Inter-cooler Placement
In my TDI Jetta, the intercooler appears in front of the front wheel. It gets forced-air through slits in the front bumper and exhausts into the passenger wheel well. Since the pressure of the wall of air through which you're travelling provides force, it doesn't need a booster fan, and it keeps the air temps heading into the engine significantly cooler. Just for background, an inter-cooler takes the air that was just pressurized in the turbo and cools it down. The charged air can get very hot because (a) it was just significantly compressed and (b) it just passed through an iron / steel block that is connected to your exhaust. HOT! The inter-cooler can drop those temps pretty dramatically by allowing the air to expand a little bit and by acting like a radiator.
So, where does one fit an inter-cooler in an old bus? Almost all of the air pressure greeted by the
nose of the bus is pressed around the sides, underneath or over the top. Within a stock VW engine compartment that is well sealed, there is negative pressure within the compartment because of the vacuum produced by the engine sucking on the available air. There is virtually no passing air. With the stock engine and seals gone, there is available air-stream flowing underneath the bus. The vanagon folks often-times will put an inter-cooler in or behind the driver-side rear wheel well. I looked at that, and in the spare battery tray, and in the stock battery tray, and next to the transaxle on the driver side... etc. I looked pretty much everywhere, and concluded that the best spot was upright just to the left of the intake. I cut down a section of the old tin-line so it would snuggle-in a little bit. The inter-cooler needs a bracket at 
the top and bottom to hold it firmly in place, but the pictures should give a pretty good idea of what it will look like.But how does it get fresh air? I have a few ideas on that. First, I can fabricate some cowling to dip down below the bus to slurp some passing air. That should be relatively easy. Second, I have a Yamaha radiator fan that I can hook up to the rear of the inter-cooler to boost the passing air. I'd rather avoid that, but its an alternative. There's also the question of the exhaust air. In my Jetta, it exhausts onto my tire. I imagine that shortens the life of the tire a little bit, but maybe it doesn't really produce that much heat. Rather than assume that, I'll probably fabricate exhaust cowling that vents down back into the air stream.
In the meantime, the distances from the inter-cooler to the bottom
of the turbo and from the top of the inter-cooler to the intake are each less than a foot. This should reduce the amount of custom material I need to add in. I have a pile of charge-air hose from the Beetle this engine came from, so I may be able to cobble most of it together with stock parts. Considering the cost of silicone hose connectors, I'm very hopeful that I can do this with a minimum of new material.Tom Passes (1/31/2010)
Tom lost his fight to cancer Sunday afternoon around 4:30. His mom Marianne, his girlfriend and his daughter were all at his apartment when he died. I knew Tom for 20 years, but hadn't seen him at all in the last 5. Its hard to really know that he's gone after not seeing him in person for so many years. My last mental image of him will be sitting on his brother Joe's back patio with the whole extended family playing bocce, and laughing. Tom was a pretty simple guy with a near-constant "are you kidding me" smirk. I'll miss you, Tom.
next...
I have 4 different systems in-flight, so I could really work on / try to finish any of the 4.
1 - cooling system (needs parts).
2 - exhaust (needs some better welding).
3 - vacuum (needs air cleaner, exhaust route finalized).
4 - inter-cooler. Looks like its finish the inter-cooler, and then move on to the air filter while waiting for parts, welding expertise.
That's all for now. I don't know if I'll have much time this week, but I should have a few hours next weekend.
pictures:
top - looking at the rear end of the bus with the engine door open. note the inter-cooler on the left side.
mid left - looking through the rear left tail-light at the cut to hold the inter-cooler. Note the little nub sticking out on the bottom - I'd may try to use that in the bracketing.
mid right - close up on the rear-side cut for inter-cooler placement
mid bottom - looking through top-side hatch at the clearance between the inter-cooler and the intake.
bottom - close up of the clearance between the bottom of the inter-cooler and the turbo outlet.
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