383/400 - Distributor shaft length and seated depth Q's?

[Sweet5ltr]

It will be interesting to see what the response is..... hopefully you told them your event is this weekend.

Yes, told them I needed to have a solution within the next few days. I do have an event next week, Cruisin the Coast.

 

[Sweet5ltr]

(Ethan my Holley Technical Representative)

Just got off the phone with MSD engineering. Here’s the rundown –

There’s a good chunk of tolerance range built into these units that the MSD design gives us. We can shim the shaft to compensate, it turns out the Pro-billet was shimmed at the high end of tolerance to get in factory spec, the Hyperspark was shimmed at the low range. We’re going to shim the Hyperspark to get in spec, there will be a variance between the two of about .013” but according to our data Mopar says that’s still in their tolerances. They will have it shimmed and both shipped back to you overnight today.

Will update you with a tracking number when we get it.

(*second email, asked was this an anomaly or a production issue*)

Couldn’t tell you exactly how the process will change moving forward, but they (MSD) have told me they will be looking for a higher range of depth on all units moving forwards.



---- That's why you buy from Holley ----

 

[Lefty71]

Good man. If they aren't just blowing smoke, then you fixed it for all of us.

 

[Sweet5ltr]

Good man. If they aren't just blowing smoke, then you fixed it for all of us.

Well, doesn’t look like they’ll be having a recall for those that purchased to correct the issue. Going to be a case by case basis to get it re-shimmed for early adopters. AndyF is the only other person I know that has this distributor, hasn’t mentioned if he’s measured the length since the issue came up with mine.

 

[HALIFAXHOPS]

Hope this helps. I also try to keep the up and down play of the shaft at .020-,010. That is on a stock MOPAR distr, don't know the MSD.
Mopar Distributor Shaft Lengths
Mopar Distributor identification guide by measuring shaft length, measured from mounting surface to lower end of distributor shaft.

Mopar LA engine – 3.875”
Mopar B engine – 3.5″
Mopar RB engine – 4″
–
Chrysler 331/354 Hemi – 4.25″
Chrysler 392 Hemi – 4.5″
–
Dodge 241/260/270 Hemi – 3.875”
Dodge 315/325 Hemi – 4.25″
Desoto 276/291 Hemi – 4.00″

 

[Sweet5ltr]

Yes, those are the numbers I went off of. MSD seems to have been shimming the 383/400 Hyperspark distributors in the 'low-range' and that's where the issues came up. Even on the high-range (maximum) the Hyperspark mounting surface to shaft length is still slightly shorter than the MSD Pro Billet it replaced.