[techinspector1]

I just got this new software and would like to get some "seat time" with it on different combinations. I'll run your motor if you'll provide me some info. Here's what I'll need:
Motor manufacturer
Number of cylinders
Rod length
Bore
Stroke
Cylinder head type
Intake valve diameter
Exhaust valve diameter
Intake and exhaust flow 0.100" to 0.700" (or whatever info you have here). I can run it without this info, but it helps to nail down the combination.
Static compression ratio (or I can figure it closely if you'll provide chamber size, gasket thickness, piston crown configuration and piston deck height)
Carb CFM
Fuel used
Manifold type
Exhaust system, stock manifolds, small tube headers, large tube, with mufflers, without mufflers, step-tube race headers.
Cam type...stock, hi-perf street, dual-purpose street/track, drag race torque, drag race horsepower, circle track, max power.
Intake lift at valve
Exhaust lift at valve
Lifter type
Cam timing @0.006" tappet lift, intake opens, intake closes, exhaust opens, exhaust closes.
Cam timing @0.050" tappet lift, intake opens, intake closes, exhaust opens, exhaust closes. If you don't have these figures, you'll need intake centerline and exhaust centerline to figure them. Here's a for instance: Intake centerline 106, intake duration @0.050" 230*. Max intake valve lift would occur at 106* after top dead center. Backing up from that point, you would subtract half the duration from the centerline. 106 minus 115 would give you -9, so the intake would open at 9* before top dead center @0.050" tappet lift. On the closing side, adding 106 plus 115 would give you 221. Now, bottom dead center is 180*, so deducting 180 from 221 will give you an intake closing point of 41* ABDC @0.050" tappet lift.

[starnest]

Here is what I know:

Chevy Big Block
8 Cylinders
Rod length is 6.135
Bore is 4.28
Stroke is 4.00
Head is 820 casting (modified)
Intake is 2.19
Exhaust is 1.88
(I don't know the flow numbers - no porting, but machined to install oversize valves)
Static Compression is 10.441 (Chambers will be polished and target is 116CC, piston is 25cc dome, gasket at .040, deck height is .010)(target is dynamic CR of 8.298)
Carb will be 770 cfm Street Avenger
Gasoline (91 octane?)
Intake manifold is Weind Stealth
Exhaust will be Hooker Competition with 3" flowmaster mufflers and pipes
Cam is Competion 280H Magnum:
.520 lift intake/Exhaust,
intake closes at 66 ABDC,
intake centerline is 106,
280 duration at .006 lift,
230 at .050 lift,
lobe separation is 110
Hydraulic lifters
Intake CL @ 106
at .006 lift
Int Open 34
Int Close 66
Exh Open 74
Exh Close 26


Please let me know how this turns out.

Any way to calculate effect of Singh grooves?

[curtis73]

Here's one for you


Motor manufacturer - Chevy
Number of cylinders - 8
Rod length - 6"
Bore - 4.030
Stroke - 3.750
Cylinder head type - fully CNC ported aluminums with flows like this:
Intake______Exhaust
67 61 .100"
143 116 .200"
197 153 .300
240 173 .400
257 188 .500
260 194 .600

Intake valve diameter - 2.00
Exhaust valve diameter - 1.56
Static compression ratio - 11.0:1
Carb CFM - 1000 cfm
Fuel used - gasoline
Manifold type - EFI, sequential port
Exhaust system - small tube headers with mufflers and cats
Cam type - high performance street, but you'll put in your own numbers
Intake lift at valve - .543
Exhaust lift at valve - .563
Lifter type - hyd roller
Cam timing @0.006" tappet lift, - don't have .006" numbers
Cam timing @0.050" tappet lift, - IVO 1, IVC 41, EVO 49, EVC 1

Its a 222/230 duration cam, 112 LSA installed on a 110 intake CL (2 degrees advanced)

This is an LT1 383 I'm building slowly but surely. I'll run the same sim on my DesktopDyno 2000 and we'll see what they come up with. I'll post a screen cap of my outputs.

[curtis73]

Ok, here it is. Its a little optimistic because it simulates really aggressive ramps on the cam. You'll do yourself a HUGE favor if you read the user's manual that came with the software. How YOU input data is far more important than just putting in data and facts about the engine.

Simulating the cam is the toughest part. Once you learn how to tweak your inputs it will be far more accurate. For instance, this exact combo that I posted has been a consistent 420 hp engine on the dyno, but because of the aggressive ramp profile that the software assumes, it simulates it at closer to 445 hp.

Here you go...

[techinspector1]

Ummmm, you may want to go back and change the bore from 4.330" to 4.030". Just a thought.

"Once you learn how to tweak your inputs it will be far more accurate."

Yep, I agree. I'm using advertised valve event timing as well as 0.050" timing, so all available data is in. The software sets the ramp rise based on those figures.

[curtis73]

Originally Posted by techinspector1

Ummmm, you may want to go back and change the bore from 4.330" to 4.030". Just a thought.

... it is 4.030".

Yep, I agree. I'm using advertised valve event timing as well as 0.050" timing, so all available data is in. The software sets the ramp rise based on those figures.

Nice touch! I didn't know they added that little feature on the DSPT version. I gotta get me some of that.

In that case, I did a search and found you some .004" lift numbers if that helps:

Opens Closes .004" Duration
Intake 31.0 BTDC 73.0 ABDC 284.0 °
Exhaust 79.0 BBDC 33.0 ATDC 292.0 °

[techinspector1]

starnest, please excuse the time lapse, had honey-do's to complete. Valve events are as follows:
0.006" 34-66/74-26
0.050" 9-41/49-1

rpm tq hp
2000 490 185
2500 490 235
3000 525 300
3500 565 375
4000 585 445
4500 590 510
5000 585 555
5500 540 565
6000 500 560
6500 395 495
7000 320 430

[techinspector1]

Curtis, before I run your combo, please instruct me how to post the graph like you did. That is way too cool.

[curtis73]

Assuming you have a PC?

-While the dyno sim window is open, hit the "prtscn" key on the keyboard; probably above the delete, home, and end keys. It might also say sysrq.
-then open a photo editing software. I use photoshop or paint.
-open new document
-edit menu, paste
-save the jpg and then upload it with the "manage attachments" button below.

The prtscn (or print screen) key captures the current display as a jpg, then you can paste it into an empty document in some editing software. I'm not sure if that set of directions will work for all of them, but it works for OpenOffice, MSOffice, Paint, Adobe, and a few others.

[techinspector1]

I can't get it to work. Sharon is sharper than I am on the computer and she couldn't do any good either. I'll mess with it tomorrow. In the meantime, here's the way your motor shook out....
rpm tq hp
2000 465 180
2500 485 235
3000 485 275
3500 485 325
4000 480 360
4500 465 395
5000 435 410
5500 395 410
6000 350 400
6500 310 390
7000 270 360
With a 3* cam advance, the motor picks up another 10 ft/lbs at 2000, then another 5 ft/lbs 2500 through 4500. Above 4500, same as 2* advance. Horsepower drops off by 5 at 6500 and 10 at 7000 with the 3* advance.

At 3*, this motor makes over 450 ft/lbs of torque from 1750 to 4750. With an 1800 stall converter, a guy would be spending all his extra dough on axles.

[Sickpuppy22]

Motor manufacturer Chevrolet

Number of cylinders 8

Rod length 5.7

Bore 4.040

Stroke 3.48 stock

Cylinder head type 186 Casting 64 cc chambers un modified only an 3 angle valve job

Intake valve diameter 2.02

Exhaust valve diameter 1.65


Static compression ratio No clue but its 0 decked with 0.0042 thickness if i wrong tell me , or ill call my engine builder tomorrow

Carb CFM 750 vac sec

Fuel used 92

Manifold type stock duel plane with 1 inches spread bore to square bore adapter

Exhaust system, 1.5 inch headers 2.5 collectors shorties (blasted S-10s lol) 2.5 inch dual exhaust with dyno max mufflers

Cam type Street machine/ bracket racing

286 magnum Hydraulic flat tappet with hydraullic lifters and 1.5 rocker arms

Duration Advertised: 286� Intake / 286� Exhaust

Duration @ .050'' Lift: 236� Intake / 236� Exhaust

Valve Lift w/1.5 Rockers: .490'' Intake / .490'' Exhaust

Lobe Separation Angle: 110�

I really appreciate the time your taking to get some seat time with your new program and thank you for you input, oops almost forgot im using flat tops with 2 vavle reliefs pardon the forget fullness just got back from work lol

[curtis73]

Hmmm... thanks for the interesting info.

That combo has consistently put out about 420 hp on the dyno, and your software estimates 10 hp below that, while mine estimates 25 hp above it.

Proof that aliens exist and are messing with our computers. 'nuff said.

[techinspector1]

Originally Posted by curtis73

Hmmm... thanks for the interesting info.

That combo has consistently put out about 420 hp on the dyno, and your software estimates 10 hp below that, while mine estimates 25 hp above it.

Proof that aliens exist and are messing with our computers. 'nuff said.

Thanks for that Curtis. Hmmm, 2 1/2% error. Guess I'll have to multiply the results by 102.5

[techinspector1]

sickpuppy, with flat-top pistons assumed, I calculated your static compression ratio at 10.37:1. The Comp timing figures on their website don't jive with the grind, they're off by 1 degree. The timing figures add up to 285/235 and they're calling it a 286/236. Whatever. Timing figures are as follows:
0.006" 35-70 / 75-30
0.050" 10-45 / 50-5

rpm tq hp
2000 355 135
2500 360 170
3000 360 210
3500 395 265
4000 410 310
4500 415 350
5000 400 380
5500 380 395
6000 340 390
6500 300 365
7000 260 345

It's pretty hard to believe, but here are the results with large tube headers and a Performer RPM intake....

rpm tq hp
2000 350 135
2500 355 170
3000 380 215
3500 420 280
4000 450 340
4500 470 400
5000 470 450
5500 450 475
6000 425 485
6500 380 465
7000 330 460

According to the software, the motor picks up 55 ft/lbs of torque and 90 horsepower with a manifold and header change. I might be re-thinkin' surgery on the steering shaft.

[1969NovaSS]

Im interested in what it will say about mine compared to my DD2000 that seems so optomistic.

Chevrolet
8
6.135 rod
4.28 bore
4.25 stroke
afr 305 heads
2.25 inttake
1.88 exhaust
int exh
.200 163 135
.300 241 192
.400 300 237
.500 344 268
.600 367 284
.700 368 298
9.5 cr
800 cfm
perf rpm air gap manifold
large tube headers
comp magnum 290hr
.578 intake
.578 exhaust
hyd roller
cam timing
ivo 37
ivc 69
evo 77
evc 29