of course) that will change guaranteed..........

Nice job! HP is about where I expected it to be. Makes more torque than I thought it would though.

Went back to look at the list of carbs.

Did 6A make it on the motor? Figure that carb might've had a little calmer emulsion than some of the others.

Get the intake ported and dial in one of those carbs and you will be over 700 hp.

If you sell all of the carbs except for the one you want to run you'll be able to pay someone to port in the intake. If you sold all of your carbs and your intakes you could buy an EFI setup. But of course, EFI can be a hassle to put in a car since you need to change the fuel system. Might be E body tanks available now that are EFI ready though. I had to modify the tank in my Coronet and that wasn't any fun....

We did run 6A... briefly. It was not a "happy" carb and didn't even make one full pull before we yanked it off and tried a different carb.

Not enough time to "go deep" on any one carb with multiple items on the test checklist.

I'm going to take a s.w.a.g. that a day on the dyno spent on tuning ONE carb is probably enough to get a basic carb sorted out, if the original tune isn't close.

That thing had issues for me also but it went into the 12's-13's on my car then I figured you'd sort it out from there but apparently Andy's testing showed it to be good also......... IF you would of spent more time on one as stated, the end results could of been better and ironed out.........good stuff and info guys........

And sometimes....... Even after a full day...... You might still not get there if what it really needs from the start is a booster change, and you don't have the pieces on hand to perform that operation.

In hindsight, we probably should have stuffed the 88/99 jets in it and made a pull with it, just to "get a number".

Agreed although a bit "outta the park" but the old adage of give it what it wants apply's a LOT when testing..........

No PCV. Unless I have some type of separator to ensure oil doesn't get sucked back into the induction system, I won't be using one, either. Oil in combustion chamber = Bad JuJu

If you notice Triple Threat copies me and than super tunes

How about going as big as possible on the pvcr? That is what I always do. But Im an idiot but it seems to work

Not sure why, but I feel a need to pick on the "big" carbs. From the results the AFR at WOT was pretty good on the big carbs, so there may not be much more power there. All of the tuning would be to get some measure of street manners. The "little" Demon didn't put up the numbers but I look at this way:
654HP
10+ with the added timing (conservative)
5+ with a flatter fuel curve (conservative)
2+ with the bigger spacer (complete guess)
=====
671HP
And it already has some decent manners. I know you go for every last bit, but are you going to even notice the difference of 10HP on a 700HP motor?!!!

For me, the Demon is the clear winner, and the best choice to spend time fine tuning.

Yeah, that'll be something I expect to try.

10 HP will definitely show up on the ET slip.

For me, there was no clear winner... but IMO one of the carbs tested isn't worth putting much -- maybe any -- effort into.

I feel if the fuel curve on the Demon could be sorted out, it would have made within a few hp of the others...... As they were.
It had the biggest spread in A/F ratio within a pull. Going from memory, it had areas near the bottom where it was in the 14's, and ended up in the 11's at the top.

I'm fairly certain there is 5-10hp left on the table if you could really get one of the annular carb combos dialed right in.

I base that off the last few pulls we made, in which we tried my dyno mule HP950, which was within a couple tq/hp of the others.
I have A/B'd that carb quite a few times against my old CFS built annular 850, and the CFS carb is usually worth 5hp+ over the my 950.
In all fairness though, while the CFS carb does make good power, it also would not have been any better at part throttle than the QFT carbs. It's pretty rich on the bottom.

The dyno mule HP950 is something I built from a bare Holley body and old style HP metering blocks. I used Braswell stepped boosters in it, and it has a tendency to slightly richen up from bottom to top.
Trying this carb on this motor for me was sort of a "control" test, to guage if the characteristic we were seeing of all the carbs richening up was something peculiar to the combo, or just what the carbs were doing.
If anything, on Brads motor, I'd say the dyno 950's tendency to richen up was slightly less than what is typical with it.

Also, I've run that carb on many motors and its never shown a problem being lean before, so again..... As a control item...... If it would have required a bunch of jet put in it, it would point the finger at a combo specific issue, not so much a carb issue.
The A/F ratio was mid/hi-12's for most of the pull, and richened up to low 12's at the end.....with the std jetting I had in it.

The motor itself didn't appear to present any out of the ordinary challenge for fuel delivery to the carbs...... The ones that required really big jets to get the wot A/F ratios right are just configured in a way where that was the case.
My dyno mule 950 was flowing plenty of fuel with only 75/84 jets(primary pv).

The motor was using about 20cfm more air at the top end of the pull with the bigger carbs....... So there is some power to be gained if the metering is really sorted out.

Yeah, something in the current tune w/ the Race Demon (which basically duplicated what my Gold Claw last used on the car) is just... wrong.

The previous dyno tests w/ the Gold Claw using a different emulsion config started & ended in a normal A-F range, but had a prominent lean swing in the mid-range. I thought the basic changes I made would have simply flattened out the curve, not make it go progressively richer as the RPM increased.

IIRC, (don't have my notes on hand), with both carbs set up w/ 1.42" venturi sleeves, .026 & 70 air bleeds, 80 pri & 90 sec jets, .035 IFRs, and the same .160" ID downleg boosters, the difference was the original Gold Claw emulsion stack was .031"/blank/.031"/blank/.031", whereas I set up the Race Demon with .028"/blank/blank/.028"/blank (more of a traditional Holley DP configuration). Regardless, the two tunes ran waaay differently re air-fuel curves than I would guessed.


That's what I'm hoping, but am in wait-and-see mode until the car's back on the track. One thing I did notice was the run w/ the QF 1.59 annular using the 32 MABs actually made more power across the RPM range, even though it went rich at the very end, than the subsequent runs where we leaned out the MABs.

That original QF 1.59 annular pull made more power across most of the RPM range than the QF 1.52 downleg did w/ the 88/98 tune, too. That 1.52 tune is quite a bit richer than I'd expected because the QFT RQ-1000 tune out-of-the-box has 82 & 88 jets and a much leaner .035 MAB. Those BLP .450" ID x .155" leg boosters worked REALLY differently than I anticipated. I thought w/ their improved booster signal that they'd want less jet, not more.

FWIW. I checked last night and verified the QFT RQ-1050-AN tune w/ THEIR metering blocks starts at 33 & 73 air bleeds, 84 pri & 90 sec jets, and .035 IFRs. I'm not 100% sure about their emulsion stack -- although I think whatever they don't plug gets .029" or .031" e-jets -- or their PVCRs size.

I put mine together using Holley Ultra XP .160" angle channel metering blocks with 32 & 73 bleeds, 84 & 92 jets, .035 IFRs (lowered), an emulsion stack of .0305"/blank/.0305"/blank/blank, and .059" PVCRs.

ALL of my carbs have room to mess w/ their tunes.

A 2-circuit Dominator built by me would of topped em all GUARANTEED as it has even on small blocks to the tune of 5-6 mph and .05+ in et reduction.........simple physics and a stout motor need lots of air n fuel and the fuel curve would make ya smile. Here's a "cool" deal I found the other day testing an 850 on my Dart. I had to put a 4150-Dommy adapter on my adapter upside down to test it and after getting heat in the motor and some foot brake climbs, I removed it and it was iced up on the base plate.......try that w/EFI.............NOT GONNA HAPPEN..........I will send Brad a 1050 to try someday if interested for a street/track test even w/out a hood if that's what it takes to see the difference so we can all get some info..........

Maybe some day Dominic.

FWIW, I plan in the next couple of days to post a "before" pull from my old combination and an "after" pull from the new one to see where & how much it picked up.

All good Brad but I always say that I will not compromise power for space or clearance especially when those that tried what I said got great results........not ALL but most...........

Here's one:
- Stg VI SFT A = Stage VIs w/ 266 at .050 x .600" on 108 SFT with ported Victor (no spacer, since it wouldn't fit under the old hood) and my Gold Claw carb set up with the 1.42" venturi sleeves

- Victor SR A = PRH Victors w/ 266 x .050 x .650" on 108 Solid Roller w/ mildy modified Trick Flow intake, 1" Super Sucker spacer, and the QFT 1.52 v downleg carb

I've got the raw #s, but thought the graph presented better. The thing that most stands out -- for me, at least -- is this wasn't simply a gain on the top end. It pretty much gained everywhere across the test RPM range.

You definitely picked up power with the Victor heads, roller cam and TF intake. Hard to say which was the most important ingredient but probably the heads. You'll feel that difference in power. Lots more area under the curve, even down low.

I like the low end TQ#,thx for posting

One more, this time showing the 1.59 annular vs the 1.52 downleg carbs... neither of which are really dialed in at this point.

That looks like a toss up. The 1.52 is a little choppy but that could be due to something else. Sometimes a dyno pull just gets choppy for some reason. How much air was the engine using during the pulls? 800 cfm or thereabouts?

Peak airflow #s ranged from about 880 to 900, depending upon carb & spacer combination.

Did you get all of the data in a .txt file so you can dump it into Excel? If so then you can look at avg power for different runs and area under the curve. Those will tell you if you have any difference or not between parts.

Nope, just standard printouts. Any data analysis requires me to fat-finger it all in.

There might be a way to export the files. Worth checking on since I'm sure you'll want to play with that info. The dyno software we use has an option of outputting the file in .txt format which you can then read into Excel. Makes it really nice for analysis.

My fingers need the exercise.

Can I ask what the BSFC numbers look like?

On the sheet I'm looking at, they start out in the very low .4's, and start creeping upward into the mid-4's at around 5800rpm, then into the upper-4's at 6800 till the end of the pull(7200).

In hindsight, I think a jet change might have been a better move than an air bleed change.

Yeah... but we were out of time... and I was about out of $$$.

We did what we could in the amount of time we had. Still learned a lot, just a few more take-aways to follow up on than I probably expected.