Monday is Dyno Day Guess my HP & Torque
 

I am going to put my 400/467 on the dyno Monday

1970 400 bored to 4.18
Block fitted with Program Engineering 4 bolt caps
Line honed for the new caps
Block filled with hard block to 1/3 above bottom of water pump holes
Final hone of bores using a torque plate
Scat 4.25 forged cross drilled crank
Eagle 6.8 rods
Ross flat top piston 13:1 compression, pistons .003-.005 above deck
Cometic .040 head gasket
Edelbrock Old style combustion chambers
Average Intake flow @ .700 331.6 CFM
Average exhaust flow @.700 lift 249.4
219/1.77 valves, CNC Ported by SD Performance in Feb of 2007
Ultradyne solid roller 264/268 @ .050, 176/187 @ .200
.3944/.3944 Lobe Lift LSA 108
Crower 1.65 rocker arms
Victor with 8896 1050 Dominator home made 1-1/2 inch spacer 4 hold to open
1-7/8 Indian Adventures headers with Flowmaster 4-2-1 collectors
MSD Pro billet Distributor, MSD Blaster 2 Coil, MSD 6AL
Sunoco Purple 110 race gas

What HP and torque numbers do you predict

Kind of close to my 500 but a you have a little more CR. I have 2" headers.
650 HP

I'll take a stab at it with 650 tq and 640 hp.

602 598

660 HP / 570 lbft tq.
That's close to the 474 I used to run. You probably have a little better Cyl.Head

Good wishes to you Tim
663 / 613

My guess is 654 Hp.
I must add that with your compression and crank stroke I think that running 1.65 rockers on the exh side will hurt your all important average power numbers.

Can you make two pulls with 1.5 rockers on the motor?

engine dyno or chassis dyno?

Engine dyno

Just exhaust or both

I don't like guessing but good luck with the dyno session.

Just on the exh if your geometry does not go too far off the rails.

Close to a engine I had done 640hp 595 trq

640tq 610hp

Curious what timing and AFR when you're done was at peak numbers.

601 TQ and 633 HP is my guess

I cant keep this drum roll up much longer! I can hardly wait!

Sometimes no news isn't good news. Hope it went well

Fingers crossed its just a dilemma , not some kind of chaos.

Could have just been a very long day at the dyno cell….:)

622 hp - 590 tq

It was a long day on the dyno tuning the carburetor to improve the fuel curve and getting the timing ideal. The engine ran great and no leaks including the rear main seal was dry at the end of the day. Didn't have time to change rocker arms with 1.5's and I didn't want to pay for another day on the dyno. I will go back on Wednesday and pick up the engine and get the printed dyno pull sheets. Best pull was under 600 HP. I will tell more after I have dyno sheets. I had my street engine dynoed at the same place I think this guys dyno is not accurate. I believe the race track will tell a better story.

What rpm?

I will provide all the details about the dyno results tomorrow and post the dyno sheet too.

Something is way not right here.

Can you also post up your flow sheets and not just your peak flow numbers as in your first post of this string.

At 600 hp your making 75 hp per cylinder and only using 280 cfm@ 28" out of what your heads can flow

I wish you would have taken Exh temp readings at each port even with a IR gun, as that info would have been very useful also.

Flow sheet for heads attached. Dyno sheets to come later today

If you dynoed on a SuperFlow. Can you take a USB drive with you and ask him for the "SFD:" files from your pulls? Unless he prints out more than 1 page for a dyno pull they will be information that was collected that you will not see.

Stan

You will have to download the program from Superflow to open them.

Not a Super Flow Dyno. Machinist says Superflow Dyno has exaggerated numbers. After a few runs he put a probe in one of the header runners to measure EGT. I am posting the first and last run. After I get the car on the track we will see if these numbers are reflected in the performance of the vehicle.

Best pull 579.8 HP @ 6,200, 570 TQ @ 4,445

There are some notes on each dyno pull but the notes are printed in green and they didn't show up after I scanned the sheets. I will provide the notes for run 1 and the final run.

Run 1, 467 CID Pontiac, 1050 8896 Holley, Victor manifold 1-1/2 spacer, 1-7/8 headers with 4-2-1 collectors, timing 31 degrees, Jets 90/97 with 2.5 PV in front, High Speed air bleed .040, Fuel Sunoco 110
Final run, 1050 8896 Holley, Victor manifold 1-1/2 spacer, 1-7/8 headers with 4-2-1 collectors, timing 36 degrees, power valve removed Jets 94/94, High speed Air bleed .044, Fuel Sunoco 110

Considering the ci and the rpm the hp is definitely low. Question is why. When do you think you'll have it in the car and at the track?

I'm a rookie bystander on race engines.
But usually guys are getting around 2x HP of their Head Flow cfm on builds like yours.
Some even more.
That's where I got my guesstimate.

You'll likely find it at the track one way or another.
Light it up

I didn't see the AFR in the chart or vacuum at WOT but I wouldn't get too upset, there's factors that might help add back some power with time.

Do a compression test and confirm this now that you have broken it in and have pulls. Possible ring gaps loose etc.

I know I needed to confirm TDC on the balancer/ timing cover because the engine shop had me way off and it killed power and my 1st engine.

To me from those dyno sheets and especially the second one your jetting looks scary lean

The specific gravity is lower that normal gasoline. probably the brand's sp.
The BSFC may be from that SP. But I haven't checked the numbers. The HP numbers I think are corrected? (BSFC is for/from uncorrected HP)

Is the dyno at altitude? (in mountains?)
The baro and temp are 'sea level' numbers it looks like, not sure if actual or just used those numbers for dyno?

:confused:

Elevation is 348 ft. This is the second engine that this same shop dynoed for me. I can say there are a few things I am unhappy about with his dyno and the way he does it. I am happy the engine had no issues and NO LEAKS, especially the rear main seal. After I get it on the race track I will have a better idea of what's what. I will jet up before I put it on the track based on what Steve said. When we ran 38 degree timing he said it had some pre detonation but after we backed it off to 36 he said the engine was happy. Throughout the dyno session he was putting in smaller jets and larger high speed circuit air bleeds because he said it was rich especially at the top end. He said the EGT is still a little lower than it should be.

AFR alone can rob big Tq and Hp numbers so there's a good chance in just this refinement alone you'll be fine.

38 degrees on our engines with aluminum heads sounds really high, did you do any pulls at 32 degrees, then say 34 degrees to see how the car responded to that isolated factor?

My car was best Tq and Hp at 34 degrees and lower timing was a little lower power. AFR refinement then added a little more power and we called it a day.

Can you get the BSAC numbers for the pulls?

Also was it confirmed that the carb was going full open?

On final pull timing was at 36 not 38. It made more power than 34 and showed no signs of detonation at 36

It was checked to verify carb full open on dyno pulls. I don't think BASC numbers were recorded

FWIW my 500" made as much HP with an 850 4150 as the 8896 , but I did have one of the 2" 4150 to 4500 adapters to use the Dominator.

Comparing this engine with the one it is replacing
455 bore .060 4.25 stroke same heads same manifold and carb same cam with 1,5 rockers 12.33 compression 3550 race weight ran 640's in the 8th and 10.30's in the 1/4
New engine 400 bored .060 4.25 stroke 13.1 compression same heads (milled .050) same manifold same carb same cam but with 1.65 rockers

John,
I did a google search and Sunoco purple 110 race gas has a specific gravity of .729

Stan

Did he record Air Fuel Ratio?

Stan

I would like to request something of someone who might be doing a up coming dyno test of a race only motor with a big Carb like this.
I would really like to see the results of a few pulls done with and without the power valves in the Carb, or maybe someone has done tests like such and can share the results.

I may be a blockhead about this but I don't see why a motor that can not climb up to its peak hp rpm instantly needs blocked power valves?
However I am am darn sure that since 1966 when Holley first came out with the Dominator series that they have done a heck of a lot more dyno testing then near anyone else and yet even though this are mainly considered race Carbs they are still supplied with power valves

Yeah, the main jetting changes essentially look the same just flip flopped and then removing the PV s really took alot of area out of the jetting. It must have been pig rich at WOT to go to that extreme. I actually like to jet the PV system for top end rather then the main jetting. Of course this is race only. The only thing that looks different with his combo is the .030 under bore from original and the heads were flowed for that bore it looks like. Did you guys read plugs?

Stan
Don't think so just what's on the dyno sheets. I think he went by BSFC #/HrHP, Fuel #/hour and EGT and reading the plugs for jetting and air bleed changes. He pulled the power valve after the second pull and jetted it square. I will put the power valve back in after I get back on the race track. I prefer the way the car runs with a mechanical advance and a power valve in the front rather than timing locked out and jetted square.

Brake Specific Fuel Consumption (BSFC)

This is a calculation of an engine’s efficiency derived from the horsepower and fuel flow rate. This figure can give the dyno operator an indication as to whether the air/fuel ratio is within the zone.
At near peak torque, BSFC will be low with numbers in the low 0.4s or high 0.3s showing excellent power production alongside with good air-to-fuel ratios.

Source: Westech Performance Group website

If memory serves me right it was Steve Brul at Westech who once stated the BSFC numbers were the first numbers he looked at.


.

I always look at the horsepower number first :D

Yes, I almost added that :)

Paul,
Have you ever dynoed an engine which had a BSFC in the 2's?

Stan

Tim you may want to just try another dyno shop

If I dropped 800$ for a dyno day and got at least 50HP under what we all know this engine has to make, I would not be very happy. Something is up with that dyno/operator IMO.
Take her to the strip and see when you got.
I should make over 650 HP.