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!