Author Topic: XXO/BVGC '38 Chevy Coupe Build  (Read 1026888 times)

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Offline Dr Goggles

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Re: XXO/BVGC '38 Chevy Coupe Build
« Reply #1545 on: January 26, 2013, 06:06:06 AM »
Can't believe how the ante has been upped on this build. After meeting the crew last year( who have more talent each than most teams) I guess it was only a matter of time before you all got the itch. Love the whole swap in front end, will learn to love the spoiler and scoop... :cheers:

go get 'em.
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Offline 38flattie

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Re: XXO/BVGC '38 Chevy Coupe Build
« Reply #1546 on: January 27, 2013, 08:24:00 AM »
James, you're way to kind, but thank you!

While we wait on the new roller cam from Dema, Dale and Don are busy with designing new lifter blocks and roller lifters. The lifters will be slightly oval, for indexing purposes.
 
From Dale:

Just finished the first design of the lifter block – talked to Don today as well.   He is going to make me a picture of the lifter design . . . so I know what he wants.    I’m going to have him make one out of aluminum first – to see what parts of the design will need to be tweaked (tough to tell without a prototype).
With sufficient thrust, pigs fly just fine. However, this is not necessarily a good idea. It is hard to be sure where they are going to land, and it could be dangerous sitting under them as they fly overhead. -- RFC 1925

You can't make a race horse out of a pig. But if you work hard enough at it you can make a mighty fast pig. - Bob Akin

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http://youtu.be/89rVb497_4c

Offline Rex Schimmer

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Re: XXO/BVGC '38 Chevy Coupe Build
« Reply #1547 on: January 27, 2013, 01:26:52 PM »
Buddy,
What it the plan for material for the lifter blocks? Steel with bronze sleeves, cast iron, block of cast bronze maybe? Does the lub for the lifters come from the crank case "splash and clatter"? or is there an individual oil line that supplies the oil?

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

Offline 38flattie

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Re: XXO/BVGC '38 Chevy Coupe Build
« Reply #1548 on: January 27, 2013, 03:12:39 PM »
Rex, the lifter blocks will be cast, and the lifters will be 1018 cold rolled steel, carbonized then drawn 400. Rollers will be Harley .850" wheels and axles.

The stock lifters were hydraulic, and fed from the pressurized oiling system. We'll add another pressure section to the dry sump, and dedicate it to the lifters, plugging the factory feeds out of the block.
« Last Edit: January 27, 2013, 03:38:13 PM by 38flattie »
With sufficient thrust, pigs fly just fine. However, this is not necessarily a good idea. It is hard to be sure where they are going to land, and it could be dangerous sitting under them as they fly overhead. -- RFC 1925

You can't make a race horse out of a pig. But if you work hard enough at it you can make a mighty fast pig. - Bob Akin

http://www.flatcadracing.org/
http://youtu.be/89rVb497_4c

Offline Milwaukee Midget

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Re: XXO/BVGC '38 Chevy Coupe Build
« Reply #1549 on: January 27, 2013, 03:37:01 PM »
The stock lifters were hydraulic, and fed from the pressurized oiling system. Well add another pressure section to the dry sump, and dedicate it to the lifters, plugging the factory feeds out of the block.

That should get you more oil where I suspect you'll be needing it - the mains.

This one just keeps getting better and better.

 :cheers:
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Well, I guess we're making a LOT of progress . . .  :roll:

Offline lsrjunkie

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Re: XXO/BVGC '38 Chevy Coupe Build
« Reply #1550 on: January 27, 2013, 04:12:49 PM »
I concur!
Maybe there is no Heaven. Or maybe this is all pure gibberish. The product of a demented hill billy who has found a way to live out where the winds blow. To sleep late, have fun, drink whiskey, and drive fast on empty streets with nothing in mind except falling in love or getting arrested.    H.S. Thompson

Offline BoredAndStroked

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Re: XXO/BVGC '38 Chevy Coupe Build - Completed Lifter Blocks and Lifters
« Reply #1551 on: January 27, 2013, 10:16:23 PM »
Hey Gang - been working all weekend on some SolidWorks 3D designs for our own custom roller cam setup - Buddy posted an earlier design yesterday (still in progress).

Don, Buddy and I have been scheming on how to make this setup --> which requires the creation of our own lifter blocks (there are four that bolt into the engine) - along with the lifters themselves. Dema Elgin is making the roller cam.

Anyway, Don came up with the idea of using 'flats' on the sides of the lifter bodies for indexing. We've never seen that done before - so we're going to give it a try. The lifter blocks will be CNC produced out of solid hunks of cast iron stock. Most of the surfaces, holes, etc - will be done on Don's CNC machines. The lifter body holes themselves will be done with a precision EDM machine - which can hold extremely accurate tolerances - should be able to get exactly the shapes we need (at least that is the theory!).

We're going to be using Harley .855 roller lifters and axles - the rest we'll make from scratch. Now it is on to some prototype blocks - to see if I have the design somewhat "close".

We're going to have a full-length oil galley in each block - so that every lifter has it's own oil supply.

Here are some pictures:

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Goal:  Have fun, make friends, be safe - learn as much as possible, contribute when I can and hopefully get in the books!

Offline Rex Schimmer

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Re: XXO/BVGC '38 Chevy Coupe Build
« Reply #1552 on: January 27, 2013, 10:42:47 PM »
Don't you think that EDMing the lifter bores is a real case of over kill. Since you are making your own lifter blocks couldn't you just make the lifters guide on the rollers like many do? I also might have a problem with the surface finish of the blocks after the EDM operation. It does leave a some what "disturbed" finish and to get better finish quality you are required to do multi passes with additional tools or hone and polish.

Rex
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Offline BoredAndStroked

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Re: XXO/BVGC '38 Chevy Coupe Build
« Reply #1553 on: January 28, 2013, 09:16:16 AM »
Hey Rex:

Can't really guide it on the rollers -- like what I call the 'T-Slot' approach that Harley uses.   With a .850 roller and a .730 body, there is not enough material (roller) left in the T-Slot when the roller is on the heal of the cam (as the cam lifts over .500).   I've only used EDM (many years ago) to remove things like broken taps - but I hear that there are certain machines that can do very high quality work.   We'll obviously test and see what we get back - if we don't like it, we can do a traditional "keyway" approach like Jesel and others do.

Anyway, I'm happy to see what can be done . . . then we'll know if this approach has merit or not.   Nothing ventured . . . nothing gained my friends!   :cheers:
Member of FlatCad Racing Team - 2011, 2012
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Offline 38flattie

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Re: XXO/BVGC '38 Chevy Coupe Build
« Reply #1554 on: January 28, 2013, 09:22:45 AM »
Rex, I passed on your concern, as well as an email I received. Here is Don's reply:

 
 
  Aw  Grasshoppers   -- Let me tell you a story !!!!! 
 
  I have no worries with an EDM  I have been using them for about 25 years,,   In the raw condition after cut there is a residue left over from the coating on the wire,  a simple electro polishing after will remove the residue, and a little -- very little hand work you can archive  a 16 ra finish !!!   Read below
 
 

Electrical Discharge Machining, EDM is one of the most accurate manufacturing processes available for creating complex or simple shapes and geometries within parts and assemblies. EDM works by eroding material in the path of electrical discharges that form an arc between an electrode tool and the work piece.  EDM manufacturing is quite affordable and a very desirable manufacturing process when low counts or high accuracy is required.  Turn around time can be fast and depends on manufacturer back log.


The EDM system consists of a shaped tool or wire electrode, and the part. The part is connected to a power supply. Sometimes to create a potential difference between the work piece and tool, the work piece is immersed in a dielectric (electrically nonconducting) fluid which is circulated to flush away debris.

 
The cutting pattern is usually CNC controlled.  Many EDM machine electrodes can rotate about two-three axis allowing for cutting of internal cavities. This makes EDM a highly capable manufacturing process.

EDM comes in two basic types: wire and probe (die sinker). Wire EDM is used primarily for shapes cut shapes through a selected part or assembly. With a wire EDM machine, if a cutout needs to be created, an initial hole must first be drilled in the material, then the wire can be fed through the hole to complete the machining. Sinker (die sinking EDMs are generally used for complex geometries where the EDM machine uses a machined graphite or copper electrode to erode the desired shape into the part or assembly. Sinker EDM can cut a hole into the part without having a hole pre-drilled for the electrode.

EDM Power System. The discharge energy during EDM is provided by a direct current pulse power generator. The EDM power system can be classified into RC, LC, RLC, and transistorized types. The transistorized EDM power systems provide square waveform pulses with the pulse on-time usually ranging from 1 to 2000 msec, peak voltage ranging from 40 to 400V, and peak discharge current ranging from 0.5 to 500 A. With the RC, LC, or RLC type power system, the discharge energy comes from a capacitor that is connected in parallel with the machining gap. As a result of the low impedance of plasma channel, the discharge duration is very short (less than 5 msec), and the discharge current is very high, up to 1000 A. The peak voltage is in the same range of transistorized power systems.

The transistorized power systems are usually used in die-sinking EDM operations because of their lower tool wear. Capacitive power systems are used for small hole drilling, machining of advanced materials, and micro-EDM because of higher material removal rate and better process stability. WEDM power generator usually is a transistor-controlled capacitive power system that reduces the wire rupture risk. In this power system, the discharge frequency can be controlled by adjusting the on-time and off time of the transistors that control the charging pulse for the capacitor connected in parallel with the machining gap.

Key EDM System Components: The machining gap between tool and work piece during EDM must be submerged in an electrically nonconductive dielectric fluid. In die-sinking EDM, kerosene is often used as a dielectric fluid because it provides lower tool wear, higher accuracy, and better surface quality. Deionized water is always used as a dielectric fluid in WEDM to provide a larger gap size and lower wire temperature in order to reduce the wire rupture risk. This fluid also serves to flush debris from the gap and thus helps maintain surface quality.

Copper and graphite are commonly used as die-sinking EDM tool materials because of the high electrical conductivity and high melting temperature and the ease of being fabricated into complicated shapes. The wire electrode for WEDM is usually made of copper, brass, or molybdenum in a diameter ranging from 0.01 to 0.5 mm. Stratified copper wire coated with zinc brass with diameter of 0.25 mm is often used.

In the traditional die-sinking EDM process, the tool is fabricated into a required shape and mounted on a ram that moves vertically. The spark discharges can only occur under a particular gap size that determines the strength of electric field to break down the dielectric. A servo control mechanism is equipped to monitor the gap voltage and to drive the machine ram moving up or down to obtain a dischargeable gap size and maintain continuous sparking. Because the average gap voltage is approximately proportional to the gap size, the servo system controls the ram position to keep the average gap voltage as close as possible to a preset voltage, known as the servo reference voltage.

In a WED machine, the wire electrode is held vertically by two wire guides located separately above and beneath the work piece with the wire traveling longitudinally during machining. The work piece is usually mounted on an x-y table. The trajectory of the relative movement between wire and work piece in the x-y coordinate space is controlled by a CNC servo system according to a preprogrammed cutting passage. The CNC servo system also adjusts the machining gap size in real time, similar to the die sinking EDM operation. The dielectric fluid is sprayed from above and beneath the work piece into the machining gap with two nozzles.

 

The power generators in WED machines usually are transistor-controlled RC or RLC systems that provide higher machining rate and larger gap size to reduce wire rupture risks. In some WED machines, the machining gap is submerged into the dielectric fluid to avoid wire vibration to obtain a better accuracy. The upper wire guide is also controlled by the CNC system in many WED machines. During machining, the upper wire guide and the x-y table simultaneously move along their own preprogrammed trajectories to produce a taper and/or twist surface on the work piece.

Advantages of EDM :


Complex shapes that would otherwise be difficult to produce with conventional cutting tools
Extremely hard material to very close tolerances
Very small work pieces where conventional machining tools may damage the part from excess cutting tool pressure.
There is no direct contact between tool and work piece. Therefore delicate sections and weak materials can be machined without any distortion.

Disadvantages of EDM :


Relatively s low rate of material removal.
Additional lead time and cost used for creating electrodes for ram/sinker EDM.
Reproducing sharp corners on the workpiece is difficult due to electrode wear.
Electrical power consumption is high.
Material mustbe electrically conductive

Mechanical Design Considerations:


Relax the surface-finish for the part, if feasible. This allows the manufacturer to produce the part with fewer passes, at a higher current level and a higher metal-removal rate.
Design or prepare the part such that the amount of stock removed by EDM is relatively small. Use traditional machining techniques to remove the bulk of the stock with the finishing operations performed by EDM. This significantly reduces the amount of time and cost for each part.
The EDM manufacturer should consider fixtures such that several parts can be stacked and machined simultaneously or a single part can have several EDM operations performed simultaneously.
When existing holes are to be enlarged or reshaped by EDM, through holes are preferred to blind holes as they permit easier flow of dielectric fluid past the area being machined
There will be some degree of materials exchange between the EDM wire / probe and the base material. Specifya cleaning procedure is galvanic corrosion is a concern.
The minimum internal corner radius of cut feature will dictate the maximum wire diameter that can be used. Obviously, the wire diameter needs to be at less than double the minimum inside corner radius. However, one also has to account for the amount of final overcut, plus a small amount of “maneuvering” room, so that the CNC can generate the corner. This is analogous to CNC contour milling, in which accurate internal corner radii are generated by machine motion, rather than just plunging an end mill into a corner and accepting the result. Usually, “the bigger, the better” for wire diameters up to .010”. It is important to note that the new “twin wire” machines can employ a different strategy for these conditions, however, most of us do not have this luxury. Recommendations for small diameter wires include: • High Tensile Brass wire for .006” diameter
• Steel Core wire from .002” to .004” diameter
• Moly wire from .002” to .004”
• Tungsten wire from .0008” to .002”


Dimensional Accuracy (+/- 0.0005 inches per inch)
Feature Profile accuracy of .0003 is obtainable with cutting path
Features to feature true position of .002 is reasonable and down to .001 is possible when geometry requires removal and reattachment of wire.

Surface Finish (micro inches Features created by EDM have an "orange peal" appearance.
16 Ra is achievable, 64 or higher Ra is typical and less expensive


With sufficient thrust, pigs fly just fine. However, this is not necessarily a good idea. It is hard to be sure where they are going to land, and it could be dangerous sitting under them as they fly overhead. -- RFC 1925

You can't make a race horse out of a pig. But if you work hard enough at it you can make a mighty fast pig. - Bob Akin

http://www.flatcadracing.org/
http://youtu.be/89rVb497_4c

Offline SPARKY

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Re: XXO/BVGC '38 Chevy Coupe Build
« Reply #1555 on: January 28, 2013, 09:26:00 AM »
COE   :? cast has a reputation of not growing much
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

"Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure or nothing."   Helen Keller

We are going to explore the racing N words NITROUS & NITRO!

Offline 38flattie

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Re: XXO/BVGC '38 Chevy Coupe Build
« Reply #1556 on: January 28, 2013, 09:27:53 AM »
COE   :? cast has a reputation of not growing much

Sparky, I'm not following you........
With sufficient thrust, pigs fly just fine. However, this is not necessarily a good idea. It is hard to be sure where they are going to land, and it could be dangerous sitting under them as they fly overhead. -- RFC 1925

You can't make a race horse out of a pig. But if you work hard enough at it you can make a mighty fast pig. - Bob Akin

http://www.flatcadracing.org/
http://youtu.be/89rVb497_4c

Offline Captthundarr

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Re: XXO/BVGC '38 Chevy Coupe Build
« Reply #1557 on: January 28, 2013, 11:11:56 AM »
Ref. flatties post detailing EDM - condensed version - works real good, real accurate, vary little hand finishing required. I / we used it to produce precision punch press dies.
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Offline SPARKY

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Re: XXO/BVGC '38 Chevy Coupe Build
« Reply #1558 on: January 28, 2013, 12:29:01 PM »
The CAST material for the bore will not likley grow as much from heat as the STEEL lifter--- will most likely will need a larger bore than one would think if the two metals had the same  COE (coefficient of expansion)
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

"Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure or nothing."   Helen Keller

We are going to explore the racing N words NITROUS & NITRO!

Offline Rex Schimmer

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Re: XXO/BVGC '38 Chevy Coupe Build
« Reply #1559 on: January 28, 2013, 12:37:38 PM »
I assume that our plan is to drill a pilot hole for the roller body and then wire EDM the final shape?

Rex
Rex

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