1973 - L82 engine optimization...
Thread Starter
Burning Brakes
Joined: Aug 2005
Posts: 1,164
Likes: 1
From: Europe, France
1973 - L82 engine optimization...
Yesterday, I posted a thread concerning the advance parameters
of a delco remy distributor part #1112150.
The answer was quick ( thank you big_G
) and it was :
Centrifugal Advance:
0°@1200RPM
2°@1460RPM
12°@2200RPM
20°@5000RPM
Vacuum Advance:
0°@6"Hg
15°@12"Hg
So, my new question is to know if these advance parameters are
optimal or not for this engine :
Corvette 1973 - Small Block 350CI, L-82 ( 350 HP ),
Comp Ratio 9.0:1, Manual transmission ( 4 spd ).
Some minor engine modifications done :
Holley carb 4 barrel, double pumper, 650CFM,
Holley Street Dominator (2000-6000RPM ) intake manifold,
Edelbroke Waterpump,
Mallory Ignition MSD 6AL,
Mallory Performance Coil,
Holley Electrical Fuel pump.
New 4in1 stainless steel exhaust headers (equal length) ,pipes & mufflers.
All other engine parts ( crankshaft, rods, pistons, headers, camshaft...)
are stock and the distributor advance vacuum is linked to the Holley carb ported vacuum.
And of course, original emission control systems have been removed.
I must say that the engine performs well, but maybe it could
do better
Any advice or suggestion is welcome
Thanks !
of a delco remy distributor part #1112150.
The answer was quick ( thank you big_G
) and it was :Centrifugal Advance:
0°@1200RPM
2°@1460RPM
12°@2200RPM
20°@5000RPM
Vacuum Advance:
0°@6"Hg
15°@12"Hg
So, my new question is to know if these advance parameters are
optimal or not for this engine :
Corvette 1973 - Small Block 350CI, L-82 ( 350 HP ),
Comp Ratio 9.0:1, Manual transmission ( 4 spd ).
Some minor engine modifications done :
Holley carb 4 barrel, double pumper, 650CFM,
Holley Street Dominator (2000-6000RPM ) intake manifold,
Edelbroke Waterpump,
Mallory Ignition MSD 6AL,
Mallory Performance Coil,
Holley Electrical Fuel pump.
New 4in1 stainless steel exhaust headers (equal length) ,pipes & mufflers.
All other engine parts ( crankshaft, rods, pistons, headers, camshaft...)
are stock and the distributor advance vacuum is linked to the Holley carb ported vacuum.
And of course, original emission control systems have been removed.
I must say that the engine performs well, but maybe it could
do better
Any advice or suggestion is welcome
Thanks !
Drifting
Joined: Sep 2004
Posts: 1,959
Likes: 1
From: North Bend Ohio
Initial advance should be between 12 and 18 degrees BTDC. Centrifugal advance should be all in by 3000 rpm at WOT. Initial + centrifugal "about" 36 degrees. Vacuum advance should be hooked to manifold for proformance or ported for emissions.
If it rattles at WOT take some initial out of it.
You may also want to think about going a little richer at WOT if you're still useing the stock Rochester.
Well I guess I should have looked a little closer. I see you got a Holley on it.
BigBlockk
Later.....
If it rattles at WOT take some initial out of it.
You may also want to think about going a little richer at WOT if you're still useing the stock Rochester.
Well I guess I should have looked a little closer. I see you got a Holley on it.
BigBlockk
Later.....
Last edited by BigBlockk; Sep 1, 2005 at 04:56 AM.
Melting Slicks
Joined: Apr 1999
Posts: 2,010
Likes: 3
From: Moon Twp. PA USA
Gonna need an aftermarket spring kit to get the 36* @2500 - 3000 rpm. Crane makes a nice kit.
If you have a damper marked out to past 36* you are ok, otherwise use timing tape, or better yet, a dial back timing light.
I set mine for 36 - 37*, all in by 2500, and I don't care where the initial timing is.
See Lars' paper.
If you have a damper marked out to past 36* you are ok, otherwise use timing tape, or better yet, a dial back timing light.
I set mine for 36 - 37*, all in by 2500, and I don't care where the initial timing is.
See Lars' paper.
Le Mans Master
Joined: Jul 2005
Posts: 5,752
Likes: 4
From: Austin Texas
Originally Posted by BigBlockk
Initial advance should be between 12 and 18 degrees BTDC. Centrifugal advance should be all in by 3000 rpm at WOT. Initial + centrifugal "about" 36 degrees. Vacuum advance should be hooked to manifold for proformance or ported for emissions.
If it rattles at WOT take some initial out of it.
You may also want to think about going a little richer at WOT if you're still useing the stock Rochester.
Well I guess I should have looked a little closer. I see you got a Holley on it.
BigBlockk
Later.....
If it rattles at WOT take some initial out of it.
You may also want to think about going a little richer at WOT if you're still useing the stock Rochester.
Well I guess I should have looked a little closer. I see you got a Holley on it.
BigBlockk
Later.....
Factory setting are usually conservative..
