New pistons from Matrix Garage

As the title says 🙂 Also, I got two Cometic MLS headgasket to choose from.

The box assistant was with me at the unboxing. Weirdly enough, her food comes in a box that is similar in size to this box. Wonder if she was actually looking for food? I know she has good memory.

One of the pistons. Designed by Yoshi at Matrix Garage, manufactured by Traum Pistons. These are MG’s shelf pistons, 81.5 oversize and with stock 1.2mm headgasket CR should be 10.5:1.

I’m going to use a 0.76mm headgasket. CR should be somewhere around 10.9:1 with that.

Some deburring is still needed. I’m going to get the same coatings on these pistons what I got for the previous ones.

4A-G headgaskets

Some of the headgaskets available, both 16V and 20V. Cometic hgs are available in every color of the rainbow and I didnt list them all.

Edit: added Toda. I didnt know they had HGs 🙂

Edit 2: the information below can be outdated or wrong.


Toyota 11115-16070 ?? 1.2mm (original)

Supertech HG-T4GE-83-1T 83mm 1mm 
Supertech HG-T4GE-83-1.3T 83mm 1.3mm

Je gasket TY1001-039 81mm 1mm

HKS Stopper 2302-RT001 82mm 0.6mm
HKS Stopper 2302-RT002 82mm 1mm
HKS Stopper 2302-RT003 82mm 2mm

HKS Bead 2301-RT008 82mm 0.7mm
HKS Bead 2301-RT009 82mm 1mm
HKS Bead 2301-RT024 82mm 1.6mm
HKS Bead 2301-RT010 82mm 2.0mm

TRD 11115-AE814 82.5mm 0.8mm metal
TRD 11115-AE802 82.5mm 1.1mm carbon
TRD 11115-AE824 82.5mm 0.5mm metal

Cometic C4166-040 83mm 1mm MLS
Cometic C4166-045 83mm 1.14mm MLS
Cometic C4166-051 83mm 1.3mm MLS
Cometic C4166-080 83mm 2mm MLS
Cometic C4166-120 83mm 3mm MLS <-seriously?

Cometic C4170-040 81mm 1mm MLS
Cometic C4170-045 81mm 1.14mm MLS
Cometic C4170-051 81mm 1.3mm MLS
Cometic C4170-080 81mm 2mm MLS
Cometic C4170-120 81mm 3mm MLS <-seriously? 

Power Enterp … 82.5mm 0.7mm bead

Toda 12251-4AG-006 82.5mm 0.6mm stopper
Toda 12251-4AG-008 82.5mm 0.8mm stopper 
Toda 12251-4AG-010 82.5mm 1.0mm stopper 

TRD 11115-ae001 82.5mm 0.8mm

Cometic H1090SP3040S 81.5mm 1mm ??

Cometic C4605-040 83mm 1mm 
Cometic C4605-051 83mm 1.3mm 
Cometic C4605-060 83mm 1.5mm

Cometic C4604-040 81mm 1mm 
Cometic C4604-051 81mm 1.3mm

HKS Stopper 2301-RT038 82.5mm 0.6mm

The piston debacle

Sheesh! Finding proper 4A-G(Z)E pistons is a mess!

The following pistons are listed with 20mm pin and 30.68mm (1.208″) compression height

  • Wiseco K506M815
  • CP/Carrillo SC7653
  • Wössner 9035D050
  • Wössner 9191D050 is strange. It has a 30.6mm compression height. WTF?
  • Wössner 9278D050

…and following pistons have 20mm pin and 30.5mm (1.200″) compression height

  • Supertech P4-T4AG16-20-81.5-CR11
  • Toda 13010-4AG-001
  • Toda 13020-4AG-001
  • Toda 13040-4AG-001
  • Arias AP331669
  • Arias 3721070
  • Arias 3731220

If my current pistons can be shaved a bit, I’ll keep them. I’d love to get the compression height from 30.68mm to 30.5mm and shave a bit off the piston crown to get dome volume somewhere around 2-3cc. This would drop the compression rate little bit below 11:1.

Otherwise I’ll get the Supertech pistons. They’re pretty damn near perfect. 🙂

Difference in compression height numbers probably comes from two pin sizes. Early 4A-GE engines had 18mm pin, later models had 20mm. Some of the companies dont seem to care about this.

I promised myself that I wouldnt get any parts from a country, which still uses imperial units. Meh…

  • Supertech = imperial
  • Toda = metric
  • Arias = imperial
  • Wiseco = imperial
  • CP = imperial
  • Wössner = metric

Wössner would do, they’re from Germany, but why do they have that compression height error too?

Matrix Garage has some pistons too, based on their own design.

Aluminium oxide inside oil passages

That white, powdery stuff there is aluminium oxide. And it’s baaaaad.

While being washed for those technical coatings, something happened and insides of the cylinderheads got exposed to washing agent. Aluminium reacted with washing agent and end result was aluminium oxide.

Aluminium oxide is that same stuff that is glued to paper to make sandpaper. Wonder what it would do inside my engine if left there…?

Nah, I’m taking it back to the coating company 🙂

Parts from coating

Got some parts back from coating!

Cylinder head has some white crud all over it. No idea what it is and how to get it off.

Valves and everything (I mean everything, even the plugs) were coated in heat resistant stuff. Outside, cylinder head got a coat of stuff that helps heat to radiate away from it.

This is a Ferrari F360 flywheel if I remember correctly. Widric found it from our stash. 🙂

Pistons got three different coatings on them. Top of the piston was coated with heat resistant, skirts with friction stuff and the underside with that same stuff as cylinder head that will radiate heat away.

Some bits are now sandblasted and powdercoated. I will have to find some nice paint(s) to do the letters.

Not pictured here are the new camshafts, all the bearings and the block. Camshafts and bearings got a coat of that friction reducing stuff, while the cylinders were rubber with tungsten powder to… well.. reduce friction 🙂

I will get my exhaust manifold and turbo coated as well.