Cleaning the upper and lower oil pans and the oil pick up.

The oil pans were factory installed with a sealant and no gasket. The sealant bonded extremely well and required the gasket scrapers to remove. The oil pans have grooves on the flanges and a pick was needed to carefully scrape out all of the factory sealant. I used a drill bit to manually clean the sealant from the thru holes in the upper pan flange. I also used a wire wheel on the stamped steel lower oil pan flange.

Note all of the bearing metal debris on the parts washer shelf.

 

Started prepping the block before cleaning and deglazing.

Given the failed rod bearings, and loose metal in the engine, I was concerned that the oil passages might contain bearing metal fragments which could damage the rebuild.

The oil galley runs thru the center of the block at the base of the Vee. There are galley plugs at the front and rear which need to be removed to clean the passages with brushes. There is also a third plug right near where the oil pump discharges to the block (not shown).

The oil galley plugs have an 8mm female hex. Using PB Blaster as a soak, a hand held impact, as well as a pneumatic impact wrench all proved useless succeeding only in wringing out the hex. I even tried heating the block with a propane torch.

I then drilled thru the plug center (start with the largest bit which self centers in the hex so as to remain concentric with the threads!) and attempted to use an EZ Out, but that would not budge and I was afraid it would break off and create a worse problem.

I then progressively drilled thru the plugs finally stopping at 1/2" bit. I then took a Bosch metal blade in an Xacto handle and cut several radial slots in the remnant of the plug. Then using a punch and hammer, was able to crush it inward and remove. The block threads experienced minor damage from this method and I plan on chasing them with a tap to clean up and use liberal sealant upon assembly.

 

I had left the 4 good piston and rod assemblies soak in the Dyna 143 for a week which did a great job on removing the oil, but the carbon was still securely attached and the pistons still discolored. The rings had been removed prior.

After searching the net, I found several positive reviews of the Berryman Chem-Dip Carburetor & Parts Cleaner for cleaning pistons although there are many naysayers out there as well. Given the positive posts that had before and after pictures, I bought a 1 gallon can at Walmart for not quite $18 and decided to give it a try.

Here is a test of a 1-hour soak on one of the damaged pistons compared to the other damaged piston both in their "as-removed" condition from the engine. Both still have the rings in place. The 1-hour soaking proved quite encouraging! After soak, remove and rinse in hot water! This test picture does not show the affects of any brushing or scraping. The piston is extremely bright and the carbon and discoloration are fading away. Note the "dip line" on the rod beam at the big end.

 

The Berryman instructions indicate a maximum of 4 hours for aluminum coated pistons. I'm pretty sure the OEM pistons are not coated, so I then proceeded to soak the remaining pistons. At first I let it soak for 2 hours, removed and inspected, and then proceed for another hour.

The 3-hour soak seems to be working quite nicely! After the soak and hot water rinse, I put them back into the Dyna 143 and will later do a detail clean of the ring grooves using a piece of piston ring as a scraper.

Not shown, but I used a piece of aluminum foil to cover the open can while soaking as the protruding rod big end prevented installing the can lid. The fumes are not pleasant and I ran my garage exhaust fan occasionally.

 

While the pistons were soaking, I used the gasket scraper to clean the engine block surfaces for the heads, water pump, coolant pipe at rear, and oil pan. After scraping, the surfaces were cleaned with CRC Brake Clean and a rag.

After degreasing the surfaces, I used a honing stone and honing oil to clean the gasket surfaces which cleaned up nicely. Lastly, I sprayed all of the bores and surfaces with WD40 to prevent any rusting.

In the last picture, you can see a before and after comparison of the coolant pipe surfaces. The surface on the left is after scraping and cleaning while the one on the right has been stoned.

I'm now at a standstill on the block until I receive the engine cleaning brushes and dingle berry hone.

 

Continued cleaning..

The varnish on the oil pan and engine block surfaces was quite tenacious and would not dissolve with the Dyna 143. Bought green "Industrial" Scotch Brite pads to scour the surfaces which made quick work of it.

Bought Moroso engine brush kit 61820 from Summit and used the brushes to scrub the oil galley and the main bearing oil feed holes. The oil passages were flushed with solvent. The block was fully degreased in the parts washer and then set back on the engine stand. When weather permits, I will take it outside to hone the bores, followed by a hot water scrubbing.

 

Mail order parts continue to arrive...

Bought most of the parts from Rock Auto including the remanufactured crankshaft with bearings. The NPR piston rings cam from Ebay seller domesticgaskets.

The OEM Mitsubishi rods and pistons I bought from MitsubishiParts.com I also ordered new OEM torque converter bolts to replace the original ones that sustained damaged during removal.

 

In my case, Rock Auto sourced the remanufactured crankshaft from Crankshaft Supply, Inc. -- Experts in Crankshafts & Cylinder Heads It was actually cheaper for me to buy thru Rock Auto than direct, and then was able to apply discount code as well.

It was packed extremely well with the crank wrapped in plastic, the bearings off to one side, then a bag in the box which was foam filled to lock everything in place.

Crank came with main bearings, rod bearings, and thrust bearings. The main bearings are by King and the box is labeled Made in Israel. The rod bearings are ACL and the box is labeled Made in China. The thrust bearings are also ACL and made in China.

 

The piston rings I purchased are NPR. Link to their catalog and technical information is here http://www.npramerica.com/attachemen...orPRINTOUT.pdf

The NPR manual specifies, that for a grey cast iron engine block, that the cylinder bore be honed between 220-280 grit using conventional stones and that it be plateau finished and scrubbed afterwards with a nylon bristle brush.

After searching on line, I found BRM Flex-Hone, Industrial Brushes, Wire Brushes They appear to be an industry leader in cylinder bore honing brushes. After reading thru the technical information, I purchased a 95 mm 240 grit hone (the bore is 93 mm, but you select the next largest hone). I also purchased their honing oil and appropriate bore brush. These were purchased from Summit.

This part of the rebuild is on hold pending better weather so I can roll the engine block and stand outside for honing and scrub cleaning.

 

When I had spoken to personnel at Crankshaft Supply, Inc. -- Experts in Crankshafts & Cylinder Heads several weeks back, they indicated that there were different crankshaft forgings that interchange in the 6G74 engine. Their catalog provides the following forging numbers which cross reference to this engine: 74K1, 94062803G4

The remanufactured crank I received is noticeably different than the original. The one from my engine has "74" cast into one of the counter weights near the snout. The remanufactured one appears to have "V35" cast on it. There are also noticeable differences regarding the width of the counterweights and location of same. Original crank is the upper one on the side by side comparison and you can see the 1/2 rod journal damage.

As a precaution, I will be contacting Crankshaft Supply this week.

Update 2/16/16 - Called Crankshaft Supply and they confirmed the forgings interchange.