blackandtan22

I bought a used VVT engine to swap into my NA perhaps next fall. My plan is RB header, RS3 exhaust, Skunk2 port matched to VICS intake, and 3d printed intake (carbon fiber version). The car is strictly for the track. I wanted opinions for the actual engine. Here are my the options I'm considering:

1. Don't touch engine except TB, water pump, etc. Engine has about 140k on it and has been tested to have good compression.

2. General maintenance + pull head to change head gasket to NA style and install coolant reroute.

3. Number 2 + mild head work, supertech springs and SS valves (not oversized though)

4. Number 3 + billet oil pump, 10.5 OEM pistons w/ coating.

Few more pieces of info. I already bought valve springs, valves, and pistons, coolant reroute (on my current engine) . So at some point I'll get to number 4.

Really trying to gauge should I pull head to just change gasket or at that point go further. Just wanted to get opinions. Currently was leaning towards 3.

Roda

I'm in the middle of putting a VVT engine into my '92, and I did #2... TB/WP, head gasket, coolant re-route, new seals and gaskets. I also did a valve adjustment because a few of them were out of spec.

If you already have valve springs and valves, I'd seriously consider going through the head while it's off.

blackandtan22

That was my exact thought, and just leave bottom alone until engine warrants it.

btabor

iTrader: (3)

I did "option 2" plus a standard valve job, seals and a 99 head gasket with a coolant reroute. Leave the bottom end alone, add a washer to the oil pump spring.

I got a rs3 exhaust and returned it for an enthuza 2.25". The enthuza looks much better in my opinion and it fitted perfectly. Got it with the test pipe for $475 shipped. Sounds amazing. I did basically the same swap you are doing. Will dyno tune in a week. Milled the head .030" stock bottom end. I added a .060" to the stock oil pump relief spring and it runs with pretty high oil pressure. It was a tip from a miata engine builder in town

Savington

iTrader: (31)

I would do #2, or maybe #3 without the valvetrain upgrades. Stock valves are fine, and your money is better spent on a good P&P than stock-sized undercut valves IMO. Valve springs and billet OPGs are a waste unless you're planning to open the motor and add rods too.

#2 is easy, no machine work needed, can be done in an afternoon for the cost of the head gasket. #3 will cost you a few hundred dollars and add maybe 8-10whp to the car at most.

This all assumes you have an ECU already.

blackandtan22

So I already bought SS Supertech Valves (the intake are the high flow undercut ones) and Supertech dual springs. Couldn't resist during black friday. I also already have the ECU.

I'd be doing a P&P for sure if I did #3. Would you recommend a mild head shave as well say .020'' range? I just don't want to be interference.

I won't touch the bottom after reading folks opinions except for maintenance stuff and maybe the shim in the oil pump.

blackandtan22

I am going with option 3. I pulled the head this weekend and wanted to get people's opinion on the condition of one of the cylinders (all seem about the same). All seems smooth, but wanted to see if color of walls or anything else is a concern.

my97miata

Why not add +1 mm valves while you're at it?

aidandj

iTrader: (5)

Pretty sure it it's interference stock. I think we determined this in another thread recently.

blackandtan22

So some time has passed and my plans have changed. I've decided to go all out. Let me know if I am missing anything big for a N/A build.

- VVT CNC head
- +1 valves
- light double valve springs
- Shim under bucket
- 85mm 11:1 pistons
- Manley forged rods
- Custom cams
- VICs intake port matched to skunk tb
- 3d printed intake
- MSLabs MS3
- Racing beat header
- 949 harmonic damper
- Billet oil pump
- Oil pan baffle
- coolant reroute
- arp bolts
- race bearings where possible
- Thermal coating: pistons, combustion chamber, exhaust ports, valves
- flow force injectors
- 8k redline