Here are some picture of your engine taken at the machine shop. Once we started tearing into the engine we found that we will have to turn the crank which means we will have to install over sized bearings when we rebuild. We will also have to bore each cylinder .030 over. The reason for this is due to rust in the cylinder. We also encountered 33 studs that were very difficult to remove leading us to believe that the engine did not have hardened exhaust valves. One valve was so stuck that it broke in three pieces and we had to remove the guide that it should slide through. While the oil pan was in the acid tank being cleaned there was a piece of JB Weld that fell off of the drain plug. We will drill and tap the plug to ensure it will seal properly. The last thing we found was that the we will have to deck the top of the block. Which means we will have to machine the top of the block flat. We found that the top of the block was not perfectly flat which could have been preventing your head gasket from sealing properly. With all of that said it sounds like a lot of issues but luckily we can fix the engine and all of the components and will not have to replace any major components.
No bad news…
• There was one cylinder that had rust pitting fairly deep. We bored it out .030 (30 thousanths) to get all the rust out. We have not bored any other cylinders yet as I was having my machine shop get the parts. They could not find the parts they need so rather than bore all cyliners .030 and find out we can only get .040 pistons for example and have to bore AGAIN we are finding the parts first and then completing the machine work. We CAN sleeve this cylinder and re-use the parts removed if that ends up being more cost effective… or if we can’t find oversized pistons. I should have no problem finding the parts at Grey Marine… he (the machine shop) was not aware they are in business again.
• Then new valve guide is in place to replace the one that the valve stem was so rusted in that we broke it getting the valve out.
• We got all the studs out so that we can install hardened exhaust seats – the studs were in the way of the milling machine used to install the new seats.
o This is probably why the engine had been rebuilt without installing those seats before.
o We DID find evidence that the engine had been rebuilt. – a number stamped on the crank shaft had been altered.
• The block has been acid treated to remove the rust from any and all water passageways (which were full of rust)
• The oil pan has been acid treated also and the epoxy product that had been put over / around the oil drain has been removed. I was concerned that this mound of epoxy had been to seal a crack in the pan … but there was no crack under there… just a pipe plug that had apparently been leaking!
o We will re-thread the pan and add a hose to make oil changes easy.
• The acid treatment has been great for the preparation of the engine for powder coating
• The crankshaft is being turned to remove some rust spots. We suspect .010 will be enough – we will know end of this week probably. We will of course use oversize bearings to take up the clearance from grinding the crank.