In virtue of the fact that you are going to dismantle the motor of my 300 ZX, (water damage) what modifications or improvments do you recommend? This motor has never been opened or taken apart prior to this occassion.


thanks Gino
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---1994 300ZX---

 

Welcome to ZDriver!

Is this the VG30DE or VG30DETT motor?
How much $$$ are you willing to spend?
Are you going to do the rebuild yourself?
What is the hp goal?

 

Is the VG30DE motor!
How much $$$ are you willing to spend? no too much (repair is around 5k)
Are you going to do the rebuild yourself? no the mechanic do
What is the hp goal? simply better performance possible, i dont want a frankestein!

 

I'd get a replacement VG30DE, if you dont want power gains. A motor alone will be around 600, and about 1000 if you want one with a gearbox.

If you're going to rebuild it, i'd take it apart so you don't have to take it to a mechanic, plus you learn how to do it yourself, gain some knowledge. CAUSE KNOWLEDGE IS POWER!

A Frankenstein...?

300HP out of a VG30DETT is a monstrosity?

 

What kind of water damage does it have?

 

who's the mechanic? i've got to speculate that it won't really matter if you put any upgrades on because if this is your average general mechanic that doesn't specialize in z32's then the build won't last long anyway.

2nd the suggestion to get a used replacement motor. you could find a low mileage one and end up with way less money invested, plus the capability of selling your bad motor for a couple hundred.

that said, it's an n/a, and the only upgrades i really find justified are exhaust, intake, lightweight flywheel, and 1 piece drive shaft. and the exhaust part is pushing it because a good system runs for a ton of money. you spend $400-1k for about 10-20 hp. trust me on this. i have an n/a, i wish it was faster, but time and studies have brought me to the solid conclusion that i'm not going to pay more than i have to for more power by upgrading my n/a.

 

Didn't we have this discussion before? Other than some tighter tolerances (in some cases), the VG30DE is just like any other engine. I built two in my garage and both lasted fine (one blew a head gasket but it was my own fault for mixing up the head bolts and not remembering that two of them are shorter).

You guys forget that a used engine is just as risky (if not more) than a rebuild. You have no prior knowledge of how that motor was treated or maintained, and it could come to you with worn rings or all sorts of problems.

If he has the money for a rebuild, I'd recommend that over a swap ANY day.

 

you yourself are the one that explained to me the little known danger of turning the crank.

anyway, are there not plenty of other things that could get screwed up? you constantly say the same thing, that average mechanics are not trustworthy for the z. perhaps the prediction that it won't last long enough to enjoy the upgrades was a little severe, but i'm surprised to hear you defend the idea of having the average mechanic work on the z.

don't take this as an argument though. i'm more just conversing because i'm bored. so sick of this weather keeping me inside.

 

In any engine, there are plenty of things that can get screwed up. He also only mentioned water damage, which does not presuppose a necessity for crank machining (more along the lines of new rods and valves), so the crank's coating wouldn't necessarily be compromised.

I didn't realize until now that he said a "mechanic" would be doing this work... that is something I do not support.

Engine machining and assembly should be left to a machine shop (or Specialty Z/Import Parts Pro), not some mechanic. A machine shop could handle the build just fine... a mechanic probably couldn't.

I've only ever been an advocate of getting a used engine when funds are lacking or a different engine (i.e. a TT engine) is needed completely. Otherwise, I consider them far too risky, given the lack of information that comes with them.

 

good point, the one that the crank won't need machining.

what can be done with these cranks though? i really can't find any testimonies of anyone having done anything to an older crank that needed work that worked out. is new the only option?

 

I'm 99.9% sure you can get it re-coated.

But I had mine re-ground... used over-sized bearings... lasted in two engines that made over 550hp and is still good. It's sitting in the block on the stand in my bedroom as I type this, awaiting a build. I was unaware of the coating when I built the first engine, so I didn't worry about it and it has worked out fine since. I don't recommend it for anyone else, mostly since I don't want to be liable if something does happen. But if my crank fails, it's my own fault and I can accept that.