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Drake_93 · 04-10-2023, 08:51 PM

Not sure whether to post this here or FI.

Picking up a blown motor Monday to rebuild, depending on what's salvageable.
Wanting to look at building something eventually capable of running 400-500 for Autocross, and eventually track days. Currently have a Td05-20g, but will be bumping up to a G25-550 or 660 when I start to push for more power.

But wondering about compression ratio, I'll be running mostly pump E85 for racing, and I'm looking for a wider smoother power band if possible. I was looking at dropping to an 11:1 JE Piston, and maybe even a thicker head gasket (depending on how bad these heads are), but I've had people mention stock compression would be able to do it, if I've got rods that will take it.

Probably not the best engine to build as a first engine, but here we go.
I've read up a lot on oiling, and was going to try to go for OEM bearing tolerances. Any insights to bearing material (King vs ACL vs OEM) or ring gap would be appreciated.

Additional modifications to the engine were going to include GSC 1mm bigger valves, beehive valve springs, reimax high capacity pump, KillerB pickup, MoneyShift racing baffle, (haven't decided rods yet). I'm also considering setting up a return style fuel system for when I start pushing.

04-10-2023, 08:51 PM	#1
Drake_93 Member Join Date: Jun 2018 Drives: 10-Series Turbo FR-S #2483 Location: Northeast Ohio Posts: 23 Thanks: 8 Thanked 8 Times in 4 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	DIY Engine Build questions Not sure whether to post this here or FI. Picking up a blown motor Monday to rebuild, depending on what's salvageable. Wanting to look at building something eventually capable of running 400-500 for Autocross, and eventually track days. Currently have a Td05-20g, but will be bumping up to a G25-550 or 660 when I start to push for more power. But wondering about compression ratio, I'll be running mostly pump E85 for racing, and I'm looking for a wider smoother power band if possible. I was looking at dropping to an 11:1 JE Piston, and maybe even a thicker head gasket (depending on how bad these heads are), but I've had people mention stock compression would be able to do it, if I've got rods that will take it. Probably not the best engine to build as a first engine, but here we go. I've read up a lot on oiling, and was going to try to go for OEM bearing tolerances. Any insights to bearing material (King vs ACL vs OEM) or ring gap would be appreciated. Additional modifications to the engine were going to include GSC 1mm bigger valves, beehive valve springs, reimax high capacity pump, KillerB pickup, MoneyShift racing baffle, (haven't decided rods yet). I'm also considering setting up a return style fuel system for when I start pushing.