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Why LSA doesn't matter

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Old 12-08-2015, 09:40 AM   #181
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Do you have to have the cam card to determine centerline? Or is there some way of figuring it out. From what i've been reading, if there is, I can't figure it out. Just trying to get a lot more learning about it in. That way I can do a better job at picking a cam for myself.
You can put a degree wheel on your cam sprocket and a dial indicator on your intake valve for the #1 piston. You can then use the peak lift, average of .050 or .200 lift to determine intake centerline. Then, you can use LSA to determine exhaust centerline
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Old 01-04-2016, 02:58 PM   #182
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Just so anyone reading this thread knows, I am the author of this thread.

When I left Tick, they changed my old account that I used to use from "[email protected]", to "[email protected]" since Matt would be utilizing my old account after I left.

I spent a lot of time writing this thread and I was flattered when it was made a sticky.

I just wanted to ensure the credit was given to the original author.
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Old 01-04-2016, 03:00 PM   #183
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Originally Posted by Darth_V8r View Post
You can put a degree wheel on your cam sprocket and a dial indicator on your intake valve for the #1 piston. You can then use the peak lift, average of .050 or .200 lift to determine intake centerline. Then, you can use LSA to determine exhaust centerline
That is true for a symmetrical lobe, but not an asymmetrical lobe.

An asymmetrical lobe will have peak lift occurring before the "mid-way" point of the lobe. The true center line is the "mid-way" point and not peak lift.
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Old 01-04-2016, 03:29 PM   #184
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Just so anyone reading this thread knows, I am the author of this thread.

When I left Tick, they changed my old account that I used to use from "[email protected]", to "[email protected]" since Matt would be utilizing my old account after I left.

I spent a lot of time writing this thread and I was flattered when it was made a sticky.

I just wanted to ensure the credit was given to the original author.
Hey Martin,

Just want to say this is the most informative, beneficial, thread I've read. Being around cars for awhile, & knowing how things work, this was like the next level. I read it over & over.

I thought that was kind of weak, changing the name, as every post you made here, under that account, is changed.
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Old 01-04-2016, 04:26 PM   #185
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Hey Martin,

Just want to say this is the most informative, beneficial, thread I've read. Being around cars for awhile, & knowing how things work, this was like the next level. I read it over & over.

I thought that was kind of weak, changing the name, as every post you made here, under that account, is changed.
Thanks SoFla01, that means a lot! I really wanted this thread to be as informative as possible and take things to a more advanced level while still allowing those who aren't quite as advanced in engine theory and physics to be able to understand.

It doesn't bother me that they changed the name of the old account. They did the same thing when I went to work for them and they changed it from "[email protected]" to "[email protected]".

It costs a lot to sponsor these forums and it wouldn't of made any sense for Tick to add another account just so my posts would stay under my name.

This thread though is my pride and joy so to speak, and I wanted to erase any doubt as to who the original author was.
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Old 01-04-2016, 04:52 PM   #186
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First, thanks for a very useful post.
However, with your kind permission?
Re: "If two camshafts no matter their duration or LSA both have the same amount of overlap and you put both cams in the exact same vehicle with everything else the same aside from the camshafts they will sound identical."

The cam with the earlier exhaust valve opening will be slightly louder (higher pressure release), especially with high static CR.
The cam with the earlier intake valve closing will be slightly louder (higher trapped compression).
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Old 01-04-2016, 04:55 PM   #187
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First, thanks for a very useful post.
However, with your kind permission?
Re: "If two camshafts no matter their duration or LSA both have the same amount of overlap and you put both cams in the exact same vehicle with everything else the same aside from the camshafts they will sound identical."

The cam with the earlier exhaust valve opening will be slightly louder (higher pressure release), especially with high static CR.
The cam with the earlier intake valve closing will be slightly louder (higher trapped compression).
There is very little cylinder pressure generated at idle so I doubt that an earlier ivc event would contribute to more lope at idle. Also remember that dynamic compression (ivc and SCR dependent) is just a dynamic way of expressing a static measurement. Your dynamic compression at idle versus your dynamic compression at peak torque will be two totally different figures.

I personally feel that DCR is only relevant for very low engine speeds such as idle and cruising.

I could possibly see an earlier evo event contributing to how loud the engine is at WOT, but again at idle there is such small amounts of cylinder pressure generated I again doubt that there would be little difference if any.
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Old 01-30-2016, 12:27 AM   #188
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I'm sitting here thumbing through gen3 internals and see the author of this sticky as [email protected] and thought to myself who the heck is Matt!?
Thanks for creating this thread Martin, like the guy above I've read it time and time again and learned a TON from it. One of the best on the site IMO.
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Old 01-30-2016, 08:38 AM   #189
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I need to see if we can get that changed. Kinda pisses me off it worked out like that.

Let me see what I can do, Martin
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Old 03-03-2016, 10:24 AM   #190
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I need to see if we can get that changed. Kinda pisses me off it worked out like that.

Let me see what I can do, Martin
I agree. Not only this thread but anything else Martin posted says "Matt" now. Complete BS in my book.
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Old 03-03-2016, 11:54 AM   #191
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Nothing we can do guys... Many reasons. It would literally be impossible to change the name without affecting every post ever made in EITHER name.
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Old 03-03-2016, 05:14 PM   #192
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Whigham is right, there isn't anything that can be done. Tick would have to spend more money and buy a brand new screen name for their account which would cost them more money out of their pocket just so my old screen name wouldn't be used. I can't expect them to do that and neither should the members on Tech.

When I first started to work there they switched the screen name over from "[email protected]" who worked there before me to "[email protected]". Chris didn't post much, but it's still the same scenario.

I do appreciate the support from old customers, current customers and members on this board about the entire situation with the screen names and who gets credit for who said what. Sometimes you just have to go with the flow and make lemonade when life hands you lemons.
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Old 04-28-2016, 10:40 AM   #193
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Wow great info but my head hurts now
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centerline, exhaust, importanta, length, lsa, pontiac

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