Question for L31 engine/head swappers
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Question for L31 engine/head swappers
I'm about to order a brand new L31 crate engine from Jegs and all the edelbrock hi-flo vortec tpi stuff, all new sensors, etc. My motor kicked the bucket on what seems to be the valvetrain, so instead of rebuilding a flat tappet I'm shooting for the all roller L31-R.
I've run a search on the forum and I've looked around in other places; I know that there are plenty of people that have run the swap and kept their stock ECM and the engine ran well, but how much base timing did you run?
Stock is 7 BTDC for my year TPI I believe. I know someone with CFI swapped to an L31 vortec engine but I don't know how much base timing a CFI comes with, or what it was adjusted to. SD's article said they ran about ~15 BTDC when keeping the stock cam, 92 octane, vortec heads, and a set of runners.
So, L31 head or engine guys, what, if at all, did you change your base timing to?
I've run a search on the forum and I've looked around in other places; I know that there are plenty of people that have run the swap and kept their stock ECM and the engine ran well, but how much base timing did you run?
Stock is 7 BTDC for my year TPI I believe. I know someone with CFI swapped to an L31 vortec engine but I don't know how much base timing a CFI comes with, or what it was adjusted to. SD's article said they ran about ~15 BTDC when keeping the stock cam, 92 octane, vortec heads, and a set of runners.
So, L31 head or engine guys, what, if at all, did you change your base timing to?
Last edited by JohnC485; Feb 21, 2013 at 10:49 PM.
Drifting
Joined: Jan 2005
Posts: 1,353
Likes: 324
From: San Antonio Tx
If you increase base timing you will have too much on top end. Vortec heads are the fast burn design. I keep kept my base timing at 6* and changed mostly mid range. They don't need more timing on the top end, just bring it on sooner. I was running 10:1 CR and it was happy on 87 octane. That was with a hotcam and lt4 intake manifold.
