Oil drain hole timing side crankcase

Can any one tell me what size to drill the oil drain hole going through the timing side crankcase. The hole is located to the lower left of the oil pump. I have put a pilot through of 1/8th but looks a bit small?

Thanks

Nigeldtr said:

Can any one tell me what size to drill the oil drain hole going through the timing side crankcase. The hole is located to the lower left of the oil pump. I have put a pilot through of 1/8th but looks a bit small?

Thanks

Click to expand...

1/4 inch. Jim

Thanks for the quick reply, I can go and finish off now

I am thinking of doing this mod and drilling the oil drain hole , as I have just replaced/upgraded my oil pump so I have my timing cover off already.
So I am wanting to know if this is wise drilling while the cases are together, as I am a bit sceptical about drilling into something blind or leaving Ali filings behind.
I have the early c'do with the large sump so I was thinking to flush any leftovers thru and set up my Vacume cleaner at the cutting point.

Should be sweet ??

cheers
8)

I think someone mentioned the idea of bunging up the breather holes and putting a bit of positive pressure into the crankcases to "blow" the swarf out once you break through the casing on the crank side. Provided you break through slowly and keep withdrawing the drill bit to keep it as free from swarf as possible, should work. A good flush through once vacuumed out should hopefully get anything else. However, you probably will have some bits of swarf in the engine unavoidable, but should be picked up on the sump filter. My cases were split and I could do it on bench drill but was surprised how thick the crankcase is, you have to drill a long way!

PS I tapped the hole at the timing cover end ready for a grub screw plug in case I change my mind