The new engine I have has a stripped exhaust manifold bolt hole. I need to order a helicoil kit. I assumed it was M8 as the Land Rover Classic Parts website shows M8 (part number ERR4961) and I used M8 in my car when I did the head gaskets a few years ago.
However, the bolts in the engine I've had delivered this week are measuring roughly 9.5mm in diameter which I make to be 3/8UNC.
The part number on the side of the block doesn't match any of the part numbers given on the Classic Parts website either. The engine is stamped with HRC2411.
Annoyingly, Googling that shows a number of forum threads referencing this part number going back as far as Discovery 1 and 2 as a 3.9/4.0. There's one or two references to this block number in a P38 but as a 4.0. No confirmation of it being a 4.6.
The engine number starts with 60D which I think means it's supposed to be a 4.6 Thor, right? Is there anyway to confirm beyond the engine number that it's a 4.6? The intake system is the Thor set up.
Something feels a bit off as the manifold bolts seem to be the wrong thread. Despite what Land Rover say the bolts should be, the guy that sold me the engine was adamant that they're 3/8UNC when I was discussing the stripped thread with him. Seems odd that he'd be right about this specific engine if Land Rover says it should M8 and my own engine used M8.
I'm a little concerned that it's an older 4.0 engine that's been converted to be a Thor and had the engine number buggered about with at some point by the previous owner of the car it came out of.