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Discussion Starter #1
i was wondering what you guys thought of this cam that Bullet Cams recommended for my build

440 Small Block Chevy
4.125 bore
4.125 stroke
6.200 inch rods
13.8:1 Compression
Brodix -13 Degree heads 283cc
2.180/1.625
Dart Iron Eagle tall deck block
.904 lifter bores
BBC cam journals

The cam specs that Bullet recommended?
DUR @ .050 277/284
LIFT .740/.720
LSA 109.5
INT C/L 106
 

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What's your rocker ratio? What is your plan with the motor? Seems a little light on the lift if anything to me.
 

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IM not a cam guru nor claim to be... but that looks to be extremely small for your build.
 

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Discussion Starter #8
What's your rocker ratio? What is your plan with the motor? Seems a little light on the lift if anything to me.
I don't have the rockers yet I was going to get them with the cam, What ratio rockers would you recommend?
Bullet Cams said either 1.6 ratio or 1.7 when I asked them.

The motor will be going into a mud truck when it is finished to do some speed mud drags and also compete in deep pit mid bogging, I also thought that the cam was a little low on the lift but I'm no cam expert
 

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I thought the cam was small before I saw what it will be used for. If the intended usage was drag racing, the cam would be different, my guess.
 

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I would say they are right on track. They are aiming on making good torque in a wide band. I would do the 1.7 but I'm no cam guru either.
 

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Here's a little PipeMax advertisement, I roughed your information in and this is what it put out. Just to let you know the cam specs don't figure in on the power output and the cuin, the peak HP RPM and the VE are all inputs, the rest are the results. (just something to look at and think about)

441.014 Cubic Inches @ 7500 RPM with 110.00 % Volumetric Efficiency PerCent

Required Intake Flow between 345.9 CFM and 366.8 CFM at 28 Inches
Required Exhaust Flow between 225.0 CFM and 257.9 CFM at 28 Inches

600 RPM/Sec Dyno Test Lowest Low Average Best
Peak HorsePower 784.2 816.4 832.6 848.7
Peak Torque Lbs-Ft 604.3 629.1 641.6 654.0

HorsePower per CID 1.778 1.851 1.888 1.924
Torque per Cubic Inch 1.370 1.427 1.455 1.483

BMEP in psi 206.6 215.1 219.4 223.6
Carb CFM at 1.5 in Hg. 1053 1171 1231 1290

Target EGT= 1187 degrees F at end of 4 second 600 RPM/Sec Dyno accel. test
Octane (R+M)/2 Method = 111.1 to 112.4 Octane required range
Air Standard Efficiency = 65.54842 % for 13.800:1 Compression Ratio

Peak HorsePower calculated from Cylinder Head Flow CFM only
600 RPM/Sec Dyno Test Lowest Average Best Potential
Head Flow Peak HP = 733.7 809.7 885.
 

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I don't have the rockers yet I was going to get them with the cam, What ratio rockers would you recommend?
Bullet Cams said either 1.6 ratio or 1.7 when I asked them.

The motor will be going into a mud truck when it is finished to do some speed mud drags and also compete in deep pit mid bogging, I also thought that the cam was a little low on the lift but I'm no cam expert

The rocker arm ratio depends on how much lift you want, just multiply your lobe lift by 1.6 and 1.7 and see what the lift at the valve may be minus your lash. If you want to use as much of your head flow as possible you need the ratio that opens the valve to match your head flow. Not only do the higher ratio opens your valve more it also opens it faster. No matter what cam you pick, the engine needs to be able to recover from the lowest rpm the motor will be pulled down to, so over caming it may not be as good as under camed.
 

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I lowered the HP peak to 7000 rpm and the VE to 106 just for comparison.


441.014 Cubic Inches @ 7000 RPM with 106.00 % Volumetric Efficiency PerCent

Required Intake Flow between 307.7 CFM and 325.8 CFM at 28 Inches
Required Exhaust Flow between 200.2 CFM and 229.4 CFM at 28 Inches

600 RPM/Sec Dyno Test Lowest Low Average Best
Peak HorsePower 690.0 718.4 732.6 746.7
Peak Torque Lbs-Ft 573.2 596.7 608.5 620.3

HorsePower per CID 1.565 1.629 1.661 1.693
Torque per Cubic Inch 1.300 1.353 1.380 1.407

BMEP in psi 196.0 204.0 208.1 212.1
Carb CFM at 1.5 in Hg. 947 1053 1107 1160

Target EGT= 1205 degrees F at end of 4 second 600 RPM/Sec Dyno accel. test
Octane (R+M)/2 Method = 110.5 to 112.4 Octane required range
Air Standard Efficiency = 65.54842 % for 13.800:1 Compression Ratio

Peak HorsePower calculated from Cylinder Head Flow CFM only
600 RPM/Sec Dyno Test Lowest Average Best Potential
Head Flow Peak HP = 628.7 708.2 787.7
 

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Another thing to look at on lobe lift is where it will put you on your oil band of your lifter, too much lobe and not enough rocker can cause it to block oil supply to the rest of the lifters or possibly uncover the oil port at the bottom of the lifter and dump oil pressure. Measuring these will help you know where your at for base circle sizing and max lobe lift.

Hey BBF612, what kind of z factor lifts is pipe max calling for? I'm not around my computer with pipe max on it.
 

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Sorry, I got busy with something else and did not see your post until now. I didn't save the PipeMax output, but by his flow chart I would say he needs between .750 and .800 net lift and I would bet that PipeMax would say he would need +-.900 lift for max effort. Just a guess. What he needs for a mud truck depends on how he has it setup and the wt. of the truck, so that might a good "first" cam.
 

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Discussion Starter #18
Sorry, I got busy with something else and did not see your post until now. I didn't save the PipeMax output, but by his flow chart I would say he needs between .750 and .800 net lift and I would bet that PipeMax would say he would need +-.900 lift for max effort. Just a guess. What he needs for a mud truck depends on how he has it setup and the wt. of the truck, so that might a good "first" cam.
The truck weighs around 3500 made some changes to it and haven't got to weigh it yet, drivetrain is a turbo 400 transmission, 205 transfer case, axles are Dana 60 front end and a GM 14 bolt in the rear, current gear ratio is 4:56 but I think we are going to change that to 5:13 sometime
 

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Discussion Starter #19
And also how much maintenance he feels like doing during the season.
Don't mind doing maintenece, just need it to be reliable enough to last all season, and a couple of the events we go to are all weekend running though several different mud pits for both days, so it will get driven around a lot and going though at least 10+ mud pit challenges all weekend
 

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Just to let you know, I'm not the guy for cam advice. But I believe in having as much information and thought about what you want to do so someone can give good or better advice. Sometimes posting information and asking questions is the only way to ferret out enough information so you can make a better choice.
 
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