Engine block - what is this hole for?

[paw140]

I’m getting ready to assemble my engine… just got it back from the machinist, bored 0.040” over. See the hole in the front of the block in the picture, circled in red? I’m assuming that this is an oil gallery drilling? Is there supposed to be a plug? There is no corresponding hole in the back timing cover plate but it would be blocked by the plate and gasket.

Thanks!

Paul

[promotor]

Have a look here :

viewtopic.php?f=39&t=49505&p=359365#p359365

Cheers.

[paw140]

Thanks for the help! I did some searches and didn’t find this. I’m a bit sensitive now because the previous owner forgot to put a plug in the right gallery, leading a massive oil leak.

[promotor]

Thanks for the help! I did some searches and didn’t find this. I’m a bit sensitive now because the previous owner forgot to put a plug in the right gallery, leading a massive oil leak.

No problem - I knew I'd commented on the linked post so it was relatively easy to search my own profile to find it. Doing a search in the search box didn't give the results I was looking for so I can see why you struggled.

The threaded plugs in the cylinder block oil galleries are all NPTF - either 1/8" NPTF or 1/4" NPTF. I doubt you'll be able to get something similar (but incorrect, like BSPT) in USA but here in the UK that problem arises every now and again where some engine parts suppliers don't know that these should be NPTF and not BSP!

Bear in mind the cylinder head is different as that uses BSP for various plugs!