Garrett Turbocharger

[cujet]

There is no need to have one extended exhaust pipe. In fact, it won't delay the exhaust pulse by any meaningful amount. Being as the pulse is moving at around 1000MPH or more under load.

You will need a fairly small turbo to achieve boost on a Listeroid. That T3 unit is way too big. It's capable of over 300 crankshaft HP at maximum flow. A slightly oversized turbo will often work because once boost is achieved, it's self sustaining as long as the load remains. But, that's too big.

One way to slightly lower the load on the compressor is to have it discharge into a plenum or tank.

[cujet]

That small fleabay turbo listed earlier is the perfect size. It will produce boost early on and result in a smooth torque curve.

[SHIPCHIEF]

Wow you guys;
That's a lot of good ideas and suggestions.
I've got the TB03 all apart and cleaned up. It was an oil leaker. Now all the reusable parts look like new.
I know the boost will be very low, but remember, with the poor head gaskets, dipper rod bearings and high compression of these engines, high boost is fatal.

[SHIPCHIEF]

I've been looking into the exhaust system. The exhaust flange has 1 1/2" female BSP pipe thread.
So 1.6" is the ID of the pipe, 1.9" is the O.D.
I'm planning to make the turbo hot side manifold from 1 1/2" Schedule 40 Butt Weld Carbon Steel fittings & pipe.
I want to keep the turbo body close to the crankshaft to keep the vibration at a minimum. My engine vibrates a bit, but seems worse at the top, and smoother at the bottom. So I'm thinking the exhaust stubs should bend down. then the Turbo air discharge should line up with the Lister inlet manifold.
I ordered a turbo rebuild kit and 1/2" thick exhaust flange for it today.

[cujet]

Ship,

I think you are missing the point. A turbocharger cannot be self sustaining if it's combustion air is insufficient. In very much the same was as a jet engine can't idle below 50% RPM.

You won't make any boost at all. None, until there is enough energy for a self sustaining situation to occur. The turbo will only become a serious restriction on the intake and exhaust.

Is there a possibility that a T3 will reach the boost point on a 2 cylinder Listeroid? Maybe, if you pour fuel into it under maximum load.

However, the problem remains, you will only have boost at the very upper end of the load curve. And, that's not ideal for a generator engine as the engine will have a very hard time ramping up to a big load. Turbocharged generator engines (which are always much more efficient, btw) always have a properly sized turbine section, often capable of producing more boost than exhaust back pressure!

You really are better off selling the T3 and purchasing a turbo that's properly sized.

[Henry W]

Another problem is large displacement slow speed single and twin diesels exhaust impulses are hard on turbo's. This can be corrected some by mounting an exhaust expansion chamber before the turbo to reduce the sharp impulses.

Henry

[SHIPCHIEF]

OK;
Well received.
I did some reference work on Garrett's site, and they admit that a turbo will boost engines that are considered 'too small'. Like a GT12 on a lawn mower engine.
If my turbo doesn't work out, I have a couple of other places to use it. For one example,the center section should go right into my son's Turbo Mustang.
remember, 8 PSI boost that is considered 'normal' would be fatal to a Listeroid. Henry Dancause got 14" of water discharge pressure when he turbo'd his 6/1. That's about a half of 1 PSI. He also got a reasonable, but substantial power increase.
If I find this turbo uninspiring, I can get another, take a saw to my exhaust manifold, and weld up a new flange for the next turbo.
When I get bored with that, I'll get back to work on the RV-8 

[LincTex]

Henry Dancause got 14" of water discharge pressure when he turbo'd his 6/1. That's about a half of 1 PSI. He also got a reasonable, but substantial power increase.

This is significant, and worthy of not ignoring. 

Although I would agree a turbo for a 2.3 liter engine would not provide boost into the "psi" realm, a few inches of water column of intake pressure increase is better than none, and I seriously doubt there will be any restriction on the exhaust side.

The Saab T-3 Turbos are desireable because of their "universal" type flanges, so you will have zero problems selling it for a good price if you choose to find a smaller turbo. Dancause used one from a 1.6 Volks diesel, correct?

[LincTex]

I took a second look, and can't believe I overlooked the dataplate.
It's a TB0343. It most likely came from a 1985 Saab 9000 2.0L

^ Forgot about this post...
So, honestly - - If Dancause is getting obvious results with a 1.6 liter sized Volkswagen turbo
( http://www.utterpower.com/turbo_6_1.htm )
on a 6-1, then I see little problem with trying this turbo on your Listeroid Twin.

I don't see exhaust pulses being a problem. A turbine wheel is pretty heavy and will easily absorb inertial changes from the pulses - and they will be pretty small. The compressor wheel is very light and won't have issues either.

[SHIPCHIEF]

I'm watching a Garrett GT15, on fleabay, it's from an Audi TDI, and is smaller than the TB03 I have. But I probably won't bid.
Right now I'm waiting on the bearing & seal kit, and making plumbing/mounting bits.
The TB03 will be very lightly loaded in this application. I wonder if the exhaust temp will get above 600F?
I need to get one of those infrared thermometer pistol things.

[quinnf]

I still like the idea of injecting propane into the exhaust and igniting it.  Just for show!

q.

[admin]

ya, propane and a little sniff of NOx!



bob g

[cujet]

If you read that Dancuse turbo writeup carefully, you will see that eventually he was able to pull 5200 watts out of a 6/1, or basically about 11HP. That is impossible on 14 inches water gauge intake pressure. It's much more likely that he was able to produce some significant boost and increased fueling accordingly.

I see no reason why 8PSI boost would be in any way harmful to a listeroid. They are subject to high internal loads already. The boost won't increase loads unless significant additional fuel is dumped in. Even then, the burn rate is lower and the peak pressure is not higher.

[SHIPCHIEF]

Actually, you're right. 8 PSI intake boost would increase the compression pressure, but combustion pressure in a traditional diesel cycle is not higher than that. THE PEAK COMPRESSION PRESSURE IS MAINTAINED ON THE PISTON DOWNSTROKE by the injection and burning of fuel over time.
You just reminded me of that.
Still, 8 psi is 50% greater than Atmospheric, so 50% increase in con-rod bearing load on comprssion stroke?
As for progress; I bought a trubo rebuild kit on epay, and the most important parts fit. The turbo just needed freshening up, It went back together easily. Once you do one of these you will no longer think it's a mystery.
Now I'm holding it up to the engine, trying to figure out the most compact and efficient way to install it.
I'm going to make a set of steel flanges, and weld up some butt weld pipe & fittings.

[cujet]

Still, 8 psi is 50% greater than Atmospheric, so 50% increase in con-rod bearing load on compression stroke?

Not if done correctly. Turbo diesels, properly designed, can lower the CR by a point or so.

But, the major loads on the bearings are the inertial loads. Stopping and starting an 8 pound piston and 9 pound connecting rod can achieve very high load factors.

Believe it or not, in most engines, the combustion related bearing loads are not the highest bearing loads, and certainly not the compression stroke.

Now, hurry up and get it done. I want to see if you can make boost!