Enders swap, Update 11/29/19 Options

[enderswift]

I'm ready

This post has been edited by enderswift: Nov 29, 2019 - 6:58 PM

[enderswift]

Hello 6gc,

it's time for a long overdue rebuild update. I've spent the past few days taking care of a lot of the tedious but important aspects of the rebuild, mainly cleaning, logistics, and organizing/cataloging. Nevertheless, there is a bunch to show and I feel that the hard part is almost behind me.

my overall goal was to prepare the bottom end for tolerancing and machining, so the first step was to remove all of the extra bits from the block and clean them up. This included the oil cooler, oil pans, and everything else not associated with the rotating assembly. Heres a photo of the oil pans after cleaning:



These pans were covered in a really stubborn layer of pure crap, so I had to bust out the simple green and wage total war. It wasn't a fun process, but I think the results were well worth the effort.

From there I had to deal with the old silicone sealant. Most people recommend using a razor blade to scrap it off, but I ended up nicking the surface without making much progress. So I decided to try out an 80 grit bristle brush. 3m makes these things and they are apparently fantastic at cleaning aluminum mating surfaces without damage:



And the results:



you really can't ask for a better finish than that. I highly recommend this to anyone working on something similar. To finish things off I put the proper bolts into the pans and secured them with twist ties so installation will be easy in the future.


Next I moved on to preparing a portion of the rotating assembly for storage until I was ready to start tolerancing. This consisted of taking the piston-rod assemblies apart and cleaning each part individually. The first thing to do is to remove the c clips that hold the wrist pin from moving axially. Easier said than done, my first attempts sent the clips flying and it was miracle that I found them. For future reference I suggest doing this with your hands inside of a box, that way the clips will just bounce around the box instead of getting lost. With the clips removed I was expecting a rough time because the factory manual insists on heating everything in a tank before pressing out the wrist pins, but I was able to just push them out with my thumb. I'm not sure if that's because it was a hot day or if I need to replace the rod bushings, I guess I'll find out soon enough.

The pistons were cleaned in a vat of simple green extreme and properly labeled before being placed into a corresponding bag. I'm not taking any chances with mixing these parts up, especially since the piston and wrists come as matched sets!



The connecting rods were just cleaned in regular simple green before being labeled as well. Here's the end result of my work:



By this point the block was almost bare and all I had to do was remove the crankshaft and the pair of pumps. I started with the oil pump and carefully removed one bolt at a time (cleaning each one) and transferring it to a corresponding location on the new pump. I then transferred over the timing gear and installed a new koyo bearing. The same was done for the water pump. I also made sure to keep the old gaskets so it will be easy to match new ones in the future:

Here is the new oil pump with everything moved over:




Having done all of this I was able to finally remove the crankshaft and place it in a tub to soak along with the rear main housing:



A quick soak later and the crankshaft was looking pretty good:



unfortunately all is not well with the crank. After cleaning I noticed that the counterweights around the #4 rod journal had some discoloration:



uh oh. The first thing that came to my mind was that I had an overheated crank. But things just didn't add up.

why is it only on the counterweight and not the journal itself?
why is it only one journal?
why aren't the bearing destroyed?
why isn't the connecting rod discolored too?
why is this happening to me?

Here are more photos to show what I mean:

#4 connecting rod, no discoloration or damage of any kind (I don't know why it came out brown in the photo, its actually cast grey after being cleaned.. I guess htc can only do so much with a phone camera):


#4 rod bearings (also came out brown in the photo). The bearings look like what you'd expect, no pitting or scoring and only light wear through two layers:


There is also discoloration around main #5 right next to the rod journal. After doing some research I found out that certain manufacturers do what's called induction heat treating. It is meant to strengthen certain points of a crankshaft and would explain what I'm seeing. The reason that its only on rod journal 4 and main 5 is because those are the two closest points to the output shaft and clutch, and therefore see the most load (or perhaps they are just furthers from the pump). It would also explain why there's no damage on anything else, not even the bearings, which would go out long before the crank discolored like that. Heres a video of the induction hardening process:

http://www.youtube.com/watch?v=52zsbqVgyP4

I'm basing my bearing assessment on a number of sources, but just to illustrate my point here's a website that shows a number of damaged bearings and their cause:

http://www.enginebuildermag.com/Article/51...ngs_go_bad.aspx

My bearings don't match any of those and instead look like normal wear from a number of other engines I've seen. So this is a real mystery to me at the moment.

I would really hope that the crank came like this from the factory but the thing is, I feel I would have heard about induction hardening on 3s cranks by now. Maybe this is a late-model 3s feature? If anyone can chime in I would appreciate it. For now I'm going to tolerance the absolute crap out of this crank checking everything from the roundness of the journals to the runout of each main. I'm also going to talk with my machine shop to get their opinion. Right now I feel the crank is fine, but I want to make absolutely sure.

Anyway, that's where I stand at the moment. I'm going to hold off on ordering new bearings until I find out what the situation with the crank is. In the mean time I'm going to send the block to my machinist and work on some side stuff

This post has been edited by enderswift: Jul 4, 2012 - 3:32 PM