Intake/Exhaust Design Literature

[afsvrf]

I am working on an intake and exhaust system for a high performance tractor pulling application. The engine in scrutiny is an International DT466. To give you a little background on the engine:

-International DT466 (straight 6 cylinder)
-Stock bore, stroke, connecting-rod length, exhaust manifold, intake, and head
-Peak horsepower of 1136 @ 3000 RPM (which will be the design rpm)
-HX60 Turbo (3in x 4in)
-etc, etc

I currently own Heywood's "Internal Combustion Engine Fundamentals". I have heard both good and bad things about "Scientific Design of Exhaust & Intake Systems" by Phillip Smith and "Practical Gas Flow" by John Dalton. My question for the learned audience is, what literature would be beneficial for gainining knowledge for intake and exhaust tuning for this particular application? I also have access to the SAE journal database, so feel free to suggest SAE documents if you know of any.

Thanks in advance!!

 

[afsvrf]

I forgot to mention, this engine utilizes a "lubricated water" injection system, injecting water into the intake to provide evaporative cooling and a higher charge density.

 

[GregLocock]

I'm not sure how much advantage you get from tuning exhausts on turbos, my impression is not much, as the turbo is designed to attenuate the pressure pulses.

Cheers

Greg Locock


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[SomptingGuy]

"Theory of Engine Manifold Design: Wave Action Methods for IC Engines", Winterbone & Pearson.

But as Greg points out, once you've got a turbine and compressor, wave action isn't that important.

- Steve

 

[patprimmer]

My experience that trying to do a pulse tuned exhaust for a turbo can be counter productive as increased volume and surface area negates any possible pulse tuning gains.

As short as practicable and no bigger dia than necessary while still streamlined seems to work best.

In most applications a gain in response more than offsets a gain in steady state power.

Regards
Pat
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[afsvrf]

Thanks for the comments. I am still in the initial stages of planning and deciding which route(s) I want to go, as far as design is concerned. I had similar thoughts about the exhaust, but wanted to read up on the subject a little further. We will probably keep the exhaust manifold that is on the engine now, but I would like to investigate the intake a little further. I will try to post some pictures of the systems so you all can actually see what I'm working with.

Thanks!!
-Adam

 

[BrianGar]

I wouldn't get too excited about making it your business to buy "Scientific Design of Exhaust & Intake Systems". Its pretty basic in ways but there are a few 'rules' in it, but you may know them all already. Its more n/a based also.

 

[TrackRat]

In my experience it depends on the application. If you're tuning for driveability and low speeds yes shorter is better. If on the other hand you're tuning for peak power or higher rpms where tip-in isn't as important, a tuned intake and exhaust system on a turbo engine work the same as an NA engine with the exception that you can run slightly higher velocities with a turbo.

 

[afsvrf]

I finally got some photos uploaded to photobucket. The links are all pasted below. They include the current intake manifold and spacer, exhaust manifold, and turbo inlet. I also plan on putting a bellmouth on the turbo inlet so my flow diameter is not decreased too much. Please feel free to take a look and make any suggestions.


[URL=http://s788.photobucket.com/albums/yy169/afsvrf/Tractor%20Pulling%20Engine/?action=view&current=100_1066.jpg]
[URL=http://s788.photobucket.com/albums/yy169/afsvrf/Tractor%20Pulling%20Engine/?action=view&current=100_1067.jpg]
[URL=http://s788.photobucket.com/albums/yy169/afsvrf/Tractor%20Pulling%20Engine/?action=view&current=100_1065.jpg]
[URL=http://s788.photobucket.com/albums/yy169/afsvrf/Tractor%20Pulling%20Engine/?action=view&current=100_1069.jpg]

Thanks!

Adam

 

[afsvrf]

Thank you for all of the comments concerning reference material. Pat and TrackRat, thanks for the comments above, simple but informative. In this application I am not worried too much about response, mostly peak power output. The engine only runs about 14 seconds at a time, pulling a heavy load (~80,000lb). The vehicle "takes off" or "leaves the line" at 5500 RPM and runs down the track at 3800 RPM until the end where the load the vehicle is pulling increases and the engine speed obviously decreases. Since the end of the pull is the most important, the design point of all systems in question is 3000 RPM. Tip-In/Out are not a factor here.

Just a thought and a couple of questions. I am planning on using a large "conical spline" plenum (volume ~1.5 - 2x engine displacement). Do you think longer or shorter intake runners would be ideal for this application? I was also planning on using constant area runners with a bellmouth at the entrance to each runner.
Any opinions on any of this?

 

[TrackRat]

Constant area runners will be fine. The tuned length of the induction track should match your desired peak power or in your case with engine pull down be slightly above the 3000 rpm point, (perhaps 3500 rpm?), I would suspect? A volume of 1.5-2x engine disp. should be OK based on my experience in other turbo applications. Max torque is what you need for the increasing load IMO, as long as you have the traction to use more torque.

 

[patprimmer]

OK

If it's a situation where the revs and boost are easily reached in time and the critical part is maintaining or increasing torqur as the revs pull down, internal volume will not be so important, but exhaust gas velocity and retaining high exhaust temperature and the lowest possible intake temperature are important.

I would think real big intercoolers and maybe water to air IC with ice water as it is a short duration test.

I know it goes against all normal practice, but would heavy flywheel and real heavy turbo wheels help.

Regards
Pat
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[patprimmer]

Also, relatively small dia pipes with equal length relativly long should help.

Re the tuned length formulas, they are about exhaust scavenging rather than turbine efficiency. I think your main focus should be turbine efficiency.

Tuned length formula does change with temperature and turbo exhausts are substantially hotter than NA temps.

Regards
Pat
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[afsvrf]

Thanks for all of the tips; you guys are great. Pat, I wish I could stick an intercooler on this thing, but the rules for this particular class strictly prohibit them. I will certainly look into the heavy flywheel and turbo wheels. With our current water injection system, EGTS are ranging anywhere between 1100-1200 F.

As far as education goes, I think I am going to splurge and buy Winterbone's two volume set: Theory of Engine Manifold Design and Design Techniques for Engine Manifolds. From everything I've heard, the set is the authority on intake and exhaust design.

Thanks for all of the help!

-Adam

 

[Tmoose]

How is your water injection controlled?

 

[afsvrf]

The water injection is controlled by a pressure switch that references the intake manifold pressure. If you look at the first URL I posted earlier, you can see the fitting/line that attaches the pressure switch to the intake manifold.

 

[dicer]

If the rules allow, fabricating your exhaust and induction system will be much better than that stock system it has now. After seeing some pictures of tractor pull engines blowing up, hows the rest of the engine going to be if you can boost it more?

 

[afsvrf]

The rest of the engine should be able to handle extra boost with no problem. The lower end already has a girdle on it, billet pistons, room to crank the injection pump up some more, etc, etc.

 

[Tmoose]

If the water injection is on/off now, I wonder if having it vary the quantity with boost pressure might allow development to provide a greater cooling effect

 

[TrackRat]

You can use various Hobb pressure switches to change the water volume based on boost.