18-20 initial too much?
Thread Starter
Senior Member since 1492
Joined: Aug 2000
Posts: 87,962
Likes: 156
From: Just because I'm paranoid doesn't mean people aren't out to get me...
St. Jude Donor '09
18-20 initial too much?
I had my timing set about 12-14 and the engine ran like crap. Absolutely bogged down and sputter from idle to 2000rpm. Couple guys told me it was attributable to the cam and I thought it was the carb. I switched out the carb today to a 4150 830cfmDP. It helped a little but still not perfect. I couldn't tool around under 2000 without sputtering.
I adjusted the idle mixture screws, reset the idle and readjusted the timing. First I did the old fashion "ear" method then checked it with a light. Found to be between 18-20.
Went for a test run and it now runs like a BB should. Pulls strong from 1000+ Just what I wanted. I can now tool around slowly too, in 2nd gear under 2000rpm. Couldn't do that before.
But 18-20 sounds a bit high? Is it? The cam is a XE 282S
I adjusted the idle mixture screws, reset the idle and readjusted the timing. First I did the old fashion "ear" method then checked it with a light. Found to be between 18-20.
Went for a test run and it now runs like a BB should. Pulls strong from 1000+ Just what I wanted. I can now tool around slowly too, in 2nd gear under 2000rpm. Couldn't do that before.
But 18-20 sounds a bit high? Is it? The cam is a XE 282S
Thread Starter
Senior Member since 1492
Joined: Aug 2000
Posts: 87,962
Likes: 156
From: Just because I'm paranoid doesn't mean people aren't out to get me...
St. Jude Donor '09
I remember it being posted here to adjust the timing to where the engine is running best as long as there's no "pinging."
Burning Brakes
Joined: Nov 2004
Posts: 1,028
Likes: 0
From: San Antonio Texas
according to lars you've got the correct setup. if you read his papers on setting performance engines, he recommends 16 to 18 initial timing and 36 total. lars himself says he runs 24 initial with about 12 mechanical (small block).
my L82 with headers ran poorly at the recommended 12 initial. i increased it to 16 and i found it starts and idles much better.
my L82 with headers ran poorly at the recommended 12 initial. i increased it to 16 and i found it starts and idles much better.
Tech Contributor
Joined: Aug 1999
Posts: 14,384
Likes: 6,409
From: At my Bar drinking and wrenching in Lafayette Colorado
Jugs -
With that cam, you want to run a minimum of 18 degrees initial. More likely, it will run better at about 20. But along with this, you need to check your total and make sure your centrifugal advance curve is short enough that you're limiting yourself to 35-36 total along with that 18-20 initial. This may take a little tweaking of your distributor setup, but it's well worth it.
With that cam, you want to run a minimum of 18 degrees initial. More likely, it will run better at about 20. But along with this, you need to check your total and make sure your centrifugal advance curve is short enough that you're limiting yourself to 35-36 total along with that 18-20 initial. This may take a little tweaking of your distributor setup, but it's well worth it.
Thread Starter
Senior Member since 1492
Joined: Aug 2000
Posts: 87,962
Likes: 156
From: Just because I'm paranoid doesn't mean people aren't out to get me...
St. Jude Donor '09
Originally Posted by lars
Jugs -
With that cam, you want to run a minimum of 18 degrees initial. More likely, it will run better at about 20. But along with this, you need to check your total and make sure your centrifugal advance curve is short enough that you're limiting yourself to 35-36 total along with that 18-20 initial. This may take a little tweaking of your distributor setup, but it's well worth it.
With that cam, you want to run a minimum of 18 degrees initial. More likely, it will run better at about 20. But along with this, you need to check your total and make sure your centrifugal advance curve is short enough that you're limiting yourself to 35-36 total along with that 18-20 initial. This may take a little tweaking of your distributor setup, but it's well worth it.
Thanks Lars & greyghost. I'm still working on the initial engine startup "tweaking". Engine probably has < 400 miles on it.
I'll refer to your papers.
Melting Slicks
Joined: Dec 2001
Posts: 2,025
Likes: 1
From: Billings MT
I am running 32-36 degrees initial and total timing (locked out). It runs best this way, the loose converter keeps it from pinging as it really doesn't "lug" around that much.
Sounds like you got it sorted out, have fun.
Sounds like you got it sorted out, have fun.
