1994 Diesel Suburban Build

[aardvarcus]

So yesterday I cleaned up and deburred the oil pan, wire wheeled the oil pan mating surface down to bare metal and sanded it with 1000 grit sandpaper. I scraped and cleaned the block and gave it a light pass with the sandpaper as well. I picked up some permatex sealant and pulled out one of the fel-pro gasket kits.

I put in the rear main seal with only a drop of sealant on each end per the directions. I decided to use the oil pan gasket with a light coating of permatex above and below it. I have read so much conflicting information on gasket vs rtv I just decided to go the belt and suspenders method. The army technical manual stated you could use both together, and the fel pro gasket kit instructions said to use a light coating of sealant with the gasket.

Anyway I snapped a few pictures during the process. Time to flip the block back right side up.

[aardvarcus]

Continuing to plug away at this. I got the block back right side up and began scraping off the remnants of the intake manifold gasket from the engine and the intake. I would love to gasket and port match everything, but that is a later down the road project. The intake gasket has a good sized gap on all sides of the intake and head, but I did a paper traced overlay to compare the head to the intake and it was actually closer than I had seen in online photos, perhaps the GEP quality control has tightened that up a bit.

I did notice on the intake manifold there were a few casting flaws where there was a slight edge to the intake manifold that formed sort of a shelf. I chucked up a sanding tool in my dremel and ran it around the intake manifold ports on all sides. I intentionally didn’t really take any meat off, just got the casting flaws gone and smoothed it out just a bit.

The rest of the intake has a “sand” finish on the inside; I don’t think it is necessary since no fuel/air mixture is traveling through there, just air. I don’t know if I will smooth it out, probably another later project.

Anyway, some pictures of the intake “porting” work, notice the before and after of the runner with the worst casting flaws.

[slowmover]

Might not make much difference, but as expression of principle in ones determination I know it felt great to have done it.

[aardvarcus]

So last night the patient got wheeled into the operating room in preparation for brain surgery. Current plan is after removing several smaller items from the engine bay is to pull the transmission and transfer case from below and then the engine from above out of the Suburban. Then I would pull the Suburban out of the garage and wheel in my older pickup and pull the NV4500 transmission, clutch, etcetera out of it and pull it back out of the garage.

I would then get all the brackets and accessories swapped over to the new motor and get all the prep work I can do in advance taken care of. Then I will wheel the Suburban back into the garage and drop the new engine in and new to it transmission into the Suburban.

I know I will probably have to order a few more little things along the way, but I think I have 98% of all the parts I will need on hand.

[oil pan 4]

What rear end gears were you going to run?

[aardvarcus]

Oil Pan,

Stock the Suburban came with 4.10 gears, so I will be running them for a bit, but the eventual plan is to run 3.42 gears. That is the highest ratio I am aware of for the stock 10.5 14bolt/9.25 IFS differentials. With 6.34:1 first gear on the NV4500, taking off shouldn’t be a problem even with the higher 3.42 gear ratio.

Stock 4.10 with 0.73:1 overdrive and 31.8” tires equates to 1800RPM at 55 mph and 2300 at 70 mph. Stock 3.42 with 0.73:1 overdrive and 31.8” tires equates to 1500RPM at 55 mph and 1900 at 70 mph.

[oil pan 4]

You might be able to find 3.23 or 3.21 gears for it.
Try nitro gear.
They had the impossible to find 3.21 gears for my 10.5 inch 14 bolt full float axle. They were impossible to find because only nitro gear has that ratio for that diff.

[aardvarcus]

Oil Pan,
I looked on their website, but I didn’t see anything taller for the 9.25” IFS differential. I had looked a while back for something taller than 3.42 that would fit the IFS differential but came up empty. I daydream about axle swaps, but it will be several years before I could pull something like that off, plus I like the idea of keeping it mostly stock.

[aardvarcus]

So last night I did the first of the prepwork for pulling the engine. First I got the batteries disconnected and out of there. Next I disconnected the air intake back to the turbo. I pulled the relocated PMD and extension harness. I pulled the stock skid plates and splash guards off the bottom front.

Next I started trying to drain the antifreeze, (without making a mess in the garage) but the drain port that you hook a hose to was pointing straight down into the lower radiator support, so no luck on that front. I started trying to siphon the antifreeze from the top radiator port, and got several gallons out. Ran out of time, but I will have to start pulling hoses off the bottom to finish getting the coolant out.

[aardvarcus]

Continued to plug away at disconnecting things from the engine bay in my spare time. Got the coolant hoses disconnected and the fan and radiator removed. It looks like the radiator has been re-cored, as the insides look new and the top and bottom flanges have been cut apart. The coolant hoses feel soft, I am thinking I will go ahead and replace them. Also need to get an appropriate coolant temperature sensor and housing to go in the upper radiator hose to trigger my custom engine fan controller.

I drained the oil and began applying wd-40 to several of the bolts on the exhaust and frame that I will have to disconnect. I also assembled a cheap engine cradle to set the removed engine in, so that I can roll it around and it will be safer to work on and remove parts from. It was a $35 cheapo stand from a big auction site, not too terrible of construction and welding but I did replace the bolts that connect the three frame pieces together with larger better rated ones.

Tomorrow I have help coming and I am going to devote an entire day to working on the Suburban, hopefully I will make lots of progress.