Using Blair to spec a Cam

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Stan Weiss
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Re: Using Blair to spec a Cam

Post by Stan Weiss » Fri May 25, 2018 12:35 am

maxracesoftware wrote:
Thu May 24, 2018 3:47 pm
Stan Weiss wrote:
Thu May 24, 2018 2:01 pm
One more try just as an experiment. If anyone just wants to look at the cam lift and duration numbers then you are not seeing the whole picture. While these number are not quite as close as the last set look at how much different the cam number are. This was done with real measured lobes data. Way more rocker arm ratio so I do not know how that would workout.

Stan

Code: Select all

Rocker Arm Ratio = 1.900         Valve Lash = 0.0240

Intake BTDC (IVO to TDC) = 7.399
Intake Pumping (TDC to BDC) = 119.107
Intake Ramming (BDC to IVC) = 14.661
Intake Overlap (IVO to EVC) = 57.195

VALVE     Lift      Opens   Closes  Duration
                 Deg BTDC  Deg ABDC             Area
         0.00000    55.53 |  76.72 | 312.25 |  70.28
         0.00200    54.56 |  75.62 | 310.18 |  70.28
         0.00400    53.63 |  74.58 | 308.21 |  70.27
         0.00600    52.77 |  73.57 | 306.34 |  70.26
         0.01000    51.14 |  71.67 | 302.81 |  70.24
         0.02000    47.52 |  67.46 | 294.98 |  70.17
         0.04000    41.64 |  60.81 | 282.45 |  69.97
         0.05000    39.19 |  58.10 | 277.29 |  69.87
         0.10000    29.25 |  47.50 | 256.76 |  69.00
         0.15000    21.47 |  39.39 | 240.86 |  67.93
         0.20000    14.68 |  32.41 | 227.09 |  66.84
         0.25000     8.40 |  25.97 | 214.37 |  65.20
         0.30000     2.35 |  19.90 | 202.24 |  63.50
         0.35000    -3.62 |  13.93 | 190.31 |  61.49
         0.40000    -9.65 |   7.84 | 178.20 |  59.18
         0.45000   -15.84 |   1.61 | 165.76 |  56.59
         0.50000   -22.28 |  -4.89 | 152.82 |  53.22
         0.55000   -29.21 | -11.80 | 138.99 |  50.02
         0.60000   -36.82 | -19.38 | 123.80 |  45.38
         0.65000   -45.44 | -27.98 | 106.58 |  40.35
         0.70000   -55.70 | -38.24 |  86.06 |  32.87
         0.75000   -69.41 | -51.73 |  58.86 |  23.40
CAM
         0.00200    73.87 |  93.90 | 347.77 |  39.08
         0.00400    67.61 |  88.84 | 336.45 |  39.07
         0.00600    63.76 |  85.20 | 328.96 |  39.04
         0.01000    58.25 |  79.68 | 317.93 |  39.00
         0.02000    49.61 |  69.90 | 299.51 |  38.83
         0.04000    38.73 |  57.60 | 276.33 |  38.48
         0.05000    34.64 |  53.20 | 267.84 |  38.29
         0.10000    19.22 |  37.07 | 236.29 |  37.07
         0.15000     7.05 |  24.61 | 211.67 |  35.53
         0.20000    -4.33 |  13.20 | 188.87 |  33.37
         0.25000   -15.97 |   1.48 | 165.51 |  30.83
         0.30000   -28.64 | -11.23 | 140.13 |  27.21
         0.35000   -43.78 | -26.34 | 109.88 |  22.27
         0.40000   -65.01 | -47.40 |  67.59 |  14.31
 
 ============
Rocker Arm Ratio = 2.020         Valve Lash = 0.0240
 
Exhaust Blow-Down (EVO to BDC) = 5.889
Exhaust Pumping (BDC to TDC) = 96.854
Exhaust ATDC (TDC to EVC) = 12.474
Exhaust Overlap (IVO to EVC) = 40.779

VALVE     Lift      Opens   Closes  Duration
                 Deg BBDC  Deg ATDC             Area
         0.00000    56.17 |  83.05 | 319.22 |  75.20
         0.00200    55.26 |  81.76 | 317.02 |  75.20
         0.00400    54.41 |  80.51 | 314.92 |  75.19
         0.00600    53.60 |  79.32 | 312.92 |  75.19
         0.01000    52.07 |  77.10 | 309.17 |  75.17
         0.02000    48.66 |  72.44 | 301.10 |  75.08
         0.04000    43.08 |  65.27 | 288.34 |  74.92
         0.05000    40.71 |  62.38 | 283.09 |  74.73
         0.10000    31.00 |  51.50 | 262.50 |  73.93
         0.15000    23.23 |  43.29 | 246.53 |  73.02
         0.20000    16.44 |  36.25 | 232.69 |  71.57
         0.25000    10.23 |  29.80 | 220.03 |  70.17
         0.30000     4.30 |  23.69 | 207.99 |  68.47
         0.35000    -1.50 |  17.81 | 196.30 |  66.47
         0.40000    -7.24 |  11.97 | 184.73 |  64.15
         0.45000   -13.04 |   6.06 | 173.02 |  61.53
         0.50000   -19.06 |   0.00 | 160.94 |  58.61
         0.55000   -25.37 |  -6.33 | 148.30 |  55.39
         0.60000   -32.16 | -13.11 | 134.74 |  51.29
         0.65000   -39.61 | -20.56 | 119.83 |  46.87
         0.70000   -48.02 | -29.01 | 102.96 |  40.72
         0.75000   -57.97 | -39.05 |  82.98 |  33.39
         0.80000   -71.44 | -52.35 |  56.21 |  23.24
CAM
         0.00200    71.27 | 105.67 | 356.94 |  39.25
         0.00400    66.41 |  96.58 | 342.99 |  39.22
         0.00600    62.92 |  92.16 | 335.08 |  39.20
         0.01000    58.03 |  85.69 | 323.71 |  39.15
         0.02000    49.83 |  74.01 | 303.84 |  39.00
         0.04000    39.20 |  60.60 | 279.80 |  38.62
         0.05000    35.12 |  56.00 | 271.12 |  38.44
         0.10000    19.33 |  39.25 | 238.58 |  37.24
         0.15000     6.77 |  26.22 | 212.99 |  35.45
         0.20000    -4.95 |  14.31 | 189.36 |  33.47
         0.25000   -16.74 |   2.33 | 165.58 |  30.73
         0.30000   -29.65 | -10.61 | 139.74 |  27.12
         0.35000   -45.02 | -26.01 | 108.97 |  21.84
         0.40000   -66.50 | -47.50 |  65.99 |  13.86
Stan , you're making good progress !

What Compression Ratio are you plan on using with this either actual or theoretical Engine ?
Larry,
Thanks. Yes it is a theoretical Engine. In my first I said pump gas and CR = ???. That said I look at 900 HP @ 7500 as more of a pump gas race engine than a real street engine. So while I was thinking in the 10.5:1 to 11:1 range I was also looking for input from others.

Stan
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Offering Performance Software Since 1987
Do you use engine simulation software that uses cylinder head flow files?
We have a package of more than 3000 DFW or FLW Files

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Re: Using Blair to spec a Cam

Post by pcnsd » Fri May 25, 2018 10:11 am

Stan,
I made up a few different models (Spreadsheets, EnginePro and Controlled induction). They hint that 7000 may be a more realistic RPM for 900hp. Solid rollers and race gas CR range help to get there too. Durations run from 276 to 290@.050" and ICL's 106 to 109. Other than running out of air they did not agree on much.
- Paul

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Re: Using Blair to spec a Cam

Post by Erland Cox » Fri May 25, 2018 1:14 pm

Has anyone ever tried to use Pipemax to spec the cam?

Intake Valve Close RPM = 7128 Exhaust Valve Open RPM = 7054
Intake System RPM = 7424 Exhaust System RPM = 7380
Intake Time-Area RPM = 7150 Exhaust Time-Area RPM = 7098
Intake Mach Z-Factor = 0,478244 Exhaust Mach Z-Factor = 0,627012
Intake Z-Factor Lift = 0,599798 Exhaust Z-Factor Lift = 0,523460

Erland

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Re: Using Blair to spec a Cam

Post by Vincenzo » Sun May 27, 2018 6:31 pm

Stan
i ran your valve lift data through Prof Blair's 4StHead, program 23, and adjusted both lift and duration to get very close matching STA values compared with the targets.
The three screenshots follow.

You'll note that in order to match the targets, the required valve lifts are pretty formidable, especially the exhaust.

And this is only a computer exercise. !
You do not have the required permissions to view the files attached to this post.

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Re: Using Blair to spec a Cam

Post by Stan Weiss » Mon May 28, 2018 12:05 am

pcnsd wrote:
Fri May 25, 2018 10:11 am
Stan,
I made up a few different models (Spreadsheets, EnginePro and Controlled induction). They hint that 7000 may be a more realistic RPM for 900hp. Solid rollers and race gas CR range help to get there too. Durations run from 276 to 290@.050" and ICL's 106 to 109. Other than running out of air they did not agree on much.
Paul,
Is that something you can post up?

Stan
Stan Weiss / World Wide Enterprises
Offering Performance Software Since 1987
Do you use engine simulation software that uses cylinder head flow files?
We have a package of more than 3000 DFW or FLW Files

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Re: Using Blair to spec a Cam

Post by Stan Weiss » Mon May 28, 2018 12:07 am

Vincenzo wrote:
Sun May 27, 2018 6:31 pm
Stan
i ran your valve lift data through Prof Blair's 4StHead, program 23, and adjusted both lift and duration to get very close matching STA values compared with the targets.
The three screenshots follow.

You'll note that in order to match the targets, the required valve lifts are pretty formidable, especially the exhaust.

And this is only a computer exercise. !
Ron,
Is it possible to get your cam files in S96 format?

Stan
Stan Weiss / World Wide Enterprises
Offering Performance Software Since 1987
Do you use engine simulation software that uses cylinder head flow files?
We have a package of more than 3000 DFW or FLW Files

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Re: Using Blair to spec a Cam

Post by pcnsd » Mon May 28, 2018 2:22 pm

Stan,
This is what I have. They are close on I durations and ICL and off on E durations and ECL, but overall better than before. The two performance models are saying 7050-7100rpm for Peak HP and 5640 for PT. I used that in the models that ask for a number. CI wants a bigger valve. Engine Designer warns of pinch point velocity and I couldn't find dimension numbers so I turned the function off in the model.
Engine Designer:
EDPontiac535Test1.png
EnginePro:
EPPontiac535Test1.png
My spreadsheet (OptCam from the HP Chain):
ECPontiac535test.png
Controlled Induction:
ECIPontiac535Test1.png
You do not have the required permissions to view the files attached to this post.
- Paul

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Re: Using Blair to spec a Cam

Post by GARY C » Mon May 28, 2018 4:42 pm

Just for the heck of it I ran Jon Kasse 851 hp 507 EMC Pontiac engine through DV's 25 year old Cam Master and it puts it around a 301 seat and a 106.5 LSA and the head seems good for that ci but for the 535 it goes to a 104 LSA unless you change it to a 2.4 valve and then it calls for a 107 LSA.
Pertaining to the cam choice, Kaase says, “With a couple of years’ data from other engines, we had somewhat of a baseline. We had two cams made for this engine–one with 257/261 degrees duration at 0.050 and the other with 261/268 degrees duration at 0.050. Though it didn’t produce much more power than the other, I decided to go with the larger cam. The 107-degree lobe-separation angle was based on previous tests, and we tried different rocker ratios, but the 1.8:1 ratio, which happens to be the highest ratio allowed in the competition, made the most power.”
http://www.hotrod.com/articles/hppp-060 ... ng-engine/
Please Note!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBER AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!

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Re: Using Blair to spec a Cam

Post by Vincenzo » Tue May 29, 2018 4:45 am

Stan

the S96 files have been completed, but I'm unable to find a way to upload them to this forum, so will have to get them to you by some other means.

Both exhaust and intake files very closely match the Blair STA targets for the Pontiac 535 engine, details as per your opening post, but with the exhaust valve size correction included.

The designs match the STA targets, but that is all one can say. The targets themselves are at best general guides, for some engines they may be very good guides, and for others far off the mark. For this Pontiac engine I fear the latter is clearly the case.

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Re: Using Blair to spec a Cam

Post by Stan Weiss » Tue May 29, 2018 1:02 pm

pcnsd wrote:
Mon May 28, 2018 2:22 pm
Stan,
This is what I have. They are close on I durations and ICL and off on E durations and ECL, but overall better than before. The two performance models are saying 7050-7100rpm for Peak HP and 5640 for PT. I used that in the models that ask for a number. CI wants a bigger valve. Engine Designer warns of pinch point velocity and I couldn't find dimension numbers so I turned the function off in the model.
Paul,
I have a different version of Rick's software and used a few different inputs. I had it create S96 files and got these TA's.

Stan

Code: Select all

Intake BTDC (IVO to TDC) = 8.202
Intake Pumping (TDC to BDC) = 135.501
Intake Ramming (BDC to IVC) = 32.236
Intake Overlap (IVO to EVC) = 44.109

Exhaust Blow-Down (EVO to BDC) = 28.131
Exhaust Pumping (BDC to TDC) = 100.256
Exhaust ATDC (TDC to EVC) = 5.242
Exhaust Overlap (IVO to EVC) = 32.878
Pont_CI.jpg
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Stan Weiss / World Wide Enterprises
Offering Performance Software Since 1987
Do you use engine simulation software that uses cylinder head flow files?
We have a package of more than 3000 DFW or FLW Files

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Re: Using Blair to spec a Cam

Post by Stan Weiss » Wed May 30, 2018 10:01 am

Vincenzo wrote:
Sun May 27, 2018 6:31 pm
Stan
i ran your valve lift data through Prof Blair's 4StHead, program 23, and adjusted both lift and duration to get very close matching STA values compared with the targets.
The three screenshots follow.

You'll note that in order to match the targets, the required valve lifts are pretty formidable, especially the exhaust.

And this is only a computer exercise. !
Ron,
I got the S96 files. I am not sure what I am doing wrong but I do not get the same TA's

Stan

Code: Select all

Bore = 4.35     Stroke = 4.5               Rod Length = 6.7     RPM = 7500
Wrist Pin Offset = 0.0                     Number of - Intake Valves = 1 - Exhaust Valves = 1
Intake Valve Size = 2.23                   Exhaust Valve Size = 1.72
Intake Valve / Bore Ratio = 0.512644       Exhaust Valve / Bore Ratio = 0.395402
Intake Valve Area = 3.905707 sq. in.       Exhaust Valve Area = 2.323522 sq. in.
Intake Valve Stem Size = 0.3415            Exhaust Valve Stem Size = 0.3415
Intake Valve Stem Area = 0.091595 sq. in.  Exhaust Valve Stem Area = 0.091595 sq. in.
Valve Lift at which the Valve Area and Window / Curtain Area are the SAME SIZE
At that point the velocity will be the same in both areas
Intake Valve Lift = 0.5575 Inches          Exhaust Valve Lift = 0.43 Inches
Throat CSA (0.91) Intake = 3.1427 sq. in.  Throat CSA (0.91) Exhaust = 1.8325 sq. in.
Effective Throat CSA = 0.89702             Effective Throat CSA = 0.88808
Valve Lift at which the Throat Area and Window / Curtain Area are the SAME SIZE
At that point the velocity will be the same in both areas
Intake Valve Lift = 0.44859 Inches         Exhaust Valve Lift = 0.33913 Inches
Intake Valve Seat Angle = 45.0             Intake Valve Seat Width = 0.08



       I  N  T  A  K  E
Rocker Arm Ratio = 1.000         Valve Lash = 0.0110         Valve Angle = 14.0
Intake BTDC (IVO to TDC) = 5.565
Intake Pumping (TDC to BDC) = 139.697
Intake Ramming (BDC to IVC) = 20.033
Intake Overlap (IVO to EVC) = 35.306

VALVE     Lift      Opens   Closes  Duration
                 Deg BTDC  Deg ABDC             Area
         0.00000    54.36 |  88.23 | 322.59 |  82.40
         0.00200    52.32 |  86.40 | 318.72 |  82.40
         0.00400    50.64 |  84.83 | 315.47 |  82.39
         0.00600    49.18 |  83.43 | 312.60 |  82.38
         0.01000    46.70 |  81.02 | 307.72 |  82.36
         0.02000    41.97 |  76.30 | 298.26 |  82.28
         0.04000    35.39 |  69.51 | 284.90 |  82.04
         0.05000    32.77 |  66.80 | 279.57 |  81.94
         0.10000    22.68 |  56.25 | 258.93 |  81.17
         0.15000    15.04 |  48.23 | 243.27 |  80.15
         0.20000     8.58 |  41.42 | 230.00 |  78.88
         0.25000     2.80 |  35.31 | 218.11 |  77.48
         0.30000    -2.59 |  29.64 | 207.05 |  75.76
         0.35000    -7.73 |  24.25 | 196.51 |  74.43
         0.40000   -12.74 |  19.01 | 186.27 |  72.14
         0.45000   -17.68 |  13.82 | 176.14 |  69.94
         0.50000   -22.63 |   8.61 | 165.98 |  67.54
         0.55000   -27.63 |   3.34 | 155.70 |  64.85
         0.60000   -32.75 |  -2.07 | 145.18 |  61.34
         0.65000   -38.05 |  -7.68 | 134.27 |  58.17
         0.70000   -43.62 | -13.59 | 122.79 |  54.75
         0.75000   -49.60 | -19.92 | 110.48 |  50.38
         0.80000   -56.17 | -26.89 |  96.94 |  44.13
         0.85000   -63.71 | -34.82 |  81.47 |  38.29
         0.90000   -72.98 | -44.44 |  62.58 |  29.49
         0.95000   -86.54 | -58.36 |  35.09 |  16.44
         

       E  X  H  A  U  S  T
Rocker Arm Ratio = 1.000         Valve Lash = 0.0130         Valve Angle = 14.0
Exhaust Blow-Down (EVO to BDC) = 16.947
Exhaust Pumping (BDC to TDC) = 115.167
Exhaust ATDC (TDC to EVC) = 4.729
Exhaust Overlap (IVO to EVC) = 28.433

VALVE     Lift      Opens   Closes  Duration
                 Deg BBDC  Deg ATDC             Area
         0.00000    87.92 |  55.92 | 323.84 |  89.36
         0.00200    86.21 |  54.34 | 320.54 |  89.36
         0.00400    84.71 |  52.92 | 317.63 |  89.35
         0.00600    83.42 |  51.69 | 315.11 |  89.35
         0.01000    81.16 |  49.49 | 310.65 |  89.33
         0.02000    76.79 |  45.08 | 301.87 |  89.25
         0.04000    70.52 |  38.62 | 289.14 |  89.01
         0.05000    68.00 |  36.01 | 284.02 |  88.91
         0.10000    58.24 |  25.81 | 264.05 |  88.13
         0.15000    50.82 |  18.02 | 248.84 |  87.07
         0.20000    44.55 |  11.40 | 235.95 |  85.97
         0.25000    38.94 |   5.47 | 224.41 |  84.56
         0.30000    33.74 |  -0.02 | 213.73 |  83.13
         0.35000    28.79 |  -5.21 | 203.57 |  81.10
         0.40000    23.99 | -10.22 | 193.77 |  79.55
         0.45000    19.29 | -15.14 | 184.15 |  77.35
         0.50000    14.62 | -20.02 | 174.60 |  74.94
         0.55000     9.94 | -24.94 | 165.01 |  72.80
         0.60000     5.21 | -29.92 | 155.29 |  69.88
         0.65000     0.37 | -35.03 | 145.35 |  66.07
         0.70000    -4.63 | -40.31 | 135.06 |  63.33
         0.75000    -9.86 | -45.86 | 124.28 |  58.93
         0.80000   -15.44 | -51.76 | 112.80 |  54.22
         0.85000   -21.51 | -58.19 | 100.30 |  49.21
         0.90000   -28.35 | -65.38 |  86.28 |  43.01
         0.95000   -36.44 | -73.83 |  69.73 |  35.56
         1.00000   -47.07 | -84.80 |  48.13 |  24.78
Stan Weiss / World Wide Enterprises
Offering Performance Software Since 1987
Do you use engine simulation software that uses cylinder head flow files?
We have a package of more than 3000 DFW or FLW Files

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Re: Using Blair to spec a Cam

Post by Stan Weiss » Thu May 31, 2018 7:20 pm

OK, I do not use the Time Area calculations in my software very often. What I found was a number of years ago when I changed one section from using curtain area calculated by valve diameter and lift to also using curtain area calculated by including valve size angle and valve seat width that I did not do that for this section. This is both the new and old time areas that i now get using Ron's S96 files.

Stan

Code: Select all

Bore = 4.35     Stroke = 4.5               Rod Length = 6.7     RPM = 7500
Wrist Pin Offset = 0.0                     Number of - Intake Valves = 1 - Exhaust Valves = 1
Intake Valve Size = 2.23                   Exhaust Valve Size = 1.72
Intake Valve / Bore Ratio = 0.512644       Exhaust Valve / Bore Ratio = 0.395402
Intake Valve Area = 3.905707 sq. in.       Exhaust Valve Area = 2.323522 sq. in.
Intake Valve Stem Size = 0.3415            Exhaust Valve Stem Size = 0.3415
Intake Valve Stem Area = 0.091595 sq. in.  Exhaust Valve Stem Area = 0.091595 sq. in.
Valve Lift at which the Valve Area and Window / Curtain Area are the SAME SIZE
At that point the velocity will be the same in both areas
Intake Valve Lift = 0.5575 Inches          Exhaust Valve Lift = 0.43 Inches
Throat CSA (0.91) Intake = 3.1427 sq. in.  Throat CSA (0.91) Exhaust = 1.8325 sq. in.
Effective Throat CSA = 0.89702             Effective Throat CSA = 0.88808
Valve Lift at which the Throat Area and Window / Curtain Area are the SAME SIZE
At that point the velocity will be the same in both areas
Intake Valve Lift = 0.44859 Inches         Exhaust Valve Lift = 0.33913 Inches
Intake Valve Seat Angle = 45.0             Intake Valve Seat Width = 0.113
Exhaust Valve Seat Angle = 45.0            Exhaust Valve Seat Width = 0.113

       I  N  T  A  K  E
Rocker Arm Ratio = .945         Valve Lash = 0.0110         Valve Angle = 14.0
Intake BTDC (IVO to TDC) = 5.226
Intake Pumping (TDC to BDC) = 131.381
Intake Ramming (BDC to IVC) = 17.776
Intake Overlap (IVO to EVC) = 34.813

Using Valve Seat Angle and Width for Area Calculation
Intake BTDC (IVO to TDC) = 3.609
Intake Pumping (TDC to BDC) = 113.710
Intake Ramming (BDC to IVC) = 13.594
Intake Overlap (IVO to EVC) = 28.237

VALVE     Lift      Opens   Closes  Duration
                 Deg BTDC  Deg ABDC             Area
         0.00000    54.66 |  86.62 | 321.28 |  77.77
         0.00200    52.65 |  84.76 | 317.41 |  77.76
         0.00400    50.94 |  83.17 | 314.12 |  77.76
         0.00600    49.51 |  81.79 | 311.30 |  77.75
         0.01000    47.00 |  79.35 | 306.34 |  77.73
         0.02000    42.28 |  74.58 | 296.86 |  77.63
         0.04000    35.58 |  67.67 | 283.25 |  77.44
         0.05000    32.89 |  64.89 | 277.78 |  77.24
         0.10000    22.59 |  54.12 | 256.71 |  76.43
         0.15000    14.76 |  45.89 | 240.64 |  75.37
         0.20000     8.12 |  38.86 | 226.98 |  74.06
         0.25000     2.13 |  32.55 | 214.68 |  72.65
         0.30000    -3.47 |  26.66 | 203.19 |  70.92
         0.35000    -8.85 |  21.03 | 192.18 |  69.59
         0.40000   -14.11 |  15.52 | 181.42 |  67.32
         0.45000   -19.33 |  10.03 | 170.70 |  64.72
         0.50000   -24.60 |   4.49 | 159.89 |  62.27
         0.55000   -29.96 |  -1.18 | 148.86 |  59.06
         0.60000   -35.50 |  -7.03 | 137.47 |  55.53
         0.65000   -41.31 | -13.19 | 125.50 |  51.70
         0.70000   -47.53 | -19.80 | 112.67 |  47.58
         0.75000   -54.39 | -27.05 |  98.57 |  42.42
         0.80000   -62.26 | -35.33 |  82.40 |  36.16
         0.85000   -72.00 | -45.47 |  62.53 |  27.85
         0.90000   -86.71 | -60.56 |  32.73 |  15.52


       E  X  H  A  U  S  T
Rocker Arm Ratio = .960         Valve Lash = 0.0130         Valve Angle = 14.0
Exhaust Blow-Down (EVO to BDC) = 16.234
Exhaust Pumping (BDC to TDC) = 110.487
Exhaust ATDC (TDC to EVC) = 4.517
Exhaust Overlap (IVO to EVC) = 27.251

Using Valve Seat Angle and Width for Area Calculation
Exhaust Blow-Down (EVO to BDC) = 12.565
Exhaust Pumping (BDC to TDC) = 95.403
Exhaust ATDC (TDC to EVC) = 3.102
Exhaust Overlap (IVO to EVC) = 21.897

VALVE     Lift      Opens   Closes  Duration
                 Deg BBDC  Deg ATDC             Area
         0.00000    87.41 |  55.46 | 322.86 |  85.70
         0.00200    85.72 |  53.89 | 319.61 |  85.70
         0.00400    84.26 |  52.48 | 316.74 |  85.69
         0.00600    82.92 |  51.21 | 314.13 |  85.69
         0.01000    80.69 |  48.99 | 309.68 |  85.65
         0.02000    76.29 |  44.57 | 300.86 |  85.58
         0.04000    69.94 |  38.02 | 287.97 |  85.38
         0.05000    67.38 |  35.36 | 282.74 |  85.28
         0.10000    57.47 |  24.99 | 262.46 |  84.41
         0.15000    49.92 |  17.06 | 246.98 |  83.52
         0.20000    43.52 |  10.30 | 233.82 |  82.25
         0.25000    37.78 |   4.23 | 222.01 |  80.85
         0.30000    32.43 |  -1.39 | 211.04 |  79.14
         0.35000    27.32 |  -6.74 | 200.58 |  77.81
         0.40000    22.36 | -11.92 | 190.44 |  75.51
         0.45000    17.49 | -17.02 | 180.47 |  73.31
         0.50000    12.63 | -22.12 | 170.51 |  70.89
         0.55000     7.73 | -27.26 | 160.47 |  68.19
         0.60000     2.76 | -32.51 | 150.24 |  65.28
         0.65000    -2.37 | -37.92 | 139.71 |  62.09
         0.70000    -7.70 | -43.57 | 128.73 |  57.98
         0.75000   -13.36 | -49.56 | 117.08 |  53.56
         0.80000   -19.48 | -56.05 | 104.47 |  48.85
         0.85000   -26.33 | -63.26 |  90.41 |  43.00
         0.90000   -34.35 | -71.65 |  74.01 |  35.94
         0.95000   -44.64 | -82.30 |  53.06 |  26.64
         1.00000   -64.15 |-102.12 |  13.73 |   7.02
Stan Weiss / World Wide Enterprises
Offering Performance Software Since 1987
Do you use engine simulation software that uses cylinder head flow files?
We have a package of more than 3000 DFW or FLW Files

hoffman900
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Re: Using Blair to spec a Cam

Post by hoffman900 » Thu May 31, 2018 7:39 pm

Stan,

I'd say that makes a quite a bit of change!
Stan Weiss wrote:
Fri May 25, 2018 12:35 am
maxracesoftware wrote:
Thu May 24, 2018 3:47 pm
Stan Weiss wrote:
Thu May 24, 2018 2:01 pm
One more try just as an experiment. If anyone just wants to look at the cam lift and duration numbers then you are not seeing the whole picture. While these number are not quite as close as the last set look at how much different the cam number are. This was done with real measured lobes data. Way more rocker arm ratio so I do not know how that would workout.

Stan

Code: Select all

Rocker Arm Ratio = 1.900         Valve Lash = 0.0240

Intake BTDC (IVO to TDC) = 7.399
Intake Pumping (TDC to BDC) = 119.107
Intake Ramming (BDC to IVC) = 14.661
Intake Overlap (IVO to EVC) = 57.195

VALVE     Lift      Opens   Closes  Duration
                 Deg BTDC  Deg ABDC             Area
         0.00000    55.53 |  76.72 | 312.25 |  70.28
         0.00200    54.56 |  75.62 | 310.18 |  70.28
         0.00400    53.63 |  74.58 | 308.21 |  70.27
         0.00600    52.77 |  73.57 | 306.34 |  70.26
         0.01000    51.14 |  71.67 | 302.81 |  70.24
         0.02000    47.52 |  67.46 | 294.98 |  70.17
         0.04000    41.64 |  60.81 | 282.45 |  69.97
         0.05000    39.19 |  58.10 | 277.29 |  69.87
         0.10000    29.25 |  47.50 | 256.76 |  69.00
         0.15000    21.47 |  39.39 | 240.86 |  67.93
         0.20000    14.68 |  32.41 | 227.09 |  66.84
         0.25000     8.40 |  25.97 | 214.37 |  65.20
         0.30000     2.35 |  19.90 | 202.24 |  63.50
         0.35000    -3.62 |  13.93 | 190.31 |  61.49
         0.40000    -9.65 |   7.84 | 178.20 |  59.18
         0.45000   -15.84 |   1.61 | 165.76 |  56.59
         0.50000   -22.28 |  -4.89 | 152.82 |  53.22
         0.55000   -29.21 | -11.80 | 138.99 |  50.02
         0.60000   -36.82 | -19.38 | 123.80 |  45.38
         0.65000   -45.44 | -27.98 | 106.58 |  40.35
         0.70000   -55.70 | -38.24 |  86.06 |  32.87
         0.75000   -69.41 | -51.73 |  58.86 |  23.40
CAM
         0.00200    73.87 |  93.90 | 347.77 |  39.08
         0.00400    67.61 |  88.84 | 336.45 |  39.07
         0.00600    63.76 |  85.20 | 328.96 |  39.04
         0.01000    58.25 |  79.68 | 317.93 |  39.00
         0.02000    49.61 |  69.90 | 299.51 |  38.83
         0.04000    38.73 |  57.60 | 276.33 |  38.48
         0.05000    34.64 |  53.20 | 267.84 |  38.29
         0.10000    19.22 |  37.07 | 236.29 |  37.07
         0.15000     7.05 |  24.61 | 211.67 |  35.53
         0.20000    -4.33 |  13.20 | 188.87 |  33.37
         0.25000   -15.97 |   1.48 | 165.51 |  30.83
         0.30000   -28.64 | -11.23 | 140.13 |  27.21
         0.35000   -43.78 | -26.34 | 109.88 |  22.27
         0.40000   -65.01 | -47.40 |  67.59 |  14.31
 
 ============
Rocker Arm Ratio = 2.020         Valve Lash = 0.0240
 
Exhaust Blow-Down (EVO to BDC) = 5.889
Exhaust Pumping (BDC to TDC) = 96.854
Exhaust ATDC (TDC to EVC) = 12.474
Exhaust Overlap (IVO to EVC) = 40.779

VALVE     Lift      Opens   Closes  Duration
                 Deg BBDC  Deg ATDC             Area
         0.00000    56.17 |  83.05 | 319.22 |  75.20
         0.00200    55.26 |  81.76 | 317.02 |  75.20
         0.00400    54.41 |  80.51 | 314.92 |  75.19
         0.00600    53.60 |  79.32 | 312.92 |  75.19
         0.01000    52.07 |  77.10 | 309.17 |  75.17
         0.02000    48.66 |  72.44 | 301.10 |  75.08
         0.04000    43.08 |  65.27 | 288.34 |  74.92
         0.05000    40.71 |  62.38 | 283.09 |  74.73
         0.10000    31.00 |  51.50 | 262.50 |  73.93
         0.15000    23.23 |  43.29 | 246.53 |  73.02
         0.20000    16.44 |  36.25 | 232.69 |  71.57
         0.25000    10.23 |  29.80 | 220.03 |  70.17
         0.30000     4.30 |  23.69 | 207.99 |  68.47
         0.35000    -1.50 |  17.81 | 196.30 |  66.47
         0.40000    -7.24 |  11.97 | 184.73 |  64.15
         0.45000   -13.04 |   6.06 | 173.02 |  61.53
         0.50000   -19.06 |   0.00 | 160.94 |  58.61
         0.55000   -25.37 |  -6.33 | 148.30 |  55.39
         0.60000   -32.16 | -13.11 | 134.74 |  51.29
         0.65000   -39.61 | -20.56 | 119.83 |  46.87
         0.70000   -48.02 | -29.01 | 102.96 |  40.72
         0.75000   -57.97 | -39.05 |  82.98 |  33.39
         0.80000   -71.44 | -52.35 |  56.21 |  23.24
CAM
         0.00200    71.27 | 105.67 | 356.94 |  39.25
         0.00400    66.41 |  96.58 | 342.99 |  39.22
         0.00600    62.92 |  92.16 | 335.08 |  39.20
         0.01000    58.03 |  85.69 | 323.71 |  39.15
         0.02000    49.83 |  74.01 | 303.84 |  39.00
         0.04000    39.20 |  60.60 | 279.80 |  38.62
         0.05000    35.12 |  56.00 | 271.12 |  38.44
         0.10000    19.33 |  39.25 | 238.58 |  37.24
         0.15000     6.77 |  26.22 | 212.99 |  35.45
         0.20000    -4.95 |  14.31 | 189.36 |  33.47
         0.25000   -16.74 |   2.33 | 165.58 |  30.73
         0.30000   -29.65 | -10.61 | 139.74 |  27.12
         0.35000   -45.02 | -26.01 | 108.97 |  21.84
         0.40000   -66.50 | -47.50 |  65.99 |  13.86
Stan , you're making good progress !

What Compression Ratio are you plan on using with this either actual or theoretical Engine ?
Larry,
Thanks. Yes it is a theoretical Engine. In my first I said pump gas and CR = ???. That said I look at 900 HP @ 7500 as more of a pump gas race engine than a real street engine. So while I was thinking in the 10.5:1 to 11:1 range I was also looking for input from others.

Stan
Come on, Stan, this is a winter project! :lol:

I've been following along, just been really busy.
-Bob

Vincenzo
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Re: Using Blair to spec a Cam

Post by Vincenzo » Fri Jun 01, 2018 6:11 pm

Stan

the S96 files are for those used in this computation in 4StHead. Note that the S96 files have an addition of E and I in the identification purely to relate to their location, exhaust or intake.
Note also, the valve lift designs feature opening and closing ramps, with tappet clearances included.
The 4StHead input and output pages show all details.

Despite the near matching STA's, when all the relevant data is run through EngMod4T and Blair's software, both computed outputs fall way short of the target 900 bhp at the stipulated 7500 rpm.
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Re: Using Blair to spec a Cam

Post by vannik » Sat Jun 02, 2018 3:33 am

Vincenzo wrote:
Fri Jun 01, 2018 6:11 pm
Despite the near matching STA's, when all the relevant data is run through EngMod4T and Blair's software, both computed outputs fall way short of the target 900 bhp at the stipulated 7500 rpm.
This is the issue I have with the current "prescribed" STA values, I do not believe the targets for a 2 valve engine should be the same as for a 4 valve engine. And the various 2 valve layouts should each have separate set of target values. As I said before, there are tuners that developed their own values and use it very successfully but do not share. DV probably has the largest database of all by a large percentage but understandably he will not share as he makes his income from it.

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