Author Topic: Milwaukee Midget  (Read 3255240 times)

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Offline Stainless1

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Re: Milwaukee Midget
« Reply #6675 on: January 23, 2018, 11:54:47 AM »

Heads up - both inlet and outlet on the radiator will be at the bottom, regardless of whether I replace or refurbish the existing radiator.

Midget please re-read 3rd paragraph of 5.E.3 and maybe get a reading from the SCTA before venturing off script with the radiator...

Might want to think about using the gas tank as a water tank, or as a radiator in a water tank...
 :cheers:
Stainless
Red Hat 228.039, 2001, 65ci, Bockscar Lakester #1000 with a little N2O

Offline Stan Back

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Re: Milwaukee Midget
« Reply #6676 on: January 23, 2018, 03:19:03 PM »
I don't know if this pertains to your packaging problems, but it doesn't say you have to use the radiator.
Past (Only) Member of the San Berdoo Roadsters -- "California's Most-Exclusive Roadster Club" -- 19 Years of Bonneville and/or El Mirage Street Roadster Records

Offline fordboy628

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Re: Milwaukee Midget
« Reply #6677 on: January 23, 2018, 05:47:06 PM »

Heads up - both inlet and outlet on the radiator will be at the bottom, regardless of whether I replace or refurbish the existing radiator.

Midget please re-read 3rd paragraph of 5.E.3 and maybe get a reading from the SCTA before venturing off script with the radiator...

Might want to think about using the gas tank as a water tank, or as a radiator in a water tank...
 :cheers:


I don't know if this pertains to your packaging problems, but it doesn't say you have to use the radiator.


Chris is involved in the "week from hell" as far as work is concerned, and probably does not have daytime computer access.    And, he probably is not going to have any time for serious cogitation.

As far as the cooling system is concerned, I don't think any decisions have been made yet.    Unfortunately, some other important decisions have languished, and it is now "crunch time" to make Speed Week 2018.

So with the intent of "full speed ahead and da** the torpedoes", some of the support systems are going to be relegated to "tried and true" formulations.    This is going to be more for speed of installation and convenience  than any other reason(s).     Cutting edge solutions may need to be resolved in Special K competition appearance, part deux.



I personally like the gas tank as a water tank idea.    It would definitely require a pressure bleed system.     I have questions about how much pressure it might tolerate though.

 :cheers:
Fordboy
« Last Edit: January 23, 2018, 07:00:37 PM by fordboy628 »
Science, NOT Magic . . . .

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"There is nothing permanent except change."    Heraclitus

"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."     Albert Einstein

Offline fordboy628

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Re: Milwaukee Midget
« Reply #6678 on: January 23, 2018, 06:32:22 PM »
Piston ring specifications:

OK, just got off the phone with Total Seal:

For a wet sump, with Darton sleeves, 10 K rpm, their recommendation:  M2973XC    (Which, I guess, makes you today's prescient genius . . . . . .)

Order placed for a 4 cylinder set of 75.5mm  (2.972"/2.973")

2/3 days shop time until shipment, sent to the ranch.


Set consists of:

Top:    1.0 mm SS T/S
2nd:    1.2 mm Napier twist
Oil:      2.8 mm low radial tension


AND, cause 'm smrt 2, . . . . .  I got the groove machining dimensions . . . . . .   :-D 

Top:   1.0 mm x .105" groove depth
2nd:   1.2 mm x .125" groove depth
Oil:     2.8 mm x .112" groove depth

 :cheers: :cheers: :cheers:
Ringydingyboy
Science, NOT Magic . . . .

I used to be a people person.  But people changed that relationship.

"There is nothing permanent except change."    Heraclitus

"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."     Albert Einstein

Offline Milwaukee Midget

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Re: Milwaukee Midget
« Reply #6679 on: January 23, 2018, 09:15:11 PM »
Thanks, Mark.

I know I've toyed with the idea of using the fuel tank for a water tank, but seeing as both the stock tank and a radiator need to be retained, I'm thinking given the tight confines of the Midget, despite the isolation in the trunk, I'd feel safer with the fuel tank outside the vehicle.
"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

Offline Rex Schimmer

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Re: Milwaukee Midget
« Reply #6680 on: January 24, 2018, 08:06:32 PM »
Chris and Mark,
I have a couple of comments regarding your cooling system thinking. 1. Chris you said that the radiator inlet and outlet will both be on the bottom of the radiator, so I am assuming that you are running a double pass radiator and that you will have vent valves on the tops of both tanks to make sure that the radiator is actually full of water before you run? I will also assume that the design of the radiator, if it is double pass, is such that the design will flow the cooling water at a sufficient velocity to insure turbulent flow and not at a large increase in back pressure due to the increase flow velocity. This is very important with electric water pumps as they do not produce much pressure without an accompanying reduction in actual flow. The largest Davis Craig electric pump EWP 150 looses 50% of its flow rating at 5 psi of back pressure! (Note that Davis Craig are the only electric water pump people that actually give you flow vs  back pressure graphs.) So any additional flow restrictions can counter the supposed cooling efficiency gain of doing a double pass radiator. 2. Mark, you  are proposing to machine a special venturi shaped water out let "restrictor". Why are you going to go to that trouble? I would assume that you are thinking about the potential to cavitate  the cooling water as if flows through the restriction if it was a simple washer with a hole in it, i.e. a sharp edge orfice. Per Chris he is planning to use a 24 lb pressure cap, and this sets the system internal ambient pressure, actually the maximum ambient internal pressure, as long as this internal pressure it above 15 psi it cannot cavitate . Cavitation in water is caused by reducing the waters pressure below its saturated vapor pressure, which for water is one atmosphere i.e 14.7 psia let's call it 15 psi. If the system is at a system pressure of over 15 psi the water cannot cavitate.

Rex

Mark,
Rex

Not much matters and the rest doesn't matter at all.

Offline Crackerman

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Re: Milwaukee Midget
« Reply #6681 on: January 24, 2018, 09:37:13 PM »
With both inlet and outlet on the bottom, will y'all be running a Degas bottle.

Offline fordboy628

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Re: Milwaukee Midget
« Reply #6682 on: January 25, 2018, 06:18:44 AM »

With both inlet and outlet on the bottom, will y'all be running a Degas bottle.


My understanding of a degassing bottle is that there is no flow per se, only space for the gases to accumulate, with perhaps a provision for the gases to be "bled off".

Since many race cars have the power units mounted higher in the chassis than the heat exchanger(s), air locks, coolant voids and proper coolant flow are constant issues.    I have a dislike of cooling systems that require complex filling procedures for proper operation.    They are not foolproof.    And any air left in the system accumulates at the highest point, typically the cylinder head.    Nothing good ever results from that situation.

A "pressure bleed" system, on the other hand, prevents this issue.    A pressure bleed system however, requires much more complex plumbing.


This is a schematic for the Cosworth designed and recommended cooling system for the Cosworth BD series engines.


This system is a "partial" pressure bleed system, as it makes no provision to bleed the heat exchanger(s).     Notice that in addition to a header tank (expansion tank) this system uses a "swirl pot" to degas coolant as it exits the engine.    This type of system is the "minimum" necessary, and typically only works well in cool environments, ie: racing in Britain.     Race cars with this type of cooling system typically need "modifications" to cool properly in the USA or in southern Europe.   Just ask Neil about CanAm cars . . . . . .

Sorry about the small size of the diagram.     Those of us with older eyes need to temporarily zoom the page to 175% or higher.

 :cheers:
Fordboy
Science, NOT Magic . . . .

I used to be a people person.  But people changed that relationship.

"There is nothing permanent except change."    Heraclitus

"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."     Albert Einstein

Offline fordboy628

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Re: Milwaukee Midget
« Reply #6683 on: January 25, 2018, 07:26:02 AM »
Chris and Mark,
I have a couple of comments regarding your cooling system thinking. 1. Chris you said that the radiator inlet and outlet will both be on the bottom of the radiator, so I am assuming that you are running a double pass radiator and that you will have vent valves on the tops of both tanks to make sure that the radiator is actually full of water before you run? I will also assume that the design of the radiator, if it is double pass, is such that the design will flow the cooling water at a sufficient velocity to insure turbulent flow and not at a large increase in back pressure due to the increase flow velocity. This is very important with electric water pumps as they do not produce much pressure without an accompanying reduction in actual flow. The largest Davis Craig electric pump EWP 150 looses 50% of its flow rating at 5 psi of back pressure! (Note that Davis Craig are the only electric water pump people that actually give you flow vs  back pressure graphs.) So any additional flow restrictions can counter the supposed cooling efficiency gain of doing a double pass radiator. 2. Mark, you  are proposing to machine a special venturi shaped water out let "restrictor". Why are you going to go to that trouble? I would assume that you are thinking about the potential to cavitate  the cooling water as if flows through the restriction if it was a simple washer with a hole in it, i.e. a sharp edge orfice. Per Chris he is planning to use a 24 lb pressure cap, and this sets the system internal ambient pressure, actually the maximum ambient internal pressure, as long as this internal pressure it above 15 psi it cannot cavitate . Cavitation in water is caused by reducing the waters pressure below its saturated vapor pressure, which for water is one atmosphere i.e 14.7 psia let's call it 15 psi. If the system is at a system pressure of over 15 psi the water cannot cavitate.

Rex

Mark,

My thoughts about your concerns, in no particular order, as usual . . . . . . .

1/    I am determined to run a "pressure bleed system".    Not just because it is foolproof, once properly sized, but because it is also low maintenance.
       The system will be similar to the Cosworth system schematic above, but with some additions.
       Since the K engine family has known cooling issues, Chris and I are agreed that preventing these issues from occurring in the MM is paramount.

2/    Yes, the radiator will need at least 1 bleed line.

3/    I'm not in favor of running only an electric water pump, for the reasons you stated.   I want the higher pressure and more turbulent flow that the stock pump can generate.

4/    The cylinder head will need 1 bleed line at the front since the water outlet is at the rear.    This is already done on the stock installation, so it will be relatively simple to plumb in.

5/    I just want to have a provision in place to install a "restrictor" in the outlet line if needed.    I want them available in my toolkit at Bonneville, not something I wish I had brought.
       My experience with washer type restrictors is mixed.    I want to avoid negative "possibilities".

6/    24# pressure caps are readily available for racing.    But you are right, we can use less pressure.    We can probably run 18# successfully and still have a bit of a "safety margin".

7/    The system we will use will be similar to the Cosworth system in the diagram above.   There will be the aforementioned additional bleed line from the cylinder head.
       And, there will be at least one additional bleed line from the upper radiator tank, for the purpose of bleeding any air from that portion of the system.

8/    Bleed lines will be 2/3 mm ID, possibly AN-3.

9/    The "suction line" will be 1/2" or 5/8" ID, possibly AN-10.

10/  The header/expansion tank will be between 2/3 pints capacity.   Bleed lines to connect near the top, suction line to exit on the bottom.
       Pressure cap neck to have a provision for a coolant recovery system.

11/  We will be running a coolant recovery tank, not just because we don't want to contaminate the salt, basically because I'm lazy.

12/  I not sure we need to run a swirl pot.    It can be added if required.

13/  I think I covered everything . . . . .

I designed this type of "pressure bleed" system decades ago, mainly to solve cooling system problems inherent in British road racing cars.    It is complex, but it works, every time, given proper component sizing and placement.    In several instances, with more efficient cooling, we were able to run smaller heat exchangers to gain a weight advantage over our competition.

The system works because small amounts of constantly bypassed coolant keep the radiator(s) and engine filled, IF the expansion tank is sufficiently sized.    Minor overheating can be avoided with the coolant recovery tank, because the system will draw coolant back in, as opposed to getting a "gulp of air".


I freely admit that this setup is undoubtedly "overkill" for Land Speed Racing.    But I also am concerned about being held at the starting line with the engine running and the water temperature rising.    I don't want to find out how much of an overheating this engine can tolerate without sustaining damage.    That would be dumb, and expensive.

This year's Milwaukee Midget Racing Motto is "stolen" from Joe Madden, manager of the Chicago Cubs, who tells his players:

    "Just get out there and try not to suck . . . . . . ."


Well, actually, we want the pressure bleed system to "suck"! ! ! !

 :cheers:  :dhorse:  :cheers:
Waterboy
Science, NOT Magic . . . .

I used to be a people person.  But people changed that relationship.

"There is nothing permanent except change."    Heraclitus

"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."     Albert Einstein

Offline fordboy628

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Re: Milwaukee Midget
« Reply #6684 on: January 25, 2018, 07:36:30 AM »
midget,

Today is:   Prince Spaghetti Day! ! ! !

OOPS! !   :?   :?

Make that:

Piston Order Day! ! ! !



I'll report back later . . . . . .

 :cheers:
Lackeyboy
Science, NOT Magic . . . .

I used to be a people person.  But people changed that relationship.

"There is nothing permanent except change."    Heraclitus

"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."     Albert Einstein

Offline Milwaukee Midget

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Re: Milwaukee Midget
« Reply #6685 on: January 25, 2018, 08:52:55 AM »


Piston Order Day! ! ! !

Seems I get piston every day . . .

Tell Tommy I will catch up with this no later than Tuesday.


"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

Offline Interested Observer

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Re: Milwaukee Midget
« Reply #6686 on: January 25, 2018, 07:07:21 PM »
From reply #6680--

Quote
Cavitation in water is caused by reducing the waters pressure below its saturated vapor pressure, which for water is one atmosphere i.e 14.7 psia let's call it 15 psi.

This is true. (At 212F)

Quote
If the system is at a system pressure of over 15 psi the water cannot cavitate.

This is not necessarily true.  In the same sense that applying a 25 lb pressure cap will raise the vapor formation (boiling point) to about 240F, decreasing the pressure below 14.7 psia will lower the “boiling point” and result in the possibility of vapor formation.

While the nominal cooling system pressure may be atmospheric (14.7psia), at the pump inlet and in the vanes the local pressure can be well below the system pressure due to the “suction” at that side of the pump.  Giving rise to the possibility of cavitation there.

However, on the output side of the pump pressure will be at or somewhat above system pressure and any water vapor bubbles will likely collapse unless the temperature is above 212F, or 240F for the 25 lb cap system.  Ergo the advantage of the pressurized system.

Offline fordboy628

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Re: Milwaukee Midget
« Reply #6687 on: January 27, 2018, 10:59:04 AM »
midget,

According to the online calculator Tom uses:

1000 cc engine,

8500 rpm peak power,

125 bhp,

4 injectors,

85% duty cycle,

43.5 psi fuel pressure,

gasoline,

.50 bsfc,

18 lbs/hr fuel flow, per injector


Small changes in bhp output, 130; duty cycle, 80%; bsfc, < .45; affect required flow by 1 lb +/-.     Fuel pressure can be raised modestly higher than 43.5, to raise total flow by a bit.

The advice is to use as small an injector as will be sufficient for peak bhp @ max duty cycle.    That way throttle respond should be crisp, coming up through the range.

I'd appreciate any thoughts from more experienced EFI guys.

 :cheers:
Carbboy
« Last Edit: January 27, 2018, 11:06:10 AM by fordboy628 »
Science, NOT Magic . . . .

I used to be a people person.  But people changed that relationship.

"There is nothing permanent except change."    Heraclitus

"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."     Albert Einstein

Offline fordboy628

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Re: Milwaukee Midget
« Reply #6688 on: January 27, 2018, 11:14:01 AM »
midget,

Spent some time on the phone with Diamond yesterday.   No engineering will occur prior to them receiving the chamber casting (lucky I made 2 . . .  :-) ) and some specs and forms.

I'm working on that stuff right now.   Sending it off USPS Priority Mail today if possible.   Monday at the latest.

 :cheers:
Fordboy
Science, NOT Magic . . . .

I used to be a people person.  But people changed that relationship.

"There is nothing permanent except change."    Heraclitus

"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."     Albert Einstein

Offline Stainless1

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Re: Milwaukee Midget
« Reply #6689 on: January 27, 2018, 12:09:13 PM »
Wow... went back 6 or 7 pages to find the throttle bodies... do you know what injectors are in there?  My guess is they should be 27-31 lb.  You should send them out to be checked and cleaned anyway... and since they came off an engine that makes a little more HP than you think you will end up with they should provide enough fuel. 
Bigger is better to a point... don't want them so big that you can't turn them off enough to idle so I would avoid 60 lb+ unless you are thinking BMS in the future.
Keep up the good work, it is looking good
Stainless
Red Hat 228.039, 2001, 65ci, Bockscar Lakester #1000 with a little N2O