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Cams and speed density

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Old 03-21-2005, 04:17 PM
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Cams and speed density

I'm finally getting ready to rebuild the ol 302 in my 91 Bronco. I've been shopping Ebay for cams, but not quite sure which one will be the best for me. Having a "speed density" type motor, should I be concerned with duration and lope. I am wanting to put a better than stock cam in with more torque and little more crisp response on the throttle. I have the specs for my stock cam, so how much can I deviate from that with out the computor freaky out? I am in no way contemplating the conversion to mass air flow so that option is out. Any of you guys done this to your Broncos yet?
 
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Old 03-21-2005, 04:33 PM
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Good question, I am looking forward to the answers.
 
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Old 03-21-2005, 07:40 PM
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Your best bet would be to check with the cam manufacturer of choice and see what they can offer you. I know Edelbrock and a few others are marketing cams that are "speed density" friendly. Lobe separation is a major factor to consider since the speed density setup cannot compensate for much at all in this area. You might do a search on this one since I seem to recall a thread that talked about the limitations on cams in this forum. Kemicalburns may be the person to wait to hear from on this one too.
 
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Old 03-22-2005, 05:10 AM
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Yes greystreak thats what I thought, I was going to call Competition Cams and see what they suggested, but also wanted some feedback from others as to what they have used and compare that to what "Comp" says I should use. I never want to take anything for granted, especially on a rebuild, only want to jerk that motor out once. (research, research, research)
 
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Old 03-22-2005, 04:30 PM
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Speed density fuel injection needs good vacuum signal because of MAP sensor. Big cams tend to have a poor vacuum at idle and this is what causes problems.
Most of what I have read indicates lobe seperation of 114 degrees is where you want to be. Comp cams And Edelbrock have Speed Density computer freindly cams. I would look for something with low Rpm torque power band from 1000 to 4000 RPM. Edelbrock has performance/power package for ford trucks with a speed density cam. I've heard a lot of reccomendations for comp cams 35-255-5 . I think I will be going with the comp cams in my 5.8.
A lot of the 1st generation Lightning guys use it for upgrade of stock lightning.
 
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Old 03-22-2005, 07:28 PM
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I have also seen the 35-255-5 recommended all over the place and if I go with a new cam I will choose this. The 35-255-5 is for the 351w and the 31-255-5 is for the 302.
 
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Old 03-23-2005, 05:05 AM
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Thanks for the great input guys!
 




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