Coolant's Full Monty

I've got all of the Rocky Mountain Westy designed cooling loop in place, from the engine output all the way down to the heater wye hole in front of the torsion bar and back to the thermostat side of the Subaru EJ22. I've got busted knuckles and I'm grinning like a madman. Someone finally got it right, and damned if I'm not the beneficiary!

For those of you coming in during the Intermission, here's the quick recap: The bright lads at Rocky Mountain Westy produced a beautiful vehicle specific stainless steel coolant tubing kit similar to what they provide as replacement components for the Vanagon's oddball plastic coolant tubing that runs the length of the vehicle. Through some polite discussion with the owners of RMW, and a willingness to be the guinea-pig as they worked the kinks out of beta testing and making it ready for production, I got hold of a set of these lovely mandrel bent tubes, fittings and miscellany required to move coolant down to the heater wye area in front of the transmission nose-cone.

We're focusing on all of the stainless steel coolant tubing in the left third of the above diagram.

I have my own engineered solution for the radiator and cooling, but needed the components in the engine bay to be reliable. While I'll only briefly touch on my radiator solution in this post, I did want to show off the beautiful and clever work that RMW has performed. The idea that underlies their design differs from every other one I've seen: It's called "Nobody Move!"

What I mean by that is the worst, yet most common attribute of conversions is the use of generic/universal/cheap components, fitted one to another like tinker-toys, just enough to make a path to the radiator and back. A reasonable car buyer who looked under the hood of a new car and saw what is under the decklid of most engine conversions would scream like a sheep in that Superbowl Sprint commercial. (I won't insult your intelligence by linking it. If you want to hear it so bad, Google it.)

Instead, the RMW coolant tubing design is a delight of components rigidly aligned in the engine bay, and when their support transfers from the engine to the chassis, there is a flexible coupler interspersed to make both fore and aft sections rigid relative to the component that they're connected to: Engine supported at the rear, chassis supported at the front leading down to the heater wye.

So let me lead you on a tour of the system. For clarity, I'll be using the orientation definitions in the classic How to Keep Your Volkswagen Alive by John Muir: "Front is Front." When working on engines which face you when installed backwards in the vehicle...people get 'front' confused sometimes. My descriptions are based upon the alignment of the vehicle. Thus forward is toward the front, rear is to the back, and so on, use your imagination: behind, in front of, left side, right side, etc. I don't use the terms like driver's side, or passenger side or 'nearside' or 'offside': They are without a referent and are confusing. Everyone can do front, back, left and right. I DO use two nautical/aerospace terms for which there is no suitable substitute on a car: inboard (closer to the centerline axis of the vehicle) and outboard (closer to the exterior of the vehicle.) This way I can say that the vehicle speed sensor signal wheel is bolted to the inboard left constant-velocity joint. And you should know where that is, exactly.

Outlet from the coolant manifold at the top left of the engine, with hot
coolant passing through a coupler and into a 130° clockwise
rotation which sends the coolant forward down the left side of the
engine bay.

Looking left down the aluminum heat shield, we pass the first hard
mount to the engine. These "T-bolt" clamps put a threaded stud
perpendicular to the side of the tube. When tightened, they both clamp the
tube (placing compression equally around the circumference) but also
create a handy 1-1/2" long thread which may be used to secure
them and the tube to other objects.

Since this is experimentation time with the components that I was
sent by RMW, I felt a certain freedom to try different methods to
 secure the tubing. In this case, I chose to use the mounting tang
to attach to the heat shield. The shield doesn't really bear any weight,
it just restrains the tubing from moving.

Looking forward down the left side of the engine, the tubing transits 

inline with the engine and then jogs inboard , tucking somewhat in 

front of the engine to clear the body cavity of the engine compartment.

Looking forward, After the jog inboard, the hot coolant pipe straightens
out as it passes the transmission. When it reaches near the nose cone,
 there is a silicone coupler that separates the rear, engine mounted tubing
from the forward leg which is supported by the chassis. The flexible
coupler isolates vibrations from the engine from shaking the whole
tube, and vice versa: chassis movement is isolated from the engine.

Hot coolant tube and torsion tube viewed while facing forward, 

detail of previous picture. After passing the coupler, the forward left length 

of tubing passes over the torsion bar tube. This needs to be secured in 

such a way that the tubing doesn't press up against the body above, 

or the torsion bar below. It must pass through the area above the torsion bar 

with 1/4" (6.3mm) to spare above and below. The secret is in the bracketry

 which again ties on to the t-bar clamp so that the tubing stays where 

you put it. The tilt in the bracket allow the tubing to be pressed inboard, 

directly over the left rear trailing arm joint.

Without the bend in the bracket, this wouldn't be possible.

The brackets clamp around the torsion bar tube so that the forward section

 of the hot-side tubing is held rigidly in place. It's best to keep the fittings

 all a bit loose while connecting everything.

Here is where the hot side terminates, just behind the rear transverse support heater wye cutout. 

(Out of frame, to the right,) I found that by loosely putting all of the components in place and then tie-wrapping the outlet/inlet tubes together at the wye cutout, when everything is tightened down and the tie-wrap is removed, the tubes want to stay in place. Note that the hot pipe coming down (middle of the frame) is SUSPENDED between torsion tube and floor. Once all of the fittings are tightened down, it's not going anywhere. Try to give it a shake and you'll just injure yourself.

Now we've reached the transition where the VolksarU system takes over. For the purposes of this overview, we're going to assume that the tubing has transited into the central box area of the frame, passed through the radiator and exited back through the other tube, 

forward on the right hand (top of frame.)

The cold return tube (foreground) while looking to the left. Return coolant travels back to the engine, but first vaults over the torsion tube the same way the hot side did on its way to the radiator. There are two critical differences on the return: the coolant re-enters the engine at the bottom, and the pipes and brackets are shaped completely differently to accommodate that need.

 Facing to the rear, the front right tubing passes over the torsion bar and joins
the rear right tubing for its final external portion of the coolant run.
This happens just behind the torsion bar, to the right of the transmission nose cone.
Note that the bracket on the return side (right) is shaped differently and located
differently (inboard of the swing arm joint, instead of outboard.)

View facing the right rear. We're past the return coupler and are on our 

way to the thermostat. There's a lot of bob-and-weave, though: 

The final tube at the right rear comes up to clear the carrier bar 

(black, foreground), and then with another t-bar clamp and 

mounting tang, transfers it securement to the engine.

So there we go! That's as complete a circuit as I can make of the RMW coolant tubing kit. I can say that between the brackets, clamps, silicone hose couplers and the perfect fit only possible with CNC bent and beaded 16ga Stainless Steel tubing, the value (price I won't mention, since this isn't a production item yet) is phenomenal.

I still have the expansion tank to get hoses on, and then it will be time to mount the radiator which has already been dry-fitted and only waits for some fan electrical fittings and the time to perform the work. At the moment, I'm flat on my back and sick as a dog from having pushed myself too hard at work and some virus got me and gave me a smack down, which is the only reason this got written.