Coolant line delete/bypass necessary for NA's?

[Foosblood24]

I've been checking out this coolant line bypass operation but every single post or search or....anything....only mentions the Twin Turbo. The closest I got to anything NA was Z32 WIKI and all they said was:

"On an NA, the simplest solution is to simply cap the water lines with rubber bypass caps. Since there are no turbochargers, removing the cooling lines to the throttle bodies obfuscates the cooling lines altogether"

http://z32.wikispaces.com/Coolant+Line+Bypass

"Obfuscates" means to confuse. Assuming the author meant to say "makes the cooling lines obsolete" it still doesn't quite tell me if it's necessary for an NA and moreover, how to do it for an NA per the instructions are all for TT and with that being the case, there are at least parts of the job that are naturally not necessary for an NA job.

[Z-owned]

I wouldn't worry about it unless something arises requiring the plenum to be removed, at that point I would delete them to make things simpler in the future.

[300ZXttZMAN]

^This

[Foosblood24]

Later on down the road, I'll be doing a carbon fiber do-up on the plenum and various other engine parts for some cosmetic dressup. It will need to be pulled for that and I was looking to do the coolant bypass while it was off.

[ThisIsSparTTa]

Definitely do it. It's a major reduction in plenum removal time. What it is implying is that it requires extra work on the Twin Turbo, which then has to be explained, because its not immediately obvious to beginners (it can be scary). However, in the case of the NA, all you would do is block it at the heater core pipes, and you're done.

Also, you will find most guides for engine stuff to be based on the TT, just because they were more complicated. You can generally just skip over any unnecessary steps.

[Foosblood24]

Well geez! Is it really this easy?


https://www.youtube.com/watch?v=_WnTkPpQ6aw

[ThisIsSparTTa]

Looks about right. You can cut all that extra crap off your plenum, etc. I'd just cap rather than running more hose to leak and get in the way in the future, but that's me.

[Foosblood24]

So now for the silly question:

After the procedure is done, will she run hotter than normal?

[RubyRed300ZX]

Depends on where you live. If you live in a cold climate area, and intend to drive your Z during the winter, you'll need to keep the coolant lines to the throttle bodies. Prevents them from icing up. That's for N/A and TT.

[zswap0429]

Actually its not that bad even if you do live in a slightly cold area. The worst that will happen is that your throttle body will freeze open if you have been driving at a constant speed for a long time. If this happens all you will need to do is engage the clutch/ put it in neutral for autos. Then hit the accelerator with a little force and it will break away the ice. Its a half a second fix.

Now if you happen to be one of our CA drivers then im sure this could become a more common issue. In which case I would just leave it and deal with the hassle every time you pull the plenum.

Ive done this modification on both my na and my tt. Its extremely simple on both And I would suggest doing it asap if conditions allow

[DCaff300ZX]

As mentioned above, the coolant line delete is more about easier plenum removal first and lack of a possible coolant leak second, and really IMO isn't a priority on a purely mechanical basis.
I even doubt the value of the coolant line system in the worst conditions, as all of the reading I've done never claims that the icing "problem" has ever really occurred and is based more on old SU carburetor vapor lock issues with the original Z's.
Nissan engineers have long worried about this issue and as best as I've ever found did/still do it just to err on the side of caution.

[jp81]

I would like to perform the same thing on my 92' TT (RHD), but I haven't seen any different procedure as to how to complete this. If the lines are being removed under the plenum and bypassed, then why are they required to be removed completely? If its for esthetics then I'd like to save myself hours of work for having the plenum removed in the first place. Does anyone have any videos/instructions on how to perform this on a TT? thanks!

[ThisIsSparTTa]

There's plenty of guides and videos out there, including the ones at the top of this thread.

You don't have to remove them completely if you don't want, but it would be pretty sloppy. Plus, to get the plenum off you're going to end up destroying most of them anyways. You don't have to remove the extra metal pieces if you don't want. Honestly, its such a small time investment, I don't know why you wouldn't do this.