Gm goodwrech low compression timing
Thread Starter
Member
Joined: Jun 2014
Posts: 393
Likes: 2
From: Montana
Car: 1986 Trans AM WS6
Engine: 383 Vortec TPI, PUTS SMILES ON FACE
Transmission: PATC LVL 3 Raptor Transmission
Axle/Gears: 3.27 POSI 9 BOLT
Gm goodwrech low compression timing
So I was wondering I have a 86 trans am with a gm goodwrench 350 and I know they are low compression engines so I am wondering about the base timing instead of 6゚ advance would it change due to lower compression would I want to adjust it more retarded or advance due to the low compression for it to run better?
she runs good just maybe the 6° adv is not good enough due to different head and compression.
she runs good just maybe the 6° adv is not good enough due to different head and compression.
Thread Starter
Member
Joined: Jun 2014
Posts: 393
Likes: 2
From: Montana
Car: 1986 Trans AM WS6
Engine: 383 Vortec TPI, PUTS SMILES ON FACE
Transmission: PATC LVL 3 Raptor Transmission
Axle/Gears: 3.27 POSI 9 BOLT
Re: Gm goodwrech low compression timing
Does anyone know?
thanks.
just shes running a little warm, around 220+/-, but figured its due to timing because after putting it at 6* tdc it runs cooler. But still gets up too hot, i have the factory fan and a 160* thermostat, and yes it is tuned so my fan is on at 165* just doesnt cool very well when im driving around town.
i have a good air dam on it so not sure why she runs so warm. She will get to 240*.... and thats way to warm.
thanks.
just shes running a little warm, around 220+/-, but figured its due to timing because after putting it at 6* tdc it runs cooler. But still gets up too hot, i have the factory fan and a 160* thermostat, and yes it is tuned so my fan is on at 165* just doesnt cool very well when im driving around town.
i have a good air dam on it so not sure why she runs so warm. She will get to 240*.... and thats way to warm.
Senior Member

Joined: Feb 2008
Posts: 706
Likes: 0
From: Central PA
Car: 1990 IROC
Engine: Rebuilt L98 with H/C/I/Carb
Transmission: TH350 with ATI Treemaster
Axle/Gears: 7.5 with 4.10's
Re: Gm goodwrech low compression timing
Lower compression and a "slow burn" combustion chamber will want more advance (generally speaking). Bump it up a little more to see how it acts.
Joined: Sep 2005
Posts: 27,861
Likes: 2,427
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: Gm goodwrech low compression timing
Advance the timing. Test drive it.
One of 3 things will happen:
Nothing;
It will run worse;
It will run better.
You will accordingly do 1 of 3 things:
Put it back and shut the hood;
Turn it back where it was, plus a little more;
Advance it some more.
Test drive it. It will be either better or worse.
Better: do some more of whatever you last did.
Worse: go back, plus a little bit more.
Repeat until no further improvement occurs. Shut the hood.
We call this process "tuning". Instead of telling the engine what we think it should have, we ask it what it wants. It answers by running better or worse.
If it RUNS good, it IS good.
One of 3 things will happen:
Nothing;
It will run worse;
It will run better.
You will accordingly do 1 of 3 things:
Put it back and shut the hood;
Turn it back where it was, plus a little more;
Advance it some more.
Test drive it. It will be either better or worse.
Better: do some more of whatever you last did.
Worse: go back, plus a little bit more.
Repeat until no further improvement occurs. Shut the hood.
We call this process "tuning". Instead of telling the engine what we think it should have, we ask it what it wants. It answers by running better or worse.
If it RUNS good, it IS good.
Thread Starter
Member
Joined: Jun 2014
Posts: 393
Likes: 2
From: Montana
Car: 1986 Trans AM WS6
Engine: 383 Vortec TPI, PUTS SMILES ON FACE
Transmission: PATC LVL 3 Raptor Transmission
Axle/Gears: 3.27 POSI 9 BOLT
Senior Member

Joined: Feb 2008
Posts: 706
Likes: 0
From: Central PA
Car: 1990 IROC
Engine: Rebuilt L98 with H/C/I/Carb
Transmission: TH350 with ATI Treemaster
Axle/Gears: 7.5 with 4.10's
Re: Gm goodwrech low compression timing
"I like big changes"...(that's a quote from Roadkill). Sofa is giving you good advice. Make a 4 degree change and see how it acts.
Supreme Member




Joined: Sep 1999
Posts: 3,002
Likes: 813
From: Colorado USA
Car: '83 Firebird (T/A Clone)
Engine: 350 with L-69 components
Transmission: 700R-4, 2000 RPM stall converter
Axle/Gears: 10-bolt/3.73 ..
Re: Gm goodwrech low compression timing
I would double it from 6 degrees to 12 degrees initial...
Trending Topics
Thread
Thread Starter
Forum
Replies
Last Post
moneyman380
Tech / General Engine
18
Oct 22, 2005 04:41 PM
327_TPI_77_Maro
DIY PROM
31
May 8, 2005 09:24 PM
1993GMCPU
TBI
4
Jan 26, 2004 04:20 PM
MikeH
Tech / General Engine
26
Nov 16, 2001 11:57 PM






