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AGGRAVATION28 08-08-2004 12:10 PM

Ignition timing small block chevy
 
Whats the correct initial and total timing (3000 rpm?) for a chevy 350 small block. Mine are Volvo 350 cubes, 270 hp. Volvo info sheets show either 6 or 8 degrees initial and 23-24 at 3000. Yet another Volvo sheet shown 30 total timing. Whats up with that? The engines are stock. Don't want to burn parts with too much advance but I've gotta get all the power these little things can produce. Oh yea, they can't get the plug gaps straight either....some info sheets show 28th and some 35th. Using ACMR43Ts.

Help!!!!!

cuda 08-08-2004 01:18 PM

Re: Ignition timing small block chevy
 
I set mine at 8 initial, and I "think" 32 total.

jaroot 08-08-2004 07:19 PM

Re: Ignition timing small block chevy
 
what fuel do you run? what is the compression ratio and more importantly the cranking pressure? if it is a non vortec motor optimal is going to be somewhere between 34 and 36 FULL advance with a non quench / swirl cylinder head design...

vortec cylinder heads, due to the quench and turbulance created prefer 29 - 32*

AC delco R43T and TS should be gapped at .035... with an electronic ignition system...

adding more total advance may induce detonation and destroy the engine if you are not running enough octane for the engine design and load imposed on them... hence reducing full advance eliminates this issue but also kills power

forget initial timing altogether.. set total advance and let the initial fall where it may.. as long as it is enough to get her to idle well

jhnrckr 08-08-2004 07:50 PM

Re: Ignition timing small block chevy
 
On the dyno my SBC made peak hp with timing set at 36*. I have played around with timing and I get the same top end RPM/Speed with timing set at 34* as I do with timing set at 36*. 34 is safer and just as fast so that is where I am at.

BAD-HABIT 08-09-2004 03:55 AM

Re: Ignition timing small block chevy
 

Originally Posted by jaroot
vortec cylinder heads, due to the quench and turbulance created prefer 29 - 32*

AC delco R43T and TS should be gapped at .035... with an electronic ignition system...

My specs say .045 on stock vortec (late model GM) motors.....

BH

Iggy 08-09-2004 07:08 AM

Re: Ignition timing small block chevy
 
My 1988 350 Mag, 270 hp, runs timing at 32* max @ 3800 rpm (8* initial) and the plugs are gapped at .035.
I set timing for max advance and don't worry about the initial setting.

robyw1 08-09-2004 09:25 AM

Re: Ignition timing small block chevy
 

Originally Posted by Iggy
My 1988 350 Mag, 270 hp, runs timing at 32* max @ 3800 rpm (8* initial) and the plugs are gapped at .035.
I set timing for max advance and don't worry about the initial setting.

If it takes 3800 RPMs for full centrifugal advance to show up then I would consider lighter springs on the weights. Centrifugal advance should be in no later than 3000 unless you're pushing a large cruiser.

Roby

Iggy 08-09-2004 10:26 AM

Re: Ignition timing small block chevy
 
Running Merc Thunderbolt IV ignition. Module is the V8-24, full advance is in @ 3750 RPM. T-Bolt IV system doesn't use a centrifugal advance, fully electronic.


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