found this in distributor....
Rabbit-Hole Researcher
Joined: Feb 2004
Posts: 466
Likes: 6
From: Middle of Ohio
Lee, Do you have any comments on which springs are used from the 925G set?
Carbo_nero, you might want to look into a more modern spark curve, since gas is now a different formulation. (Not that I know what that is exactly...)
Carbo_nero, you might want to look into a more modern spark curve, since gas is now a different formulation. (Not that I know what that is exactly...)
Thread Starter
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Freshman User
Joined: Feb 2017
Posts: 43
Likes: 0
You'll need to look in the Shop manual to determine the advance curve for your truck/engine/transmission combination.
It sounds a little like you'd be time and money ahead by installing a remanufactured distributor. It will have tight bushings and freely moving breaker plate and also have a vacuum advance can that is more easily adjustable. The factory types are adjusted by removing shims, more modern types like the Crane use an allen wrench through the hose port. Original vacuum cans will often have leaky diaphragms by now.
Distributor advance
It sounds a little like you'd be time and money ahead by installing a remanufactured distributor. It will have tight bushings and freely moving breaker plate and also have a vacuum advance can that is more easily adjustable. The factory types are adjusted by removing shims, more modern types like the Crane use an allen wrench through the hose port. Original vacuum cans will often have leaky diaphragms by now.
Distributor advance
Thread Starter
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Freshman User
Joined: Feb 2017
Posts: 43
Likes: 0
Thanks, I decided on a new distributor to remove any possible issues, and a pertronix II to top it off. Still rebuilding the water pump etc so I have to wai to see the result but it should be much better.
Laughing Gas
Joined: Jul 1999
Posts: 1,048
Likes: 22
From: Lacey, WA
If I remember correctly the 925D only comes with 2 springs, a heavy, light? I went with the 928G as it has more variety of springs.
Here's a re-cap of my re-curve.
As from Ford, my total timing (Initial + Mechanical = 36*) was not all in until ~4000 rpm. Research shows that 3000rpm was my goal for my heavy truck. A car could get away with 2200-2500rpm without "pinging".
My distributor has a 13L – 18L reluctor set at 13L. This will equal 26* mechanical advance. The stock springs were a heavy and a medium thus causing the late 4000rpm total timing.
I replaced the stock springs with the Mr Gasket light springs from the set (928G). Mechanical timing advance curve is as follows with 10* initial at 800rpm idle with Vac advance plugged.
10* initial + 26* mechanical = 36* total and it was all in by 2200rpm. This caused "pinging".
I then changed to 1 light and 1 medium spring. Now have total in at 3000rpm. No pinging.
RPM Advance
Both light (pinged) 1 light, 1 Med.
1000 10* 11*
1500 20* 15*
2000 31* 24*
2200 35*
2500 35* 32*
3000 35* 36*
I recommend you experiment with a few different spring combo's to get the total in ~ 3000 rpm. BTW: Try and stay under 38* total...... so, find out what Reluctor you are running and multiply this valve by 2 (mine's a 13, .... 13 x 2 = 26*) subtract this number from the goal (36* in my case) and that is what to set the Initial timing to (10* in my case).
Hope this helps,
Thread Starter
|
Freshman User
Joined: Feb 2017
Posts: 43
Likes: 0
Hi,
If I remember correctly the 925D only comes with 2 springs, a heavy, light? I went with the 928G as it has more variety of springs.
Here's a re-cap of my re-curve.
As from Ford, my total timing (Initial + Mechanical = 36*) was not all in until ~4000 rpm. Research shows that 3000rpm was my goal for my heavy truck. A car could get away with 2200-2500rpm without "pinging".
My distributor has a 13L – 18L reluctor set at 13L. This will equal 26* mechanical advance. The stock springs were a heavy and a medium thus causing the late 4000rpm total timing.
I replaced the stock springs with the Mr Gasket light springs from the set (928G). Mechanical timing advance curve is as follows with 10* initial at 800rpm idle with Vac advance plugged.
10* initial + 26* mechanical = 36* total and it was all in by 2200rpm. This caused "pinging".
I then changed to 1 light and 1 medium spring. Now have total in at 3000rpm. No pinging.
RPM Advance
Both light (pinged) 1 light, 1 Med.
1000 10* 11*
1500 20* 15*
2000 31* 24*
2200 35*
2500 35* 32*
3000 35* 36*
I recommend you experiment with a few different spring combo's to get the total in ~ 3000 rpm. BTW: Try and stay under 38* total...... so, find out what Reluctor you are running and multiply this valve by 2 (mine's a 13, .... 13 x 2 = 26*) subtract this number from the goal (36* in my case) and that is what to set the Initial timing to (10* in my case).
Hope this helps,
If I remember correctly the 925D only comes with 2 springs, a heavy, light? I went with the 928G as it has more variety of springs.
Here's a re-cap of my re-curve.
As from Ford, my total timing (Initial + Mechanical = 36*) was not all in until ~4000 rpm. Research shows that 3000rpm was my goal for my heavy truck. A car could get away with 2200-2500rpm without "pinging".
My distributor has a 13L – 18L reluctor set at 13L. This will equal 26* mechanical advance. The stock springs were a heavy and a medium thus causing the late 4000rpm total timing.
I replaced the stock springs with the Mr Gasket light springs from the set (928G). Mechanical timing advance curve is as follows with 10* initial at 800rpm idle with Vac advance plugged.
10* initial + 26* mechanical = 36* total and it was all in by 2200rpm. This caused "pinging".
I then changed to 1 light and 1 medium spring. Now have total in at 3000rpm. No pinging.
RPM Advance
Both light (pinged) 1 light, 1 Med.
1000 10* 11*
1500 20* 15*
2000 31* 24*
2200 35*
2500 35* 32*
3000 35* 36*
I recommend you experiment with a few different spring combo's to get the total in ~ 3000 rpm. BTW: Try and stay under 38* total...... so, find out what Reluctor you are running and multiply this valve by 2 (mine's a 13, .... 13 x 2 = 26*) subtract this number from the goal (36* in my case) and that is what to set the Initial timing to (10* in my case).
Hope this helps,
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 790
From: Simi Valley, CA
C5AZ-12192-J .. Secondary Spring (Motorcraft (MS-473) / Obsolete
GREEN SALES CO. in Cincinnati OH has 6 = 800-543-4959.
-------------------------------------------------------------------
C5AZ-12192-K .. Primary Spring (Motorcraft MS-474) / Obsolete
GREEN SALES CO. has 10.
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