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OK, here is a picture of that rarest of spare parts. The series 1 plenum drain tube, also known as the elephants trunk (BD 34735). This one is cracked and split - useless. I have been chasing one of these for 35 years - almost as soon as I bought my car back in 1983. Must have been one of the first parts for this car to become unavailable.
Does anyone know where to get a replacement? Any suggestions as to a solution to draining the air plenum? I have been thinking of fitting a radiator hose with a right angle bend, problem is that it needs to fit the one way rubber valve at the drain end. Apparently this part is available, but not the tube itself.
Thanks Roger for your offer, but as said I believe I can get the valve locally.
This tube, drains the air chamber on the scuttle at the base of the windscreen. The chamber draws in air to feed the heater and ventilation system. It is not under pressure, but fully open to the outside air & rain, so needs a drain. Instead of a small tube, it drains into a wide (almost 2") opening. It is highly unlikely any parts car would have this part remaining. In fact I have rarely seen them on any series 1 cars.
I was hoping that someone may have found a particular radiator hose that could be modified, or knows where they could be re- manufactured.
Thanks Roger for your offer, but as said I believe I can get the valve locally.
This tube, drains the air chamber on the scuttle at the base of the windscreen. The chamber draws in air to feed the heater and ventilation system. It is not under pressure, but fully open to the outside air & rain, so needs a drain. Instead of a small tube, it drains into a wide (almost 2") opening. It is highly unlikely any parts car would have this part remaining. In fact I have rarely seen them on any series 1 cars.
I was hoping that someone may have found a particular radiator hose that could be modified, or knows where they could be re- manufactured.
I'll pull what's left of the hose out of my parts car tmrw and see if I can find anything that matches it. 2" ID clear plastic plumbing hose seems like a good solution to replicate the original...
I just realized my car is missing this "plenum drain tube". It actually is a very strange piece of engineering. You really only need a small hose (3/8" ID clear plastic hose for example) to drain the water from the bottom of the air intake. I will try to find a rubber bung or cork big enough to fit in that 2" hole and drill a small hole at the bottom to fit the small hose. ideally the hose should run down to under the engine so that no engine fumes can get into the air intake.
in my '65 S type it had long dissapeared. I went to an auto parts store and they found a radiator hose that fit the pipe stub coming out of the firewall, had a 90 degree bend and was long enough to go down past the manifolds.
it can also be a plumbing part made of PVC pieces. After all, it is a drain. isn't it? For the end piece, a hair dryer kit comes with a reducer piece that you put on the dryer and it is shaped just like the membrane.
I am also missing the whole assembly and would like to cobble something together that will function well. I’m certain that I am getting some engine bay fumes into the cabin. Would anyone kindly share pictures of the “valve”part of the assembly? —Regards
1. PVC Plumbing 90 degree elbow with a 1.5" interior diameter. These are the standard black plumbing elbows sold in North America
2. About 16" of flexible nylon shopvac hose or similar. As close to 1.5 outside diameter as possible.
3. A rubber or plastic bung in the bottom of the nylon hose. Drill a 1/4" hole through it and stick it in the hose.
I needed to wrap the outside of the air intake outlet tube (in the engine compartment) with duct tape to form a tight seal. The hose fits nicely in the engine compartment and goes through the metal retainer on the inner part of the engine compartment behind the exhaust manifold.
I've noticed the resemblance to the mitral valves in our hearts. And the resemblance to the cap worn by bishops, a Miter!!!
The valve indeed is to function as a compound one way valve. The weight of collected water in the plenum opens the valve and it drains. If no water, it remains closed to air or vapor from the engine bay.
More elegant Jaguar engineering... Or is it interesting engineering ala the transmission mount
Carl
Last edited by JagCad; Oct 17, 2018 at 12:24 PM.
Reason: Text added
1. PVC Plumbing 90 degree elbow with a 1.5" interior diameter. These are the standard black plumbing elbows sold in North America
Will add a picture in due course
Not sure that 1.5" is correct. Mine is 1 3/4" diameter. Are later series 1 cars different?
Right now my engine is out and having painted the engine bay, I am refitting the accessories.
I will be searching my local auto store for a radiator hose I can modify.
Last edited by The Mekon; Oct 17, 2018 at 03:52 PM.
You're right. I was going by the "1 1/2" stamped on the PVC elbow, but that would be ID of the inner pipe. The actual flange that fit around the metal pipe is probably 1 3/4 - 1 7/8"
The duckbill valve is available however the drain line is not available. So I came up with this solution using a 90 degree silicone reducing ellbow.
Looks good! Separate point on this: I'm just finally finishing stripping my parts Series 1 and noticed the tube when degraded is an excellent route into the area above the heater box for rodents. There was evidence of a big nest in that area on my parts car. It's probably a good idea to put some mesh in the bulkhead end of the tube to prevent this happening in future.
Series 1 "elephants trunk"
