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Discussion Starter · #1 ·
My brother bought an engine ready to go, carb to pan; water pump to flywheel. It has a MSD Pro Billet Distributor (P/N 85561)on it but it also has a crank trigger on it. We run the 7531 MSD box and had problems last night getting the car started. We hooked the Crank Trigger wire from the MSD box to the Crank Trigger and the car will not start. We unhooked the wire from the crank trigger and plugged it in to the pigtail on the distributor and the car fired right up and ran fine.... so my question is:

Is there anything that I can do to make this Pro Billet Distributor work with the crank trigger..... maybe pull the guts out of the distributor or something. Or do I just need to get a Crank Trigger distributor. And how is it that I am not getting fire when it is plugged in to the Crank Trigger but works fine when it is hooked to the distributor. Is it someway that the MSD box can sense what distibutor is in the engine?

Joshua
 

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My brother bought an engine ready to go, carb to pan; water pump to flywheel. It has a MSD Pro Billet Distributor (P/N 85561)on it but it also has a crank trigger on it. We run the 7531 MSD box and had problems last night getting the car started. We hooked the Crank Trigger wire from the MSD box to the Crank Trigger and the car will not start. We unhooked the wire from the crank trigger and plugged it in to the pigtail on the distributor and the car fired right up and ran fine.... so my question is:

Is there anything that I can do to make this Pro Billet Distributor work with the crank trigger..... maybe pull the guts out of the distributor or something. Or do I just need to get a Crank Trigger distributor. And how is it that I am not getting fire when it is plugged in to the Crank Trigger but works fine when it is hooked to the distributor. Is it someway that the MSD box can sense what distibutor is in the engine?

Joshua
You need neither. I have a crank trigger with a MSD distributor with a pick up inside. maybe you have a bad pickup, to much air gap, or the trigger wheel isn't phased correctly.
 

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X2 Also, make sure you have it plugged into the correct pigtail coming out of the 7531 box; there are two pigtails that it will physically plug into if memory serves... Only one will work.
 

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The crank trigger does the signaling to the box to fire. Just unhook the distributor pickup wires and forget they are there.

Check the timing on the crank trigger as well as the phasing of the distributor. Sounds like it may be out of time or something.

Go back to square one and put the engine on TDC, then at your baseline timing (on the balancer) and see if the crank trigger pickup is lined up with a magnet on the trigger wheel.
 

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Discussion Starter · #5 ·
X2 Also, make sure you have it plugged into the correct pigtail coming out of the 7531 box; there are two pigtails that it will physically plug into if memory serves... Only one will work.
Yeah I have checked that.... been there done that before!
 

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Discussion Starter · #6 ·
Go back to square one and put the engine on TDC, then at your baseline timing (on the balancer) and see if the crank trigger pickup is lined up with a magnet on the trigger wheel.

O.k. how close does the magnet need to be lined up? Does it have to be directly over top of the magnet or will like a 1/4" off be good enough? When we dropped the distributor in, on my baseline timing the closest magnet was like 1/4" before the pickup.
 

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the msd distributer has a multi- relucter wheel in it right ?

meanwhile the crank trigger has a few magnets, which must align.. say @ 20 BTDC (for sake of argument) when your crank trigger is at 20, does your rotor face the number 1 terminal ? the crank trigger must align at 20, it cannot be "off" because at that point your timing will be off, and your distributer phasing will be "off" as well.

with the distributer pluged in, i do not belive the issue would still be there, being you have a multi tooth trigger. perhaps its creating enough voltage to trigger your ign.
 

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You need neither. I have a crank trigger with a MSD distributor with a pick up inside. maybe you have a bad pickup, to much air gap, or the trigger wheel isn't phased correctly.
X4....I have the same exact setup. I believe the air gap should be .060-.080"? You should be able to set the dist. @ #1, timing pointer to desired timing and pickup at the magnet for a close starting point. Timing will still be several degrees off and will need to be set with the engine running. If that doesn't work the pickup or wiring may be bad.

Craig
 

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O.k. how close does the magnet need to be lined up? Does it have to be directly over top of the magnet or will like a 1/4" off be good enough? When we dropped the distributor in, on my baseline timing the closest magnet was like 1/4" before the pickup.
That should be close enough for it to run, just will change your timing some. With the engine sitting with the crank trigger timed properly, then pop off the distributor cap and verify the rotor is pointing to #1. Loosen the distributor and move it to get it as close as you can by eye.

Now the engine should start and run. If it does, set your timing with a light and the crank trigger pickup location. Last step is to have a large hole in a spare distributor cap and point the timing light down the hole with the engine running to phase the distributor cap.

With timing retards and nitrous, I'd imagine you guys have specific methods to how and where you phase the distributor.
 

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Discussion Starter · #11 ·
That should be close enough for it to run, just will change your timing some. With the engine sitting with the crank trigger timed properly, then pop off the distributor cap and verify the rotor is pointing to #1. Loosen the distributor and move it to get it as close as you can by eye.

Now the engine should start and run. If it does, set your timing with a light and the crank trigger pickup location. Last step is to have a large hole in a spare distributor cap and point the timing light down the hole with the engine running to phase the distributor cap.

With timing retards and nitrous, I'd imagine you guys have specific methods to how and where you phase the distributor.

O.k. let's say for instance on this motor the timing will be set at 37° and the distributor is out of it. I will crank the motor to 0° with #1 up and then rotate the motor to 37° BTDC and check the placement of the magnet and adjust the magnet to get it lined up with the pickup and set the gap to .050-.080. Now with the nitrous and retards let's say we want to phase the distributor in at 25°, I will then rotate the engine to 25° BTDC and drop the distributor in making sure that the rotor is pointing to #1. Then start the engine and check through the cap to get the distributor "phased" in properly. Does this sound like the correct way to do this?
 

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O.k. let's say for instance on this motor the timing will be set at 37° and the distributor is out of it. I will crank the motor to 0° with #1 up and then rotate the motor to 37° BTDC and check the placement of the magnet and adjust the magnet to get it lined up with the pickup and set the gap to .050-.080. Now with the nitrous and retards let's say we want to phase the distributor in at 25°, I will then rotate the engine to 25° BTDC and drop the distributor in making sure that the rotor is pointing to #1. Then start the engine and check through the cap to get the distributor "phased" in properly. Does this sound like the correct way to do this?
I don't run nitrous, but that would make sense to me.
 

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Discussion Starter · #13 ·
Thanks for the help guys, I'll go back and start over and hopefully I can get it straightened out!
 

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O.k. let's say for instance on this motor the timing will be set at 37° and the distributor is out of it. I will crank the motor to 0° with #1 up and then rotate the motor to 37° BTDC and check the placement of the magnet and adjust the magnet to get it lined up with the pickup and set the gap to .050-.080. Now with the nitrous and retards let's say we want to phase the distributor in at 25°, I will then rotate the engine to 25° BTDC and drop the distributor in making sure that the rotor is pointing to #1. Then start the engine and check through the cap to get the distributor "phased" in properly. Does this sound like the correct way to do this?

No, phase the rotor with the engine running. Set the timing to 25* then (with engine running) looking thru a hole in the dist. cap check / align the rotor directly on #1. Or what I do is just phase the rotor before #1 with the motor running and timing set at the max. Then as timing is pulled the phasing gets closer.

Craig
 

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O.k. let's say for instance on this motor the timing will be set at 37° and the distributor is out of it. I will crank the motor to 0° with #1 up and then rotate the motor to 37° BTDC and check the placement of the magnet and adjust the magnet to get it lined up with the pickup and set the gap to .050-.080. Now with the nitrous and retards let's say we want to phase the distributor in at 25°, I will then rotate the engine to 25° BTDC and drop the distributor in making sure that the rotor is pointing to #1. Then start the engine and check through the cap to get the distributor "phased" in properly. Does this sound like the correct way to do this?
The first part is right about getting it pointed at a magnet with the motor turned 37 degrees, and then put the rotor button pointing at #1 plug wire contact.
Fire the motor and check the timing with an adjustable light set at 37 degrees.
Then signal the 7531 to retard the timing to the maximum the box will be pulling out when the nitrous is on. You will have to rev the motor to 4500 or so to keep it from dying.
With a hole drilled in the cap right at the #1 contact and a white mark on the rotor tip put a timing light on the cap and turn the distributor to line the white mark up at the hole. When doing this with an adjustable light, set it at 0 degrees.

It is better instead of starting at 37 degrees, start with the mechanical timing at the lowest point that it don't fowl the plugs and can still do a good burnout. If it was say 30 degrees you wouldn't have to use so much digital retard and can save some of that 20 degrees the box can take out for the launch curve.

Get that pig ready for ol Kid Rocket at the Bridge on Saturday.:butthead:
 

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Dumb Question

Dumb Question, but do you have a cam sync wire on the number one spark plug hooked into the box, so it know when #1 fires? I have a Pro Billet in mine with the acvance locked out running a crank trigger and have to use the Cam sync to make it fire.
 

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http://www.candbmotorsports.com/camsync.html

There is how to modify a SBF distributor for use as a cam sync signal for the 7531 (or an EFI setup). Modding a GM distributor should be similar. The basic steps are sync the crank trigger magnets at your base timing, then rotate the motor to TDC and drop the distributor in and lock it down with the rotor lined with #1 and lastly set your reluctor up with the motor at the least amount of timing you will run. Then you can program in all your retards in the 7531.

Chris
 

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depending on your total retard i would defentaly check your rotor phase with your 25* retarded
 
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