MPJG Fastener Size

[Steve Simmons]

As I recall, the threads on an MPJG are the same "mad metric" as XPAG. 8x1.0mm, etc. Can someone confirm that I'm remembering correctly? I'm away from the engine at the moment and need to order a few things, namely rear bolts.

[frenchblatter]

Steve, as far as I'm aware all MG (and athers) were metric threads with Whitworth spanner sizes. The tooling folowed on from Moriis's purchase of Hotchkiss engines after the first world war (The factory was set up in the uK to keep it away from the Germans)

[Steve Simmons]

Not all M.G. engines were Metric, but I know those around the WWII era were. I just can't remember if there were exceptions in the early 30s. I'm pretty sure the MPJG was though. I'll be able to measure tonight if need be.

[martinjames]

There is quite a mixture of threads on the MPJG. For instance the fan is held on with four 2BA bolts.

[Steve Simmons]

Confirmed, rear bolts are 8mm x 1.0mm

[cdrolshagen]

Hi Martin,
no, the fan is held by 4 bolts M5 x 0,75 mm, a very odd thread,
cheers Carl

[Steve Simmons]

Anyone know the timing cover thread size on MPJG?

[Bill Davis]

Steve,
I’m a little late in finding this but according to a list compiled by Bob Butson the MPJG Timing Cover uses 8 - 1MM 3/4” long bolts. He also gives part numbers from Moss (320-260) and Abingdon Spares (Use 3 - 39).
Cheers,
Bill

[Bill Davis]

Steve,
In another doc I’ve found Bob Butson lists this:
Timing Chain Cover, eleven used:
cover to front mounting plate……...Five used……….M8x1, length 13mm. Bolt 5mm unthreaded. Head size 5/16 BSF.
cover through front mounting plate..Three used……..M8x1, length 15mm. Bolt 5mm unthreaded. Head size 5/16 BSF. (Nuts used)
cover through to block…………….Three used…. … M8x1, length 20mm. Bolt 5mm unthreaded. Head size 5/16 BSF.

I was thinking that they weren’t all the same length, as mentioned earlier, and this confirms.
Bill

[Steve Simmons]

Thanks Bill! I don't know why I was thinking the timing cover bolts were smaller than 8mm.