MSD 8365

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Firedome8
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MSD 8365

Post by Firedome8 » Mon Aug 28, 2017 11:18 am

Working on a typical sbc engine runs fine customer wants it fixed!!! Wants to upgrade ignition I recommended a MSD Pro billet 8365. Put dist on tester to verify the advance have it set to 21 crankshaft degrees but when I spin it up it jumps 12 crankshaft degrees @ 2300 rpm...for a total of 33° ???? Locked out advance still jumps 12° @ 2300 rpm.... Sent back to MSD they sent a new in box 8365 and it does the exact same thing,,,replace module with old one out of module pile and advance is ok???? Put original back in 12° extra advance jumps in @ 2300 rpm...MSD says can't happen...your thoughts greatly appreciated,thanks for any input.

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Re: MSD 8365

Post by cgarb » Mon Aug 28, 2017 11:30 am

The first rule of problem solving is if it happened then it is possible....lol. Good job MSD techs.

olescarb
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Re: MSD 8365

Post by olescarb » Mon Aug 28, 2017 6:15 pm

I have seen the timing jump like you describe if the supply voltage drops below 12 volts but it only happens on the newer style MSD distributors that have the gray wire that can be used for a tach lead. When we supplied full battery voltage to the module in the distributor you could hear a difference in how the motor idled and the timing jump problem went away, this problem mainly happens with the MSD ready to run distributors but it could also effect the 8365 MSD HEI distributors


Henry @ oles carb

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Re: MSD 8365

Post by Tuner » Mon Aug 28, 2017 6:21 pm

Hey Henry, you treed me. Good job! How've you been?

The MSD HEI modules (and ready to run standard size cap external coil billet distributors) which have the built in rev limiter will not correctly trigger a Sun distributor machine. You need to fire the coil and use a timing light.

Use a length of mechanic's wire looped around 7 cap terminals with the free end connected to a grounded (to the battery) spark plug. For the timing light put a spark plug wire on the 8th terminal connected to a grounded plug with a large gap.

It depends on the individual timing light but you may need 1/8" to 3/16" gap to get enough voltage in the wire to reliably trigger the light.

Use a 12V battery and ground negative post to the distributor machine and distributor housing, 12V positive to the cap (coil) BAT/B+ terminal. Regular 14 or 16 gauge jumper wires will power this but smaller than that will struggle with the amperage load and may cause error if the supply voltage at the coil is less than 12 V. Those MSD modules draw more amperage than standard HEI.

This is so in the car too, what Henry said in his post above, these modules and distributors must be powered with full battery voltage through large enough wire to not cause a voltage drop. 12 gauge minimum, 10 gauge preferred, just like a stock GM HEI. The high energy can only come from more energy in = more energy out.

Enjoy the smell of fresh Ozone.

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Re: MSD 8365

Post by Firedome8 » Mon Aug 28, 2017 9:47 pm

I am using an 1956 vintage Alleniser,,,Voltage is 13.4 ,will do the timming lite test. Thanks everyone for your insights, I will report back.

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Re: MSD 8365

Post by olescarb » Wed Aug 30, 2017 5:40 pm

[quote="Tuner"]Hey Henry, you treed me. Good job! How've you been?

Hello Tuner I am doing well still playing with carburetors. PM sent Take care Henry @ oles

Firedome8
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Re: MSD 8365

Post by Firedome8 » Fri Sep 08, 2017 5:22 pm

Update:
Contacted MSD today about the 2 8365 pro billet distributors I sent them to check the trimming issue I described, the tech still wanted to tell me 5 ways from Sunday what I could be doing wrong with my 5 timming lights and hook up, finally I suggested he go test the distributors and just settle it, 10 minutes later he tells me the output is bad ???? so I ask how about timming???? output is bad,,,I ask if the output effects the timming (pause) yes,, and when we get modules in stock he will replace them and return distributors.

thanks for any input.

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Re: MSD 8365

Post by FC-Pilot » Fri Sep 08, 2017 6:20 pm

Thanks for he update. The more info we get on here the more each of us can look for in the future.

Paul
"The latest tests prove exactly what my money tells them to prove".

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Re: MSD 8365

Post by Firedome8 » Mon Sep 25, 2017 9:40 pm

Update : Received distributors back from MSD today. The report says Failed,,, MSD installed new module, pickup, and cap coil rotor. Tested the distributors as per Tuners suggested setup and all is well. Thanks for all help given.
I like Tuners method and will use it in future. :D

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