986 3.2 home engine rebuild

[Robert986]

May I ask, the parts that where mediablasted, eg the gearbox. Did you clear coat them after? Any trick to make them stay that clean?

[OldManMo]

Originally Posted by Robert986

May I ask, the parts that where mediablasted, eg the gearbox. Did you clear coat them after? Any trick to make them stay that clean?

Hi Robert986

Different parts had a different finish. For the gearbox, I didn’t mediablast as it was too big for my machine, but I cleaned it with degreaser, then wire bushes, then used a lot of carb and brake cleaner, scotch pads, then I gave it a light coat of alloy wheel silver paint. One year it is still holding up. With hindsight, I probably sent this out to be media and vapour blasted then had a anti-corrosion coating applied.

For other parts such as suspension parts I did media blast with soda and fine glass beads (taken care for smooth finished areas) then applied either silver alloy paint or anti-corrosion coating. For the exhaust,, this was a couple of hours spent using a fine scotch brite wheel then a polishing wheel with a polishing compound like autosol

I need to do the front suspension and brakes so I will share what I do, again not to say this is the “right” way to do this but just what I did/do

[OldManMo]

Hi all

I know, its been ages. Lots of reasons, Christmas, holidays, work, home, waiting on parts, waiting on parts, waiting on funds and so on

Spent most of the time since my last post cleaning, measuring, investigating, learning while I waited to order and receive parts. I should hopefully be in a position to start the rebuild in the next month or so. Dont get me wrong, I currently have a small mountain of nice new engine parts, but still quite a bit more to get.

While cleaning the many parts in the ultrasonic tank, I could clearly see particulates fallen to bottom. These were mostly plastic from the chain guides and some pieces of carbon. There was however, lots of pieces and they came out from almost everything that was cleaned, Crank, Cams, lifters, lifter housing, IMS itself once the bearing was removed.

All honesty, I am not sure I didn't find lots of damage as it does look (and maybe I am fooling myself) as I caught it in time

So while I get ready to start the rebuild here is some photos from what has been done so far.

In almost all cases parts started in the tank, then cleaned and polished by hand, then back to the tank, then cleaned with carb cleaner, then back into the tank, then polished by hand again, then back to the tank...well you get it. BTW, I dont mind cleaning and polishing by hand, I find it therapeutic and I get up close and personal with the part

[OldManMo]

The IMS took lots of nice gentle work but ha come up nice. Lots of nasty sludge came out from the inside but more so when I used a bottle brush to get to the end






Will still go through one more round of cleaning before I fit it

[OldManMo]

Crank took some time also and I found a lot of sludge and a small piece of plastic in the oilways. The journals where hand polished. I used 10,000 grit wet and dry on the heavily soiled journals. The specs where in line with what is published else where on the net. It has been crack tested, but will have it tested once more and run through final cleaning just before fitting

This is how I started




after a few round in the ultrasonic bath




And a number of hours later by hand

[OldManMo]

Crank carrier also had the tank and hand polishing treatment. Had a strange one here as I reassembled without the bearing to torque to measure the roundness of the bearing seats and was seeing about 0.01-0.02mm differences across the face. I found that there were deposits of carbon/oil/stuff that I didn't notice the first time.

Spent some more time cleaning and polishing the seats and was seeing, sometimes only 0.01mm differences. Didn't think that the build up could be as much as that, but it could have dried on when I removed the bearing I guess.

You can see it a little in the phot below between the first seat on the left and the next ones

[OldManMo]

The cams also had a thick (well less than 0.01mm) build up. Took a while and again by hand, though I did use a fine glass beads on shaft between the bearings and cams but they cam up nice










lifter carrier also came up nice though this had a lot of deposits at the bottom of the ultrasonic bath when cleaned. Still needs a little more work and polishing