fordmuscle83
Well-known member
Is there such thing as a trial download etc for this computer software where u can play with different cams etc to see the output in your engine?
Pete
Pete
Engine analyser pro-free software?
- Thread starter fordmuscle83
- Start date
Yep. Two areas to investigate.
Talk to someone on the HardCore forum,
or the Big Six Forum.
I think Floridapahtman may have a copy which he may work through for you, as might Jack (MustangSix) but it'd only be a favour. It's illegal to trial it as freeware.
I can go heads up with it using the formulae I've piriated from English, American and Aussie textbookes over the last 15 years. Funny thing is, thats how I suspect the program runs...on emperical formulae from years of drag mracing and dyno runs!
I've also got a rather odd ball method which allows you to estimate hp +/-20 hp. There are nine inputs, and it allows you to work out the hp levels. The cam selections are based on gross duration, and are descripitive only.
There is an effective compression calculation which can help, and there are a bunch of formulaes I use from David Vizard books which can rate which cam is better than another, based on vehicle weight. The rest is all from information I've gleaned from indusrty people and car mags of repute.
I don't have a copy of the Engine analyser pro myself, but if you give me the cam data, I'll draw the curves form all my data, and I'll show you how I derived it. Then you can cross-check me with what you end up getting form elseware.
Sort of a duel!
Talk to someone on the HardCore forum,
or the Big Six Forum.
I think Floridapahtman may have a copy which he may work through for you, as might Jack (MustangSix) but it'd only be a favour. It's illegal to trial it as freeware.
I can go heads up with it using the formulae I've piriated from English, American and Aussie textbookes over the last 15 years. Funny thing is, thats how I suspect the program runs...on emperical formulae from years of drag mracing and dyno runs!
I've also got a rather odd ball method which allows you to estimate hp +/-20 hp. There are nine inputs, and it allows you to work out the hp levels. The cam selections are based on gross duration, and are descripitive only.
There is an effective compression calculation which can help, and there are a bunch of formulaes I use from David Vizard books which can rate which cam is better than another, based on vehicle weight. The rest is all from information I've gleaned from indusrty people and car mags of repute.
I don't have a copy of the Engine analyser pro myself, but if you give me the cam data, I'll draw the curves form all my data, and I'll show you how I derived it. Then you can cross-check me with what you end up getting form elseware.
Sort of a duel!
fordmuscle83
Well-known member
Thanks xecute.
Recap on what my car is (im sounding like you, lol):
Realistic weight with me and half tank: 3300lb
2.92 diff
Four speed single rail
9.2compression
500 holley
STD manifold
Regrind cam: Kelford cam H40
273 adv dur
214@50thou
0.429'' lift
108 lobe sep (or should i go 110?)
Crow cam 14892:
280 adv dur
214@50thou
0.51''lift
110 lsa
The regrind is possible with my $$$ situation now but the crow isnt. I was just wanting to know what the differences with the two would be?
While your there xecute, how much diff would a compression increase to 9.5 make?
Pete
Recap on what my car is (im sounding like you, lol):
Realistic weight with me and half tank: 3300lb
2.92 diff
Four speed single rail
9.2compression
500 holley
STD manifold
Regrind cam: Kelford cam H40
273 adv dur
214@50thou
0.429'' lift
108 lobe sep (or should i go 110?)
Crow cam 14892:
280 adv dur
214@50thou
0.51''lift
110 lsa
The regrind is possible with my $$$ situation now but the crow isnt. I was just wanting to know what the differences with the two would be?
While your there xecute, how much diff would a compression increase to 9.5 make?
Pete
fordmuscle83 wrote:-
First Step, Compression increase at the lower ends is proportional:-
Use either http://falconperformance.sundog.net/compcalculator.asp or Bruce Bowlings Compression Ratio influencehttp://www.bgsoflex.com/crchange.html
The first gives:-
Number Of Cylinders__________________________6
Bore Diameter [inches]________________________3.68
Stroke Length [inches]________________________3.91
Combustion Chamber Volume [cubic centimeters]__53
Head Gasket Compressed Thickness [inches]______0.041
Head Gasket Bore Diameter [inches] ____________3.81
Piston To Deck Clearance [inches]_______________0.16
Select Piston Type____________________________ Dished [positive cubic centimeters]_____________________19
Volumetric Efficiency: _________________________ 85%
RPM: ______________________________________ 4000
Results:
Displacement, [cubic inches] ________________________250
Displacement, [liters] ______________________________4.1
Static compression ratio____________________________ 9.2:1
Cubic Feet per Minute required @ 3500 rpm, [cfm]______ 215
Estimated Horsepower @ 3500 rpm
(Assumes altitude of sealevel, barometric pressure of 14.696 and 60° air supply to carburator)______________________________126 hp
This is a stock 4.1 XF Falcon, and near enough. Raise the compression by shaving head with a 50 cc chamber, and you get
That's a 3% increase
Both give:-
So anywhere between 1 and 3% seams to be the go power-wise.
Right, next step is to see what happens with the cam selection.
The correct way to do this is to nail down the effective compression. Using the formula here,
Stage 1 Stock hyd" cam 15/ 52 and 52/19, 182/185, 248/251, 7.850:1 effective, okay as it is at 9.26:1 on a stock XF already. The Baseline.
If you go up in cam duration, you loose effective compression. Since the 50 thou figures are the same for your tow cam choices, then any performance increase will come via lift.
Maximum hp is limited by any thing that influences
Pressure, Leverage, Amount of work(efficiency) Number of cycles
Broadly, they are:-
a) carb (allows more fuel/air if the engine can use it),
b) lift (increased lift increases cfm head flow)
c) duration (wont go over 215 deg at 50 thou, but its only about 200 deg at 50thou stock)
d) head flow (won't go over 206 cfm)
e) exhast type ( right size helps low end torque or raises upper end power)
So, a stock Falcon has 1.8" intakes and a 256 deg cam with about 420 thou lift. Ratio of valve to lift is 0.23. Go to the 510 thou lift, and its 0.28. That's a potential 21% increase in power, not including duration
Carb area is about 3 sq inches for 250 cubes, rather than 1.91 sq in for the Weber 34 ADM. It can therefore flow 50% more hp, or 206 hp with ease, not the 131 hp of the stocker
Taken together, the estimated power increase just via lift if the head isn't flowing at a critically high air speed is from 131 hp to 164hp. With a lift of only 429 thou the head flow is about 176 cfm from the figures I have. That's about 170 hp with the Kelford H40 cam.The carb is able to cope with a 206 hp flow rate, and a 206 cfm head flow at 510 thou is able to give a 206 hp maximum power. After that, it flat-lines unless you increase the cam scavanging.
The other method of calculating the power is this:-
Well, here is how to get the numbers. This system is very accurate to +/- 10% from my calculations, and is resonably easy to work through.
Here goes
9 things influence this 'k-value' above:
Intake manifold efficiency (ranges from 5%, 10%, 15%, 20%, 25% in most cases, with a rating of 1 for the best, to 5 for the worst). Pick the best choice form a rating 1 to 5 which replicates your intake. Most early 1.5" logs with 1" plugs will be rated at 5, while the later 1.75" hole logs with bigger welch plugs would be 4. A 250 2V is about 3, as is the 188 ME or 221 SP. An Offy 300 intake of any type should rate at 3. An independent runner EFI is about 2 for a stock 250 one, or 3 for an EFI 300. The Hillborne-type or Weber intakes are state of the art, rating at 1.
Degree of Carburation (ranges from about 15 cubic inches of engine to 1 square of carby venturi area to 44 to 70 to 98 to 125 for most carbs. A stock 300 I6 is about 125, rating at 5. A full on Triple Webered 250 can go down to 15, a rating of 1. Pick the best choice form a rating 1 to 5.
Camshaft Intensity (1= ~340+ degrees at lash, 2=~313, 3=~286, 4=~259, 5=~232). Pick the best choice form a rating 1 to 5.
Head Flow Subjective. 1= state of the art, 2=an aftermarket or reworked stock, 3= for a high-output, 4= most production head(s) for a stock lo-power version, 5=lousy. Pick the best choice form a rating 1 to 5.
Exhast Subjective. For branched controlled vortex with a primary size in excess of 0.8 times the intake valve is a 1. A standard aftermarket tubing header is a 2. A longer cast header with dual outlets can be 2 to 3 depending on the smoothness of the branching. A cast header with an outlet of in excess of the valve size is 4. A cast, undersized, sharp bended header is 5.
Examples of 1's are custom headers, 2 is an over the counter header, 3 is a great cast header, 4 is a ho-hum stocker, 5 is a nasty 1960 item.
Valve train configuration 1= Formula 1, 2 = DOHC 4V or State of the art Polyspheric or Hemi 2 valve, 3 = OHV wedge or SOHC wedge, 4 = Flat angle parallel valve OHV or lower rent wedge OHV, 5 = Side valve, unworked. Pick the best choice form a rating 1 to 5.
Rod Ratio 1=~2.1, 2 =~1.95, 3 =~1.80:1, 4= ~1.65, 5 = ~1.5.
Take the rod length, and divide it by the stroke. If you don't know, ask.
Compression Ratio 1= 15:1, 2 = 13:1, 3 = 10.5:1, 4= 9:1, 5 = 6.5:1
**Valve Size. Take intake valve size, and divide by bore size. 1= 0.54 or greater (4 or 5 valve per cylinder exceeds this often), 2= 0.50, 3= 0.47, 4= 0.44, 5 = 0.40. Pick the best choice form a rating 1 to 5. Side valves should use 5, because some valves are bigger but don't flow as well.
These 9 factors all get summed together to get a number, and then a scale factor is applied depending on the average of all 9 factors. So if you get a 27.5 for your X-flow Ford 250, the average is 3.10. For the 1,2,3,4, and 5 averages there is a number you use multiply the sum of the nine factors.
For an average of 1, multiply the sum of the nine variables by 362. For 2, multiply by 250. For 3, multiply by 204. For 4, multiply by 228. For 5, multiply by 265. For anywhere in between, use math or make an approximation.
So our 250 x-flow adds up to 27.5, or an average of 3.1, and its gets a multiplier of (204) or 27.5*204
This adds up to 5610. Take the cubic capacity of the motor in question (250), multiply it by the peak power rpm (often 10% off the maximum safe rpm for the engine [5400 rpm], but it can vary a little. This is 4900 rpm) and divide it by one of the 'K-factor' we've found.
Remeber the K-values?
Answer for the 280 degree high lift camed engine is:-
250*4900 = 218 hp net, the most you could hope for.
____5610
Sorry its a kaotic mess, but the numbers are very,very close to the mark.
First Step, Compression increase at the lower ends is proportional:-
Use either http://falconperformance.sundog.net/compcalculator.asp or Bruce Bowlings Compression Ratio influencehttp://www.bgsoflex.com/crchange.html
The first gives:-
Number Of Cylinders__________________________6
Bore Diameter [inches]________________________3.68
Stroke Length [inches]________________________3.91
Combustion Chamber Volume [cubic centimeters]__53
Head Gasket Compressed Thickness [inches]______0.041
Head Gasket Bore Diameter [inches] ____________3.81
Piston To Deck Clearance [inches]_______________0.16
Select Piston Type____________________________ Dished [positive cubic centimeters]_____________________19
Volumetric Efficiency: _________________________ 85%
RPM: ______________________________________ 4000
Results:
Displacement, [cubic inches] ________________________250
Displacement, [liters] ______________________________4.1
Static compression ratio____________________________ 9.2:1
Cubic Feet per Minute required @ 3500 rpm, [cfm]______ 215
Estimated Horsepower @ 3500 rpm
(Assumes altitude of sealevel, barometric pressure of 14.696 and 60° air supply to carburator)______________________________126 hp
This is a stock 4.1 XF Falcon, and near enough. Raise the compression by shaving head with a 50 cc chamber, and you get
That's a 3% increase
Both give:-
So anywhere between 1 and 3% seams to be the go power-wise.
Right, next step is to see what happens with the cam selection.
The correct way to do this is to nail down the effective compression. Using the formula here,
Stage 1 Stock hyd" cam 15/ 52 and 52/19, 182/185, 248/251, 7.850:1 effective, okay as it is at 9.26:1 on a stock XF already. The Baseline.
If you go up in cam duration, you loose effective compression. Since the 50 thou figures are the same for your tow cam choices, then any performance increase will come via lift.
Maximum hp is limited by any thing that influences
Pressure, Leverage, Amount of work(efficiency) Number of cycles
Broadly, they are:-
a) carb (allows more fuel/air if the engine can use it),
b) lift (increased lift increases cfm head flow)
c) duration (wont go over 215 deg at 50 thou, but its only about 200 deg at 50thou stock)
d) head flow (won't go over 206 cfm)
e) exhast type ( right size helps low end torque or raises upper end power)
So, a stock Falcon has 1.8" intakes and a 256 deg cam with about 420 thou lift. Ratio of valve to lift is 0.23. Go to the 510 thou lift, and its 0.28. That's a potential 21% increase in power, not including duration
Carb area is about 3 sq inches for 250 cubes, rather than 1.91 sq in for the Weber 34 ADM. It can therefore flow 50% more hp, or 206 hp with ease, not the 131 hp of the stocker
Taken together, the estimated power increase just via lift if the head isn't flowing at a critically high air speed is from 131 hp to 164hp. With a lift of only 429 thou the head flow is about 176 cfm from the figures I have. That's about 170 hp with the Kelford H40 cam.The carb is able to cope with a 206 hp flow rate, and a 206 cfm head flow at 510 thou is able to give a 206 hp maximum power. After that, it flat-lines unless you increase the cam scavanging.
The other method of calculating the power is this:-
Well, here is how to get the numbers. This system is very accurate to +/- 10% from my calculations, and is resonably easy to work through.
Here goes
9 things influence this 'k-value' above:
Intake manifold efficiency (ranges from 5%, 10%, 15%, 20%, 25% in most cases, with a rating of 1 for the best, to 5 for the worst). Pick the best choice form a rating 1 to 5 which replicates your intake. Most early 1.5" logs with 1" plugs will be rated at 5, while the later 1.75" hole logs with bigger welch plugs would be 4. A 250 2V is about 3, as is the 188 ME or 221 SP. An Offy 300 intake of any type should rate at 3. An independent runner EFI is about 2 for a stock 250 one, or 3 for an EFI 300. The Hillborne-type or Weber intakes are state of the art, rating at 1.
Degree of Carburation (ranges from about 15 cubic inches of engine to 1 square of carby venturi area to 44 to 70 to 98 to 125 for most carbs. A stock 300 I6 is about 125, rating at 5. A full on Triple Webered 250 can go down to 15, a rating of 1. Pick the best choice form a rating 1 to 5.
Camshaft Intensity (1= ~340+ degrees at lash, 2=~313, 3=~286, 4=~259, 5=~232). Pick the best choice form a rating 1 to 5.
Head Flow Subjective. 1= state of the art, 2=an aftermarket or reworked stock, 3= for a high-output, 4= most production head(s) for a stock lo-power version, 5=lousy. Pick the best choice form a rating 1 to 5.
Exhast Subjective. For branched controlled vortex with a primary size in excess of 0.8 times the intake valve is a 1. A standard aftermarket tubing header is a 2. A longer cast header with dual outlets can be 2 to 3 depending on the smoothness of the branching. A cast header with an outlet of in excess of the valve size is 4. A cast, undersized, sharp bended header is 5.
Examples of 1's are custom headers, 2 is an over the counter header, 3 is a great cast header, 4 is a ho-hum stocker, 5 is a nasty 1960 item.
Valve train configuration 1= Formula 1, 2 = DOHC 4V or State of the art Polyspheric or Hemi 2 valve, 3 = OHV wedge or SOHC wedge, 4 = Flat angle parallel valve OHV or lower rent wedge OHV, 5 = Side valve, unworked. Pick the best choice form a rating 1 to 5.
Rod Ratio 1=~2.1, 2 =~1.95, 3 =~1.80:1, 4= ~1.65, 5 = ~1.5.
Take the rod length, and divide it by the stroke. If you don't know, ask.
Compression Ratio 1= 15:1, 2 = 13:1, 3 = 10.5:1, 4= 9:1, 5 = 6.5:1
**Valve Size. Take intake valve size, and divide by bore size. 1= 0.54 or greater (4 or 5 valve per cylinder exceeds this often), 2= 0.50, 3= 0.47, 4= 0.44, 5 = 0.40. Pick the best choice form a rating 1 to 5. Side valves should use 5, because some valves are bigger but don't flow as well.
These 9 factors all get summed together to get a number, and then a scale factor is applied depending on the average of all 9 factors. So if you get a 27.5 for your X-flow Ford 250, the average is 3.10. For the 1,2,3,4, and 5 averages there is a number you use multiply the sum of the nine factors.
For an average of 1, multiply the sum of the nine variables by 362. For 2, multiply by 250. For 3, multiply by 204. For 4, multiply by 228. For 5, multiply by 265. For anywhere in between, use math or make an approximation.
So our 250 x-flow adds up to 27.5, or an average of 3.1, and its gets a multiplier of (204) or 27.5*204
This adds up to 5610. Take the cubic capacity of the motor in question (250), multiply it by the peak power rpm (often 10% off the maximum safe rpm for the engine [5400 rpm], but it can vary a little. This is 4900 rpm) and divide it by one of the 'K-factor' we've found.
Remeber the K-values?
Answer for the 280 degree high lift camed engine is:-
250*4900 = 218 hp net, the most you could hope for.
____5610
Sorry its a kaotic mess, but the numbers are very,very close to the mark.
