Heat Synch info

Looked and could not find a good answer.

Why is the control module screwed down to the top plate?
I mean why does it have to be screwed down to it and use the heat synch grease to insulate it?

Can't it be raised off the flat surface with some spacers to keep the heat from transferring and making it so hot? I saw someone had raised theirs up?

I did it to mine today just to check and see if the skip might have been because of an overheating module. NOPE still skipping.
I will tell you that Heat Synch grease was HOT HOT HOT! Burn your finger tips HOT!

Drove it to the hardware store, bought 8 washers(8mm Stainless), stacked 2 high under all 4 corners to raise the module off the flat plate of the mount.
Started and ran no problem, just asking the Pro's and Con's

The white grease is for heat transfer not insulation. Do Not lift the module off of the mount or eliminate the grease or it will eventually overheat and fail. I think it also provides an electrical ground connection as well. It is designed to operate at a specific temperature which is maintained by firmly mounting it to the base. It may seem to be too hot but it is within the operating parameters of the module. If it is heat sensitive now it is probably in the process of failing. I work with these types of electronic modules all day long and replace heat sensitive parts all the time.

If you're going to "fix" the problem, one way is to buy a regular heat sink(s) from an electronics store and use some ingenuity to mount it to the back of the DIS. I'm sure it would remove more heat than.. lets get this.. a cast block of aluminum designed to hold an AC compressor.

However, having said all that, the stock setup seems to be sufficient as is. I have what amounts to the OEM units in my drivers forever in Texas heat with no problems.. Not entirely true as I had 1 fail after 200,000 miles or so.

Help me with clearing this up...
Mounting the module on the top plate is to transfer heat IN to the module and keep it HOT, not help transfer heat OUT to keep it COOL?

How does the module fail then?
have read modules have overheated and failed, haven't heard one failing because it was too cold.

This is what I use and have not had a failure since using it.

http://www.radioshack.com/product/index.jsp?productId=15438946

Had a bucket of DIS and took them in to the local autozone and had them tested. Everyone failed. So, I bought a new one and had them test it. It did pass, so the machine wasn't rigged.

The air cannont get rid of the heat those put out. The synch is needed to keep the electronics within their operating temp.

Take the DIS in and have it tested. It's free and then a person knows instead of guessing what the solution is.

Regul8r said:

Help me with clearing this up...
Mounting the module on the top plate is to transfer heat IN to the module and keep it HOT, not help transfer heat OUT to keep it COOL?

How does the module fail then?
have read modules have overheated and failed, haven't heard one failing because it was too cold.

Click to expand...

No actually even with the thing in the engine compartment with the engine running, heat is still pulled from the DIS. Mounting it to an actual heat sink, like you'd see on a computer board but bigger, could only help.

Regul8r said:

Help me with clearing this up...
Mounting the module on the top plate is to transfer heat IN to the module and keep it HOT, not help transfer heat OUT to keep it COOL?

Click to expand...

Heat goes from the hotter point to the cooler point.

Strange as it sounds, the DIS gets HOTTER than the engine bracket normally ...

The heat SINK (not SYNC, and sure not "synch") compound is to help transfer the heat better than the air gap would.

If you want to improve cooling, find a bigger heat sink, or one with more cool air blowing over it, and move the DIS module there.

There's a reason why the spark controller for the dizzy'ed motors was moved to in front of the airbox from the older (pre-MN12) location on the distributor ...

And why it's on a big heat sink still!

RwP

Good info.

as a caveat(sp?) I have the radio Shack Heat sink on it and when the engine is hot that stuff is like frying oil hot! the damn stuff burned the tip of my finger!

Will pick up another tube and get it re-installed down on to the bracket.

Thanks for the info.

Just remember - heat sink compound doesn't transfer heat as well as metal does - you want as thin a layer as will completely fill the gap.

Also, it doesn't hurt to clean the two sides of the interface (the DIS and the heat sink both in this case), to keep the gap as small as possible.

RwP

RalphP said:

Just remember - heat sink compound doesn't transfer heat as well as metal does - you want as thin a layer as will completely fill the gap.

Also, it doesn't hurt to clean the two sides of the interface (the DIS and the heat sink both in this case), to keep the gap as small as possible.

RwP

Click to expand...

YUP, did it last time, will do it again.