|» Index Page
||Introduction, About the BMW M70 V12
|» Page 1
|» Page 2
||Fault finding, condition checking
|» This Page
||Stripping and cleaning
|» Page 4
||Re-assmebly, Timing chain & heads
|» Page 5
|Here you can see the various timing chain covers
soaking in a diesel/petrol mix. After a few days it becomes
really easy to remove the hard black gunk, so its worthwhile
taking your time to save on elbow grease.
You can see clearly that the diesel has discolored to the point
of being completely opaque. This is without agitating the mixture
for several days.
Here is a nice picture of the engine part
way through cleaning. Most of the grime is first removed with
a power washer, an airline used to blast off most of the water.
Do not use wire wool to scrub the block, as small fragments
of the wool get stuck on the aluminium and cause it go 'rusty'.
After all the crud is removed, you should be left with a clean
but corroded block. The next stage is to use alloy wheel cleaner
to remove the corrosion. This stuff smells awful, the closest
smell I can think of is concentrated cats piss, but it really
does the job. It washes off with water and leaves the block
looking brand spanking new.
You can see from this picture the good condition of the bores.
The dark ring at the top is where the combustion actually
takes place. Any scoring on the bores of the block would mean
this engine being scrapped, and another one needing to be
It should be noted that if you need to clean the surface of
the block for a new head gasket, do not use a scraper. The
light alloy of the block is soft and easily damaged, the tool
of choice to use here is a drill with a nobly nylon pad attached.
Go slowly and polish the surface clean. The same rule applies
to the timing covers.
|This is the gentleman who is allowing me use
of his tools and workshop space to undergo yet another of my
hare-brained schemes. I have known Danny for a good number of
years and can say he is the only honest car mechanic I have
Here is Danny gazing upon my engine in a pose you are likely
to find him in, i.e. holding a cup of coffee and laughing.
|Here is why you should wait until your significant other is
out of the house for a while before completing some jobs. Dishwashers
are great tools for removing crud from hard to reach places.
Just remember to run a cycle on the machine empty to get rid
of the smell. These timing covers came out looking brand new.
As I am not painting the engine, I will be looking to get each
component looking as good as possible before putting it all
back together again. Time taken now getting everything to look
clean will pay dividends when it comes to finding elusive oil
leaks in the future.
Keeping everything as clean as possible also serves the very
practical reason of making sure that grit or dirt does not find
its way into the engine during the rebuild. You don't want anything
getting into the oil which could damage bearings or block oil
|This is the steam cleaned sump cover. Most of
the dirt and grime have been removed but its still pretty shabby
looking. The valve covers are not much better either, with lots
of surface rust from leaking coolant.
First job is to remove the oil level sender unit from the sump
cover. I wont be using it, I have a dipstick for telling me
the oil level anyhow. The oil level sender only has two readings.
Oil ok, and not enough oil. I will machine a cover from aluminium
to replace the hole left by the sender at work.
The paint off the valve covers had mostly fell off anyway, removing
it did not take too long.
|Here the sump cover has been repainted and is
ready to reinstall. The paint I used was high temp aluminium
colour paint (Three for two at halfords). It is supposed to
be baked on but my significant other came back home early so I didn't get
a chance to pop them in the oven.
The dents and scratches are still present in the sump, but the
fresh paint makes it look a hundred percent better. All of the
old paint needs to be removed first with a wire brush or coarse
sandpaper. You must take all the paint back off, right back
to bare metal. No primer is needed, just a good key to the metal.
So I made sure it was nice and scratched all over before applying
|Here are my nice clean and repainted engine covers.
Much better looking than before. The colour is pretty different
to what it was before, but seeing as my other choices were black
or red, its close enough. I have removed the valve cover breathers
as well, the rubbers were shot and will require replacing anyway.
The old paint came away from the rear of the engine easily.
In fact most of it here had peeled off. The paint closest the
timing chain was much tougher to remove. Again these covers
need to go back to metal before repainting. The rust was very
deep and I thought about sandblasting these but decided against
it as I did not want sand anywhere near something covering sensitive
parts like the camshaft and valves.
Here is one of the inlet manifolds before
cleaning and machining. The manifolds are of the log long
header type. It provides better torque at low to medium range
rpm's. The manifolds are quite a clever design in that they
are both identical and are designed to interlock. The temperature
senders and the throttle bodies can bolt to either end which
is useful as they will need to in my application.
The BMW logo and the long stripes will be machined off and
I will make plates bearing the lamborghini logo to dress these
manifolds. I wanted to do it this way so that I can screw
up making the plates any number of times. If I machined directly
into the manifolds and make a hash of it, I would need to
get new ones.
You can also see that these manifolds are once again pretty
dirty. There's a lot of this yellowed lacquer which will need
to be removed. I plan on painting these black, and use yellow
paint to pick out the highlights on the new logo.