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Rose's Ride


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The first thumbnail below shows the electric pump assembled with its brackets, prefilter and fittings, together with some of the other parts which will be needed. The brackets will bolt to the spare tire well, with the pump below the low point of the gas tank.

 

The pump is a Holly red top, which will be more than enough for a twin SU induction on any L engine. The prefilter is 100 microns. The main filter located on the fuel rail (shown above) is 40 microns. The mechanical pump will be removed and blocked off. Note the wire. This two conductor jacketed wire (12AWG) is actually automotive wire, not speaker wire. It is rated at 105 C. See the discussion on grounding above for the reason for using it.

 

The second thumbnail shows the oil pressure (safety) switch assembly. The existing analog oil pressure guage line connects in a very crowded area, with the pancake adapter for the oil cooler taking up the space needed for a tee and the switch (third thumbnail). The switch assembly will be remoted to the nearby wheel well. The existing guage line goes in the open side of the tee.

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  • 3 weeks later...

Finally got the pressure switch in and wired. It was a pain because of the crowded area for the plumbing connection, due to the pancake adapter for the oil cooler.

 

If you would like more information on how this is wired, go here:

 

http://forums.hybridz.org/showthread.php?t=151929

 

and scroll down to post # 4.

 

The two thumbnails show the completed installation. The top wire on the RH column of the ground buss is the ground for the pump.

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The electric fuel pump is finally bolted in, plumbed and wired. It is bolted to the spare tire well, in a space in front of the stock fuel tank. This spot is convenient for line routing and is in a good spot for future maintenance (thumbnail 1). Note in the second thumbnail that the inlet to the pump is about an inch below the bottom of the fuel tank. This is to insure either a gravity feed or an effective siphon so the pump inlet is flooded all the time. This plan worked, as fuel ran all over me while I was making the connections. It looks like the pump might be exposed to road hazards here (speed bumps), but this is more a photo illusion than real. The rear suspension is lower, and would protect the pump. This picture was shot behind the RH rear tire, at the back of the wheel well.

 

The third thumbnail gives you a better perspective on the installed height. Note that the siphon side of the pump uses rubber line. The bend to get around to the tank outlet is too tight for braded steel line.

 

The last thumbnail shows the results. The car started first try, and the fuel pressure came up to 6 psi on the fuel rail at idle. This is with the stock pump still in line and the pressure regulator left set as it was. You may remember from the Problem post above (# 19) that fuel pressure varied randomly between 0 and 2.5 psi all the time.

 

Time to road test the car; one more post to follow on this topic.

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In the process of installing the electric fuel pump, I had to partially disassemble the star ground buss (Post # 15, above). I found that the steel hardware on the copper buss bar was corroding at an accelerated rate. There are only 961 street miles on the car, (over 3½ months), and there should not have been nearly that much corrosion in this period of time (thumbnail 2). It’s true that Florida is a big corrosion laboratory, but even so….

 

I have replaced half the bolts with brass hardware (thumbnail 1), and will do the rest when I get the larger hardware. This should resolve the issue, and brass is a better conductor anyway. I think this corrosion is probably due to dissimilar metals corrosion (galvanic corrosion or electrolysis), brought on by the high humidity, rain, heat and the current flowing through the star grounds. Although these copper buss bars regularly use steel hardware indoors and it works fine, apparently it isn’t a good idea on something exposed to the elements. Brass, being an alloy of copper and zinc, will not do this.

 

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In a discussion on another thread, grounding came up, and I did a quick study on star grounding versus stock grounding to prove a point. So if you followed Electrical Part 2: Grounding (Post #15, above), here is some further information which may be interesting:

 

Take this link, and scroll down to Post # 15 there:

 

http://forums.hybridz.org/showthread.php?t=151560

 

The sheer amount of voltage drop through the stock grounds surprised me, and I had expected it. (See the chart in the link.) The take-home lesson is that the small amount of voltage drop you experience in a properly done ground buss will be less than the voltage drop in a stock ground, and the star ground will improve the electrical performance of any device connected to it.

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With no other changes but the addition of the electric pump, the car is now running very strongly. The “running out of gas†feeling in the higher gears is entirely gone, and the engine now pulls strongly to redline in all gears. Acceleration is also improved, along with a newly-found tendency to break the rear tires loose.

I consider my hypothesis (from Post # 19 above) to be proven. In summary, it was:

“… the inlet of the mechanical pump is 18†higher in the chassis than the opening of the siphon tube in the gas tank. … most fluid pumps do not “suck†well, although they will “push†fluid quite well. Most pumps prefer their inlets be gravity fed, so that they are flooded continuously. This is obviously impossible as the car was originally made.â€

 

“From all of this I have concluded that installing an electric pump at the gas tank should solve the problem.â€

 

The thumbnails below show the homemade adapter for the fuel pressure switch NC contact-to-starter connection. This adapter avoids having to cut up the stock wiring loom.

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  • 3 weeks later...

The next step was to remove the mechanical pump, and re-set the fuel pressure regulator to about 4 psi at idle. Unfortunately, doing this caused readings on the fuel pressure gauge which didn’t make sense. I really hate things which don’t make sense. So, I left the mechanical pump connected and re-thought the fuel system.

After fooling with the fuel pressure regulator for a week, and being unable to get it to adjust correctly, I finally got annoyed and shot-gunned the problem. The first thumbnail below shows the fuel plumbing at the carburetors “beforeâ€, the second thumbnail “afterâ€. The major change was to re-connect the fuel bypass line, which necessitated the following:

The existing fuel pressure regulator was removed, and replaced with a bypass-type regulator. Although they look the same (both are Holley), they have different internal valving and different port assignments. The bypass regulator goes behind the filter and distribution, rather than ahead as the old one did.

It also turns out that no one makes a fuel log with a 3/8†port both in both ends. The “out†end port on everything I found was 1/8â€. So I drilled and tapped the one I had to 3/8†(thumbnail 3). The 40 micron filter remains as it was.

Thumbnail 4 shows the mechanical pump removed and blocked off, as well as the new braded steel lines on both supply and return. The Holly electric pump added previously flows more than double the later-years Z electric pump/mechanical pump combination, so there was no performance penalty. On the contrary, the Holley pump works better without the mechanical pump.

The shotgun scheme worked. The fuel pressure gauge now makes sense, the pressure adjusts, the electric pump is obviously much happier, and, most surprising, performance has increased yet again.

OK, now I’m done. With this project. Forever. Well, for now….

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  • 1 month later...

Even though I haven't posted in a month, work has been continuing. Much of it has been preparation for bigger jobs. The B+ power buss is nearly ready for construction. This will be a multi-part post when it's ready. I have also been working on recalibrating the fuel gauge (this one contains surprises), which I will post when I finally get it right.

 

The main progress has been in the area of making the cabin habitable. Rose's Z suffers from the usual exhaust fumes inside. I have looked at the considerable number of posts on the subject here on Hybrid Z. My conclusion from reading them is that there is no "silver bullet" fix. Rather, the ultimate fix is just a methodical sealing job on anything which will allow air infiltration from the rear. To that end, so far we have:

 

*replaced the windshield, its weatherstrip, and the chrome surround

*replaced the inner & outer weatherstrip on the quarter windows, and installed new stainless hardware

*replaced the rear hatch glass weatherstrip and its chrome surround

*replaced the inner & outer weatherstrip on the rear hatch

*replaced the taillight boots

 

The difference is already day and night. Where before there was a very distinct odor which would give you a headache in a half hour, now the odor is hard to detect. This project will continue.

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  • 3 weeks later...

The brass hardware on the buss bar is doing much better than the steel hardware did in resisting corrosion. However, it turns out that I could only find brass in sizes up to ¼â€. The larger terminals on the buss are 5/16†hardware, so I used silicon bronze hardware, which is available. Bronze, usually being an alloy of copper and tin (copper and silicon in this case) is an excellent electrical conductor, and is mostly very resistant to corrosion. Silicon bronze hardware is often used in marine electrical applications.

The thumbnail below shows the star ground buss with its bronze and brass hardware, new mounting hardware, and, at long last, the 1/0 battery cables I had originally specified. These were custom made. Also attached below is a schematic drawing (.pdf) of the star ground buss as it is currently configured. It has evolved somewhat since the original post # 15, above.

You are welcome to make use of the design for your own purposes, with the following limitations: if you post it elsewhere, please cite the source. Please remember this design is specifically for a normally-aspirated car, with an internally-regulated high output alternator.

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Star Ground.pdf

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With the grounding well in hand, it is now time to start working on the positive part of the circuit. On the 1971 Z, it really is necessary to sort out the grounding first, as it creates more problems than the B+ side of the circuit. That is not to say that there are not significant problems with the B+, which need to be rectified.

This first post on this topic covers the basic redesign of the high-amperage portion of the system. The design goals are extreme reliability, high performance, and very low maintenance.

The PDF file below is a single-line schematic of this portion of the circuit.

The first thumbnail below shows the parts for the project. The second shows the completed subassembly.

The main battery cable is being sized up to 1/0. The StreetWires fused distribution block eliminates the Z’s stock fusible link(s). The internally-regulated high-output alternator is connected via a 4 AWG cable and a 125A fuse. The other 4 AWG cable goes to a Flaming River battery switch, through a 100A fuse. This side of the circuit will feed everything on the car excepting the starter and alternator. The switch is not shown because it is already mounted on the car.

Thumbnail 3 shows the B+ buss mounted on the car and connected.

Sources for the components are as follows:

Custom battery cables:

http://www.kayjayco.com/index.htm

StreetWires components:

http://www.crutchfield.com/brands/StreetWires/

Flaming River switch:

http://www.summitracing.com/parts/FLA-FR1002/

B+ Main Buss.pdf

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  • 11 months later...

I can scarcely believe it has been nearly a year since I have posted to this thread. Some minor work has continued on the Z, and it has been driven pretty much daily. My project focus has been elsewhere. However, the emergency flasher switch broke, putting the car out of commission. As many of you know, this switch also takes out the turn signals and brake lights when it goes. Anyway, take a look at the posts here for a description of the fix: Hazard Switch Sticky Scroll down to #18, 19, and 20. This is a pretty good solution, if I say so myself.

Edited by Oddjob
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  • 1 month later...

Well, the odd behavior in the fuel supply system returned, despite all of the work detailed above. I got really sick of it, so I went completely back through every part of it, troubleshooting as I went. It turned out to be a multiple-failure sort of a problem, which meant I had been chasing it in a circle. The source of the problem was a failed coating in the stock gas tank (apparently done before I got the car). That was clogging the little siphon tube in the tank, which would get bad, and then clear at random intervals. This in turn was alternatingly clogging the two fuel filters.

 

I posted the solution here A "Stock" Fuel Tank Solution , as it is of general interest. Here's a preview:

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  • 4 weeks later...

This is a continuation of Post # 30, above, which shows the B+ Main Buss. This post covers the intermediate portion of the B+ wiring, and taken with the post above, completely resolves a major weakness in the original 240Z wiring.

 

Beginning on the Main Buss drawing, the 100A feeder (#4 AWG red) connecting to the Flaming River switch is the branch of the circuit shown as the input on the B+ Intermediate Buss drawing below. This connection, through the switch, literally feeds everything on the car excepting the starter and alternator.

 

Notice that an intermediate amperage fuse/distribution block is added immediately behind the switch. Two of the fused outputs feed the "original" fuse block. These two white wires originally connected to the fusable links in the engine compartment. They have been stripped out of the wire loom, shortened, and are now fed from the intermediate block. Notice, also, that the headlights and horns have been removed from the original fuse block and fed directly from the intermediate block. This is to remove the highest amperage draws from the original fuse block. Since there are now relays to operate the actual lights, only a small control current passes through the old block and headlight switch. These have historically been major failure points. The lights are also brighter, as the relays greatly reduce voltage drop.

 

The "original" fuse block is in quotes above, because it is actually the MSA upgrade. (MSA 50-5011) online catalog page

 

The other parts sources are the same as those shown above in Post #30.

 

This circuit has actually been on the car and running for quite some time and works well. There have been no blown fuses or burned out wires in the last year.

 

B+ Intermediate Buss.pdf

Edited by Oddjob
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  • 2 months later...

Bodywork on the car has started. It is being done in phases, as the car can't be off the street for an extended length of time. The first phase was a group of small, annoying modifications, including new outside mirrors, new marker lights, new rear bumper, better fit for the antenna, and sealing the badge holes. Note that these are not repairs, but hybrid solutions to various common problems. All of these are detailed below with pictures and parts lists:

 

Unusual Body Details

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