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I have an MSD distributor and high voltage/current module and 6A spark discharge pack. The car is fairly new to me. I took the cap off and found this.
Does any of this need to be replaced? I don't have any experience with MSD stuff. I'm not 100% sure what all this is called. The car runs well. It doesn't miss. I think I should replace the rotor cap, but I don't know about all the other rusted stuff. Can you replace the internal parts? Should I just buy a new distributor and swap the whole thing?
Clean it, remove the rust, and then use rust encapsulator on it.
Mine has never failed.
Even when it looked like crap. Let me find the link where I last buffed it up.
Yep you need to replace that.......and the super stiff springs for the mechanical advance. You have almost no curve in that distributor with two heavy silver springs.
Refer to Holley dot com and download the distributor instruction manual for how to change this.....but I can tell you that one blue and light silver spring and a blue bushing is about right for a mild street engine. https://static.summitracing.com/glob...4_frm28727.pdf
Jebby,
It's a 383 that was 425 HP as bought and then had a cam, heads, high rise intake, Holley 750 DP. It should be over 500HP now although never dyno tested. It was balanced at 9600RPM. It runs really smooth up to 8000 RPM and rips second gear. The original owner got the tires hot a sticky and really got on it. When it hit second, it snapped the half shaft when the tires didn't break loose. I don't generally run it that hard, but trips to 4-5000RPM are probably pretty regular. It was built to drag race. Given that, what curve would you think would be best?
Thanks,
Rob
You're going to need more information like compression, cam specs, gear ratio. Convertor Stahl speed if automatic.
But first clean it up change the cap and rotor.i think MSD use to give pretty good directions for set up.
I would definitely keep the MSD parts working as they are. I have been using MSD parts for decades with no issues. Getting a new cap and rotor for sure and vacuum out the crud inside the distributor.
The Silver Springs are the "default" that MSD puts into their distributors. It is the slowest curve of all. MSD has a very informative set of instructions for setting up a Advance Curve. I would make changes slowly with your advance curve to avoid any problems. One step at a time...
I have the MSD with the Mechanical Tachometer Drive as needed by my tachometer in my 1968 C3. Here is a link to a generic GM Distributor's Instructions for reference: https://documents.holley.com/85551.pdf
With your Blaster Coil and a MSD 6AL your sparks will sound more like an arc welder. On my 12.25-1 Compression 427 it really helps as it fires the plugs without any trouble with a huge gap.
Normal arcing within dist cap ionizes constrained moisture-laden air ... byproducts can be very corrosive ... Do vent.
Do vent via either drill thru top of cap or drill vertically thru bottom of dist base ... Then clean it up ...
... ensuring No particles stuck to magnetic pickup or "star" reluctor ... New cap & rotor.
IIRC, MSD offers a "cap-adapt" retrofit option using a large diameter Ford HEI cap which can help ... back when Cup used distributors, that's what most had.
FWIW, many vented caps available as marine options.
Vent not BS ...OE Vortec crab cap distributors in millions of Chev/GM trucks w/ L31 motors do have an OE vent-hole in bottom of dist base.
Folks way smarter than me figured this out Long ago.
I have been trying to document what's actually in the drivetrain. It hasn't been easy.
I think the cam is https://www.compcams.com/magnum-224-...all-block.html
Sportsman 2 heads
Edlebrock air-gap intake
Holley 750 DP carb
Automatic with shift kit but I don't know the stall converter.
You have a lot of time, work, and money in your motor. I would call it a day with the MSD. All kinds of options on what to get but you will have multiple opinions here that differ.
I wouldn't put that back in my car...
The male caps already have a venting port to solve the moinsture issue.
But the old females don´t. I have drilled a hole into the cap with the same setup and old fashion cap.
I didn't build the motor. The original owner did. I just bought it this way. Now I'm trying to figure out what all was changed. Talking with him, looking up numbers. Trying to figure it all out.
I would keep the MSD. Definitely get a new cap and rotor and change the springs ( I use the blue and light silver in mine). Zuendler is correct about the caps. Mine has the male terminals and looks exactly like new inside.
I have been trying to document what's actually in the drivetrain. It hasn't been easy.
I think the cam is https://www.compcams.com/magnum-224-...all-block.html
Sportsman 2 heads
Edlebrock air-gap intake
Holley 750 DP carb
Automatic with shift kit but I don't know the stall converter.
If that motor is built to run up to 8000 rpm then that’s not the cam you have. Hydraulic roller lifters generally are good only to 7500 tops plus that is a really small cam. I would expect that cam to peak out power wise 6200-6500 head and intake depending. Maybe the previous owner embellished the RPM range a little?
The male caps already have a venting port to solve the moinsture issue.
But the old females don´t. I have drilled a hole into the cap with the same setup and old fashion cap.
That's the cap that is already on it and what I ordered to replace it.
Seems a vented cap alone wasn't enough.
Perhaps you should drill base & vent it as well ... like marine dist is quote for MSD 8560 Marine UL dist: For marine use, the distributor cap is bolted to the aluminum base. There are two flame arrestor holes with brass screens machined into the base of the distributor to prevent ignition of gas fumes that may build up in the engine compartment.
So - this post made me curious so I went and checked to see how my MSD was looking almost exactly 2 years after I painted it with POR-15. Note that I have the "good" vented cap and all that. Anyway, here are some pictures. It's a lot better than when I just coated it with WD40 but still....... it must just be some crappy quality metal in there. I cleaned it up and put another coat of POR-15 on there since it worked better than anything else. Recoated with POR-15
MSD distributor Should I replace?
