Belly Tank Build Diary

[Mike Brown]

The attachment to the outside of the rod end bracket (the rod ends are attached in double shear) needs have compliance.  I machined bushings that can be pulled tight and still allow the plates to rotate.  My plan is to swing the plates up out of the wind and secure them with wire ties when not in use. 

[Mike Brown]

I attached a photo of the plate with the strap hook inserted.  The "D" shaped hole gives the hook much better bearing than a round hole would. 

[Stainless1]

Mike, we use tire tie downs on our lakester.... just the fronts at the races, all 4 for the road. 

[mc2032]

Kinda like this except on the front tires.

[Jack Gifford]

Mike- Can I assume you don't fiddle with a manual mill for shapes like that- especially D-shaped holes?

[Mike Brown]

Mike- Can I assume you don't fiddle with a manual mill for shapes like that- especially D-shaped holes?

Jack, my mill is a toolroom style milling machine.  It has handles for manual operation and I then use the CNC control as a digital readout.  It is a bed type mill so the head moves up and down on the Z axis.  It does have a quill so I can use it like a drill press.  I made the part from 1/4" bar stock.  Two round holes were drilled and the part was held to a fixture plate with plugs inside the holes.  I used CNC to machine the perimeter.  After the perimeter was machined the parts were held in step jaws in the vise.  The "D" shaped holes were created using a 1/4" diameter mill to square off the bottom while in manual milling mode.  The toolpath for both CNC and manual milling was generated in AutoCAD.  I make a lot of parts in this manner, I call them cookie cutter parts.  Holding the part down with fasteners allows access to all sides of the part. 

[WOODY@DDLLC]

I can testify to that!  :-P

[Jack Gifford]

But aren't the corners of the 'D' only about 1/16" radius, requiring a 1/8" or smaller diameter cutter?

[Mike Brown]

But aren't the corners of the 'D' only about 1/16" radius, requiring a 1/8" or smaller diameter cutter?

The inside radius of the "D" hole is 1/8", I used a 1/4" cutter. 

[Mike Brown]

I installed new belts for this season as the originals were out of date.  I had been searching for belts and looked at many at the PRI show.  I liked the Ultra Shield belts and they manufacturer their belts in Texas.  They were able to supply a five point harness with 3" to 2" shoulder straps to fit the Hans device and camlock on the sub belt.  The price was reasonable and the belts arrived in less than a week.  The belts fit well and I feel that I can get them tighter much easier than the original belts.  Practicing my bail out I find that the camlock is easier to release than the original latch and link.  I am very pleased with the new belts. 

[Mike Brown]

I am researching the possibility of running a low dose (20-25%) of nitromethane next year.  I want to do this in conjunction with electronic fuel injection.  My research so far indicates that with my current engine this will generate approximately 100 additional horsepower.  I have been doing fuel requirement calculations based upon published air fuel ratios.  VP has been very helpful with information.  My fuel pump and injectors will need to change to larger versions and be compatible with nitromethane.  Jim Craig at Weldon recommends their 2345-A pump.  I have two injector manufacturers that can supply injectors for the application.  It seems to be a daunting task to collect information on low dose nitromethane applications with lots of conflicting information.  Nobody does it better than the Afflick team that has been 131+mph on a 100cc blown fuel motorcycle.  100cc, 54hp, 14,800rpm, 24psi of boost on 40%nitro.  As they point out their application is gravity fed and carbureted so not much information can be exchanged or interpolated for my application.  Hopefully more to come. 

[Rex Schimmer]

Mike,
You are treading a pretty lightly treaded path, nitro using electronic fuel injection. Went through your calculations and not having any actual background in what you are attempting I can only say that your numbers look good. Are you running E85 presently? Have you tried methanol? VP makes an "oxygenated" version the call M-5 and it is supposed to provide a 5-7% power boost, Duke and I are "hopefully" going to give that a try this year but we also have at least part of the injector set up to run nitro. We use a Kinsler mechanical injector system, i.e. lawn sprinkler, but because we are really pretty much only concerned with the air/fuel mixture at max hp the mechanical system works pretty well. One of the drag racing forums on nitro stated that up to approx 30% nitro a well set up methanol system, (with mechanical injection) can be used as is and this is because of the higher density of nitro.

Keep us all up to speed on what you are doing as I think you are treading on new ground and I like your approach.

Rex

[stay`tee]

G'day Mike,  have successfully ran 30* naturally aspirated (EFI) in my Kawasaki ZX12R (1200cc) @11500rpm, and set 4 FIM and one DLRA record in the process,, I profess to know little, and as you say, information regarding small doses is almost non existent,,

First suggestion, do not ask advice of any top fuel persons because all thay know (and want to talk about) is 95+*,,

The temperature of the mix is critical, as you would be aware temperature changes percentage,, (ambient, blower, 5mile)

You are attempting to burn/ignite two different fuels,, Below 30* Nitro dilutes the Methanol, above 30* the BTU's in Nitro take control over the Methanol, the heat energy released becomes much more pronounced with each percentage added,,

I ran your calculations against mine (long hand, not computer generated) and came up pretty close to yours,, I note that yours are based on 4.81a/f, .744 lambda, may I suggest go richer,,

Volume, you can never have enough volume, also that methanol/Nitro mix is heavy so slow down the injectors duty cycle to 40-60*(larger injectors), did I mention volume  ,,

Dose small percentages make a difference ?, you betcha it dose 

[Mike Brown]

Mike,
You are treading a pretty lightly treaded path, nitro using electronic fuel injection. Went through your calculations and not having any actual background in what you are attempting I can only say that your numbers look good. Are you running E85 presently? Have you tried methanol? VP makes an "oxygenated" version the call M-5 and it is supposed to provide a 5-7% power boost, Duke and I are "hopefully" going to give that a try this year but we also have at least part of the injector set up to run nitro. We use a Kinsler mechanical injector system, i.e. lawn sprinkler, but because we are really pretty much only concerned with the air/fuel mixture at max hp the mechanical system works pretty well. One of the drag racing forums on nitro stated that up to approx 30% nitro a well set up methanol system, (with mechanical injection) can be used as is and this is because of the higher density of nitro.

Keep us all up to speed on what you are doing as I think you are treading on new ground and I like your approach.

Rex

Rex,

Thank you for your comments.  I am currently running VP's MS109 which is an oxygenated racing gasoline with an octane rating of 104.  My stock injectors are maxed out running about 90% at wide open throttle.  With anything that I do I have to switch to larger injectors.  Working small steps at time up to nitromethane I do plan to run E-85 (probably VP C85) to insure that I have the fuel pump/injectors worked out before making the switch to nitromethane.  My methodology to date has been to have a professional tuner generate the tune up on a chassis dyno.  I then make a few laps at the local 1/4 mile dragstrip to gather data on the logger.  When everything looks good I am then ready to make mile passes. 

I ran Hilborn mechanical fuel injection on the street with a blown early Chrysler Hemi.  Junior Thompson of drag racing fame prepared the mechanical fuel injection.  I had air bleed nozzles which "drooled" all over after the engine was shut down.  I had to deal with an electric priming system and bad behavior.  My goal is utilize the good things in electronic fuel injection like injectors that shut off completely when the engine is shutdown and very precise fuel/ignition control for much better drivability. 

[Stainless1]

Mike, you might want to work out the injectors on methanol... it will be a big jump from e85 to methanol, and even bigger when you add nitro.