Duplicate post.

 

So far so good. I installed mine at the front near the battery.

Looking at your distributor and ICM made me ponder this entire issue of ICMs failing due to heat. When I installed my replacement distributor I followed standard procedure. I installed the new distributor in the same position and set the timing. This ended up with the ICM rotated much nearer to the engine, and thus heat, as it always has been, such that it is impossible to access the retaining screws to remove/install the ICM without removing the distributor.

Now someone correct me if I'm wrong. I understand the distributor sleeve (hexagonal female end) engages with the oil pump shaft (hexagonal male end). Thus the distributor can be installed with the icm pointing at 1 of 6 different angles, probably 3 practically speaking. It can be rotated anti-clockwise before install 30, 60, 90 degrees etc. So a distributor that is installed with the ICM too close to the engine can be removed, rotated 30 or 60 degrees etc. and re-installed, so long as the rotor and cap relative positions stay as originally installed still firing correctly. In other words remove the distributor & rotate the entire distributor counter clockwise (shaft and cap together keeping their same relative positions) 30 or 60 degrees and re-install. Set timing. Reduces heat and provides easy access to the ICM.

Am I correct and could this be the cause of the failures or am I having a senior moment?

Example ARP Oil Pump Shaft 351W

 

The Distributor, ICM and ECM literally do *not* care what orientation the distributor is in, as long as the spark plug wires match the firing order, and match up to where the rotor is. It is *customary* to install the distributor with the #1 distributor terminal, pointing at the #1 cylinder, but there's absolutely no technical reason that you have to do it that way.

There are some odd-fire engines (this isn't one of them) where physical distributor clocking makes a difference, but those are *very* much the exception.

 

my understanding is that its because the icm is on the dizzy and the dizzy is attached to the engine thus a lot of the heat from the engine goes to the icm and cause failure. Not to mention there isn't a lot of air circulation in that area. around 257F is failure point for the icm from what I have read.
I am thinking about getting a thermal gun to measure the area that the dizzy is located.

 

Yes. But surely if the ICM is 1/2" from the engine parallel to it, versus 90 degrees to it, the heat would be much less.

 

Precisely. On my truck (351W), #1 terminal is pointing more toward #7 cylinder. If I re-install the distributor 90 degrees anticlockwise it will probably point toward #3, but the ICM (now a connector not an ICM as I now have a remote mounted one), would be 90 degrees to the motor, accessible, and much further away from the engine surface with more air circulation.

 

My new dizzy and icm from about 11k miles ago. The icm failed recently. I could be wrong in that most of the heat is coming from the dizzy. If you touch the metal part of the distributor after a good drive its really hot. It burned my skin. I live in South Carolina so that doesn't help at all. The icm that failed was the standard brand icm 5 year 50k warranty. It lasted a little over a year.
I could be wrong.

@Gee150 Did you put any no-ox-id paste on the dummy icm 3 contact points that go into the distributor?

 

Neighbor, I also live in SC so I know exactly what you mean. I hear what you say about the dizzy heat. I always assumed (bad word) that if you had thermal paste on the ICM and it died it was because of heat in the engine bay but based on what you say that's not the case. My connector is EXTREMELY close to the engine. I did not put no-ox-id paste on the dummy icm 3 contact points. Did I miss that? I believe I put regular dielectric on them.

After I do my new radiator install (just received it) I am going to re-install the distributor so I can get to that ICM connector easily, so I? re-visit that.

 

No I don't think you missed it. I didn't see anything on the new icm 3 contact points when I took it off. So I just left it the same.
I read and if it is true that its not good to use dialectic grease on the actual contact pin or a electrical connections. Something about it being silicon based.

 

This is the standard image of the 351W firing order. My cap is precisely like this. It puts the ICM pointing in the direction #7 on the cap to maybe 5 or between 5 & 6. Pointing almost parallel to the motor. That puts the ICM quite close to the motor. If I re-install the distributor rotated 60 degrees that should put the ICM connector facing more like #6 to #4 in the image - i.e 90 degrees to the motor, unless there are cabling or other impediments.




My remote mounted ICM

 

Did you put THERMAL PASTE between the ICM, and the distributor mounting pad? That is the most common mistake, and what kills ICM's more than any other reason. Most of the schmoo that comes in the boxes, or is put in there by rebuilders like cardone (if you're buying a drop in unit, with the ICM already installed on the distributor) aren't supplied with, or assembled with proper thermal paste. I've had 302 and 351W trucks go well over 100K without eating an ICM in the past, *maybe* I got lucky and got super duper modules, but I'm going to go out on a limb and say it was more due to using the right schmoo when mounting them.

 

The new-ish icm had what looked like dialectic grease on the heatsink part. I noticed this when I moved it with the relocation kit. So that's a big fat NO lol. The shop that did my dizzy and icm along with 2nd icm "warranty replacement" didn't add thermal grease. I have some NT-H1 thermal paste that I will use at a later date. As I am sure the dummy icm is fine without thermal paste.

 

Yeah, the dummy is just fine. Just make sure you've got actual thermal paste between the module and remote heatsink now =P It's less critical, but it will make the heatsink more effective.