I rebuilt a 302 for my cobra and fitted it just before xmas. It ran beautifully 'till 300 miles when I noticed a knock at start up that went away when hot. by 400 miles, it was knocking even when stinking hot. I pulled the car off the road and dropped the sump, thinking it may be a big end. They were in perfect condition, but I replaced them anyway. Started it up and it still knocked!! tore it down (still in the car)and fitted a new cam and lifters. Started it, it still knocks!!!
What the hell is it??? It was rebored, crank reground, new pistons rings, no mechanical fuel pump. The sound doesn't go away when any of the leads are taken off, it doesn't sound like the mains (they'd rumble rather than knock..right?)
At the moment the only thing I can think of is piston/wrist pin problems, that means the whole thing'll have to come out and be sorted, but before I do, does anyone have any other ideas? I'm using a 15w40 oil surely that wouldn't cause any harm?
Any advice appreciated.
Thanks guys
Simon