well i wish i would of read this before ive got said feed but about 3 months ago i was on the motorway sat at about 75_80 in my gt6 mk2 with an engine which had done only 3000 miles and al lof a sudden burning smell ,then knocking its brains out , then the temp went up to 100+ so slowed right down to 50 the temp went down to normal, turned off at the services lifted the bonnet couldnt see any thing wrong so thought damage is done and went on my to newbury plenty of power but knocking its nuts off any way when i got there had a closer look and the block had burned by number 2 cam bearing, so had a machanic look at it he said its terminal so i had it towed back to cardiff. i then stripped the engine down to find one cam bearing compleitly obliterated, cam was stuck in the block 2 tappets stuck (thay did go up and down but were stuck in the block) one piston compleitly wrecked one big end and two mains down to the copper and well let say thay looked like corse sandpaper one cylinder was blue where it got so hot, and the oil was burned and black as can be. my oil pressure has olways bee great and even this happened it stayed good. i always had some blue smoke on start up and was told its fine (bronze guides with oil seals on the inlets from chris witor very expensive but none on the exhaust as you dont need them) i think this explains the culprit being the external oil feed to the head !!! THIS ENGINE WAS ROLLING ROADED AND PRODUCED 139.9 BHP. i have just finnished rebuilding another engine 2.5 spec , and have re fitted the oil feed today ,i most surtainly am going to take it off tomommrow after reading whats been said in this post by some members. I think the saying IF ONLY ID KNOWN THAT BEFORE. i hope this post gets read as i really do feal that it was the external oil feed is what caused this problem PS the engine had a full service to day before i left for Newbury i traveled about 70 miles into my trip. Cheers all Mike