Piston engine exhaust. Diesel punk

For some time I was interested in piston engine exhausts. I like header, collectors and then turbines. I remember that I was not able to understand the good texts about that topic at first. Now, what they wrote, sound natural to me. I got used to it, somehow trained it by reading multiple texts. Then on the other side there are films that work the first time. I mean engine start with zoomies: Like P51 Mustang plane, or funnyCar dragster at night. I would be cool to imitate that in a film in blender. The question is: is there a tool for smoke and flames? Then I read that exhausts-gasses can become supersonic. The SR 71 on take-of has these very nice disks in it. Or on shuttle start. But after some estimating I think that these will not appear on exhausts. I do not imitate, I want to add something to it. So lets blend it with a screamer. That is a zoomy like short exhaust from the waste gate of an old ralley car or of the Ferrari F40 (yeah the 80ies). Next ingredient would be Pantera I found on the internet with a 8 to 1 collector. My idea is, to use a Pantera, open the hood over the V8 (or use a V12), place exhaust on top (like in tank or in the new Porsche hybrid, or AMG GT), and arrange the exhaust headers so that they meet in circle with the exhaust pulses exiting clock-wise (or counter-clockwise). I know how to model the pipe, but in the end the cross section needs to change as all pipes are squeezed together on that circle (ring). Then on a film with the view from behind at 300 RPM idle, which is made possible by large displacement, conservative cams and fuel injection, flashes of flames would go around the circle and smoke would diffuse out of the dark pipes. To combine this with the screamer idea and to give it a Diesel-Punk touch, a turbine housing could be placed behind that. This housing would rotate and be driven by the camshaft (or in sync with), and collect the flames, to produce a constant stream at the turbine, which is located co-axially. In the past I was thinking like: No move-able parts in the exhaust! Pure acoustics. But in this case, the bearing could be placed in the cold center, and we do not care for a perfect seal between the turbine housing, and because the exhaust has momentum and at full throttle only a small percentage escapes through the gap, making from some nice flame effects suitable for Diesel Punk (although it is gasoline,). I would even be possible to use the gap as a waste gate and change it in a sequence, like on upshift the flames suddenly escape there, and light flashes up. The turbine housing covers only 1 to 2 zoomies, the ones with the flames. At idle the smoke coming from the uncovered pipes would still be visible. I would like to be more technically and direct exhaust from on open valve to a valve just to be opened in order to let it bounce back there and strengthen the main pulse for the flames and the turbine, but I do not know how to not let this look too technical. At least this would lead to some more detail: a pipe attached to the turbine housing connecting the zoomies around the flaming one. The turbine shaft is connected to a compressor, the compressed air would go to side/top mounted inter-coolers, and then down to the inlets. This would emphasize a technical Diesel look. Even some real racing cars are naked (behind the cabin). With a clean layout (symmetric inlet air, filters in front, intercoolers behind), exhaust in the center, cylinder heads visible in between, turbo in the back, I could cater to the eye. To focus on the engine, on that model, all suspension stuff or wheels need to be under cover (unlike in a real F40).

Problem is, this is punk. I will never get real. It is loud. It is not green. I have no application for this. It is beyond my modelling skills, or not suitable to blender. So I thought I dump this topic here you cheer me up and in a dark winter night, I might give it a try. Also I have trouble to attach the exhaust pipes to the cylinder head. C3 continuity and all that.

I’ve tryed to understand… maybe sketch your idea ?

It is pretty hard to follow when you don’t break your text into paragraph. What i understand is you want to model a “Piston engine exhaust. Diesel punk” and animate it right? If it so then start like anybody else start by sketching on a paper then modeling it piece by piece and then you can start to think about rigging for your animation (film). And about the .blend file what are asking?

I think the trick would be to combine some aspects from a “muzzle flash” tutorial with some things from a “heat distortion” tutorial. Searching for those subjects along with Blender as a keyword should give a decent starting point. I think that’ll give you what you need to make the kind of straight-pipe exhaust one sees on a nitro-burning funny car. Unfortunatlely the particle sim fire/smoke seems to have some limitation of velocity (I could be wrong, but I couldn’t get it to behave) - so flashier high speed flames have to be faked. The smoke in blender seems more suited to a chugging train, or slower more drifty smoke, or perhaps diesel exhaust after it gets to the point where it slows down and starts billowing into a smoggy cloud.

Started to model the exhaust. I think, I have a red line in my text. Only if there really is a break in my thoughts, I dare to end the paragraph. I will edit that text when I have images. Usually my text gets better after that cycle.

I screw up on array modifier. Dunno why. One rotation too much I guess.

Attachments

engine2014-11-25.blend (121 KB)


I would do slow motion only. I am looking forward to the simulation. Still at the modelling stage :frowning:

I’m not much into anim so find it interesting
can you explain the Piston rig step by step
or did you follow a specific tuto on this?

nice work

happy bl

I copied the piston rig from an old post and now strongly recommend using Blender > 2.66 and physics and then make simple mesh objects the parents of NURBS, modifiers, and bones, which I need for motions breaking any modifier symmetry. The complexity grows so much that I need a lot of time for even simple changes in my supsension.blend. For the engine I started modeling the exhaust:



I want to misuse Array.Mod.Merge with its endCaps to merge meshes. I find that there is no clear order in which I apply the modifiers. I am wondering if I only deform the tube, or if I let it bleed two nodes into the exhaust valve and one node into the collector or so. I am scared by labor of the tube layout.

Using the experience from the modelling of the collector I modeled the top of the combustion chamber.

As the filenames indicated I was very unsecure while modelling and thus counted up the version number. I will probably not post an update before the date lies above the version number.

Please download the file and criticize the modifiers!

Attachments


modifiers20141228.blend (552 KB)

couldn’t resist. Now need to make multiple NURBS tubes and give them common large end caps.

Attachments


modifiers20141230.blend (630 KB)

I tried Physics.Smoke, but Blender 2.27b crashes my complete Windows 7 on Dell Studio 1746. I tried fresh air (real air), chimney, blowing through the cooling fins (before turn on), disabling aero, closing all other apps and searching on google :frowning:

Shame you’re having trouble with the sim. For smoke you really have to start with some relatively low settings and dial up. It can easily be a memory hog.

As for the headers and stuff, those are starting to look pretty wild. (In a good way.) Seems somewhere between what’s on a radial engine and the crazy stuff seen on 2-cycle V8 outboard engines.

I started the sim with the monkey in a box. My computer halts after the animation plays from frame 1 to 250. Then after 2 sec the screen goes black. I fear that it is a graphics driver bug. If it is memory, it is kind of expected. Yeah the header is for V8. V8 because it looks crazy. Originally I planned for a V12, but that looks to boring.

Radial has two problems for me: I cannot do my beloved DOHC, and oil pan is difficult. The exhaust routing for a four stroke would not be fully symmetric, but not crazy enough. I like either straight zoomies or totally crazy.

As I modelled the exhaust I got some ideas for the crank. I think we have to relearn some parts of Blender because N-gons and boolean now really work:


Okay here come some more internal parts of the engine. Not really useful for a car model, but for education or so. In that spirit I tried to color the bearings in different colors (vertex paint should go to the mesh?), but failed.

There are 9 modifiers.

Attachments


crankshaft20121225.blend (104 KB)

My first try at scale within array modifier

Attachments

turbine.blend (96.3 KB)


not quite polished. The green part rotates and directs the gas pulses from the exhaust down to the turbine. Some planetary gear / differential gear or a screw is placed on the shaft to shift to “early” if turbine spins fast enough.

First I wanted to place the turbine inside the rotating part, but that did not work out (in my head). Now I have a second leak. On the good side: This will produce some nice flames in night view.

Attachments

waste_gate20141226.blend (112 KB)


  • DCBloodHound

sorry don’t do much rigging
but how can you the armature bones in viewport for the last file!

is there like a picture showing all the constraint and ob names
wish we still had this in 2.6 like we had in 2.49 !

thanks

Not sure what you are asking,you can press alt-H to unhide the armature.

All of the objects have “Child Of” constraints to the armature bones (except the crankshaft which is the only object with keyframes attached)

The only interesting parts of the bones is their relations,constraints and Inverse Kinematics.

the hide function again !
now I can see it

got a good look at the constraints and have to review these to better understand how this works!

for the multiple piston do you only copy all the first piston ob
but then what do you change for the different crank angle !

thanks

I seem to have an of by one error in the circles in the meshes. And BI crashes, while editing runs like a charm. This took me 4 hours :frowning:

If I was faster I would have started the intake (on the outside). I plan cone shaped intake runners. Two discrete ones for every cylinder (like on the Vette 16V test vehicle) with a large plenum right to the side of the block. Block is also missing. Compressor over the clutch, air-to-water intercoolers before the turns. With a large open bay this could be visible from above. I have seen Lambos prepped for racing featuring an open bay.

For the vehicle I plan double wishbone all around and the springs attached to to the upper wishbones like in Gumpert Apollo. This is relative aerodynamic. Then a smooth cabin with some ground effect below. Watercooler go in front of the front tires.

For rigging see my last post. It was about my car suspension. The BGE works like a charm within Blender (to repeat that phrase).

Good night! I am to exhausted to read more of your comments, but sure will tomorrow!

Attachments


modifiers20141237.blend (707 KB)