1972 240Z restomod

[sweatybetty]

3 hours ago, Namerow said:

Chris:

While you've got all these parts out on the bench, perhaps you can try a little experiment to verify something that I found with my own Z's blower motor/fan:  With the fan mounted in the blower casing, try running it first with 12V power connected with the 'normal' polarity, and then with reverse polarity. I found a significant increase in the volume of output airflow with the fan running in 'reverse' (and, no, I can't explain why)

i found the same thing with mine

[Namerow]

2 hours ago, sweatybetty said:

i found the same thing with mine

Even more puzzling is this:  I bought a Honda Civic blower so that I could swap out the 'underperforming' Z blower.  Same squirrel-cage impeller design, same inner and outer diameter, ~ same blade profile and chord. The motor, of course, is different. 

Installed in the Z blower housing, the Honda motor/impeller pair generates less overall noise than the Z's and it does put out more apparent CFM than the Z unit.  A lot more when compared with the Z impeller operating in the 'correct' direction but probably only a 25% improvement in comparison with the Z impeller operating in the 'reverse'.  As a side note, I seem to recall that the Honda impeller was relatively insensitive to direction-of-rotation.

So:  If you observe the same results as did sweatybetty and I, you might consider wiring up your Z blower motor to run in reverse.  Could be a low-impact way to enjoy the bonus airflow.

[grannyknot]

The squirrel cage on my blower is the amber coloured clear plastic cage, not the original white steel cage.

I found the opposite than you guys did, red wire from the blower motor to battery positive, black wire from blower motor to battery negative, with the squirrel cage turning in the proper direction (that is, with the sharp edge of the vanes of the cage pointing forward and cutting the air, counter clockwise as viewed from the passenger seat)  is at least 3x the speed and air volume as in the reverse direction and reverse polarity.

[grannyknot]

I started work on the quarter windows, the fixed corner at the bottom of the frame is where water can accumulate and rot out the steel brace that is welded to the stainless steel frame. After soaking the brace in Evaporust I drilled through the spot welds and Mig welded it the frame back together and sealed it all back together.

The brace really should be SS as well and maybe before it all goes back together I'll grind out that old peice and replace it with SS.

[grannyknot]

Namerow, Sweaty, I wonder if the 3 speed resistor has anything to do with your blowers running faster with reverse polarity?

[sweatybetty]

im going to re-neg my previous post

after looking at it again, what i did was re-wire so 12v runs to the switch, through the resistor, through the motor and then to ground. iirc, the factory used the switch to direct the ground.

[grannyknot]

I wish I had taken some pics of the inside of this gas tank before I took it down for chemical stripping, it was nasty in there. Here are a few pics of the outside, you get the idea.and this is how it turned out, this is the same company that is going to dip the whole car for me. I poured some Eastwood's After Blast, phosphoric acid inside and out to keep the rust off.

[wheee!]

Did you strip it yourself? What chemicals were used? Looks incredible!

[Patcon]

Looks spotless inside!

[grannyknot]

I took it to Techno strip, a chemical dip company in Etobicoke south of me,http://technostrip.com/restoration.html they have these chemical vats 20ftx8ftx6ft. Mostly they do industrial stuff but they also do brisk business in auto restoration. They can put the whole vehicle in at one time, grease, rubber,seam sealer, paint and rust are gone. All you get back is clean metal with a water soluble rust inhibitor sprayed on. So far I've used them for the frame of a Triumph TR6 and this gas tank, both came back perfect.

Once I get the Z torn down it's going to them for the big dip, I'll be taking lots of photos.

8 hours ago, wheee! said:

Did you strip it yourself? What chemicals were used? Looks incredible!