Sunday, November 14, 2010

heat placed, intercooler displaced

My time availability hasn't meaningfully improved since the last post. Somewhere I heard that the US is most productive (in GDP terms?) between Labor Day and Christmas. I can say that work has been distracting, but it wouldn't be fair to say that was the cause. Anyway, I have found a few hours here and there to get banging on the bus. I'll cover the highlights.

Heater Core Placed
After looking at putting the heater core inside the bus in a few locations, and trying to fit it under the floor of the cab, I have placed it in the alternate battery spot (under the spare wheel well). This location is already a little busy, with the intercooler and air filter as well as a bunch of wiring. So, this wasn't easy to get going. It still needs to be mounted. When I was working on the intercooler placement last Summer (or the Summer before..) I cut a section of tin out of the left side. To get the heater working in that space, I needed to cut the rest out of the way. The coolant lines will run from the left side of the engine, under the spare wheel well and along the body, curling back towards the right to the heater core. For a core, I'm using an old Vanagon rear-heater unit with a snorkel attached to it. The snorkel is still getting firmed up, but the mock-up worked well. Anyway, the snorkel will connect to a 4" diameter insulated flex-pipe that runs under the bus (over the axle) around the radiator to the original air line at the middle/front. Switching the fans and controlling the flow of coolant into the heater still needs to be devised.

Intercooler Displacement
Fitting the heater demonstrated that the intercooler was just in the wrong spot. As it was, getting in and out of the engine compartment on the left side was virtually impossible with it placed where it was. I found myself removing it frequently to do pretty much anything on the left side. Since the turbo an the intake are on the left side, the intercooler will stay on that side, but I'll be dropping it lower, down into the slipstream and rotating it flatter so access is much easier. Ultimately, it will operate much like the radiator does - with a puller fan placed underneath it.

Air Filter hassles
Another challenge on the left side is getting the air cleaner space to do its thing. I had something pulled together "well enough", but it wasn't game-ready. I'll need a 45* bend (another part to buy) to stitch into the set up, as the stock flex-tube is just too long to be effective. This became more obvious as the coolant lines and the flexi-hose for the heated air were introduced. Once the 45* bend arrives (still to be ordered), I'll be able to finish this off much more cleanly.

Exhaust Reroute
With the move of the heater into the engine compartment, and, more importantly, the insulated flexi-hose, the route of the exhaust has to move. The route from the turbo has been unchanged from stock, so it ran straight to the left out behind the rear tire. That was not ideal anyway, when we think about the "fresh" air we would want entering the heat system, or an open window when sitting at a red light. I was assuming I would need a custom run anyway, and now there's no question. The exhaust will route straight down, instead, and curve back to the rear along the bottom edge of the engine block. I will mock-up something so I can account for it while placing the intercooler. I don't want either the intercooler nor the engine to pick up heat from the exhaust as it passes. This will get interesting.

As you can see, things are getting more challenging, but I'm glad I'm finding these issues now rather than after a Summer of camping fun while winterizing. I'm going to focus on finishing the heat and the air filter completed first. Once they are done, I'll work on the exhaust and intercooler at the same time. I didn't mention that I did get the temperature sensor replaced, but with the different systems opened up, I can't test the engine. My plans for a holiday-season test flight may have to be pushed out. We'll see. Thanks for following along, and I'll post some pictures of this stuff when I'm on my other computer.

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