The Real Bev > wrote:
>On 07/09/2020 12:30 PM, Steve W. wrote:
>> Yep, pretty much every engine still has core plugs in the block and
>> head(s). The only easy way to get the sand out of the water jacket
>> areas. The ones that don't have them are normally engines that use wet
>> sleeves like diesels and large engines that have hatches into the block.
>
>For extremely difficult and time-consuming values of 'easy'. Where does
>the sand come from and what does it do? We've been driving old cars
>(1968-70) for a long time and if we have sand we sure don't know it!

The block is sandcast, then some stuff on it is precision machined. It is
not just machined out of a solid billet. When you pop off the head cover,
you can see the rough surfaces that result from unfinished sand casting.

And when you sandcast, you have to get all the sand out because it is
abrasive. Even with pretty aggressive removal, there's usually still some
left that comes out during the break-in process.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."