My 1990 300zx Twin Turbo build by megaDan

7 minute(s) of a 731 minute read

Small update. Pissed I keep forgetting to upload photos, they're all on my old phone and camera at home. Rule #1, I know

I've put over 300 miles on it so far. First 300 or so were gentle, no boost, no higher than 3500 RPM, lots of engine braking. I changed the oil at 50 miles, 250ish miles, and I'll probably change it again at 500 or so. Currently using 5w30 conventional, and after about 200 miles the oil seems to thin out and at idle oil pressure drops below where im comfortable with. I was running 15w40 Mobil 1 in the old motor, and I'll probably go back to that after the breakin is fully complete. I need to do some more research on proper oil for new VG30DETT's.

I drove a lot this weekend, and the heater core started leaking again. The hose I used to splice the connections was too short, and as I tightened the clamp, it slid between the connection and just clamped the hose shut. Coolant all over. I fixed it Monday night and I really hope to not have any more problems with it.

Last night I took it out again to check my heater core fix and see if I remembered what boost feels like. I feel like I babied it enough for the first 300 miles, and now it was time to get a little more agressive. I still kept it under 60% throttle, but let boost get up to 5psi and 4500 RPM. Felt great! SMOOOOOOTH power delivery. Although it does smell a bit 'burny' after I boost which concerns me. I'm not gonna worry until I drive it a little more and maybe switch to a heavier oil.

Oh right, this weekend I filled up for the first time since November of 2010 (ouch). 15.7mpg! Not as good as I was hoping for, but this involved lots of idling and a pretty massive fuel leak after I pulled the motor (clamp on the fuel line let go and fuel siphoned out for hours).

I'm really hoping to see low to mid 20's after I get this tuned properly.

Next update will include pictures, I promise. 

4/19/2012

Thanks for all the positive comments guys. Its definitely been trying at times, especially dealing with all the stuff that has gone bad which I took for granted *cough* headwork *cough*.

The work itself is pretty easy, although my definition of 'easy' is probably skewed based on the two cars I own. It just comes down to a little basic knowledge, a factory service manual, some DIY guides on the internet, and tools. I bet I've spent less than $500 bucks on tools for everything I've done here (engine hoist and stand are borrowed). It all started with a 200 some piece Craftsman set I got for xmas a few years ago. 

Don't let the apparent scale of the work deter you. As long as you have some free time, a space in your garage, and a few extra dollars, you can tackle just about any project. Hell, I work 45-50 hours a week, marathon train on the weekends, play softball, ultimate frisbee, and have a (awesome supportive) girlfriend, and I've still got time to repair both my cars

As promised, here are some pics I took last week with our new DSLR. Still learning; and its been a few weeks since I had used it so I forgot most everything I read. Unfortunately no shots of the interior or the engine bay; they're still a work in progress while I sort out these little issues. The exterior looks pretty good though for an original 23 year old car.

4/19/2012

I took the (very) long way home from work today. Approximately 60 miles through the hills in Northeast Ohio (okay that doesn't sound very pleasant, but the Kirtland Hills/Chardon area has some really nice scenery) in 70 degree weather with he tops off and windows down. Days like today, even if I'm still babying it, make EVERYTHING worth it. Its an absolute dream to drive. Even with the minor annoyances.

50 miles into my drive I pulled up to a stoplight and it was misfiring at idle and at 18-19 AFR.

After I babied it home I found a vacuum cap had popped off. and  At least it was nothing major. Put a new one on with RTV this time.

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There were more than a few occasions when I didn't wanna deal with the car, which is partly why I put it back into storage in the fall instead of trying to finish it up. Especially when its just myself doing the work. But the turning point was my buddy Pat coming to help for a weekend. Just getting the motor to fire was BIG motivation; even if it required more 'redo' work afterwards.

AND...now that I've done it this many times...its not as much of a hassle. If it wasn't for all the coolant in the system and not wanting to make a mess, I could probably do a timing belt job in 3 hours now. Shutoff to restart.

If you're on the fence..go get one now. Before they're ALL molested. Its not that bad :-)