When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
When I bought the car I saw it there and really didnt think nothing of it. I knew what it looked like but it didnt grab my attention that it was the ICM, and one of the po's had moved it from the block to the rad mounting frame. I guess they did it to keep it cooler ? I would assume moving it there is a cooler location.
When I bought the car I saw it there and really didnt think nothing of it. I knew what it looked like but it didnt grab my attention that it was the ICM, and one of the po's had moved it from the block to the rad mounting frame. I guess they did it to keep it cooler ? I would assume moving it there is a cooler location.
That does not look like a good location unless the fan shroud is metal.
The ICM needs to mount to a metal surface (with heat sink compound between the ICM and metal surface) to dissipate the heat otherwise it will fail.
That does not look like a good location unless the fan shroud is metal.
The ICM needs to mount to a metal surface (with heat sink compound between the ICM and metal surface) to dissipate the heat otherwise it will fail.
Well I do not know when it was installed, nor how many miles was put on it before I bought it. I have had it for 5 months/4,000 miles and all is well. I am going to leave it there and see what happens I will check back in on this thread when I hit 10,000 miles or if it goes bad before then.
That does not look like a good location unless the fan shroud is metal.
The ICM needs to mount to a metal surface (with heat sink compound between the ICM and metal surface) to dissipate the heat otherwise it will fail.
Not sure about that. Mounting it to a hot engine doesn't make much sense.
That finned aluminum plate under the ICM is the heat sink, no?
This could be an excellent idea. I would like to see surface temps in both locations from a FLIR or a laser thermometer after a ten mile run.
It can't possibly be worse than having it attached to the engine. Anything attached to the engine after running is pretty hot to the touch (duh). If the heatsink is taking on the heat of the engine it can't effectively do it's job. The heatsink does not need to be attached to a metal surface, it can do the work of heat dissipation on its own. Processors in computers are attached to a heatsink and no other metal.
It can't possibly be worse than having it attached to the engine. Anything attached to the engine after running is pretty hot to the touch (duh). If the heatsink is taking on the heat of the engine it can't effectively do it's job. The heatsink does not need to be attached to a metal surface, it can do the work of heat dissipation on its own. Processors in computers are attached to a heatsink and no other metal.
You're underestimating the heat that the icm maoes, and overestimating the cooling capacity of that heatsink.
The headhead is warm, but it is MUCH larger than the small aluminum heatsink and the icm. The icm creates more heat than the heatsink and itself can dissipate, and so bolting it ti the head allows for it use the thermal capacity the head offers. While the head may be warm, it has the thermal capacity and cooling to dissipate the heat the icm unit can't.
In short, the icm won't overheat the head. It will overheat itself. The head keeps the icm cool relative to what it would be without it.
Sorry to bring up the"F" word but Ford did something similar with their tfic (ignition) modules that they mounted to distributors. They also used heat sink grease with the modules.They moved them, to the radiator support, behind the grill, so they had plenty of air movement across the module. It did help drop the failures. It will be interesting to see how this works out.
Not a bad idea! But I think mounting it with a larger piece of aluminum plate behind it (with thermal grease between) would help that heat sink perform better.
older Buick with points, when they mod them to HEI, they mount it right in the open so the air from the fan cools it [ Buick's have front mounted dizzy, not rear ]
Why many run external coil on a stock HEI engine, to remove all the heat from inside the cap, and the spinning parts keep it cool.
The internal transistor junction temp is still a lot hotter than the exterior of the front of the cylinder head so it DOES cool it self mounted to the engine. If you want to keep it mounted remotely, find a piece of steel like the cross bar frame down by the steering rack or somewhere near the suspension a-arm. it needs a mass of conductive metal to draw heat away from it. Use that white thermal heat transfer paste on it too.
It has nothing to do with temps or engineering, it has everything to do with $$$; GM believed the engine should leave the engine plant as a complete assembly to reduce installation time at the vehicle assembly plant; see "101 Projects for Your Corvette" at page 52.
p.s., engineer's license exam question: What reduces life of electronic and electrical components? answer: heat and vibration. Guess GM engineers went to a different engineering school than I did.
Last edited by mtwoolford; 04-13-2017 at 11:32 AM.
The internal transistor junction temp is still a lot hotter than the exterior of the front of the cylinder head so it DOES cool it self mounted to the engine. If you want to keep it mounted remotely, find a piece of steel like the cross bar frame down by the steering rack or somewhere near the suspension a-arm. it needs a mass of conductive metal to draw heat away from it. Use that white thermal heat transfer paste on it too.
As I stated before, do not know when how long or how many miles it has been there, but I have gone 4,000 miles without an issue. So unless I have an issue, I will not be messing with it.
It has nothing to do with temps or engineering, it has everything to do with $$$; GM believed the engine should leave the engine plant as a complete assembly to reduce installation time at the vehicle assembly plant; see "101 Projects for Your Corvette" at page 52.
p.s., engineer's license exam question: What reduces life of electronic and electrical components? answer: heat and vibration. Guess GM engineers went to a different engineering school than I did.
Mr Woolford's correct in GM's thinking. There is a thought to have as much the powertrain as assembly as possible prior to the assembly line. It's about the assembly line not serviceability. The Vortec ICM is on a bracket above intake, the 2.0,2.2, and 2.5 L4 along with the 2.8 and 3.1 V6 mounted the DIS to the sides of the block the LT5 under the intake, packaging. All the while engineers bragging about the remote mounting capability of the new ignition system. Technicians' had a different opinion of that concept.
If the ICM with just the heat sink runs lower peak temperature than the peak head temperature then running the ICM and heatsink off the engine will result in the ICM running lower peak temperatures
If the ICM with just the heat sink runs higher peak temperature than the peak head temperature then running the ICM and heatsink on the engine will result in the ICM running lower peak temperature
If the engineers felt like it had to be on the engine, buy that thermal transfer wasn't important, they could have placed it many other places. It could have been bolted to the intake, or they could have put in the spacers that people seem to like.
IM guessing those are 4in screws run right into the rad that act as a heat transfer rods...
But serious, the problem with waiting till there is a problem. won't be a just move it problem. It will be bad and need replaced, with out knowing for sure if it was heat or just its time. Moving it, it could die in 3 days just cause.
04-10-2017, 05:00 AM
Anyone else on here do this with their ICM
but Ford did something similar with their tfic (ignition) modules that they mounted to distributors. They also used heat sink grease with the modules.They moved them, to the radiator support, behind the grill, so they had plenty of air movement across the module. It did help drop the failures. It will be interesting to see how this works out.
