The Wounded Z

slmjim+Z1BEBE wrote:

Nerdy wrote: We can't claim the cup method ourselves. Saw it pictured long ago on a forum somewhere, don't remember where, maybe here on KZR?

I like the way you did that Jim. I did something similar when I was first restoring my bike, I posted it on my YouTube Channel at the 3m 10 sec mark :

But I like your implementation much better if used with four cups, one for each carb. Like the idea of not having to screw anything on each time.

Love what both of you are doing on this project!

Try mineral spirits as a fluid. You need a fluid with the a close specific gravity of gasoline.

Joe

If you want to use pure gasoline in the engine you need to find a liquid with an SG of about 0.71. If you want to use gas with ethanol you will need a liquid with a slightly higher SG because ethanol has an SG of about 0.79. A 10% (by volume) ethanol mixture would result in an SG of about 0.72.

TexasKZ wrote: Several companies offer calibration fluids that mimic gasoline, but are far less dangerous to work with. Sadly, they tend to be quite expensive.

Link?

Good Ridin'
slmjim & Z1BEBE

hardrockminer wrote: If you want to use pure gasoline in the engine you need to find a liquid with an SG of about 0.71. If you want to use gas with ethanol you will need a liquid with a slightly higher SG because ethanol has an SG of about 0.79. A 10% (by volume) ethanol mixture would result in an SG of about 0.72.

Few stations around here sell pure gasoline, and none are close enough to be practical for routine use. Those that do only sell it during the cooler fall/winter/spring months. We do use it in the lawn equipment.

We use 10% ethanol pump gas in all of our bikes & cages because it's ubiquitous & convenient. Local stations switch formulations twice a year from 'winter blend' to 'summer blend' and back as a smog control measure; something about vapor pressure...

We looked at SG some time ago & didn't find anything both common and safe to use in the shop where a standing pilot light in the water heater poses an ignition risk. Shop is in the basement, so odor in the upstairs living quarters must be considered too.
We'll have to revisit SG now that we have an easy test setup & warm outdoor weather. We'll focus on both at distilled water and glycol-based antifreeze again and calculate the difference between float levels of both and gasoline level. We'd prefer distilled H2O just for simplicity and safety around our dogs.

Neither of us are materials scientists or chemists. What we think we understand is, SG is the same as specific density (SD) (?) We get lost in that.

Perhaps our test liquid could serve dual purposes, to eliminate waste, dont'cha know. :dry: Here we see that beer & water have virtually identical SG.
www.engineeringtoolbox.com/specific-gravity-liquids-d_336.html

Might be entertaining...

Good Ridin'
slmjim & Z1BEBE

No eBay APP ID and/or Cert ID defined in Kunena configuration

slmjim+Z1BEBE wrote:

TexasKZ wrote: Several companies offer calibration fluids that mimic gasoline, but are far less dangerous to work with. Sadly, they tend to be quite expensive.

Link?

Good Ridin'
slmjim & Z1BEBE

www.hartridge.shop/shop/calibration-flui...luid-25l-8802012-25/

Don't know if these folk ship to the U.S.
www.voulis.com/en/car-workshops/workshop...ne-calibration-fluid


Also ---

www.rockvalleyoil.com/cf.html

According to this scientist, density and SG measure different things, but the resulting values are ALMOST the same.
www.thoughtco.com/density-and-specific-g...y-differences-606114

Considering that we are talking about a measurement with fairly wide latitude in a fairly primitive device, I reckon we can call them even and go on with life.

Specific gravity, or SG is simply the density of something divided by the density of water. It is therefore a dimensionless number. In the metric system the density of water is 1 gram/cubic centimeter (or milliliter) under standard conditions, so the unit number of SG is the same as the unit number of density for any object. In the English system the units of density would be weight/unit volume, such as lbs/cubic foot. Water (if I recall correctly) weighs 62.4 lbs/cubic foot. Pure gasoline weighs about 45 lbs/cubic foot. The SG would be around 0.72.

I looked up the weight of gasoline. It varies considerably for some reason from 45 to 49 lbs/cubic foot.

Jim, you mentioned using 3 mm. I have it in my head that it's 3.5 to 4.5, so I use 4 mm. Am I using the wrong number?

That's interesting stuff! Great ideas about specific gravity, even with the 10% ethanol blends. I will be in this predicament soon. When I finish the 28's I am rebuilding. I don't want to put anything flammable into them. As I plan to sell. I always went by 1/8" under the body. That's 3.17mm.
I procrastinated so long, after I had parts zinc coated before holidays. Then after Mecum Las Vegas, third week January . Everybody with any Z1 oem stuff was all over eBay! Early 73 Carbs were sold for $1000? So then the world changed, and I missed the selling boat! But soon my carbs will be on eBay for sale. Dry, no fuel levels set, just by proxy, like I always have done. Just think of all the people here and about the FB forums, that have no clue what their float levels are set at? JMO!
Stay Safe as always!

hardrockminer wrote: Specific gravity, or SG is simply the density of something divided by the density of water. It is therefore a dimensionless number. In the metric system the density of water is 1 gram/cubic centimeter (or milliliter) under standard conditions, so the unit number of SG is the same as the unit number of density for any object. In the English system the units of density would be weight/unit volume, such as lbs/cubic foot. Water (if I recall correctly) weighs 62.4 lbs/cubic foot. Pure gasoline weighs about 45 lbs/cubic foot. The SG would be around 0.72.

I looked up the weight of gasoline. It varies considerably for some reason from 45 to 49 lbs/cubic foot.

Jim, you mentioned using 3 mm. I have it in my head that it's 3.5 to 4.5, so I use 4 mm. Am I using the wrong number?

Weight, SG, SD... that's all what confounds us when searching for a suitable substitute for gasoline. We'll be looking at the calibration fluid TexasKZ linked to. So far, everything we've looked at that is close to gasoline SG / SD is too volatile for use in our shop.

Can't say that 3.5mm - 4.5mm is 'wrong' because it falls within the spec in the White manual.
Pg. 75 of the White Manual, paragraph titled "Fuel Level Measurement and Adjustment" states:
"... .10 - .18 inch (about 1/8 inch, or 2.5 - 4.5 mm below the edge of the carburetor body.)" Also, Fig. 273 on Pg. 75 indicates "about 1/8 inch" while at the same time indicating fuel level (about?) at the bottom edge of the shoulder of the float bowl.

I'm fairly simple-minded sometimes, and the visual of Fig. 273 led me astray for years, making me focus on fuel level at the bottom edge of the shoulder. That was before I reconciled in my mind the horizontal axis of the venturi bore in Fig. 273 with the "32mm +/- 1mm" fuel level spec in Table 3, Carb Specs on Pg. 72, which places fuel level somewhat higher than the edge of the float bowl shoulder.

Our experience, particularly with the late '74 & all '75 carbs (side drain screw, 1.5 slide, etc.) is, if fuel level is set at the bottom of the float bowl shoulder, that results in lean running in the needle and main jet ranges. 3mm is about (there's that word again... :dry: ) 1/3rd. of the way up from the bottom lip of the float bowl shoulder to the lower edge of the carb body.

1/8" = 3.175mm. That's on the rich-ish side of the 2.5mm - 4.5mm spec. That being said, we have a dislike for vague-ish qualifiers such as "about". So, based on experience, we focus on 3mm at the bottom of the concave fluid meniscus.

Good Ridin'
slmjim & Z1BEBE

Does this mean that if I set my fuel levels using E10, and later decide to run a few tanks of E0, that I should reset the fuel levels?
Put another way, how big a change in SG will there need to be to make a measurable difference in fuel level?

Warning for Slimjim and Z1Bebe, there will be many assumptions in the following question----

Assuming that I set the levels using a liquid with a 10% lower SG than the fuel I normally use. Will the levels be 10% lower when I reintroduce the .72 fuel? If so, then we are talking about the fuel level dropping from 3mm below the body to 3.3 mm below? Do any of us measure that accurately, and would that make any difference in how the engine runs?

This is really getting "technical" now. I can't possibly envision resetting float levels based on what type of gasoline I am running. Is there really that big a difference in them? Slimjim and Z1 Bebe: Is it possible for you to post a picture of where you would normally set the fuel level? If I set mine near the top edge of the float bowl I immediately have issues with one or two carbs pushing fuel out of the overflow tubes. So for right now I have the float levels on carbs 3 and 4 set a bit lower then the FSM recommends to avoid this. Nothing scientific here or recommended, just a SWAG as to where I should set the level to avoid fuel dump. Thanks...
Rick H.

It also occurs to me to wonder how much the fuel level varies while the engine is running.

Dare we even consider the effects of vibration, bumps, or omg, fierce cornering?

AAAAAARRRRRRGGGGGGHHHHHH!!!!