[pastry_chef]

Results.
Lobe numbers and specs are listed. The minor variances are due to matching to exact lobes in Comp's database.

The TMC valve timings with the monster rocker ratios are impressive. Also clearly Dynomation 6 cam3 did its job with that lobe lift and 1.8 rockers.

Power and valve trace graphs provided for cam 1 and cam3. Cam1 are the dark traces.


TMC Cam 1
--------- 2.1 intake rocker 2.0 exhaust rocker.

109 LSA - 105.5 IC.

Intake
13086 296 246 168 .366

Exhaust
13145 302 250 171 .363

4500 to 6500 avg = 608 HP. Peak 678 HP at 6500.

--------------------------------------------------------

Cam 2 - 1.65 rockers.
112 LSA - 112 IC

Intake
13462 311 259 179 .399

Exhaust
13491 319 265 183 .389

4500 to 6500 avg = 580 HP. Peak 671 HP at 6750

------------------------------------------------------------

Cam 3 - 1.8 Rockers.
107.5 LSA - 105 IC.

Intake
13964 315 263 182 .384

Exhaust
13492 321 267 185 .389

4500 to 6500 avg = 603 HP. Peak 677 HP at 6500

[Stan Weiss]

Originally Posted by pastry_chef

Results.
Lobe numbers and specs are listed. The minor variances are due to matching to exact lobes in Comp's database.

The TMC valve timings with the monster rocker ratios are impressive. Also clearly Dynomation 6 cam3 did its job with that lobe lift and 1.8 rockers.

Power and valve trace graphs provided for cam 1 and cam3. Cam1 are the dark traces.


TMC Cam 1
--------- 2.1 intake rocker 2.0 exhaust rocker.

109 LSA - 105.5 IC.

Intake
13086 296 246 168 .366

Exhaust
13145 302 250 171 .363

4500 to 6500 avg = 608 HP. Peak 678 HP at 6500.

--------------------------------------------------------

Cam 2 - 1.65 rockers.
112 LSA - 112 IC

Intake
13462 311 259 179 .399

Exhaust
13491 319 265 183 .389

4500 to 6500 avg = 580 HP. Peak 671 HP at 6750

------------------------------------------------------------

Cam 3 - 1.8 Rockers.
107.5 LSA - 105 IC.

Intake
13964 315 263 182 .384

Exhaust
13492 321 267 185 .389

4500 to 6500 avg = 603 HP. Peak 677 HP at 6500

Mike,
Thanks for the information. I have am updating the PON_HRT.xls file (I will send you the update when I am done). I have 2 cam if you can run them.

Thanks
Stan

[pastry_chef]

Originally Posted by Stan Weiss

Mike,
Thanks for the information. I have am updating the PON_HRT.xls file (I will send you the update when I am done). I have 2 cam if you can run them.

Thanks
Stan

Cool Stan, thanks.
The monster rockers combo are still the winner over these two new cams.
Looking at a valve lift curve comparison shows much meat missing from the flanks. Dark traces are the 2.1 / 2.0 rocker combo (TMC1 above), light trace is the .444 lobes with 1.72 / 1.67

lobes 13455 / 13457
245 / 249 @ .050
109 LSA - 105.5
Rockers 1.92 / 1.86
Avg from 4500 to 6500 = 595 HP. Peak 656 @ 6500 RPM.

--------------------------------------------------------------------

lobes 13982 / 13984 - .444
109 LSA / 105.5
247 / 251 @ .050
Rockers 1.72 / 1.67
Avg from 4500 to 6500 = 591 HP. Peak 647 @ 6500 RPM.

[slowbird]

Since we're doing these sims, Pasty Chef i have a cam sitting on the self im curious about. It's SR 286-299adv 258-269@.050 .466-.465 lobe 112ls 108lc meant for 1.65 rockers. Im sure you probably need more info but that's what's on the cam. Just wondering how it stacks up

[pastry_chef]

Originally Posted by slowbird

It's SR 286-299adv 258-269@.050 .466-.465 lobe 112ls 108lc meant for 1.65 rockers.

It likes it, pretty good.

I found some lobes that line up close to those numbers.

Intake lobe
12907 286 259 186 .465
-------------
Exhaust lobe
12300 297 269 195 .465

1.65 Rocker - .020 lash.
112 LSA - 108 IC.


Avg 4500 to 6500 = 603 HP.

Peak HP 675 @ 6500, 671 @ 6750

[Stan Weiss]

Mike,
When you have time. Can you run this SR?

Thanks,
Stan

[slowbird]

Originally Posted by pastry_chef

It likes it, pretty good.

I found some lobes that line up close to those numbers.

Intake lobe
12907 286 259 186 .465
-------------
Exhaust lobe
12300 297 269 195 .465

1.65 Rocker - .020 lash.
112 LSA - 108 IC.


Avg 4500 to 6500 = 603 HP.

Peak HP 675 @ 6500, 671 @ 6750

Cool, thought it was a decent cam. Although you sim shows less hp than it made for real.

[pastry_chef]

Originally Posted by slowbird

Cool, thought it was a decent cam. Although you sim shows less hp than it made for real.

Yes, sims often won't match the HP numbers. I think this program is conservative.
Performance trends between different components will line up most of the time.

Stan, I'll run that solid roller later today.

[Steve C.]

Years ago I used the Performance Trends Engine Analyzer v3.0 and found you needed to manipulate some of the input in order to provide results to mimic actual engine dyno sheets. It was a learning curve.

Example, how much to input for carb cfm. I was using a worked HP950 at the time and used around 823-825 cfm for input if I remember correctly. And how much loss in total cfm air flow with the intake and carb attached was important. And when you enter a specific static compression ratio into the program, it did not "know" if that input was for iron heads or aluminium heads in use. In a real engine situation the results would be different using the two different situations. Intake runner volume. Actual flow curve on the cylinder heads. Etc.

Also using the "Standard" or "SAE" Dyno settings made a difference. Using the Standard setting gave much higher numbers.

[Steve C.]

On one example of a proposed cam mentioned here it had a .3600" lobe lift on the intake side and the software suggested a very high rocker ratio to obtain maximum valve lift. On some of these programs topping the list regarding output is often valve lift, and for a good reason. The engine wants all the lift it can, but often noted the valve lift figures provided indicate engine requirement but may not be mechanically achievable or prohibitive because of cost limitations.

A rhetorical question and something to consider. Do you want to obtain this max lift with less lobe lift and a higher rocker ratio or more lobe lift and less rocker ratio.

Example, the .3600" lobe lift posted vs another lobe mentioned with .4000" lobe lift. Both rated with the same 246 degrees duration at .050" lift.


.

[pastry_chef]

Originally Posted by Steve C.

A rhetorical question and something to consider. Do you want to obtain this max lift with less lobe lift and a higher rocker ratio or more lobe lift and less rocker ratio.

Example, the .3600" lobe lift posted vs another lobe mentioned with .4000" lobe lift. Both rated with the same 246 degrees duration at .050" lift.

One thing I really like for Dynomation6 is the lobe database. The program does not guess a valve lift curve from a handful of timings. It has something like 200 data points for each lobe. The lift curves I've posted in this thread are from that.

Many years ago Audie Thomas who helped on the early development stated a correct full valve lift curve is mandatory to try and predict the gas flows.

[Stan Weiss]

Originally Posted by slowbird

Cool, thought it was a decent cam. Although you sim shows less hp than it made for real.

Brian,
Was that cam tested in this combination or a different engine? Can you share what the HP was and at what RPM?

Stan

[TCSGTO]

Originally Posted by slowbird

Cool, thought it was a decent cam. Although you sim shows less hp than it made for real.

That’s because there hasn’t been, or ever will be, a dyno sim written that can account for all of the variables in a running engine so assumptions have to be made when writing the program.
They can show trends that can you in the right track though.

[slowbird]

Originally Posted by Stan Weiss

Brian,
Was that cam tested in this combination or a different engine? Can you share what the HP was and at what RPM?

Stan

This thread is about a theoretical engine. That cam made over 700hp in the stock block it was ran in with smaller/less cfm heads than what's being discussed.
My comment about the sim showing less wasn't meant as a dig at the software just an observation

[Stan Weiss]

Originally Posted by slowbird

This thread is about a theoretical engine. That cam made over 700hp in the stock block it was ran in with smaller/less cfm heads than what's being discussed.
My comment about the sim showing less wasn't meant as a dig at the software just an observation

Brian,
I was just looking to get the specs for the engine in which the cam was tested. In most simulations keeping everything constant and just increasing the CR will cause the simulation to show an increase in torque and HP.

Stan

[389]

1966, Dyno Don, "young man, there is no such thing as street and strip, buy one car and build it for one thing"....

Nothing more miserable then trying to drive a drag car on the street for extended periods of time...

[pastry_chef]

Originally Posted by 389

Nothing more miserable then trying to drive a drag car on the street for extended periods of time...

Slowbird has higher tolerance for large cams than most.

[slowbird]

Originally Posted by pastry_chef

Slowbird has higher tolerance for large cams than most.

Lol very true

[slowbird]

Originally Posted by Stan Weiss

Brian,
I was just looking to get the specs for the engine in which the cam was tested. In most simulations keeping everything constant and just increasing the CR will cause the simulation to show an increase in torque and HP.

Stan

The engine had 11:1 compression.

[pastry_chef]

Originally Posted by Stan Weiss

Mike,
When you have time. Can you run this SR?

Thanks,
Stan

Intake 11468
Exhaust 11470

252 / 256 @ .050
111 LSA - 107.5 IC
Rockers 1.92 / 1.86 - .020 lash.

Peak 663 @ 6500 RPM - 663 @ 6750
4500 to 6500 avg = 595 HP.

Another metric 255 / 259 dur @ .050 valve lift.
----------------------------------------------------------------
For a few of the combinations I looked at duration @ .050 VALVE LIFT.

TMC cam 1 with 2.1 / 2.0 rockers = 269 / 271 dur @ .050 valve lift

Brian .465 lobe solid cam with 1.65 rockers .020 lash = 259 / 268 dur @ .050 valve lift.

-----------------------------
New combo.
HXL 2231 intake, HXX 12203 exhaust.
270 / 274 @ .050 cam duration
108 LSA - 105 IC.
1.7 rockers - .020 lash.

Top performance so far.
Peak 684 @ 6500 RPM.
Avg 4500 to 6500 = 612 HP.

Duration @ .050 valve lift is also the highest - 270 / 274 dur @ .050 valve lift.