Last week, after7 months of running quite nicely, engine decided to knock for a few seconds on start up. Pulled it out last Wednesday and swapped over cranks with a spare I had, took a while to get the crank to turn, as every time I went to second torque, main or big, the engine locked, checked shells against crank for size, all ok. Built engine up, was tighter than I would of liked. Fitted back, started up nicely, now 70 miles on the same thing. Looks like at some point the blocks been cooked and has twisted 😟 So looks like engine out again in a few weeks and into the machine shop, possibly have top hats at the same time funds allowing ! So much for thinking I might have a quite year, lol, changing front diff and top and bottom ball joints this week, won't be long and bloody thing will have been completely rebuilt .. The joys of P38 ownership,, lol

Hi Chris
Sounds like you know what you're doing on this, but a few questions.<br>
Did you V block and DTI the crank (s) to check that they were straight before fitting? Did you Plastigauge the crank/ mains in the block without rods etc? Did you Plastigauge the rods on the crank on the bench and check rod to rod clearances when assembled?<br>
What were the old shells like when you took them out? Was it one in particular that had failed or were they all worn the same amount?<br>
I'm assuming that everything's getting lubed correctly, although if it went tight on assembly it's not a lube problem.

you name it, I did it, took best part of 12 hours to get the engine as loose as I could, on the first main, 2nd torque, it locked, did the same for every shell, I treble measured the shells, rang engineers who confirmed was a +10 regrind, right shells, but tight as hell, got the mains turning reasonable, it was the con rods that really stiffened it up, I pulled them all out again, did what I could to check there were straight, lightly sanded with 1400. It was a gamble as I knew it was reasonably tight, but funds didn't allow more work at the time. So end of this month out it comes again, me swearing who did these bolts up ? It was me ! Lol, blocks getting machined , I'm letting the engine shop install it this time,crank etc, , I'm getting to old for this, plus bonus of arthritis doesn't help