Restoration of BringaTrailer 240z - HLS30-35883

[inline6]

34 minutes ago, Captain Obvious said:

Yes, I believe a commercial setscrew type of device would work just fine. But as for the material composition... I believe that brass has a higher density than steel. So if your steel on is heavier, that would only because it's longer:
https://www.engineeringtoolbox.com/metal-alloys-densities-d_50.html
https://www.engineersedge.com/materials/density_of_common_engineering_materials__15896.htm

As for screwing it up into the bottom of the float, that would also satisfy the failsafe of closing the valve instead of holding it open. Only reason I didn't do that is I wanted gravity to have as little effect as possible on pulling the insert out of the float. I figured that gravity would have less of a tendency to pull it out if it were stuck into the side. Not that I really expect that gravity could possibly pull it out, but put it on the side just to be sure.

Thanks.  I found a weight calculator:
https://www.globalfastener.com/standards/detail.php?sid=Mjk5OQ==

Plugging in stainless steel and M8 X 14 mm, it shows 4.08 grams.  Just such a size is available from Belmetric without having to buy a whole bunch: 
https://belmetric.com/m8x1-25-a2-stainless-iso-4026-flat-point-allen-socket-set-screw/?sku=SS8X14FLATSS

I drove the car around the neighborhood again today with the engine up to temp.  There is a steep hill in the neighborhood, which is good for loading the engine.  At 2.5 turns out on the mixture screws, the car powers up the hill ok.  Still feels a bit lean though. 

Drove around for 10 minutes or so total.  Came back to the garage, and hopped out to look the engine over briefly while it was running.  Blipped the throttle a few times.  It sounds nice.  I blipped a few more times...  and the rear float bowl started spewing fuel up through the float vent again.  ☹️

While my intermittent overflow issue could be something else, (maybe the needle and seat is not working properly after all)  I think the problem is the extreme angularity of the float.  I am going to set the float height one more time using the 14-15 mm distance as shown in the factory workshop manual instead of wet setting at 20 mm below the float chamber cover bottom edge.  Using this method, I will check the fuel level using the clear tube as when setting the floats using the wet set method.  I want to see where the fuel height is compared to when wet setting at the 20 mm spec. 




Depending on what I find out, I may proceed with modifying the floats by installing one M8 X 16 stainless screw per float.

[SteveJ]

1 hour ago, inline6 said:

Does "Power Brake Exchange" only do swaps, with me having to "exchange" my Master vac for another?  I want to hold onto my original one.  

 

There is a local place to rebuild boosters.

[inline6]

Is this the place? https://harmonclassicbrakes.com/

[SteveJ]

4 minutes ago, inline6 said:

Is this the place? https://harmonclassicbrakes.com/

It could be.

[inline6]

I worked on the other seat today. 

Lots of setting them out in the sun to assist with making the vinyl fit.  My thumbs are jacked up - all the effort with persuading the vinyl onto the seat frames and pulling on it to get it over the hooks!  The bottom cushion is a breeze.  The backs are a pain.  This time I did not use any thin plastic.  I honestly don't think it made a difference.  Getting the seat back upholstery down low enough to get onto the hooks is difficult.  

Having done two seats now, I think I see another improvement that can be made with the foam.  Like the bottom cushion, and removing a bit from the front most edge, the seat back cushion could be modified for a better fit.  I don't have great pictures to show exactly, but the back seat foam rises above the top edge of the metal seat back by quite a bit.  You an kind of see that in this first picture.  The foam is molded with an indention that the frame bar fits to.  The head rest portion of the foam rises up over the frame by a good inch  or more.  However, as you can see (if you look closely) in the second picture, when you get the upholstery pulled down to where it belongs (to get it on the hooks on the bottom of the seat back frame) the foam which extended past the top of the back seat frame is compressed substantially, so that it is nearly in the same plane as the top of the frame.  In the second pic, the seat frame is what is locating the vinyl when looking at the vinyl on the back half of the head rest.  And the foam on the front half is not longer sticking up higher.  The vinyl on the front half of the head rest is quite tight, as is the vinyl on the back surface of the sear rest.  However, there is a bit of "void" around the periphery of the back half of the head rest vinyl.  

  

 

With some experimentation, I believe that again trimming and sculpting the top edge of the back seat foam (to lower it a bit), as well as adding some pieces of foam around the edge of the seat frame at the top and about 3-4 inches down the sides would provide a better finished result.  And, it would make it easier to get the back upholstery onto the hooks.

Thought I would show where I added some wire as well.  The bottom "roll" of the seat back uphostery (the back panel) has no cord or wire.  So, I inserted some annealed wire that I go from Home Depot.  I just ran it into the loop and pushed it through so that it ran the full distance of the loop   With this in place, I cut the vinyl at each hook.  And when I bent the hooks over, they hooked this wire, which spans the entire length of the loop.  Without the wire, the hooks would only be grabbing the vinyl for the width of each hook - there would be no reinforcement.

  

 

With both seat backs, I ended up with this in the corners:

  

 

I  think I will try some needle and thread work to tidy this up.

Edited October 27 by inline6

[Captain Obvious]

22 hours ago, inline6 said:

Using this method, I will check the fuel level using the clear tube as when setting the floats using the wet set method.  I want to see where the fuel height is compared to when wet setting at the 20 mm spec. 

Depending on what I find out, I may proceed with modifying the floats by installing one M8 X 16 stainless screw per float.

I suspect you'll find the fuel level lower than spec. I also suspect that it'll run ok even with the lower level. You might starve for fuel at WOT going up a big hill, but for around the neighborhood testing, I would wager that you'll be OK.

As for final positioning of your nozzles, I've found that 2 1/2 turns down is pretty good for stock. With the changes you made to the engine, maybe you need a little more than that? I wouldn't start to be concerned until you're finding it won't run well below say three turns down. At that point, I'd be looking for a vacuum leak.

[inline6]

I find it interesting that setting the float using 14 to 15 mm (I use a 3d nail cut and then ground to size and then fit between the metal part of the float and the roof of the float casting cover), achieves nearly level angularity of the float top surface with the underside of the float chamber cover.  The two methods are wildly different. 

I wonder if going down the road and chopping through bumps... I wonder if the float level rises up a bit more because the float is bouncing around in the chamber.  I don't know what the performance difference is with the fuel level too low vs "higher".  I guess more experimentation is in order.  I do have a LM-2 Innovate wideband sensor, and my exhaust has a fitting for it.  Maybe some testing with different fuel level settings is in order.

Edited October 28 by inline6

[Pat Carr]

On 10/26/2024 at 10:30 PM, inline6 said:

Is this the place? https://harmonclassicbrakes.com/

They are in Canton. I used them a year or so ago. They rebuild your unit. I think it took a week or so.

[Patcon]

Absolutely, if you have a wideband use it!

[Captain Obvious]

11 hours ago, inline6 said:

I wonder if going down the road and chopping through bumps... I wonder if the float level rises up a bit more because the float is bouncing around in the chamber.  I don't know what the performance difference is with the fuel level too low vs "higher".

I think the float bouncing around is part of it. I also think that you can get on the downhill slope of the float tang, and once that happens, you're doomed.

Wideband testing would be cool. I know there are people here that think the mixture ratio is highly affected by the float level. I'm not one of them. I believe float level has an effect, but I don't think it's that stark. Of course, however, without testing data, neither camp is anything but speculation. Wideband data would be very interesting.

[inline6]

20 minutes ago, Captain Obvious said:

I know there are people here that think the mixture ratio is highly affected by the float level. I'm not one of them. I believe float level has an effect, but I don't think it's that stark. 

It seems like the only thing it could effect would be fuel flow, and that with the level lower, it would "less".  Are there other effects you are can think of?

[inline6]

Some of my progress over the weekend included some modifications to the new interior trim panels.  First, I glued some faux suede material (purchased from www.yourautotrim.com) in the spot where the quarter panel trim piece overlaps with the rear panel.  I did this because the original trim panels in my track car squeak when they rub together.  While my restoration car may have a bit more torsional rigidity (being relatively rust free and much lower miles), the torsional rigidity is not high on these cars by today's standards.  So, this is an attempt to prevent noises.  I think the material these aftermarket replacement panels are made out of is less likely to squeak from rubbing also.

    

 

Additionally, I placed foam in the same locations as on the original pieces: 

    

I have some of this Gore-Tex that has been laying around for ages.  I use it for various rubber gaskets like the ones at the back of the rear panels (panel for the first two pics, and the third pic is of the aftermarket panel):

    

I put one piece of Gore Tex on the frontside , and one on the backside, and pinched them together at the back edge.  The aftermarket quarter panel trim has slight differences as seen in pics two and three here:

    

 

I used a 4 1/2" grinder with a mild sanding disc on it to quickly (and carefully) re-contour the front edge in a few places to improve the fit of the quarter panel piece to the car.  The front edge was taller than it needed to be in some places.  Fitment was much improved after removing some material.   

Can anyone tell me what this bracket on the quarter windows is for?  There is a small hole in the original quarter panel trim at this location.  I think it is simply there for securing the front edge of the quarter window interior trim panel, as it would be loose for most of the front edge otherwise.  Anyone have any pics of the hardware used at this location?  It may be specific to the 1971 cars.

Edited October 29 by inline6