Why does a large cam make a car lope
09-12-2002, 01:40 AM
#2
Re: Why does a large cam make a car lope Overlap.
If you make the intake and exhaust valves open at the same time at low rpm there will be air that passes right though the engine and it causes lope.
Overlap can be caused by alot of duration, a small LCA (lobe seperation angle) or a combo of both. Most old muscle cars have this sound because of those things. Now we can make more power with less overlap due to advances in cam lobes and valve springs. (to make a long story short)
A stock Z28 has a 116 LCA (or around that) and most cams have a 112 or 114 LCA so it lopes more. On top of that we have more duration so that adds more overlap. Go to www.compcams.com and you can find out more about cams.
I hope that helps some.
Bret
If you make the intake and exhaust valves open at the same time at low rpm there will be air that passes right though the engine and it causes lope.
Overlap can be caused by alot of duration, a small LCA (lobe seperation angle) or a combo of both. Most old muscle cars have this sound because of those things. Now we can make more power with less overlap due to advances in cam lobes and valve springs. (to make a long story short)
A stock Z28 has a 116 LCA (or around that) and most cams have a 112 or 114 LCA so it lopes more. On top of that we have more duration so that adds more overlap. Go to www.compcams.com and you can find out more about cams.
I hope that helps some.
Bret
09-12-2002, 04:39 AM
#3
Staging Lane
Join Date: Nov 2001
Location: Sydney, Australia
Posts: 68
Likes: 0
Received 0 Likes
on
0 Posts
Re: Why does a large cam make a car lope Have a look a this for LSA pros and cons ;
www.co.jyu.fi/~rax/lobe.htm
I have a 'moderate' LSA according to this but I won't pass a 'sniffer' test. Removed a lot of the lump with a real time dyno tune.
<small>[ September 12, 2002, 04:44 AM: Message edited by: 8POTS ]</small>
www.co.jyu.fi/~rax/lobe.htm
I have a 'moderate' LSA according to this but I won't pass a 'sniffer' test. Removed a lot of the lump with a real time dyno tune.
<small>[ September 12, 2002, 04:44 AM: Message edited by: 8POTS ]</small>
