cam question for the guru's?
04-02-2008, 11:13 PM
#19
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Location: Bay Area, CA
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I should say, ignore half of it...kind of like reading the back of a book and expecting to know what the whole story is about. There are many places where you can read about camshafts on the internet, and it has been discussed here many times before.
04-02-2008, 11:27 PM
#21
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Location: Central, KY
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Which part are you saying is wrong? The lobe seperation? Seems odd to me that nhra pro stock engines run cams that are like on 120lsa's and stuff and they turn 10,500rpms. Usually cams with narrow lobe seperations work better on a lot of n/a applications and for lower rpms. When you start going higher into the rpm band or run boost/nitrous or something you want to go wider. If you think the lobe seperation info i'm giving is off you need to re-read your books and think about that again or just buy a new book.
Last edited by git_sum; 04-02-2008 at 11:34 PM.
04-03-2008, 01:21 AM
#22
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Which part are you saying is wrong? The lobe seperation? Seems odd to me that nhra pro stock engines run cams that are like on 120lsa's and stuff and they turn 10,500rpms. Usually cams with narrow lobe seperations work better on a lot of n/a applications and for lower rpms. When you start going higher into the rpm band or run boost/nitrous or something you want to go wider. If you think the lobe seperation info i'm giving is off you need to re-read your books and think about that again or just buy a new book.
You are proving my point about only understanding it halfway by making a blanket statement about lobe separation....when you look at IVC and overlap as it relates to LSA -> duration of each lobe, then you will see why saying that cams with wider LSA's vs narrow will have certain characteristics is crap.
Why don't you get some graph paper and map out some stock cams, performance cams, and "NHRA" cams - then tell me how all the above relate with LSA.
04-03-2008, 08:46 AM
#23
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Which part are you saying is wrong? The lobe seperation? Seems odd to me that nhra pro stock engines run cams that are like on 120lsa's and stuff and they turn 10,500rpms. Usually cams with narrow lobe seperations work better on a lot of n/a applications and for lower rpms. When you start going higher into the rpm band or run boost/nitrous or something you want to go wider. If you think the lobe seperation info i'm giving is off you need to re-read your books and think about that again or just buy a new book.
Pro stocks run on a 120?
I learn something new everyday
04-03-2008, 02:19 PM
#25
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Location: Central, KY
Posts: 147
Actually yea they really do.... Not exactly a 120 but they run a really wide lobe seperation. Last i had heard was around a 120....
And yea stock cams are usually ground on around a 116-118... performance cams a lot of the time are ground between even as low as like a 104 to 114 or so. After you start climbing the grid and get higher and higher in performance(more duration, higher rpms) your lobe seperation starts to get wider again. And yes a lot of that is because of overlap...
And yea stock cams are usually ground on around a 116-118... performance cams a lot of the time are ground between even as low as like a 104 to 114 or so. After you start climbing the grid and get higher and higher in performance(more duration, higher rpms) your lobe seperation starts to get wider again. And yes a lot of that is because of overlap...
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