Experimental Engine Surgery

[Rusty's Uncle]

Not sure if it is experimental or just mental but I need to get my 126 back on the road after the sand blast grit disaster with the engine that I put my heart, soul & wallet into. The gearbox also quit on the Retro Rides weekend. I have what I believe is a good gearbox standing by but needed an engine. The engine I replaced in the car had no oil pressure having been run with one of the core plugs blown out of the crankshaft. I fixed that in situ but by that time the bearings were worn so very poor oil pressure.
Not wanting to undergo a major engine rebuild at this stage as I think I will have my work cut out with the MOT that is almost due I had a think ,  , always dangerous.
The engine ran very well before I removed it , complete , from the car and so I reckoned that I could replace the main & big end bearings to restore the oil pressure.
So the experimental bit is to ignore the workshop manual , remove engine pulley, front cover with oil pump, timing chain & cogs then pull out the front main bearing and slide a new one in. All sorted after checking out the oil pump. Then turn the engine onto its front, remove clutch & flywheel, slide out the rear main bearing and slide a new one in. All sorted so now just need to remove the sump and fit new big end shells and hopefully be back in business 

[Darrell]

Sounds a bit like what I went through

Oil pressure dropped-off, took the bearings out to find the rear one had lost a 'chunk' which eventually worked-out was due to overheating (bearing pinched) due to a certain cdi ignition set-up over advancing the ignition. Told the story before but thought I'd remind you of it. I replaced the oil pump along the way too 

Now that it is sorted (diferent cdi) it is like a wood stove, add petrol and go provided drive couplings stay in one piece

Your gearbox didn't sound too good at Retro Rides

MOT time for mine too...question is, do I bother as I'm not driving it this winter as last winter resulted in a shattered alloy 

[Rusty's Uncle]

Keeping my fingers crossed that this is going to work and things I have found so far. The item that is refered to in the Haynes manual as the piston ring type oil seal was wrecked with part of the ring missing, a damaged housing and the remaining part having worn a groove around the inside of the front main bearing housing. First time I have come across a problem with this important but barely mentioned part.
Also I removed 68 grams of crud from the centrifugal oil filter, not the worst one I have cleaned out.
Then the rear crankshaft oil seal had hardened and had been leaking oil.

[Darrell]

How the..... did that break?

[Rusty's Uncle]

I would guess that someone was a little heavy handed when fitting it at some stage. It is very much like a piston ring except at the join the ends are angled & overlap to cope wit the rotary motion rather than the axial motion of a piston. The missing parts of the ring had exited out of the side of the retainer ripping a chunk out of that then the remaining part of the ring was free to try and expand with the squared off ends ripping into the main bearing housing.
Lucky I had a good used spare one, it came out of a 40 year old Fiat 500 engine