Crank girdle stuck

KrazyKarl · 11-13-2009, 07:00 AM

I'm in the process of disassembling the engine in my s2 and I'm having difficulty removing the girdle from the bottom of the engine. All the underside bolts have been removed and the girdle lifts at the front fine but will not release at the flywheel. Does the rear main seal have to be pulled in order for the girdle to come off? Is there another bolt or lock that I'm not seeing?

krystar · 11-13-2009, 07:43 AM

not sure on the s2...i do remember my 8v was just unbolt and lift. maybe there's a alignment stud or something on that side?

KrazyKarl · 11-13-2009, 08:15 AM

Managed to break it loose with a bit of leverage under a couple of tabs on each side of the girdle. Looks like years of hardened oil had stuck the two pieces together

krystar · 11-13-2009, 08:50 AM

heh. got sludge? :P

KrazyKarl · 11-13-2009, 09:04 AM

More like, got a worn thrust bearing?

krystar · 11-13-2009, 10:40 AM

wtf? how does that side wear?

KrazyKarl · 11-13-2009, 10:47 AM

Only theory I've heard is that a previous owner could have sat at lights all the time with the clutch pedal in, and that pull on the crankshaft slowly wore the bearing out.

HondaDustR · 11-13-2009, 09:08 PM

That's an interesting point. Another reason to not hold the clutch in any more than needed.

MarcM · 11-16-2009, 05:23 PM

Karl,

I've got an 87S with the same issue. Originally the clutch started to stick near the floor so I thought it was one of the hydraulic cylinders going bad. Turns out it was the thrust bearing. You doing a full rebuild or just the lower end?

KrazyKarl · 11-16-2009, 07:15 PM

Planning on doing a full rebuild, rods, mains, and rings.

HondaDustR · 10:47 AM

I wonder if the thrust bearings on the crank are still in spec. What plans do you have for the cylinders? Oversize or just rings, and are you going to have a shop work the cylinders or DIY? I've heard that new rings on broken in Alusil cylinders is pretty hit or miss unless the surface is re-prepped with some method to remove the glaze and expose the silicon particles.
Have fun!
I just got mine together and it would have been alot more fun if it hadn't been my daily driver.
Project 924 S engine replacement

KrazyKarl · 11-17-2009, 11:01 AM

the thrust bearing surface on the crank looks alright, but the side were it was spinning against the worn bearing did take some abuse. It should be fixable for a lot less then the $1000 it would cost to find a replacement

Not sure what I'm going to do about the cylinder walls yet, I'm trying to locate a gage to measure the bores for wear.

HondaDustR · 11:37 AM

Oh... that might need some help. The thing is, I don't believe there are any measurements for thrust bearing sizes in the shop manual other than endplay clearance with the crank and bearings installed. It will probably polish out as long as it's not too worn. The thrust clearance range is fairly wide (.11-.312mm, max .4mm).

It would obviously be the best to find someone who knows what they're doing with Alusil cylinders to work them, but as long as the cylinders and pistons measure up well and are not damaged, the DIY scotchbrite and Sunnen AN-30 lapping paste on a felt hone seemed to work like a charm. I've got no trace of oil smoke and good compression from mile 0 to ~400 so far with the procedure in my rebuild link. YMMV, since the Deves aftermarket rings are not exactly the same as OEM. Once the pistons are removed, there's no going back without something done to prep these cylinders to break in rings unless you want to make a BIG gamble (not worth it considering the time and expense of a full rebuild), unless the motor has next to no mileage on it.

The rings and the cylinder break in down to the microscopic level and is virtually impossible to line back up once disassembled, rendering them no longer perfectly broken in. The surface of a properly prepped alusil cylinder has a very fine but dull, rough finish needed to wear the rings in. Once both the rings and the rough edges of the silicon crystals wear down initially, the extra roughness is gone, the rings are seated, and wear slows down considerably. The cylinder hardly wears at all compared to a standard cast iron lined cylinder, since the exposed silicon crystals, which almost exclusively makes up the cylinder surface by protruding from the aluminum substrate, are much harder than the rings. Without that surface restored, the rings would just glaze, take forever to break in, don't break in as well, or maybe not at all.

MarcM · 11-19-2009, 03:25 PM

We're heading down the same path. How many miles on the motor? Curious if you had done the clutch prior?

KrazyKarl · 11-19-2009, 05:02 PM

117k on the motor, clutch was replaced by a PO at around 104k miles.