Category Archives: e-fab parts

Iron Triangle Race to the Finsh


Making a taillight on the ol’ end mill.

tailight IT

 

Oil Tank, battery box, regulater/rectifier mount installed….

oil tank IT

Vent and return lines plumbed…

oil tank 2 IT

Top motor mount, check….top motor mount IT

I like this area…lots going onoil area IT

alt IT

Notice 3 wires coming out of that alternator! 48 amp 3 phase charging system from Cycle Electric feeding an Anti Gravity lithium ion battery. Less drag, lighter weight, faster recharge times.

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Iron Triangle Fender


The fender for my new bike (for the brooklyn invitational, then artistry in iron), has an entirely stainless steel rear fender. Recently I made the wiring conduit that leads the taillight wires from the frame backbone to the taillight location at the rear of the fender. To curve the thin walled tubing, I used a low-tech method that works well for tubing too thin to be formed in my roller- torch bending. Common thought is that using a torch to heat and bend thin tubing would result in the tube collapsing and “pinching”, but thats not the case if done right. By heating a large area of the tube to an even cherry red, and applying soft pressure, a perfect curve can be achieved!

here she is finished and installed:

fender 1

 

fender 2

 

fender 3


Iron Triangle Update


Bike is progressing! not long now…

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Making stainless steel exhaust clamps. I made a simple fixture to form the flat stock to the correct diameter.

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After a lot of metal finishing….

image (11)

 

My only gauge will be cylinder head temp, which is the hottest part of the engine. Gauge itself is from an airplane.

photo (31) image (13) image (15)

This box got recessed into the top of the gas tank, and the other cutout is for my two mil-spec toggle switches. This is all cut out with basic hand tools and my sander.

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Iron Triangle Progress


Bike so far

complete bike 1

Gas tank is mounted on three points, here are the front two mounts

tank mounts

The exhaust pipes are 1 3/4″ OD, the common header pipe size. The problem with that is the actual exhaust port size on twin cam heads is 1 5/8″. Usually there is an abrupt step where the heads meets the flange. I machined the flanges with the inside tapered to perfectly blend the two sizes. Also, they have a flat, perfectly matching taper on the outside of the flange, so there is no way the gasket material can squeeze into the exhaust flow. This happens often with aftermarket exhausts! These are machined from solid stainless steel on my manual lathe.

exhaust flanges 1

exhaust flanges 2

Here is the underside of the gas tank, with two giant mounts welded in. They are 1.5″ OD flange, milled down where it goes through the tank. This distributes the load over a larger area of the floor of the tank (which is made from 1/8 chrome-moly flat stock).

underside of tank


New Bike Update


Since returning form California I have been focusing entirely on the new bike, the “Iron Triangle”. It will be powered by a new engine I am building, which I have nicknamed the “Mini Stroker”. I will attempt to explain why I named it that: It is a hybrid of a Harley Evolution motor (built from 1984-1999) and a Harley Twin Cam motor (built 1999-present). In a nutshell, what I am taking from the Evo are the case mounting system, the bore and stroke, and the wrist pin. The Twin Cam parts are the cams, oiling system, heads, and crank assembly. The reason for this is because I feel that the Evo bore and stroke combo is superior, in many ways, to the twin cam. However, the Twin Cam is a far stronger motor (due mostly to the robust flywheel design) , and has a far more reliable oiling system.

So, since a first generation Twin Cam was 88 cubic inches (3.75″ bore by 4″ stroke), and an stock Evo is 80 inches (3.5″ bore by 4.25″ stroke), that means that in a Twin Cam crankcase I have increased the stroke from stock, making it a “stroker” motor. however, due to the reduced bore it has less displacement than a stock Twin Cam- hence “Mini Stroker”.

In addition to all this, I also changed the cylinders from stock cast aluminum with an iron liner to billet ductile iron. This is heavier, but also far stronger and more dimensionally stable under heat. In other words, as it gets hot it doesn’t change shape as much. This means tighter tolerances all around. I also used a head/ base stud pattern for attachment to the case and heads, instead of the thru-studs an Evo or Twin cam would have had. Again, stronger. In order to make the Twin Cam heads work with my new bore and stroke combo, (as well as a copper o-ring head gasket) modifications had to be made. I wanted to reatain the stock Twin Cam combustion chamber, but it needed to be reduced to 72 cc’s of volume to achieve my 10.5-1 static compression ratio. This meant decking (milling down) the heads significantly. In addition, the new flange system was milled into it to accept the o-ring gasket.

Ok, enough about all that, here are some pics:

I was lucky to have two trusted advisers here to help, my main man Alex Lerner from SL NYC in Queens, and Satya Kraus from Kraus Motor Co in northern Cali.

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This is the “cam-plate”, the component that supports the cam shafts, routes oiling, and holds the oil pump.

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Installing the bearings on the flywheel

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Checking the endplay on the left case half

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Completed short block

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Here is completed frame. All chromoly, all made here at Efab

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closeup of front motor mount

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More to come!


Mini Stroker Progress


In between various customer projects, I have slowly been making progress on my engine. The Heads are twin cam 88 originally, but have been modified. I reshaped the majority of the fins, rounding them around many of the sharp edges. Here is an overall view of the cylinder, head, and rocker box mocked up.

cylinder and head

A typical twin cam has aluminum cylinders with an iron sleeve pressed into it. I had Randy at Hyperformance make me billet iron cylinders. The advantage being that there is no way for the iron sleeve to become loose in the aluminum cylinder, because it is all iron! These are secured by a “head and base” stud setup, much like a knuckle, pan, or shovelhead would have been. Here a set of 4 studs hold the cylinder to the crankcase, and another set of 4 hold the head to the cylinder.

An evo or twin cam, traditionally, used a set of 4 studs that ran all the way through the head, cylinder, and into the case. This  is a simpler way to attach all the parts, but not as strong.

In addition to the stud conversion, I have adapted the heads to use a superior head gasket method, the metal o-ring. On a stock twin cam (or any other harley) a composite flat gasket was used, sandwiched between the head and cylinder. They work fine, but can blow out if extreme cylinder pressures are achieved. The metal o-ring setup eliminates the flat gasket, instead using a series of steps machined into both the head and cylinder, with a copper ring integrated into it. All of the mating surfaces make contact with each other at the exact same time. This requires extremely precise machining, but results in a nearly indestructible union. I can only assume, too, that heat transfer between the head and cylinder will be improved, due to the metal to metal contact.

Here is the top of the cylinder. The surface rust inside the bore will be gone when the final honing happens.

cylinder top

You may have noticed that there are no oil drain passages in the cylinder. This is because I have re-routed them to the outside of the head and cylinder. This is good for 2 reasons. One is it keeps the oil cooler, since it is not touching the approx 300 degree cylinder walls. The second is that there is no chance of oil weeping between the head and cylinder surfaces, since it bypasses that area completely.

I had to machine a passage through the fins of each cylinder, through the wall, and into the oil drain passage inside the head. This was then tapped for a custom made fitting. Obviously, the original hole underneath has to be plugged as well.

Here is the stainless drain fitting coming out of the head. It has a 6 AN fitting on the end for hose attachment…

oil drain

I have also added compression releases to the heads. Compression releases are simply tiny valves that allow the cylinder pressure to be bled off as the starter motor rotates the engine. This takes a huge strain off the starter motor and battery, and they simply pop shut when the first combustion occurs, allowing the engine to start. It is unusual to see them on motors with small displacement,  but there is no downside to using them. Also, my compression ratio and the resulting cylinder pressures are far higher than either a stock evo or twin cam, so despite the small displacement, the starter will still need all the help it can get.

compression releases

Installing compression releases is easy with the right tools. It requires a precise hole to be drilled and tapped, which enters the combustion chamber between the exhaust valve and the spark plug hole. More to come…


Hand Made Handle Bars


After a brief hiatus I am back on the “mini stroker” chopper project. I decided that it was the right time to make handlebars. The first step, for me anyway, is to make a wire form of what I want so I can hold it up to the bike and get a visual. This is not a precise thing, rather just a basic reference. I know roughly how much rise I want, and know roughly the whith, but that still leaves a lot of room for creativity.

bars 1 wire form

 

I am making these bars out of 304 stainless steel, 7/8″ OD, .120″ wall thickness, seamless tubing. I will end up using about 4 feet of it, approx $80 worth of raw materials. This is opposed to the catalog bought, .049″ wall, recycled mild steel, chromed Chinese bars found on most “custom bikes”.

bars 2

 

I start with the center bends and work outward. I have reference marks drawn on the tubing. This is so I can take the bars out of the bender, check them, then put them back in the exact same location for further bending. Speaking of bending, this is my bender. It consists of a typical bottle jack and various mandrels, a few of which I made specifically for tight radius handlebar bends.

bars 3

 

For tight radius bends like these, I use two different mandrels, a gradual “starter” mandrel and a secondary tighter one.

bars 4

 

The hardest part of making bars is keeping everything symmetrical. The exact location of the bends, the angles relative to each other, equal pullback on each side, etc. This is all done through bubble levels, angle finders, and measuring them against a flat table. There are a minimum of 6 mandrel changes, each of which entails some dis-assembly of the bender. Oh yeah, the material is springy, so I have to “overbend” each bend past the point I want, then let it spring back slightly to where I want it.

bars 5

 

Almost done with the bending stage….

bars 6

 

The next stage is polishing them. Sounds easy enough but keep in mind I cant just go straight to the buffer- First I have to sand them. The buffer can only take out microscopic scratches, not the deeper ones left from the manufacturer. For that I need my trust Burr King sander, set up with a slack belt, and a variety of sanding grits.

046

 

Not a great pic I know, but trying to simultaneously sand the bars and take a picture was not easy. Same for the buffing. Needless to say there were about 2 hours worth of sanding and buffing to get them to a mirror finish level.

bars 7

 

bars 8

 

I threw the grips on there to see how it looked. I am happy for now, but there is always the chance that they will need further modification as the bike evolves.

I’m sure I will get many comments on my “sweet chrome apes” from the local do-rag crowd. Followed by “how much for a set uh dem?”. Followed by a look of disgust and confusion…