Originally Posted by 19_Dart_68
Originally Posted by AndyF
I wouldn't worry too much about that but it would make me want to double check the passages that feed oil to the mains from the gallery. The main oil feed passages need to be verified on any race engine since the factory often did a poor job of machining them. They work fine on a 300 hp passenger car but they won't flow enough for a 600 or 700 hp race engine. Some engine builders know to run a reamer thru them, others don't.


I've seen multiple recommendations on the passage enlargement.
What do you recommend as far as sizes of the reamers (1/4" vs. 9/32") and which passages to enlarge? I think Herb McCandless originally said to not touch the #1 main passage....which is why I ask.


I don't enlarge the passages, I just make sure that they are open all the way thru. Sometimes they are stepped down internally or partially blocked. You need extra long reamers for the task which you can buy from McMaster Carr. You need to be super careful when messing around with those passages. If you but a reamer off inside the block then you just created a big paperweight.