Friday 11 November 2016

Dismantling The Engines (Part 1)

I finally got round to starting to strip the engine. I've never done anything like this before so had been very nervous. But there was no going back. I was going to get plenty of experience as I as going to dismantle two!

The procedure for dismantling the engine is covered in Operation 100-3, which you can find in Section 2 of Volume 2 of manual 814. I was going to start by dismantling the DX engine engine I'd bought from Adie Pease at the back end of 2015, so I also studied the version of operation 100-3 that is in the older Manual 518.

I'd asked for a lovely shiny engine stand as a Christmas present back in 2015 and now was going to build it and get it dirty. As well as deciding what weight the stand needed to be able to bear, I'd also  done my research on how to actually fit a DS engine to a stand: The stand was going to bolt to the gearbox end of the engine. Engine stands tend to have four arms with a good level of adjustment - but you need to decide what mounting points you can/ will use on the DS engine itself. And you need to make sure that the engine stand arms spread wide enough for these.
Research: Mounting An Engine (Photo Credit: Pallasuto.co.uk)
SAFETY: I bought myself a pair of steel toe capped shoes: you don't want to drop and engine block on your feet. You don't want to drop a crankshaft on them. While I wanted to pour as much of my available money into the car as I could, my feet were worth the £35 it cost me for some proper footwear.

My engines had been sitting on a couple of trollies rigged from pallets and castors. Using straps and my engine crane, and through a bit of trial and error, I managed to get the engine in the air and fairly level. 
Using a Crane at the Barn - September 2016
I wheeled the engine stand over and introduced the two. I tried to pick mounting points that held the engine evenly around it's circumference but that's not that simple: One of the mount points was going to need to be on the top of the 'eye where the starter motor fits. With gravity pulling the engine down, I felt there was a risk that the cast block could break at that point.

Mounting An Engine over the Starter Motor Point  (Photo Credit Unknown)
Based on the bolt holes from where the gearbox is mounted to the engine, I ended up putting two bolts directly into threaded holes on the casting (so no nuts on the end) and putting too long bolts and nuts  straight through holes. In all cases I used several large washers to spread the load - and to stop the bolts pulling through the mount points

Engine stands allow you to rotate the engine to work on top, bottom or side.  I fiddled with the adjustment of the arms and positioning of the engine so that the engine was central to the axis of the engine stand and the weight distributed fairly evenly.

Having tightened the bolts I gingerly lowered the crane. RESULT! It didn't all buckle and fold into crumpled heap!

The very rusty timing chain cover was removed to reveal very clean and tidy gears and chain within. I compressed and locked the timing chain tension before removing it. How you do that will depend on which of the two chain tensions you have fitted. See step 6 of Operation 100-3 in the workshop manual for details. The hole it locates to on the block is an oil shaft and, if it doesn't come out on the end of the chain tensioner, you will find a delicate meal gauze oil filter hiding in that hole. Winkle it out carefully.

Adie had already removed and inspected the tappets when i bought the engine so, I turned the engine over and removed the sump. A couple of the bolts were stubborn and I gradually loosened and tightened them to get them going, giving a blast of WD40 as I did so. Not all the bolts holding the sump in place are the same length. In particular there are two longer bolts that also serve as a mounting point for the bracket that supports the down pipe/ flexi pipe joint. 

Removing the sump was very satisfying and gave me my first sight of the workings of a DS engine!
DX Engine Bottom End - 10 November 2016
Having first removed the locking pin in the tower, I'd removed the oil pump. I'd been warned these could bind. Mine was very tight but by some twisting action and a spray of Plus Gas, I managed to gradually corkscrew it out. The timing chain tensioner was removed, as was the chain and large gearwheel on the end of the camshaft.

I removed the bearing caps - noting that they were numbered according to position and relative to the water pump/ flywheel end of the engine.
Caps On The Crank Bearings Are Numbered
The caps were reluctant to pull off. I don't know if they are intended for this purpose but there is a small metal tab at one end that proved very useful for lifting the caps free.
A Bit Of Leverage.....
As well as taking lots of reference photos, I was carefully popping all these dirty greasy parts into ice cream tubs already labelled up with their respective positions. A quick glance at the bearing shells showed these to be in very good condition. No significant pitting at all.

With growing confidence, I moved on to the caps of the piston con rods. These are paired with their respective con rods. There is a hand written 3 digit number written on the two halves. it's sometimes very difficult to see these under all the grease and dirt. 
Con Rods and Caps are Numbered Pairs
I'd labelled up tubs and dropped the bits in as they were removed. One of the trickiest things (especially with the upside down, in bits and with points of reference removed) was to remember which cylinder was which: Cylinder 1 is at the water pump end. Cylinder 4 is at the timing chain end.

With the con rod caps off, the crank was ceremonially lifted off the block.
Crankshaft Removed - 10 November 2016
As this was my first engine strip down I'd like to say I held it aloft over my head like the conquering god I surely was - but I'm no weight lifter and that thing was heavy. So I popped it on a workbench out of the way and took a photo instead.....
Hammer of the Gods - Crankshaft Removed
With the crankshaft out of the way, the con rod rod and piston combinations were pushed down and through the block, being caught neatly under the engine. Well - three of them were.......When I'd bought the engine from Adie it was seized and hadn't turned over - I knew that. I had been liberally dosing all four pots with Plus Gas to loosen them up but, in the case of one of pot, it stubbornly sat and pooled. Guess what? It was this same piston that wouldn't now shift. 
THAT Piston.......
With the engine suspended on the engine stand I didn't want to risk trying a few hammer blows to loosen things up so moved on.

Removing the locating fork, the camshaft was carefully pulled out from the block. It wasn't that heavy. I held it aloft over my head - like the conquering god I most definitely was! A triumph of man over machine! The rest would surely be easy.........