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Playing with some other stuff over the weekend.

I picked up a dirty cheap M90 supercharger from a Ford Thunderbird which is in much nicer condition then the M90 from the L67 Commodore I picked up around xmas. It’s got better mounting points, better ports and is a more compact unit. So I decided to play around with some potential fitments for the supercharger in the engine bay.

Mount it standing upright like the factory TRD unit. However not a lot of space to fit an sizable intercooler between the outlet and the intake.

Next up I tested it with the longer drive snout from the L67 M90 (TB one is just too short for this position).

There is plenty of space to build a laminova intercooler in the valley of the motor, however due to the position of the pulley directly above the engine mount, it will require a couple of idler and tensioner pullies.

Or it could even be mounted like this (factory Thunderbird orientation), this allows plenty of space for everything.

A quick dummy fit of some pipe work shows it is a good option.

During the weekend I helped B24 collect his 2GR from the engine builders and he offered me some spare 2GR valves to do some dummy fitting into the 1MZ heads I have sitting around.

The 2GR valves are a honking big valve compared to the 1MZ.

Intake valve diameter: 34.0 mm
Exhaust valve diameter: 27.3 mm
Intake valve overall length: 95.50 mm
Exhaust valve overall length: 95.50 mm
Valve stem diameter: 5.5 mm

Intake valve diameter: 38.0 mm
Exhaust valve diameter: 32.0 mm
Overall intake valve length: 105.85 mm
Overall exhaust valve length: 110.4 mm
Valve stem diameter: 5.5 mm

First think I noticed was, the two heads I have here are not a matched pair… One is a VVT head and one is not.

There is a noticeable difference in combustion chamber, valve guides and valve seats.

Plonking the valves in one head showed they were very close to touching, however they are unseated and would clear once fitted to the heads correctly. It would just be a case of ensuring the duration/overlap of the camshafts would not cause an interference.

Dropping them into the other head showed that due to the increased squish area, the valves will not sit without machining it back. However I reckon it can still be done.

One of these heads has had the intake ports ported out, so I thought I would show a quick comparison.

Stock porting, pretty rough and pretty average.

Ported head, cleaned up and looks the goods.

Gives me ideas for when I get around to porting some heads….

More tinkering.

Roughed out the intake ports, just need to tidy it all up now with the dremel.

Had to chop some clearance out of the supercharger mount.

Plenty of room to access for the bolts on the manifold. Same from the top once the fuel rail is removed.

It’s all fits, but is still tight.

Time to test fit it in the engine bay

Supercharger fits with a lot more room.

Pulley clears with 40-50mm now

Outlet pipe clears with a good 30-40mm of space, I could possible even remake it as a 2.5″ outlet

Looking at options on setting up the W2A

Intercooler outlet to intake manifold has a real nasty S bend to fit.

However, this might work. Pipes line up really nicely with minimal bends. Even leaves enough space for the battery to stay in the factory spot.

Quick belt test fit.

Till next time…

Another quick update.
Started making ShitManifold v1.0 to get this show on the road.

Bought a $30 vice from Bunnings and taped some random bits of alloy to it to make it into a pipe crushing machine.

Bought some 3″ aluminium tubing and crushed it over a 36mm pine plug to form the plenum chamber.

Brings it down to below the 45mm gap I have between the chopped 4AGZE manifold and the twinscrew unit.

A quick dummy fit shows it will do the job.

Quick dummy up of the intercooler placement and intake pipe paths.

Had a friend weld some plate to the chopped 4AGZE manifold. Each hole is for the cylinder runners and needs ported out to suit.

First port roughed out.

Few lumpy bits to smooth out.

It’s nothing special, but it will work.

I’m working with minimal tools at the moment, just a rotary file bit in my dewalt drill

The plate welded to the manifold will be trimmed to size once the porting has been completed.

Then a section of the plenum will be removed to match the trimmed plate on the manifold.

Then the two halves will be welded together forming a sealed manifold/plenum.

Quick fitment to the motor to have a look.

Add the plenum.

Another angle.

Till next time…

Bit more tinkering on the twinscrew tonight in an attempt to bed down on how it’s going back together for Nationals. Finished a half assed mount for the supercharger top. Needs some plate welded onto the angle to reach the remaining 3 holes, however I might just make this part out of some 150x100x10 steel instead as it’s easy to source and I can weld/cut it with ease.

I rotated the position of the bypass valve to provide more space on the head side for the intake manifold.

Some kind of intake manifold to be made in here. Will probably be ****, but I just want to get this running ASAP and it can’t be any worse then the stock setup.

Lower supercharger mount modified to suit new position.

Quick layout of the belt position, however I might need to add an idler between the supercharger and water pump to provide more belt wrap between the two. Also added the oil return hose, just need to weld in a AN-10 fitting into the sump to accept it.

Oil feed for the supercharger, need to get a hose made up to this then plumb it into a spare port on the thermostatic oil cooler plate.

Fitted aforementioned thermostatic oil cooler plate.

Need to do a quick test fit into the engine bay tomorrow to see how everything sits and where I will locate the W2A core.

Continuing from the engine tear down.

Just like working on a Fallcon or Commondoor, minus the sea sickness.

Off came the head.

Pistons look okay.

Bores…. Less so.

Headgasket was blown across all three dividers.

Head seems okay, needs a decent investigation though.

This wasn’t good to find…

Or this…

So time for some new parts and a quick rebuild!

Plan now will be.
– Drop the motor, inspect the bottom end – Replace bearings if necessary.
– Hone the block and fit new rings to pistons – Maybe upgrade to some 8.9 small port pistons while they are cheap.
– Replace the camshafts and damaged buckets – Maybe ‘invest’ in some Kelford cams.
– Check head for defects, replace with another if necessary.
– Replace timing belt, water pump, thermostat and transmission filter.
– Replace head gasket, head studs and exhaust studs.
– Build a new custom intake manifold to make better use of engine bay space for installation of the twinscrew.
– Reassemble engine and get it back in the car.
– Fit the DIYPNP MegaSquirt ECU.
– Do skids all the way to MTC2015

Out of the workshop and onto the drive way!
Some supercharged progress today.

Comparing technology from the 1950’s and something from recent times.

Now I should have continued on the process of stripping the motor down to replace the head gasket, however I just couldn’t help test fitting the twinscrew supercharger…

Doesn’t fit particularly nice, so time to make some custom stuff 😀
Started designing a new compact, equal length runner intake manifold to replace the dogs breakfast that is the factory SC manifold.

I did a big interstate trip home (14hrs each way) and brought the SlushDub and some stuff home.

Home and unloaded…

With her home, it’s time to start the repairs, restoration and upgrades!

I recently had to move interstate for a new job, so somethings got put on hold for a bit. However, I can still order parts!
One step closer to fixing the SlushDub

Now just need to get the car into the same state as me and try to get it fixed!
Hoping to get her running for MTC2015 and give it a shake down with the twinscrew!

Since the head gasket let go good and proper on the SlushDub, it’s time to repair and upgrade it. While I was ordering parts to replace the headgasket, I also bought this thing….

An Autorotor S3-2087 Twinscrew 0.87L Supercharger.

This was another abandoned project from a former AW11 owner, so looking forward to making this work on the SlushDub.

So we had a total of 5 MR2’s on this damp day, not a bad turn out really considering it’s a Friday and the weather was meek.

First session out, the SlushDub decided after just half a lap, the intercooler hose should no longer be apart of the intake path.

Thanks to BEN77 for the spare hose clamp!

The best place for a P Plater to be getting to know their car and their limits.

Red ones go faster!

Ben found out what happens when you come into a corner too fast in the wet…. Lucky it wasn’t Mt Nebo…

Graham also found his way off the track, but didn’t bring half the field home…

Eric back in after a session of chasing Excels…

Goodbye head gasket!


The main reason why the SlushDub did so many circles…