Deck water hole plugged
 

Looking at deck of small bore bowtie block and noticed what appears to be silicone in small assuming water holes located just above dial pins at #1,2,7,and 8. I purchased block with most machine work completed. Holes are roughy 1/4" diameter. I ran motor earlier this year but had water in oil and thinking it was head gasket. I don't want to take any chances and eliminate all potential water leaks. Head gaskets and heads have same hole. Why would someone plug holes on block and what if any concerns about leaking?

Re: Deck water hole plugged
 

There's good info of block circulation in the old book, The Chevrolet Racing Engine - Bill Jenkins
Here's a PDF version, check out page 15

https://vdocument.in/reader/full/the...e-bill-jenkins

Re: Deck water hole plugged
 

Good morning Ed,
Check the deck surface to be flat.
Check the deck surface in case it was milled and there's a course surface to seal the head gasket.
What type of head gasket being used - Steel shim or composite ( like Fel Pro ).
Have you had the block pressure checked ? This will determine any cracks that will allow coolant to seep into the oil pan.
Basic stuff, but in case there's something unforeseen, needs to be checked.
If all that checks out, look at Head sealing surfaces and check the intake coolant passages to intake manifold and make sure there isn't any gaps or voids that allow coolant to leak. Make sure the "China Wall" isn't sticking up to far and holding up the manifold from sealing to the heads.
Got to suspect everything now!

Respectfully,
Henry Kunz H/SA 1534