"3)This type of cooler does give a restriction to flow/pressure Vs oil/air type 4)Never hear of many non SVT's with oil pressure probs...just food for thought..."
OK Terry, you are giving me a headache.

The oil cooler has been mentioned before as a possiblity because it "holds" a bit of oil - less available to sump? Is this "restriction" a real concern of yours or more hypothetical? Can you test this by measuring oil pressure before & after cooler? The "doughnut" cooler is a Mondeo part as I understand, do Mondeo V6s have more oil related failures? But if its a problem its easy enough to remove.....
The other unique thing about SVTs is that they rev better (light flywheel), and as they make power to redine (better breathing), probably spend more time at higher RPMs. This may have implications on both the oil situation (increased pooling in the heads?) and on the crank harmonics. How many failures are crank whip related and how many are oil starvation??
