Reversion, cam limits for common setups.
03-06-2016, 10:47 AM
#11
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Just curious, what are the specs roughly on say a 741 or 651 cam, they seem to be talked about a lot, and how do they fare reversion wise? Never really hear what exhaust folks are using with them.
Edit:looked up the specs,still curious about reversion in 651 or 691 cam. Looking at something similar except in a solid roller
Edit:looked up the specs,still curious about reversion in 651 or 691 cam. Looking at something similar except in a solid roller
Last edited by hotjava66; 03-06-2016 at 10:52 AM. Reason: Found info
03-06-2016, 11:03 AM
#12
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iTrader: (3)
Just curious, what are the specs roughly on say a 741 or 651 cam, they seem to be talked about a lot, and how do they fare reversion wise? Never really hear what exhaust folks are using with them.
Edit:looked up the specs,still curious about reversion in 651 or 691 cam. Looking at something similar except in a solid roller
Edit:looked up the specs,still curious about reversion in 651 or 691 cam. Looking at something similar except in a solid roller
03-06-2016, 06:13 PM
#13
because the duration is so small the 109 lsa is ok.
I concur totally. It's just an oddball configuration that will throw people unless they look at the entire cam profile. I think the .050" duration is like 196 on the intake for this cam.
03-06-2016, 09:04 PM
#15
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What matters is how long the exhaust valve is open ATDC during overlap. If you do a search, I have many cams, including the popular blue motors, showing specs including overlap #'s.
Even if not shown, overlap is easy to calculate - it's the # of degrees from when the intake opens to when the exhaust closes. ie: IVO to EVC.
Way back when, Crane said it's easy to get into reversion issues when overlap at .050" specs exceeds 6 degrees or more.
Again, if not stated, most cam companies with show events at .050" also. Take how many degrees from IVO at .050" to EVC at .050"
Even if not shown, overlap is easy to calculate - it's the # of degrees from when the intake opens to when the exhaust closes. ie: IVO to EVC.
Way back when, Crane said it's easy to get into reversion issues when overlap at .050" specs exceeds 6 degrees or more.
Again, if not stated, most cam companies with show events at .050" also. Take how many degrees from IVO at .050" to EVC at .050"
03-06-2016, 09:06 PM
#16
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iTrader: (1)
Yes, it's 196/206 at .050" with 109LSA. Overlap at .050" is a negative number. It's a truck cam...literally.
03-06-2016, 09:17 PM
#18
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03-06-2016, 11:00 PM
#19
It does idle smooth. Pulls strong in the midrange then falls on it's face above 4000-4200 rpm.
03-06-2016, 11:19 PM
#20
Registered
iTrader: (3)
What matters is how long the exhaust valve is open ATDC during overlap. If you do a search, I have many cams, including the popular blue motors, showing specs including overlap #'s.
Even if not shown, overlap is easy to calculate - it's the # of degrees from when the intake opens to when the exhaust closes. ie: IVO to EVC.
Way back when, Crane said it's easy to get into reversion issues when overlap at .050" specs exceeds 6 degrees or more.
Again, if not stated, most cam companies with show events at .050" also. Take how many degrees from IVO at .050" to EVC at .050"
Even if not shown, overlap is easy to calculate - it's the # of degrees from when the intake opens to when the exhaust closes. ie: IVO to EVC.
Way back when, Crane said it's easy to get into reversion issues when overlap at .050" specs exceeds 6 degrees or more.
Again, if not stated, most cam companies with show events at .050" also. Take how many degrees from IVO at .050" to EVC at .050"
