GC8 Engine Rebuild – Part 8

Moved onto wiring up the injectors today, removing the stock Denso plugs and fitting the Bosch ones.

Cut the Denso plug off.

Stripped back some of the plastic sleeve, fitted the rubber seal, crimped and soldered the pins on.

Pushed the pins into the Bosch plug housing.

Slid the seal up over the plug.

Then plugged them on.

Next up will be to play with the fuel pump setup and find a place for the flex fuel sensor to go.

GC8 Engine Rebuild – Part 3

Life has become busy again, so this post is a bit late and lacking!

Dug the tiny torque wreck out and did all the camshaft caps.

Intake gaskets fitted and cam covers refitted.

Intake back on.

Putting the timing assembly back on

Cam gears back on.

Torqueing the cam gears to a crazy 98Nm…

Locking the gears for the job.

Covers back on and buttoned up.

Oil cooler, cleaned, flushed, then cleaned and flushed again!

Sump getting gooped and being ready to be fitted.

Sump and engine mounts bolted back on.

GC8 Engine Rebuild – Part 2

While the motor was apart, the missus decided she wanted to add some color to the engine bay.
Purple is her color and wow, engine bay is going to stand out now….
The cam covers have now been shipped off to get the same treatment.

A stark contrast when bolted to a filthy motor…

This has been a long time coming! Side feed injectors are hard to find decent upgrades for a most are not E85 friendly. I was looking to make my own rails using some universal fuel rail and TIG weld some tabs and spacers, but really, for the cost of the Radium Engineering conversion kit, it was just easier to open the wallet.

I had been keeping an eye on Raceworks 980cc injectors for a while as there are affordable (compared to the recommended Injector Dynamics injectors which are $1200/set!!), I priced them up at my local AutoOne who stocks them and they were $155ea. I decided to do one last google pass before committing and found that EFI Solutions was selling genuine Bosch 980cc injectors with plugs for $93ea! So in the shopping cart they went!

They are actually a 1/2 long snout injector with an adaptor over the snout to turn them into 3/4 length injectors.

They fitted perfectly with the Radium kit!

Next up I’ll be ordering some parts to make some -8 hoses for the fuel rails to the Turbosmart FPR1200 I have.
Till next time!

GC8 Engine Rebuild – Part 1

Well the engine has been broken for long enough, I hummed n harred over various options and what to do with this (weighing everything up from a slap job to a $10k full forged rebuild) engine. In the end I decided it was time to dig out a spare bottom end (A $750 STI bottom end I picked up years ago for this situation), throw on some new head gaskets, ARP studs and send it. I was planning to service the block and heads, including some basic machining, but COVID and lock down has prevented me from transporting the parts over to my usual engine builder.

I missed a few photos at the beginning which mostly included me putting the motor on the stand and then cleaning a bunch of shit off it.

Motor on the stand, ARP studs fitted.

The deck cleaned up with the nylon brush.

Head gasket on

The head is filthy AF.

Lots of brake cleaner, razor blading and the nylon brush to clean these (this is half way done)

Head on

ARP studs torqued to 90ft-lb.

Cams back in for the short term, I need to order new cam cap bolts as a few are starting to round off and will likely fail to torque spec

Half the side done.

This head is also filthy AF.

So it got the brake cleaner, razor and nylon brush treatment as well.

Block cleaned

Head gasket on

Torqued to spec like the other side.

Cams added to that side as well and it’s starting to look like a motor again.

While the VF34 turbo is off the motor, it’s a good time to remove the P20 rear housing. (Legnum’s cute little TD03 rear turbo to the left)

I’ve had this smaller P18 housing ceramic coated and waiting for this opportunity. Hopefully we can reduce the spool down to the low 3000rpm range and improve the transient throttle response.


Till next time!

GC8 Engine Tear Down – Part 2

And on with part 2!

The special Subaru Cam gear tool was ordered and arrived, $120 later… Sadly if I had not stripped down the CNC for service and upgrades, I could have made one of these….

Semi plastic camgears…

Tool on and time to yeet it.

How does it work here you say?

Here it just pops inside the cam gear and works.

Unfortunately I didn’t have an impact 10MM hex for the bolts, I’ve been wanting a set for a while for these kinds of job, so a trip to Bunnings and I acquired this Kincrome set.

Two gears off.


Giving it a yeet.

And it rounded off… Hoorah!

Drilling time! The Milwaukee M12 drill does the job again and again.


This lets the cam gear off easily and just leaves the bolt core to be removed.

In this case, it wound off with fingers.

Cams out.

They look to still be in reasonable condition.

ARP nuts off and plonked the first head on the floor.

Interestingly one ARP stud has a lot of corrosion on it. I was going to reuse these but will likely just keep them for spares now.

Head gasket is in good condition.

Block is pretty filthy.

Pistons on this side have a bunch of carbon.

But nothing compared to our failure and award winner!
Lean n Mean Melty Piston!

That alloy is toasted.

No other cylinder shows any form of alloy speckling, so currently I’m assuming we have a fueling issue on this one. The fuel pressure regulator, injectors and fuel pump tested in the near future.

The bore suffered some serious damage to the liner.

The bottom has now been thrown on top of the wheel stack so we can pick the odd sensor and hose off it and swap it to the spare bottom end.

This explains the rebuild.

And with that, I ran out of garage time and knocked off for the day.
Next time we should be starting to put the engine back together using the spare block, the new gaskets/ARP studs and reusing the old heads.
We will also look at painting some of the bits and pieces, like coolant cross over pipe, the intake manifold, etc etc.

GC8 Engine Tear Down – Part 1

After yeeting the motor in the GC8 at the track, it’s been gathering a bit of dust in the shed as I ordered a couple of preemptive parts (head gaskets and ARP bolts), but this weekend we finally decided to get into pulling the motor out of the car and begin tearing it down.

The Legnum is still hogging the hoist so this will be an on the floor job 🙁

I’m not a big fan of jack stands, so I always throw these trusty rims under the wheels…

Dropping the oil showed some interesting colours

Plenty of metal.

Radiator is out and stacked aside

Now to move onto removing the alternator and unbolting the air con compressor.

I will use the AC mounting points as a lifting point.

The AC just moves to the battery bay and gets tied up out of the road.

Bellhousing and engine mount bolts are then removed and we are ready to start lifting.

Nearly out!

And done!

And now it’s on the engine stand, ready for tear down.

The intake manifold was removed.

And then I realized I had made a rookie error, I removed the flywheel before I had undone the crank pulley bolt… So I had to resort to an old trick I learnt years ago. You pull a spark plug out, and you feed a bunch of rope into the cylinder bore. Then you wind the crank to the point where the rope is jammed between the piston and the head. The soft rope prevents damaging any parts but jams up the assembly solid enough to be able to undo the crank bolt.

It did require a big bar…

Then the timing covers could be removed so the timing belt can be accessed and removed.

Timing belt removed, now I just need to order a Subaru SST to lock and remove the cam gears.

Now to remove the cam covers.

The heads are very clean in side, this was surprising but shortly it was known why.

This motor has been previously rebuilt and had a set of ARP 2000 studs fitted. Shame I just ordered some!

Time to remove the engine mounts.

Now to pull the sump off.

Oil has that nice metal flavor to it.

Lots of metal!

Ooo, chunky.

More metal…

Well until the cam gear tool arrives, we’ve got to leave it there.
Part 2 coming soon!

NightShift Track Day Prep

Booked in for a track day with a few friends at SMSP, so I decided to finish off the new water to air intercooler setup using the Liberty RS factory core.

This required tearing the whole front end off the car. Yay.

When I did the first version of the water to air, I had just a couple of basic tools and no work shop, so a lot of this was done with a cheap materials from Bunnings. These heat exchanger up rights were made from 25×3 aluminium bare and mounted with tek screws 🙁

The front end of the car has been involved in an impact at some point an various bits are out of shape. To tidy some of this up, I fix part of the lower radiator damage and rolled the seam over with a hammer.

This provided a little more clearance for some of the changes I would be making while improving the condition.

Sadly, someone had bastardised part of the front bumper up right to fit a filthy front mount intercooler… Now the torn steel is rusting, another job to fix.

The place where the coolant pump will be mounted

The last setup had 3/4″ hoses running through the inner guards as I had no tools to do the install properly. This time however,  it will be done through running some hard pipes that will enter the engine bay from beside the battery tray.

I made the pipes out of copper tube and off the shelf bends that were just soldered together.

This worked out super easy to make and install

To keep the hard lines aligned, I CNC’d a couple of B clamps.

With the pipes run, I needed to mount the pump, so with the router working, I tasked it with the job of making a billet pump mount.

Pump fitted into the mount

And then mounted onto the chassis.

Something else I decided was that I needed a second set of rims for the car so I was not always driving on race tires. COVID has driven up the prices of the secondhand market and everyone wants a million bucks for their 20 year old flogged hektic JDM wheels, so I purchased my first set of new wheels, ever.

A nice set of Enkei RPF1 wheels in 17X8 +45.
The come packaged so pretty!

Oh so shiny.

Things going back together

The bumper has been out of shape a fair bit due to the holes being worn, so I added some washers to help clamp the bumper into the proper alignments.

I gifted myself with one last present, a brand new set of Nankang AR-1 semi slicks.

The weather has been shit all week, here is a prayer that it clears up before the track night…