Positive Displacement Blower cam
02-23-2012, 08:39 AM
#1
Staging Lane
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Positive Displacement Blower cam Just a general question about cams for positive displacement blowers... What general cam specs do these blowers like to be at?? I know centri's like alot of split in duration and super wide LSA.. I have seen PD blowers cams range from small splits 2*-3* up to 12* split in duration... Most LSA's seem to be from 113-115.. I have heard that these types of blowers work well with N/A type of cam with a wider LSA. Any thoughts??
03-01-2012, 06:20 PM
#2
Launching!
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It sucks no one is posting on this thread, I'm looking for the best PD blower cam too.
From what I have read you don't want any over lap with the lobes. Lingenfelter uses 121 LSA for their blower cam but it also has a lot of lift, .629 intake and .656 exhaust. Hopefully someone who know's will post.
I'm going to pay Patrick G to spec a cam when it comes time to buy one. If I can't find a cam close to it I will have one made. For $25 dollars what do you have to lose with Patrick G
From what I have read you don't want any over lap with the lobes. Lingenfelter uses 121 LSA for their blower cam but it also has a lot of lift, .629 intake and .656 exhaust. Hopefully someone who know's will post.
I'm going to pay Patrick G to spec a cam when it comes time to buy one. If I can't find a cam close to it I will have one made. For $25 dollars what do you have to lose with Patrick G
03-01-2012, 06:28 PM
#3
Launching!
I asked a similar question about 6 months ago. Pat G responded with this advice regarding an LS3 blower cam. I quote:
"I would run a cam lobe that is more boost friendly than XFI lobes, LSL lobes, or the Lingenfelter GT9 high lift lobes. I'd run a lobe with a smoother endurance profile so the lifter stays planted on the cam lobe at higher rpm under lots of boost. Comp has a number of lobes that work well here. The new LXL lobes, the HUC lobes, plus the venerable XE high lift and Xtreme Marine high lift lobes work well. I'd recommend going a little bigger on the intake duration. 218 if it's mostly a street car and smooth idle is paramount. 222 if this is more of a strip car.
The exhaust duration depends more heavily on your goals. Also depends if you have headers. If mostly a daily driven street car and stealth is important, keep the exhaust duration around 230. If you are looking for more street strip, then go 234. If this is more strip than street and you anticipate taking the engine to 6800-7000 rpm on a regular basis, then you can stretch the exhaust to 238. LSA and advance of course depend on your mods and goals. Just because a cam works well in a cathedral application does not exclude it from a forced induction rectangular port application."
I heeded his advice and am very happy.
"I would run a cam lobe that is more boost friendly than XFI lobes, LSL lobes, or the Lingenfelter GT9 high lift lobes. I'd run a lobe with a smoother endurance profile so the lifter stays planted on the cam lobe at higher rpm under lots of boost. Comp has a number of lobes that work well here. The new LXL lobes, the HUC lobes, plus the venerable XE high lift and Xtreme Marine high lift lobes work well. I'd recommend going a little bigger on the intake duration. 218 if it's mostly a street car and smooth idle is paramount. 222 if this is more of a strip car.
The exhaust duration depends more heavily on your goals. Also depends if you have headers. If mostly a daily driven street car and stealth is important, keep the exhaust duration around 230. If you are looking for more street strip, then go 234. If this is more strip than street and you anticipate taking the engine to 6800-7000 rpm on a regular basis, then you can stretch the exhaust to 238. LSA and advance of course depend on your mods and goals. Just because a cam works well in a cathedral application does not exclude it from a forced induction rectangular port application."
I heeded his advice and am very happy.
03-01-2012, 06:33 PM
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Thank you for the info FLYZNTN.
Here are the specs from the EPS blower cam.
Product Information
Intake Duration: 214 Degrees at .050" Tappet Lift.
Intake Lift: .600" with 1.7 rockers.
Exhaust Duration 230 Degrees at .050" Tappet Lift
Exhaust Lift .604" with 1.7 rockers.
117 Degree LSA
Here are the specs from the EPS blower cam.
Product Information
Intake Duration: 214 Degrees at .050" Tappet Lift.
Intake Lift: .600" with 1.7 rockers.
Exhaust Duration 230 Degrees at .050" Tappet Lift
Exhaust Lift .604" with 1.7 rockers.
117 Degree LSA
03-01-2012, 07:19 PM
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I'm looking for cam that is close to 220/243 .600/.620 with 119 to 120 LSA. I have an L99 and the pistons already have fly cut relief for the exhaust valve so I was going to take advantage of that with more duration on the exhaust. I will pay Patrick G to spec one before I buy anything, I could be way off on my thinking.
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03-24-2012, 01:08 AM
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04-09-2012, 08:16 AM
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Launching!
It's a quality product. Mine is painted black. Fits underneath the factory strut tower brace. Giant heat sink. 2.9L Twin Screw Compressor has some advantages. Comes with 63 pound injectors. I'm happy with it. Cam made a big difference.
04-23-2012, 09:15 PM
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06-27-2014, 03:05 PM
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Teching In
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Op, replacing stock cam on a LSA (198/216 - .480/.480 - 122.5) with positive displacement supercharger cam (223/242 - .610/.595 - 119). Dyno with CAI and ported tb only is 490 rwhp - 465 rwtq....will post results.
