Mystery hole in block

[TonyWylde]

Hi everyone. I'm rebuilding my twin cam after a 20 year layup. I've come across an unexplained hole in the front of the engine block. I haven't removed anything from this hole and I'm at a loss to see what it's for. It will be blanked off by the backplate of the chain case with only a paper gasket holding back whatever will be trying to get out. I can't see it being watertight. Should this have a plug of some sort?
Thanks in advance for any help.
Tony.

[promotor]

Hi everyone. I'm rebuilding my twin cam after a 20 year layup. I've come across an unexplained hole in the front of the engine block. I haven't removed anything from this hole and I'm at a loss to see what it's for. It will be blanked off by the backplate of the chain case with only a paper gasket holding back whatever will be trying to get out. I can't see it being watertight. Should this have a plug of some sort?
Thanks in advance for any help.
Tony.

No need to worry - it never had a plug in any fitment - it is a vestige from when the engine blocks were used in pre xflow engines. Ford didn't bother changing anything as they didn't need to.
It was used with tappets in the block for the pre xflow engine with a single camshaft where the jackshaft of the T/C sits - it is just an oil drain back hole that doesn't do anything in the Lotus Twincam. It's not under oil pressure so nothing to worry about.
It is also present in the crossflow engines.

[TonyWylde]

Thanks for that. I couldn't find any reference to it in the Lotus manual, Miles Wilkins book or this forum. People like yourself are an absolute godsend to people like me. I can tell this forum is going to be priceless as I get deeper into my +2 restoration.
Thanks again.

[The Veg]

Welcome Tony!

Agreed, the work I've done with my Lotus would have been impossible without all the helpful guidance and expertise in this forum! I owe pints to so many of this lot!