MSD Mechanical Advance issues

[CGT80]

Well, I finally checked the timing on my truck again. 406 sbc 10:1, Scat 9000 crank and rods, trw hyper flat top pistons set to 0.005" out of the hole, capped with ported and flow benched aluminum heads, and intake, with a comp cams 270 magnum hydraulic flat tappet (224/224 @ 50).

I am running the MSD 8365 pro billet HEI. It is a copy of the original HEI. I replaced the weight set and springs when I built this engine. MSD tech gave the part number for the springs. The instructions for that weight set says not to use it with the 8365.

I think I am running the silver bushing, heavy silver spring, and a light blue spring. This should give me 25 degrees of mechanical advance all in at 3250 rpm.

This is what I got this morning:
11.5 initial advance
18.5 mechanical advance (without vac can hooked up)
30 degrees of total advance

The big problem is that all the advance is in by 2200 rpm. Both the springs and bushing don't match MSD's charts for what they should be. The advance is off by 1000 rpm. No wonder I had pinging when hauling my 9,000 pound toy hauler (truck weighs about 6500 lbs). It also runs warmer than I would like.

When I first dropped in the engine, I had a faster advance. When the weather warmed up I had some pinging while running without a trailer and the temps seemed high. I slowed it down and saw a big drop in temps, and got rid of the pinging for the most part. I also run an in cab timing retard knob. I don't let the engine ping.

I am going to try the heaviest springs next. I am already at the second to the slowest curve. I think the weights are not correct for this dizzy. If they are too heavy, they would advance faster than what MSD shows in their chart. I can't seem to find a set of stock HEI weights for a 79 chevy.

A few knowledgeable people have told me to set the advance to be all in by 3000 rpm, and to slow it down if it doesn't like it that quick. I know 2200 isn't going to cut it, especially on an engine that can be pushed to 6,000 rpm (I don't usually push it past 5,000 rpm).

I run an adjustable vac advance, and will tune that more after I get my centrifugal set right. I had to set the can to allow advance only at vacuum levels higher than 6 inches, since the engine pulls 5" of vacuum at 5500 rpm at WOT due to the small 600 cfm carb. I may try my 895 Q jet that I ran on the previous engine.

Well, this helped me to organize my thoughts. I just wanted to share my experience and also ask if anyone else has run into the same problem with the springs being so far off from what the manufacture lists them at.

PS. The MSD 8365 is kind of a bastard dizzy. It doesn't use all same parts as the non-smog legal distributors from MSD. I found that I had to use a stock HEI pickup when mine went out, the one from MSD that says it works on ALL MSD distributors, did not even come close to matching what I had. I don't think the tech. I talked to realized this when he told me what weights to run. I have talked to MSD twice, but didn't get anywhere with them.

For the visual people (sorry I don't have a better photo as I was focused on getting it in the truck):

 

[sweetk30]

msd problems pm this guy . resident msd guy here. http://coloradok5.com/forums/member.php?u=974

 

[CGT80]

Thanks for the heads up. I'll send him a message.

I changed the springs out to: 2 heavy silver springs. This gave me full advance at 2500 rpm. This is better than 2200 rpm, but now I am as slow as I can go with these springs and weights. My results are 1000-2000 rpm off from what MSD's charts show for this combo. I will also call MSD tomorrow, for the third time now.

 

[CGT80]

I called MSD today. This was my third call regarding this issue. The tech could not tell me why the directions for weight kit 8628 said that it was not for the pro billet hei part number 8365. The spring and bushing kit I am running is part 8464. MSD doesn't seem to know what weights are used in the 8365. The tech then asked me what color my ignition module was. He thought that maybe I had the streetfire HEI. I know that mine is a billet distributor, I know that the model number is correct, and I bought it in 2003. I had never even seen the streetfire offered back then. I did find the module, I don't use it anymore due to the in cab timing retard having it's own module. It doesn't really have a color other than the green circuit board.

After I asked the tech about sending me the parts that are used in their factory for the 8365, he said he would send out a weight and spring/bushing kit.

I can not believe MSD is so stupid as a whole, when it comes to this distributor. They copied the GM HEI design, but don't warn people in the directions that this distributor doesn't use the same parts as the rest of their line. They don't list a part number for a weight replacement kit for this dizzy, in the instructions. They specify a part that says it is not to be used with this dizzy. They make a weight and spring kit for GM HEI, but it says it can not be used with the MSD probillet HEI-only stock GM HEI distributors.

What a pain in the ass!!!

I will wait for the parts and hope that they are correct this time. I could always get another set of weights and lighten them to get the curve I want, but I shouldn't have to do that. If I did that, I would probably run the dizzy on a distributor dyno instead of going through the trial and error in the truck. I have a dyno, but it needs repaired and I don't know much about them. I do know a local guy that has a working dyno though.

End of Rant!!

 

[sweetk30]

wait for philly to get back to you . he is the sh!t . he helped me and few others out big time.

and yes customer service does suck at a lot of places these days.

 

[76zimmer]

Phil is the man...he helped me out a bunch!

 

[Philly87]

Hey Chris,

Ok here we go.

MSD PRO BILLET HEI Part Number 8365 - This is the high dollar AMERICAN MADE HEI that we offer. It uses the same weights, springs and bushings as the rest of our Pro Billet line. The replacement spring and bushing kit for this distributor is part number 8464. This is the same kit that originally comes with the distributor in the parts bag when purchased new. The replacement weights for this distributor are part number 8628 and again are the same as what comes in the distributor when new.

In order to modify your advance curve the only parts you should need are the springs and bushings; we do not offer a different weight set for the PRO BILLET HEI.

MSD STREET FIRE HEI Part Number 8362 - This is our run of the mill compete with the economical competition Chinese distributor. I know I know, Chinese is the last thing I want to here also and we flame upper management about it constantly. As unfortunate as it is other companies building their parts overseas forces us to offer this product to keep a portion of the market. This distributor uses the HEI Advance Kit part number 8428. The 8428 spring and weight kit will work on stock GM HEI distributors as well as our Street Fire HEI. The only reason we offer this kit is to accommodate the Street Fire distributor.

I realize this is a bit confusing and our technical staff should have been able to easily clarify this for you and I apologize on their behalf. I also assure you that I will bring this thread to the attention of the customer service manager.

P.S. The motor looks great! Let’s make it run great. Start by going back to the original weights that came with the distributor that way the curve specs you are following in the instructions will be accurate. From there check the curve with the springs you want and see how it looks. You are correct that the silver bushing will provide 25 degrees of mechanical advance.

Hope this helps…
-Phil

 

[CGT80]

Hi Phil,

Thanks for taking a look at this. Looks like I need to clarify what is going on. I have basically matched what you said to do, but don't get the results you seem to think I should get. I am running two heavy silver springs and a silver bushing with the part numbers you listed. MSD's "A" curve shows 25 degrees of advance at 4750 rpm. I got 18.5 degrees at 2500rpm.

Here are my parts:
MSD 8365 distributor
MSD 8628 weight kit
MSD 8464 advance kit
MSD 84281 vacuum advance stop plate
MSD 8782 adjustable timing control
Moroso 72315 adjustable vacuum advance canister




I will put some responses in bold below:

Hey Chris,

Ok here we go.

MSD PRO BILLET HEI Part Number 8365 - This is the high dollar AMERICAN MADE HEI that we offer. This is the distributor that I bought for big bucks in 2003. It uses the same weights, springs and bushings as the rest of our Pro Billet line. The replacement spring and bushing kit for this distributor is part number 8464. This is the new advance kit that I bought when I built the 406 a year and a half ago. This is the same kit that originally comes with the distributor in the parts bag when purchased new. The replacement weights for this distributor are part number 8628 and again are the same as what comes in the distributor when new. This is the weight kit that I bought to replace the weights that had some wear on the edges, and the pads that were falling apart. The photo below shows the instruction sheet. "for MSD pro-billet distributors (except the GM HEI)." Does that mean it includes MSD's pro-billet HEI, but excludes the stock HEI? The photo in the directions for 8628 shows a different distributor than what I have. The pickup in my 8365 went bad. I bought part 84661. It said it was for MSD pro-billet distributors, but didn't match the pickup I had. I bought a stock pickup from the parts store and it matched. Maybe I screwed up on this part.

In order to modify your advance curve the only parts you should need are the springs and bushings; we do not offer a different weight set for the PRO BILLET HEI.

MSD STREET FIRE HEI Part Number 8362 - This is our run of the mill compete with the economical competition Chinese distributor. I know I know, Chinese is the last thing I want to here also and we flame upper management about it constantly. As unfortunate as it is other companies building their parts overseas forces us to offer this product to keep a portion of the market. I don't think this distributor was available in 2003, but I know I don't have this one. This distributor uses the HEI Advance Kit part number 8428. The 8428 spring and weight kit will work on stock GM HEI distributors as well as our Street Fire HEI. The only reason we offer this kit is to accommodate the Street Fire distributor. I saw this kit the other day, and thought it might work in the 8365, but the directions said not for the 8365. It sounds like you are right about the 8365 using the same weights as the other pro-billet designs vs. stock HEI weights, but it doesn't explain why they are not working for me.

I realize this is a bit confusing and our technical staff should have been able to easily clarify this for you and I apologize on their behalf. I also assure you that I will bring this thread to the attention of the customer service manager.

P.S. The motor looks great! Let’s make it run great. It runs strong, and has 20k miles on it, but obviously needs some tuning. Thanks for the compliment. Start by going back to the original weights that came with the distributor(i threw these away as they were worn and stepped on the edge.I replaced them with part number 8628.) that way the curve specs you are following in the instructions will be accurate. From there check the curve with the springs you want and see how it looks. You are correct that the silver bushing will provide 25 degrees of mechanical advance. The silver (95% sure I am running silver) bushing only gives me 18.5 degrees of advance.

Hope this helps…
-Phil

Thanks for the help. Let me know if you can make any sense of all this.

 

[Philly87]

Chris,

You do in fact have the correct weights for your distributor. I have a simple question for you; are you positive the heavy springs are in the distributor and not the light springs? There are two sets of silver springs that come with this distributor and by looking at the graphs below it sure looks like you may have the light springs in.

Looking at the two sets one set is very thin while the heavy set is a thicker gauge.

Also, what kind of timing light are you using? Make sure it is not adjustable or digital. Use a simple standard timing light.

 

[CGT80]

I installed the two heavy silver springs yesterday. I had one heavy silver and one light blue. I still have two light weight silver springs in my bag of parts. The heavy springs were tight enough that I had to use needle nose pliers to get them installed all the way. The light springs I can put on by hand.

I use a craftsman adjustable light-dial on back. I don't have a standard light.

With the dial on 0, I get 11.5 initial on the scale over the balancer
with the dial on 18.5 at 2500 rpm, the mark is back at 11.5 over the balancer
with the dial at 30 at 2500 rpm, the mark is at 0 over the balancer.

I tried a different light, I think it was a digital snap on, a while back. I don't recall what happened though.

Why is an adjustable light bad? I don't have tape on the balancer right now to read it that way, but I could try and find some.

 

[CGT80]

Curve "F" is still quite a ways off from what I have. I don't know how much variance there is from your charts and real world results though. I would think the charts would be within a few hundred rpm. They would be off by 700 rpm, even if I had the black bushing installed. If I do have the silver bushing, my advance should be closer to 25 additional degrees, but I am only at 18.5.

 

[CGT80]

It looks like the local auto stores don't carry timing tape (according to their web sites). I could order some from summit racing.

I am going to pickup a different timing light tomorrow morning. My uncle owns a shop and bought a new blue point light a few weeks ago. He said it will run fixed or adjustable.

 

[CGT80]

I don't have timing tape, but I do have a measuring tape and calculator.

My balancer is 25 3/16" in circumference
25.1875/360=0.0699" of circumference per degree.
2.25" x 0.0699=32.18 degrees

I put a piece of white electrical tape on the balancer with a black mark at 2.25"
I set my dial back light to 0 degrees.
The distributor stopped advancing at 2400 rpm
My black mark on the tape was at 2 degrees btdc on the scale on the timing cover. This puts the total timing at 30.18 degrees advanced. My previous reading with the dial back was 30 degrees at 2500.
This light seems consistent.
It is still possible it is wrong.

I will try the other light tomorrow.

One other thing while I am at it. Lately, when I turn the ignition on, the tach (Autometer procomp ultra light) needle will jump around sparatically. It doesn't happen all the time. I can also hear a sparking sound from the ignition. When I had the cap off, I saw that there was arcing next to one of the terminals (inside the cap) for the spark plug wires. The cap and rotor are MSD that I bought from auto zone. What is the difference between msd 84023 (this had parts 84111, 84101, 84022) and 8416? 84023 matches the part numbers for my distributor, but I don't know what part numbers 8416 includes. I don't remember if I have the low or high resistance button under the coil. Any thoughts?

 

[4X4HIGH]

I installed the two heavy silver springs yesterday. I had one heavy silver and one light blue. I still have two light weight silver springs in my bag of parts. The heavy springs were tight enough that I had to use needle nose pliers to get them installed all the way. The light springs I can put on by hand.

I use a craftsman adjustable light-dial on back. I don't have a standard light.

With the dial on 0, I get 11.5 initial on the scale over the balancer
with the dial on 18.5 at 2500 rpm, the mark is back at 11.5 over the balancer
with the dial at 30 at 2500 rpm, the mark is at 0 over the balancer.

I tried a different light, I think it was a digital snap on, a while back. I don't recall what happened though.

Why is an adjustable light bad? I don't have tape on the balancer right now to read it that way, but I could try and find some.

Throw that light away as fast as you can. I used to own one many years ago until I finally figured out that the damn thing was inaccurate as all hell. I finally bought a Mac digital advance light and haven't looked back since.

 

[CGT80]

I just checked my timing with a new blue point timing light. I got the same results. Looks like something must be off with the internals of the distributor. I'll wait for Phil to get back to me, and when I get the new parts from MSD, I'll try those out.

 

[CGT80]

I got a package from MSD today. Not only did they send me new weights, but the distributor shaft is also included. This will eliminate possibilities of my old shaft having something wrong with it, and messing up my tuning.

+1 for MSD. They got the parts to me quick and didn't charge me for it. Now, if it works like it is supposed to, it will all be good.

 

[Philly87]

Glad you got the parts Chris. Let me know what you find when you take the distributor apart. If there is still a problem after this I'd probably like to see the distributor here so we can see what's going on.

 

[4X4HIGH]

Here is Phil handling business again as usual.

 

[CGT80]

OK guys. I have to hand it to Ford.................the one thing they got right was putting the distributor on the front of the engine where you can get to the damn thing.

I put the new shaft in the distributor. That was the easy part. When I dropped it back in the engine, it must have been off a tooth. My timing was of by 50 degrees. I pulled it back out and then lost track of where I was.

I pulled plug one and bumped the starter with my remote. I let go as soon as the compression pushed my finger off the hole. My timing mark lined up to zero and the rotor was in the same general area I had it set to before. Only problem is I was off a tooth this time too. After much fustration I finally got it (I think). I also changed the position of the number one wire on my cap. I had it on the back right, or 1 oclock position as you look at the front of the engine. I moved it to 5 oclock, front right. I found a diagram on the net that showed this order for 84-86 HEI. Firing order 1-8-4-3-6-5-7-2. Mine is a 79, so it might be the same. The wires fit a little better now.

I got it fired up and set my initial to 8 degrees advanced (for smog). Boy that cam (Duration 270/270, Lift .470/.470 in a 10:1 406) doesn't seem to like that little advance. You can really hear an unevenness to the idle. It doesn't rev as quick as when I was running 12 degrees initial either.

I checked my centrifugal advance with the vac can unhooked. I got 22 degrees of centrifugal at 2700 rpm and a total of 30 degrees. When I bump it back to 12 initial I should get the 34 degrees that i was shooting for. The rpm is dead on to MSD's charts and the advance is within 1 degree. I can slow down the curve a lot more if needed. Right now my Vac advance is set to 16 degrees for a total of 46 combined at 2700. I can reduce that with the MSD vac adv stop if needed.

I don't know what the heck was going on with the old weights, springs, or shaft, but MSD finally got me in business. Third time is a charm. Thanks for your help Phill.

One last thing I noticed was that my timing mark would sometimes hop up by 6-8 degrees in the advanced direction. From 0 it would flash to 8. I don't know if it is due to arcing in the cap or if the light had something to do with it. I used my craftsman and my uncles blue point. I also tried using cylinder 6, and got similar results. I didn't have this problem before I changed the shaft, with these two light. I'll recheck it tomorrow. For now I am glad to just get the advance working right.

 

[4X4HIGH]

I got it fired up and set my initial to 8 degrees advanced (for smog). Boy that cam (Duration 270/270, Lift .470/.470 in a 10:1 406) doesn't seem to like that little advance. You can really hear an unevenness to the idle. It doesn't rev as quick as when I was running 12 degrees initial either.
I checked my centrifugal advance with the vac can unhooked. I got 22 degrees of centrifugal at 2700 rpm and a total of 30 degrees. When I bump it back to 12 initial I should get the 34 degrees that i was shooting for. The rpm is dead on to MSD's charts and the advance is within 1 degree. I can slow down the curve a lot more if needed. Right now my Vac advance is set to 16 degrees for a total of 46 combined at 2700. I can reduce that with the MSD vac adv stop if needed.

I don't know what the heck was going on with the old weights, springs, or shaft, but MSD finally got me in business. Third time is a charm. Thanks for your help Phill.

One last thing I noticed was that my timing mark would sometimes hop up by 6-8 degrees in the advanced direction. From 0 it would flash to 8. I don't know if it is due to arcing in the cap or if the light had something to do with it. I used my craftsman and my uncles blue point. I also tried using cylinder 6, and got similar results. I didn't have this problem before I changed the shaft, with these two light. I'll recheck it tomorrow. For now I am glad to just get the advance working right.

Houston we have a problem, if you set the initial at 8* and then you have 22* centrifugal and 16* vacuum that means you now have 46* of total timing, waay too much. You want between 32-36* total.