M20 twin turbo cracking heads. Please help

[TobyB]

Have you checked the basics- fuel pressure, injectors all flowing correctly, coolant bled, etc?

I know it's frustrating, but something as simple as a bit of junk in one of the injectors will make that cylinder
run lean, and at boost, >pop<

t

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Some specs as well:
M20B28 Fully rebuilt (m52b28 crank, 130mm rods, m20b25 low comp pistons skimmed)
M21 Oil Pump
M52 Oil spray nozzles installed on the engine block.
Head is (was) stock with CatCams Springs, Vac Motorsport spring retainers, custom stainless steel rockers and CatCams Turbo camshaft (270/249)
Nuke Performance adjustable cam pulley
Turbos are 2xTD05-16G off RB26DETT
Custom Exhaust manifolds with individual external wastegates (Chineese Tial replicas)
Mitsubishi Evo intercooler and 63/76mm turbo piping.
76mm stainless steel exhaust
660cc fuel injectors Siemens Deka
Individual coils from M50 with custom ignition leads
MS2 Extra with wideband 02 sensor for real time corrections.
6 plate ceramic clutch with hevy duty pressure plate

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Thanks, it drives awesome as well (for the short distance I drove it), but I dont want to install another head before I figure this out

[gath]

Wow! I don't have an answer, but it looks very impressive. ;D

[zoomer]

I've been struggling with a very strange issue.
Let me begin a little bit further:
M20B25, stroked to B28 fully rebuilt, with stock internals and Catcams turbo camshaft. I've been driving it for 3-4k km NA without any problems.
Than we built a twin turbo setup and than the issues started:
During the initial tune up of the car (running at arround 0.6-7bar) on the highway the head cracked (I saw that there was water in the oil). The car was running stable 80 degrees.
Initially I thought that I pulled the short straw with the current head and it was defective, so I got a replacement head, and installed some upgrades (catcams valve springs, vac motorsport valve retainers, custom made stainless steel cam followers). I also poured some Motul racing coolant to avoid the normal coolant boiling at low temp. Also installed ARP Head studs.
To my surprise 20km after the car was read - there was coolant in the oil once again. Both heads were pressure checked, skimmed and fully rebuilt before they were installed.
Since I checked the first head and it turned out that it was cracked, I am fairly certain that this one is cracked as well (havent removed it yet as its quite a pain in the ass to remove the turbos)
I really dont believe that I got a defective head twice in a row. And I am really lost why this is happening.
There is one theory I have - the turbos have water cooling as well, and I am using the line for the Throttle Body warming, from the thermostat the water goes into one of the turbos, than to the other one and than to the engine block. The only thing I can think of is that the water/coolant is very hot when it goes into the engine. As a result one end of the engine/head is getting much hotter that the other and than the head wraps and it cracks.
If anyone has any other ideas/advises I would appreciate it greatly.
Some pics:









And the old(cracked) head