IDIBRONCO
IDIBRONCO
I have no pictures because I did this to mine a couple of months ago. This is also only my experience and I've only done this once. Explanation: this mod doesn't actually increase the cooling of a 7.3 engine. This is a preventative procedure. With the 6.9 block and heads, as you're looking at the mating surface (the deck on the block and the bottom of the heads) from the side of the engine as if it's out of the truck on a stand, at the bottom front and rear of the surface, there is a coolant port that has been blocked off on the 7.3. The 6.9 head gaskets have a roughly triangle shaped insert that you have to put in place in these locations. The insert appears, to me, to be made of thin steel with a rubber coating over it. there is a small hole in the insert that allows some coolant to flow through the insert. The reason for the blocked off ports on the 7.3 seems to be for emissions purposes (that's the best guess of several knowledgeable members on here). This causes some heat to be held in these spots on the 7.3. My opinion is that this is also the cause of the "chuffing" with the 7.3 exhaust valves. They aren't cooled as well and tend to wear out faster than those on the 6.9s. Under normal, unloaded, operation, this is not a problem, unless it actually does contribute to the accelerated exhaust valve guide wear. When these blocked off ports become a problem is when you are putting a lot of heat into the cooling system. My example would be when you're towing heavy in the summertime while running the A/C, while your turbo is also boosting high and putting that much more heat into the cooling system. What happens under this type of situation is that your coolant can actually start to boil inside your engine. Steam has more pressure than hot coolant does and this can cause your heads to lift slightly off of the block. just a few thousandths of an inch isn't much, but it's enough for the steam inside your engine to escape to the outside, causing your head gasket to "blow". By removing the plugs in the 7.3 block and heads and then using 6.9 head gaskets, you get the same coolant flow as the 6.9 does thus greatly reducing, if not completely eliminating, the head lift problem. I thought about using 7.3 head gaskets until I realized that the 6.9 inserts appear to be steel with a rubber coating. 7.3 head gaskets may work if you make holes for your coolant to flow through them, but I wouldn't recommend it. I figure there was a reason for International to use the inserts instead of making holes in the gaskets. Now for my experience doing this. I tried drilling a 1/4" hole in one of my block plugs. It didn't work very well because the plug seemed to be very hard (I'm thinking stainless steel like the core plugs in the outside of our blocks). I then tried to punch a divot in the plug with a center punch and the I punched whole plug through the hole in the block into the cooling jackets. Then I took a small chisel and carefully punched it into the outside edge of the next plug. By doing this, the plug actually rotated in the hole and was sticking up sideways. I could then take a pair of Vise Grips and carefully, with a rag underneath them for a cushion, clamp them onto the lip of the plug and lever it up, out of the hole. This was MUCH faster than trying to drill a hole in the rest of the plugs. The plugs in the heads came out the same way. As an added bonus, at the time I ordered, I bought 6.9 head gaskets for about 1/2 the price of 7.3 head gaskets and they were all Fel-Pro which are .010 thicker than Victor Reinz. I'm sorry that this was so long. I tried to be very detailed for new members who don't know a lot about their engines yet. This was my experience. I'd like to hear opinions
and other experiences. I did this because Thewespaul asked for it and others ask for it too.
and other experiences. I did this because Thewespaul asked for it and others ask for it too.
