The case for overlap (and LSA).
Drifting
Joined: Mar 2006
Posts: 1,263
Likes: 188
From: Wabasha Mn
There is a great thread that is now a sticky over on LS1Tech forums. You can see it here.
It does a great job explaining what LSA is and isn't. It also goes into overlap. What I gather from that write up and others are that LSA and overlap alone in STREET CARS won't change top end significantly but will drastically change drive-ability and tune-ability. So if it's a street application and you want to be able to idle at a stop sign and you want it to be easy to tune then you need a cam that will give up power everywhere. Just like increasing lift and duration can increase power so can changing the LSA but all of these dimensions can and will effect "drive-ability". The thing is that concept is subjective to the individual.
I could care less if the motor has chop. Also I don't care if I leave 5 to 10 hp on the table so to speak. My criteria in a camshaft is low cost, and easy tuning with a cam that can meet my power goals. This is why I always go with an off the shelf cam that was designed for factory length push rods. I totally avoid the custom or re-ground cams.
Companies like Elgin and Summit Racing have done an amazing job making good low cost performance cams that are easy to tune. But again this is for a street car. If this is a racing application then it is a totally different scenario and far outside of my wheel house.
It does a great job explaining what LSA is and isn't. It also goes into overlap. What I gather from that write up and others are that LSA and overlap alone in STREET CARS won't change top end significantly but will drastically change drive-ability and tune-ability. So if it's a street application and you want to be able to idle at a stop sign and you want it to be easy to tune then you need a cam that will give up power everywhere. Just like increasing lift and duration can increase power so can changing the LSA but all of these dimensions can and will effect "drive-ability". The thing is that concept is subjective to the individual.
I could care less if the motor has chop. Also I don't care if I leave 5 to 10 hp on the table so to speak. My criteria in a camshaft is low cost, and easy tuning with a cam that can meet my power goals. This is why I always go with an off the shelf cam that was designed for factory length push rods. I totally avoid the custom or re-ground cams.
Companies like Elgin and Summit Racing have done an amazing job making good low cost performance cams that are easy to tune. But again this is for a street car. If this is a racing application then it is a totally different scenario and far outside of my wheel house.
Le Mans Master
Joined: Mar 2004
Posts: 7,437
Likes: 1,463
From: Little Rock AR
Some of the old California cam makers like Crower, Isky, and Clay Smith still have quality cams and decent prices. Have used them all and never had a problem. Currently using 2 Isky solid lifter cams, one in my 84 C4 and another in my 65 Gto. Old school grinds that are easy on the valvetrain. Both cams ground on 108 LSA .
Drifting
Joined: Mar 2006
Posts: 1,263
Likes: 188
From: Wabasha Mn
Last edited by wilcar; Feb 12, 2022 at 08:27 AM.
