Degrees of timing N/A - 2003-04 Mach 1 Registry Owners Club

systemdz · 10-16-2013, 06:29 PM

What is average for degrees of timing naturally aspirated on a 4v motor? Curious as to what mine should be seeing. It's a .20 over bore, 10.8-1 compression, 98 cammed motor.

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tmhutch · 10-20-2013, 09:36 PM

Most 4v's run very good at 23 - 26 degrees. Any more than that and some have an issue with pinging on pump gas. Every once in a while one will make more power with 27 - 28 degrees.

311-420 · 10-21-2013, 06:42 AM

Mine is tuned with 23.5* on 93 octane. Car didn't like anymore than that.

JeromeMach1 · 10-21-2013, 10:51 AM

On 91 octane max 22 degrees for my car.

Jerome

Mach828 · 10-21-2013, 11:26 AM

Quote:

Originally Posted by tmhutch

Most 4v's run very good at 23 - 26 degrees. Any more than that and some have an issue with pinging on pump gas. Every once in a while one will make more power with 27 - 28 degrees.

Really? Thats a lot of timing.

I dyno'd mine with e85 and took it up to 28 degree incrementally, and it made no more power than it did at 23. It actually started losing power.

The runs with 21-23 were so close to one another I couldn't tell if the power difference was from the additional timing or just normal fluctuations.

311-420 · 10-21-2013, 12:09 PM

B head cobras like upwards of 30*, but our cars don't. Machs simply don't need that much advance. The combustion chamber of the C heads burns the fuel more quickly/efficiently than the older 4v heads, thus why they don't need more time.

lcaptmorg · 10-21-2013, 05:35 PM

On e85 I had mine up to 28 as well but no additional power to be had up there so backed it down to 24.

tmhutch · 10-21-2013, 10:30 PM

My 01 runs 24 - 25 with a/f at 12.8 - 13.2 without detonation . There seems to be variance between cars.

Ben99GT · 10-22-2013, 02:46 PM

The best way to get the timing ballparked is to read the spark plugs.

na svt · 10-22-2013, 03:29 PM

Quote:

Originally Posted by Mach828

Really? Thats a lot of timing.

The computer sets the timing based the signal from the crank position sensor (CKP) which may or may not be accurate. My friend has installed the Holley HP ecu on a couple mod motors and verified the ignition timing with a timing light; one was dead on while the other was 3 degrees retarded. This can be attributed to manufacturing tolerances of the crank's keyway, trigger wheel, front cover and the CKP.

My B headed engine made the most power with 30 degrees advance and my Mach made the most with 24, but pinged in third at full throttle. Under 4000rpm it would take 24 deg and 24 deg worked well in first and second. I reduced it to 22 degrees from 4000-7000 and kept it at 24 up to 4000.

It sure would be nice to have an ecu that would allow unique advance settings for each gear.

na svt · 10-22-2013, 03:30 PM

Quote:

Originally Posted by Ben99GT

The best way to get the timing ballparked is to read the spark plugs.

That is good but requires you to shutdown the engine as soon as you cross the traps (or after a full throttle blast under load).

Ben99GT · 10-22-2013, 05:20 PM

Quote:

Originally Posted by na svt

That is good but requires you to shutdown the engine as soon as you cross the traps (or after a full throttle blast under load).

Correct, a fresh plug helps as well.

systemdz · 10-22-2013, 07:53 PM

Quote:

Originally Posted by Ben99GT

Correct, a fresh plug helps as well.

Yea. Before each run, fresh plug and immediately checked plug after each pass. Actually my a/f gauge was reading rich but the plug was showing little lean. Ill add a little fuel. Timing seems to be about right @ 21* on a 100 shot. I'm planning on pulling another degree of timing and spraying a 150 shot.

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10-16-2013, 06:29 PM	#1
systemdz systemdz Join Date: Mar 2010 Location: Murray, KY Posts: 1,131	Degrees of timing N/A What is average for degrees of timing naturally aspirated on a 4v motor? Curious as to what mine should be seeing. It's a .20 over bore, 10.8-1 compression, 98 cammed motor. Sent from my iPhone using Tapatalk hopefully if this frickN app is working!!! __________________ 2003 Mach 1 Torch Red, 4.6 WAP block .20 coated manley pistons, manley h-beams, 98 cobra cam, BTR springs, Fererra valves, BC auto 4r75w w Freddie Brown MVB w brake, CircleD 4c, built rear and baseline drag suspension. NOS wet kit w NANO.

10-20-2013, 09:36 PM	#2
tmhutch 4v>3v>2v Join Date: Jun 2004 Location: Pacific Northwest Posts: 727	Re: Degrees of timing N/A Most 4v's run very good at 23 - 26 degrees. Any more than that and some have an issue with pinging on pump gas. Every once in a while one will make more power with 27 - 28 degrees.

10-21-2013, 06:42 AM	#3
311-420 Can't be bridled Join Date: Sep 2007 Location: Texas Posts: 7,006	Re: Degrees of timing N/A Mine is tuned with 23.5* on 93 octane. Car didn't like anymore than that. __________________ 2004 Mach 1 #6956 5spd w/IUP Eaton swap, longtubes, built 3.73 SRA 452hp/409tq dynojet🏁

10-21-2013, 10:51 AM	#4
JeromeMach1 Registered User Join Date: Aug 2003 Location: Simi Valley, CA Posts: 1,383	Re: Degrees of timing N/A On 91 octane max 22 degrees for my car. Jerome __________________ 03 Mach1 5spd BB/Stroker built by Eddie Rios Addiction Motorsports P&P 03 Heads by Al P Custom cams by NASVT Nazty PSR SAE 420rwhp SAE 387rwt 1.56 60ft 11.44ET 122.1mph 1700 DA

10-21-2013, 12:09 PM	#6
311-420 Can't be bridled Join Date: Sep 2007 Location: Texas Posts: 7,006	Re: Degrees of timing N/A B head cobras like upwards of 30*, but our cars don't. Machs simply don't need that much advance. The combustion chamber of the C heads burns the fuel more quickly/efficiently than the older 4v heads, thus why they don't need more time. __________________ 2004 Mach 1 #6956 5spd w/IUP Eaton swap, longtubes, built 3.73 SRA 452hp/409tq dynojet🏁

10-21-2013, 05:35 PM	#7
lcaptmorg Registered User Join Date: Jun 2007 Location: Las Vegas Posts: 1,086	Re: Degrees of timing N/A On e85 I had mine up to 28 as well but no additional power to be had up there so backed it down to 24. __________________ 03 We call her Hooker. Stock Long Block 301/310 12.08@110 1.58 60ft 4400da Cams and intake 365/338 SAE 11.73@115 1.54 60ft @3400 ft DA 13.6:1 Cornfed NA 5.0 497/421 SAE 10.66@128 1.42 60ft 3000ft DA

10-21-2013, 10:30 PM	#8
tmhutch 4v>3v>2v Join Date: Jun 2004 Location: Pacific Northwest Posts: 727	Re: Degrees of timing N/A My 01 runs 24 - 25 with a/f at 12.8 - 13.2 without detonation . There seems to be variance between cars.

10-22-2013, 02:46 PM	#9
Ben99GT 4V GT Join Date: Apr 2004 Location: MS Posts: 1,205	Re: Degrees of timing N/A The best way to get the timing ballparked is to read the spark plugs.

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