That's Coolant, not Mountain Dew!

So after standing on my head thinking my way though coolant routing, I've decided that, again, the bright beans at Fellows Speed Shop have already done the brain work, and I'm simply going to sponge off of them.

Here's their setup stripped out for its first public appearance at DubFreeze in England last year. They set up the rear of a split-window Bus frame and bolted their gear onto it so that you can see how it works (though I note that they've left the scoop off.) I've taken a picture from the event and overlaid it to show the coolant loop. The area at the bottom left shows the coolant pipe hidden by the muffler assembly. The coolant enters the engine at the bottom right corner of the case, and exits at the top left (not visible in the picture.)

BLUE is return from radiator. Note the cold return goes through the frame, and rides the

outside of the frame before ducking under the torsion tube, and then back

to the engine. 

RED is the coolant output of the engine toward the radiator which passes 

through the rear cross beam. 

The ORANGE is the tap for the expansion tank.

To me the most striking thing about the coolant connections is that, with the exception of the 90* turns, everything is stainless steel, even components that would have been faster and easier to do with silicone. I think there's a lesson here: this setup is built to take the maximum amount of punishment, both from the elements and corrosion, but also from 'tough knocks' that any vehicle accumulates underneath. Sure, you could do all of this in silicone or even high temp multi-ply rubber, but there would be more joints to deal with, and a glancing blow from just one thrown tread on the interstate could slash up your soft coolant hoses that are exposed under the vehicle. Yes, a belly mounted radiator isn't an ideal for protection, but they've made the design as otherwise durable as possible.

Now the real question is, how am I going to do it. The cost of straight T304 or even better, marine grade T316 Stainless Steel isn't cheap, even in unbent sections. Cost of the pipe would be about $300 (two lengths of 7 ft) for T304SS. I'll need to check with my local metalworks (Fazzios) to see what their prices are like. Since the engine case and heads are aluminum, there's nothing that keeps me from using aluminum piping either, as long as I can get the bends in them without squashing the pipe. If I pay a custom shop to do it, they'll know how. If I DIY, I'll have to buy the equipment and wreck a few pieces of pipe learning how. The cost would probably come out even, especially once I add in the cost of the bender (about $70 from Harbor Freight for a 12 ton unit with mandrels.)

The dilemma is that I don't know exactly what dimensions I need to have all of this pipe bent to, I don't KNOW that all of the bends are in 2 dimensions, and how would I have the hose bent at a shop without having the vehicle their to fit it to. Sure, I could measure out (with thumb-fingered accuracy) the correct bends for the pipe and have that drafted accurately (I know someone) but if you've made a mistake, you're stuck with the an expensive pipe that doesn't fit.

Almost better to DIY for the same price and have the luxury to screw it up as many times as needed while in your own shop and at the end you have a new tool, new skills, and you didn't have to tow your vehicle off to someone else's shop.

Here are two alternatives:

1. Get corragated hose, the cheapest plastic stuff you can find that is about 2" outside diameter. Lay it out along the pathway that the production model will follow, zip tied in place so that it stays where it needs to. Once you are satisfied with the layout (remember, you've tacked it down along to way so that it won't move, you fill it....with curing drywall mud, aka '40 minute mud' which does not dry, but CURES. Fill it under pressure from the bottom, that way when it leaks out the top, you know it has pushed all of the air out. Seal the bottom. Take a break for a few days. Now come back and you have a rigid dummy of your final 'pipe' with all of the bends in the correct place. If you can get get it out in one piece, great. The finished product can go back in the same way. If you CANNOT, then you give it a registration mark where you're going to cut it, and then have the two sections fabbed separately and couple them with silicone hose at that joint.
2. Much of the hose is not hose, it is pipe, a critical difference in rigidity. For the straight shots, use the Stainless Steel pipe, and couple them together with Form-a-Flex (or newer flexible metal hoses by Spectre Performance.) This lets me avoid exposing the coolant pipes to damaging debris (like the type of thing that could slice a silicone fitting) and still keep most of the coolant pipe Stainless Steel.

So there are whole fist full of ideas for how to deal with the plumbing. This is made even funnier in that I've found a 'Custom Radiator kit' from Northern which comes in a standard size, but without the inlet or outlets welded on. Solid tanks, ready for cutting on and ready for YOU to put YOUR taps on where you need them. After quite a bit of tail chasing, I discovered that Northern wants $190 retail for this non-application specific radiator, but if they've done all of the work of fitting inlets and outlets to it for a specific application (like Ford or Chevy motorsports) the MSRP is....less. Wait....what?

I need a drink. Mountain Dew!