jdeignan
Full Member
- Joined
- May 24, 2015
- Messages
- 205
I have been trying to get to the bottom of my timing and AF ratio.
Backstory: When i bought the truck, the PO had rebuilt the engine, and it seems like he threw a bunch of extra parts together for everything else. Its got a serpentine pulley system, a huge electic fan, Edelbrock 1405, MSD 6AL ignition and the MSD 8479 Pro Billet distributor- nice, but I am pretty sure he never put a timing marker on the truck.
Issue: I’ve got idle vac at about 13-15inHg and a cam in there (unknown specs) that doesnt help. Cool lopey idle sound though.
It runs eye watering rich at idle and gas mileage is pretty poor.
I would like to fix that but I need to rule out a few things before I can blame Edelbrock. Let me know If I am off base:
1. Set timing. My radiator hose blocks the stock 302 marker at the 2oclock position. I brought it in to the shop because I was frustrated with it. The mech used this object at the 10 oclock position. https://ibb.co/g8xKj6
https://ibb.co/irRej6
Is that a timing marker? If so, how do i read it, because I dont see any markings on it for precision.
Regardless, he said he set the initial at 10.
So I threw ny timing light on there (vac advance unplugged), and read 16deg at 3k RPM. So I calculate 26deg total timing. Anyone else think it should be more?
2. Check floats and set to 5/16. Set idle to 700 and adjust idle screws for max vacuum.
3. Vac advance... I am going to switch to full manifold vac. Additionally, I just bought a vac advance (P28) that is all in at 8inHg. The canister installed is currently all in at 15inHg and with the low vacuum at idle, I dont want continuous changes in advance as the vac signal bounces from 13-15.
I figure if I dial in the correct timing, I can calibrate the carb. If it is still rich after all other variables are set, I can blame the carb and shop elsewhere.
Long read, but I look forward to hearing any advice yall have to offer.
Backstory: When i bought the truck, the PO had rebuilt the engine, and it seems like he threw a bunch of extra parts together for everything else. Its got a serpentine pulley system, a huge electic fan, Edelbrock 1405, MSD 6AL ignition and the MSD 8479 Pro Billet distributor- nice, but I am pretty sure he never put a timing marker on the truck.
Issue: I’ve got idle vac at about 13-15inHg and a cam in there (unknown specs) that doesnt help. Cool lopey idle sound though.
It runs eye watering rich at idle and gas mileage is pretty poor.
I would like to fix that but I need to rule out a few things before I can blame Edelbrock. Let me know If I am off base:
1. Set timing. My radiator hose blocks the stock 302 marker at the 2oclock position. I brought it in to the shop because I was frustrated with it. The mech used this object at the 10 oclock position. https://ibb.co/g8xKj6
https://ibb.co/irRej6
Is that a timing marker? If so, how do i read it, because I dont see any markings on it for precision.
Regardless, he said he set the initial at 10.
So I threw ny timing light on there (vac advance unplugged), and read 16deg at 3k RPM. So I calculate 26deg total timing. Anyone else think it should be more?
2. Check floats and set to 5/16. Set idle to 700 and adjust idle screws for max vacuum.
3. Vac advance... I am going to switch to full manifold vac. Additionally, I just bought a vac advance (P28) that is all in at 8inHg. The canister installed is currently all in at 15inHg and with the low vacuum at idle, I dont want continuous changes in advance as the vac signal bounces from 13-15.
I figure if I dial in the correct timing, I can calibrate the carb. If it is still rich after all other variables are set, I can blame the carb and shop elsewhere.
Long read, but I look forward to hearing any advice yall have to offer.