100shp bike

[dieselguy86]

Hello all, after all these years watching everyone elses builds, im happy to finally be starting my own. This is my first scratch built engine, I built a turbo based engine years ago but this is on a whole nother level. Compressor is for a Borg Warner S480, 80mm inducer x 118mm exducer. Turbine wheel, with a lot of help from John, had to be figured, then modeled. A company in Pennsylvania can take my 3D model, 3D print and cast it. Heres some screenshots of what ive come up with so far. Keep in mind, this is my first go at CAD drawing, and ive only spent maybe 1 1/2 days on it. The turbine wheel is VERY rough, but it atleast gives me something to design around.

Once the engine is built, tested, and measured. Ill be hooking it up to a Holset HP841 gear reducer, fitted with reverse cut gears and an Allison 250 4th stage wheel that was cut down by John himself. I really cant give him enough credit, without him this would never have possible to get off the ground. The bike will be built with an SR 71 theme, so black, bare bones, and lots of titanium. It will also be capable of daily riding, all day if the wallet is full enough. My goal is reliability and durability. Stainless shaft tunnel that is sealed, engine driven oil scavenge and pressure pumps, and alternator.

Anyways heres some screen shots of what I have so far. Like I said, its only my second day. The last shot of the blade profile shows how rough it is, but atleast its to dimension so I can model around it while I figure out how to do it up proper.

-Joe K

[racket]

Hi Joe

Let the build begin :-)

Cheers
John

[dieselguy86]

Hi John,

I think the physical building will be easy compared to designing it all up on cad. I normally build as i go, but since the machining work will be farmed out i need the proper prints. Plus, in a way, I'm "building as i go" on a computer, where it's free if i screw up a part lol.

I found my 3ft section of .250" OD stainless tubing for the fuel manifold. Also found the needles i ordered, i bought 21ga, hope that isn't too big.

Started drawing up the combustion chamber today. And my oil scavenge and pump gears came. They're bronze helical cut gears, that come out of the scavenge pumps you see on Ebay and Amazon. They look to be decent quality. I'll start modeling the housing for it soon, the guy sent a housing i can copy. Ive been brainstorming how i want to drive the accessories.

At first i was going to do an all geared housing, but i felt it was going add alot of complexity. So I'm going to do a simple single stage redux box at a 10:1 ratio. The output of the box will drive a serpentine belt. Then i can use different size pulleys for different accessories. Alternator i feel could live at 8,000rpms, but if i use a hydraulic pump for a fuel pump, max rpms on those are usually 4,000 rpms, so i can play with pulley sizes to act as a sort of second stage redux. Atleast with a belt i don't have to worry about gear spacing, and another oiling system, and it's quiet.

Ill probably drive the gearboxes input with an externally splined nut, and use a floating sleeve coupler. Not sure if this is the best way, i just figured it would prevent any issues if things aren't perfectly aligned. It's at the bottom of the priority list, lots of other things to get sorted first.

-Joe

[dieselguy86]

Working on the combustion chamber today. Should I include some 1mm cooling holes? it will be laser cut, so it doesn't matter how many holes I have, the laser will punch them out for me. The larger dilution/mixing holes will be bellmouthed like normal. Also the cc will be made out of .060" thick stainless sheet. I figured the cooling holes will help the ss last longer, in the future ill probably do one out of inco, but for now im just aiming for durability with the thin sheet I have. Heres a pic of the currently designed outer liner, I believe there is 630- 1mm cooling holes. Is that going too overboard? CC will be 140mm OD by 90mm long.

[dieselguy86]

Hi all, I spent almost all day modeling, I skipped the chambers cooling holes for now, I can always add them in later. I wanted to keep progress moving on the design. spent probably 4 hours watching youtube videos and trying to copy my comp wheel. Its definitely rough and not an exact copy, but it sure makes the engine look nice. let me know what you guys think.

Still lots to do, have to get the NGV modeled, and start figuring out my fuel and oil pipe routing. other than the case, the basic engine will be complete. then itll be on to stuff like reduction box, scavenge/pressure pump case, and the freepower stage.

Hopefully chips will be flying by the end of march, and a running engine by Christmas if all goes well. Theres good chance ill be reading this a year from now laughing my ass off at how optimistic I am

[dieselguy86]

forgot, heres some pics of the cut down 4th stage, as well as the 80mm x 118mm comp ill be using. Also, if anyone can decipher some of the programs numbers that would be awesome. I understand most of it, I input my temp, pressure, rad/sec, and that's what it output.

[racket]

Hi Joe

The outer wall of the combustor has too many holes , it needs to be as we discussed in my PM .

What is the radial width of the flametube annulus , 140 mm OD whats the ID ??

Cheers
John

[dieselguy86]

Hi John,

Id is 70mm.

I thought i split the hole area like we discussed, I'll go back over my notes and check...

I am slightly high in the primary area, by 200mm².

Inducer area 5,024mm². 30% into the primary(1,507) 37% of that into the front wall, 557mm², i have 753mm² now. The remaining 63% was divided 63/37 outer/inner.

Front wall has 36 4mm holes, and i think 96 2mm holes.

Outer wall has 70 3mm holes, staggered.

Inner wall has 47 3mm holes, also staggered

Re did the math, i need to enlarge the cc to 150mm od, 60mm id. Which will be about the max i can go, i might could squeeze a few more mm's here or there.

-joe

[racket]

Hi Joe

So 12 injection points , yes/no ??

You need the same number ( 12) of Primary holes in both outer and inner walls positioned at 1/2 annulus width, so 22.5 mm, downstream from the front wall in a 150/60 FT , positioned midway between injection points , the equal number of opposing holes between inner and outer will provide solid jets that will collide and create the correct recirculation/turbulence , 2 X 12 =24 , 753/24= 31.4 sq mms/hole = 6.32 mm , go 1/4" holes .

Cheers
John

[racket]

Hi Joe

So 12 injection points , yes/no ??

You need the same number ( 12) of Primary holes in both outer and inner walls positioned at 1/2 annulus width, so 22.5 mm, downstream from the front wall in a 150/60 FT , positioned midway between injection points , the equal number of opposing holes between inner and outer will provide solid jets that will collide and create the correct recirculation/turbulence , 2 X 12 =24 , 753/24= 31.4 sq mms/hole = 6.32 mm , go 1/4" holes .

Cheers
John

[dieselguy86]

Hey guys, 


This thread has been dead for awhile, but behind the scenes it has not, slow, but not dead.

I acquired a holset hp841 pt unit off a Detroit dd15 engine. Of course with John's guidance I optioned to use its restrictive turbine wheel, but opened it up ~25%. This meant I could back off the flow requirement, but replace it with pressure. This let me use a 70mm compressor, which then allowed me to use an available 84mm axial wheel, way easier than making my own! 

Today I got to carve out some time to redesign the diffuser. I wanted to try something new, so I made it expand 10° axially along with 15° radially. Here's a highlight of the flow path I was able to achieve. 

[dieselguy86]

Was sitting in my truck this morning after a storm had rolled through and I happened to notice a spare ether injector that I had. My first thought was it would make a nice fuel injector. Probably about a .020" hole, fed by 1/16" pipe and compression type connection. Thoughts anyone? 

[slittlewing]

Nice work on the turbine wheel!

I probably wouldn’t use that, as it’s brass and a previous brass burner nozzle of mine melted. Also it looks to spray sideways.

Difficult to justify not using a burner nozzle when they are available in so many flow rates, spray patterns and are inexpensive!

Cheers
Scott

[dieselguy86]

Hi Scott,

This engine will be using an annular combustor so the nozzles won't work as well as if using a can style one, and that's assuming there is enough room that those nozzles could be fitted. Also, there's a good chance the nozzles will be throwing fuel too far into the cc before being burned.

The original plan was to use "racketjectors" to just barely protrude through the front cc wall, and spray almost 90° where it hits primary hole airflow and mixes with the turbulence and burns. The injectors will be in the relatively cool p2 air, and should only see radiant heat, hopefully.

I think I need to do some flow tests to see what they put out.

[dieselguy86]

Looks like #73 drill bit, so .024" hole. not sure the hole size on the "racketjectors"?

Also I took the injector apart, it's 1/8"npt, and has a nice screen to keep crud out of the hole. I think this could be a very viable injector. The mass of it should make it pretty sturdy for the job as well.