L48 low-cost performance
Racer
Joined: Jan 2003
Posts: 383
Likes: 0
From: Columbia SC
The Dist recurve brings all of the advance (base, mechanical and vacuum) in early, usually by 2500 RPM. As such you get more power quicker. On my 76 I have all of the advance in just before 2500 RPM with no engine knock and it is a BIG difference then stock.
New springs and weights and an adjustable vac diaphram are all you need to get this done. You also need an adjustable timing light.
LARS had a kit that I purchased to do this job. I am not sure if they are still available.
New springs and weights and an adjustable vac diaphram are all you need to get this done. You also need an adjustable timing light.
LARS had a kit that I purchased to do this job. I am not sure if they are still available.
Last edited by Pete76Shark; Aug 17, 2005 at 02:24 PM.
Melting Slicks
Joined: May 2005
Posts: 2,143
Likes: 0
From: San Diego California
Most SBC like about 32-38 degrees total advance at WOT. the HEI has 20 built into the stock mechanism, so you need an initial advance between 12 and 18
know you want the centrifugal advance to come in at 2800-3200 RPMs you do this by changing the springs to lighter ones if you use the Crane advance kit like I do you are looking to install one Blue (heavy) spring and one Silver one (medium). These springs are located directly under the rotor and are easy to remove/replace by hand or with needle-nose pliers. These springs will give you an advance curve that starts at about 800 RPM and ends at 2800. Since the srping I recomended starts at about 800 RPMs if you try to set your initial timing with the engine idling ABOVE 800 RPM you will NEVER get a true initial advance set it with the idle temporarily slowed WAY down if you have to but DO IT RIGHT
Vacuum advance for the street: You want about 12 (crankshaft) degrees total vacuum advance if you run WITHOUT a functional EGR system I recomend to use the Crane advance kit (the one in the picture) install their can with about 9 turns tighter than the loosest setting on the adjustable advance can spring use the little lockout cam that comes with the kit to lock out as much advance as possible this will still leave you with about 12 degrees of available vacum advance
know you want the centrifugal advance to come in at 2800-3200 RPMs you do this by changing the springs to lighter ones if you use the Crane advance kit like I do you are looking to install one Blue (heavy) spring and one Silver one (medium). These springs are located directly under the rotor and are easy to remove/replace by hand or with needle-nose pliers. These springs will give you an advance curve that starts at about 800 RPM and ends at 2800. Since the srping I recomended starts at about 800 RPMs if you try to set your initial timing with the engine idling ABOVE 800 RPM you will NEVER get a true initial advance set it with the idle temporarily slowed WAY down if you have to but DO IT RIGHT
Vacuum advance for the street: You want about 12 (crankshaft) degrees total vacuum advance if you run WITHOUT a functional EGR system I recomend to use the Crane advance kit (the one in the picture) install their can with about 9 turns tighter than the loosest setting on the adjustable advance can spring use the little lockout cam that comes with the kit to lock out as much advance as possible this will still leave you with about 12 degrees of available vacum advance
Last edited by Empatho; Aug 17, 2005 at 02:40 PM.
Drifting
Joined: Sep 2004
Posts: 1,959
Likes: 1
From: North Bend Ohio
Go here to find out more about head porting. It's a PDF file.
http://www.sa-motorsports.com/diyguide.shtm
BigBlockk
Later.....
http://www.sa-motorsports.com/diyguide.shtm
BigBlockk
Later.....
Burning Brakes
Joined: Jul 2000
Posts: 1,162
Likes: 2
From: Beaverton, OR
Originally Posted by Hef
When you say recurve the distributor, what are you referring to? New springs and the metal "plate" inside the distributor? Then setting mechanical timing to 36 deg?
I was thinking of just trying out new springs and adjusting my timing that way. Thoughts?
Hef
I was thinking of just trying out new springs and adjusting my timing that way. Thoughts?
Hef
