Ok so my mis-diagnosed smokey turbo has now turned into an engine rebuild. Oil was puking into my air intake via the crank case breather thanks to excessive blow by, finally diagnosed via a leakdown test which in hindsight should have been done from the beginning. A Turbo replacement later we find 3/4 Cylinders are screwed, compression wasn't too bad but the leakage test had 50% leakage on the worst cylinder (#3). All of which were leaking down into the crank case.
Engine Leakdown results for those that are interested were:
CYL1: 165PSI 5% LEAKDOWN
CYL2: 150PSI 35% LEAKDOWN
CYL3: 140PSI 50% LEAKDOWN
CYL4: 150PSI 40% LEAKDOWN
Most of my questions have been answered in the last few weeks and now that things have started I might as well keep some kind of diary, I will put interesting pics and observations in this first post. Not a lot of people build an engine that hasn't turned a single revolution yet so this might be interesting to some. Particularly the fact that the new motor wasn't exactly perfectly assembled to begin with.
Build diary goes thusly:
I ended up buying a brand new (2013) Long Block directly from Mazda:
And immediately started pulling it apart (Well, I didn't, Mitch is doing all the work)
During dis assembly Mitch noticed a couple of interesting things. Remember that this is a BRAND NEW ENGINE from Mazda, that has not turned a revolution in its life.
Firstly, the rear main seal was not seated properly. If we ran this engine it probably would have had an instant oil leak on day 1.
Secondly, the piston ring gaps had been perfectly aligned. This was consistent on all 4 pistons:
A 1 way ticket to excessive blow by and high oil use.
Which brings us to here, pulled apart, ready to be balanced and reassembled with forged Rods + Pistons. Hopefully it goes back together better than it did in the factory!
Pistons are CP-e Stage 2
Rods are Manley H+
Also have a set of CP-e Injector seals that will be going in.
I also bought a Quaife for good measure. I've wanted one for years and figured if I was going to pull the motor out I might as well put this in while i'm at it. This will be going in along with a new (NPC) Clutch
We have got our hands on a low mileage gearbox that we will put the quaife in and swap both engine + gearbox out in one go as a complete driveline.
Parts finally came back from the machinist last week. The Gearbag has been rebuilt with the Quaife fitted. Time for assembly combined with dickloads of measuring.
Finally commencing assembly!
More Assembly, timing etc.
Balance shaft clearance after cutting the ARP studs down
Aaaaand it's done!
Finished Product:
Out with the old:
Old motor decommissioned.
One troubling thing noticed on the old motor is oil getting past the injector seal on cylinder 2. This is a fairly high stress component being direct injected but I'd expect to see blow by gases here. Not oil.
Glad I am upgrading the injector seals in the new engine!
New one going in
All Done!
I'll be spending the next 1000k's driving it fairly conservatively, once that's done then I'll get it tuned properly and start really ripping in.
First impressions so far after a quick blat down the Old Pacific Highway:
Engine Balancing is definitely worth doing. Low RPM vibes are way lower than the old motor
Lightweight flywheel makes gear shifts WAY smoother and faster. Minimal impact on driveability in stop/start traffic
Quaife LSD is pretty freaking cool, no understeer and locks into turns like nothing else. It's also a lot smoother at low speed maneuvering like turning into driveways, the old LSD was kinda snatchy when creeping up kerbs, this one is barely noticeable.
Can't wait to hit the track with this LSD and see how much of a difference it really makes.