lobe seperation angle

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lobe seperation angle

Post  motorhead on April 5th 2012, 9:37 pm

Can someone give me a detailed description of lobe seperation angle? Shocked

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Re: lobe seperation angle

Post  rmcomprandy on April 5th 2012, 10:11 pm

motorhead wrote:Can someone give me a detailed description of lobe seperation angle? Shocked

Not much detail ... it is all geometrical. It is the distance in camshaft degrees between the center of the intake lobe and the center of the exhaust lobe pertaining to the same cylinder.

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Re: lobe seperation angle

Post  cooter on April 5th 2012, 11:27 pm

degrees closest to 108 means the cam will have lots of overlap and operate at a higher rpm and less bottom end, degrees closest to 114 means more bottom end, mild idle (more suited to a tow truck)

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Re: lobe seperation angle

Post  rmcomprandy on April 6th 2012, 10:02 am

cooter wrote:degrees closest to 108 means the cam will have lots of overlap and operate at a higher rpm and less bottom end, degrees closest to 114 means more bottom end, mild idle (more suited to a tow truck)

Don't try to over simplify the reasoning ... in that case WHY do Pro-Stock engines have lobe separations of 116 to 118 ...?

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Re: lobe seperation angle

Post  cooter on April 6th 2012, 12:37 pm

Rm, you write "not much detail" and i am over simplifying? Pro stock engines have there own set of guidelines. Add to the conversation if you have something to add, i fail to recognize how your last post helped motorhead to understand lobe seperation. I understand you are experienced but why not stick to info useful to 90 percent of engines? Not trying to be an ass but it drives me nuts that some people want to throw a curve to everything. Why not tell us why a 100 thousand dollar prostock motor defies the principles of lobe seperation so we can all learn something?

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Re: lobe seperation angle

Post  Paul Kane on April 6th 2012, 1:33 pm

cooter wrote:degrees closest to 108 means the cam will have lots of overlap and operate at a higher rpm and less bottom end, degrees closest to 114 means more bottom end, mild idle (more suited to a tow truck)
The amount of overlap a camshaft has is not a function of LSA by itself. In fact it's entirely possible for a cam with an LSA of 112 to have more overlap than a cam with an LSA of 108. Duration also comes into play.

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Re: lobe seperation angle

Post  cooter on April 6th 2012, 1:48 pm

If only the lsa changes between 2 camshafts, is there a situation where the 112 lsa cam would have more overlap?

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Re: lobe seperation angle

Post  DFI429 on April 6th 2012, 4:22 pm

cooter wrote:If only the lsa changes between 2 camshafts, is there a situation where the 112 lsa cam would have more overlap?

If you're talking about two identical camshafts save the LSA.. yes - going from a 114 to a 112 Rolling Eyes

The OP asked for a "detailed description" of LSA.. Randy gave him a 100% correct answer, you gave an answer that applies to some engines under some circumstances of what LSA contributes to, as Paul alluded.

No one is "throwing curves".. the experts responded with fact.
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Re: lobe seperation angle

Post  cooter on April 6th 2012, 5:05 pm

You guys are correct and i apolagize for my post. My shitty morning caused me to throw my own curve here. Please except my retraction, i love this site and to learn from everyone on here.

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Re: lobe seperation angle

Post  rmcomprandy on April 7th 2012, 10:35 pm

As I read the original question, it only asks what lobe separation IS and nothing to do with any "cause & affect" of what it may or may not do.
Whatever curve certainly didn't originate from here.

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Re: lobe seperation angle

Post  cooter on April 7th 2012, 11:28 pm

When the post said DETAILED, i assumed he was looking for more info to aid in the understanding of LSA. I did apolagize and retract and even sent a pm to you randy which i hope you except. I would however love to discuss LSA in a new post if anyone is up for it.

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