Here is a diagram of the various turbo, inter-cooler & oil cooler on a secondary cooling circuit:

http://i1311.photobucket.com/albums/...psa3mmvkh3.png

CAD file
 

Do you guys happen to have a CAD file for how you are going to have yours cut from? I am rebuilding my D24T, out of my Pinzgauer, now and also noticed how restrictive those holes really are...

Thanks,
Phil

Do you notice cooler head temperatures with this gasket?

While it is running, I haven't run it hard - I am upgrading the turbo. Once that is done I will thrash it and see what happens.
If it runs a lot cooler, I won't know which of the following mods contributed how much:
-Porting the head gasket
-removing the thermostat and using Evan's waterless coolant.
-Fixing an auxiliary coolant pump.
-Adding a much larger oil cooler - taking the old one off the engine cooling circuit.
-The fluid/air intercooler, turbo water and the oil cooler are on a secondary cooling circuit I built with a fan/radiator at the back of the truck.
-Larger turbo (GT-3076R) should lower EGTs.

As for a CAD file, I don't think I should share. Two reasons:
1. I have a slightly different block in my Pinzgauer than what is in a Volvo. Pinz guys I will share, but is at your own risk - and I could even do them and then sell you the thing. If I did a few the cost would go down.
2. What if my new head and block are not the same for porting the head gasket?

I could easily see someone wasting $100 on an MLS gasket, $100 for water-jet cutting and then have it not work - so you have a huge amount of labor to go back and fix it.
I suggest you look at my very first post on this thread and find a way to do what I did for your setup - then you know it will work.

Will there be any issues with no tstat top hat to block off the coolant bypass path when warmed up to operating temp.?

I would expect so, and advocate a pinned open thermostat instead.

I also noticed on changing the water pump on a late D24TIC that the water pump pulley had a smaller gear for faster rotation.

Don't do this. Srsly.

The coolant flow through the engine starts with the WP shoving cold coolant in the front of the block. Coolant moves to the rear of the block, circulating around all cylinders. At the rear of the block, coolant moves upward through large openings in the HG. It then flows forward through the cylinder head. exiting out the front side of the head to go to radiator.

If the t-stat is left out, then some of the coolant will flow through the bypass circuit, instead of the radiator.

If the HG is opened up everywhere, then the coolant will take the path of least resistance, coming in the block at the WP and going straight up to exit out the side of the head. Coolant will not be forced to circulate to the rear of the head or block. The coolant gage will not get hot because the coolant is not pulling waste heat out the back cylinders. BTW, the tiny holes in a HG are called steam holes, because they are supposed to allow air bubbles out of the block to prevent small air pockets from turning into large steam pockets. They are not for coolant circulation.

HTH

Very true.. But there is only steam holes on the injection pump side, the manifold side of the head gasket is for coolant flow, notice the picture of the head gasket, the coolant passages on the manifold side get larger from cylinders 1 to 6.

Sorry for hijacking this thread but since you have a gasket to look at can you tell me where the oil ports are in the cylinder head? I have a D24T fitted to my boat and there is an oil leak from the front of the head behind the timing back plate, there is no sign of oil looking from the top but you can see it running down below the water pump. I have replaced the valve cover gasket so I am pretty sure it isn't the valve cover.
I once had a Ford Sierra which leaked at the front of the gasket at the oilway for a bit, then blew out suddenly, so I am wary of oil leaks.

I believe it is the only tear-drop shaped hole (near the middle). This is oil pressure, return.... I would have to look at a block to determine.

Spenser