Yes they appear to be the same diameter the entire length. I will check those other two ports. Can't get my calipers all the way in so it's a bit of a guess.
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A drill bit, as a gauge, and used the old manifold or the new spare as an original bore size, Which is what I did.

The other two outlets were good, just the inlet legs were really small bore internally.

Always wise to check everything on (critical) replacement parts who ever makes them.

Received yesterday and from first impressions looks well made. Did a air blow test and could feel a stronger flow of air thru the pipe than on the 2 piece version. Will need to get my mechanic to do a more closer inspection with a camera inside and look for any blockages potentially. The O ring's on the cast metal are curved & raised instead of flat as per the 2 piece version

Thanks much bydand! You were right too.

The coolant passages were all smooth with no flashing but when probed with drill bits they all narrowed considerably the deeper they went. I think this is just inherent when casting metal. They have to pull the molds out and that requires a tapered wall.

Here are the area's I drilled out with a .422" (7/16") drill bit. This was slightly smaller than the inlets diameter. I removed a good bit of Aluminum. Be very careful and go slowly as it drills real easy. Just stop when the drill bit touches the end of the tube. You can see that from the other end.




This would have been impossible to tell if it was one solid casting so that is one advantage of the two piece design.
Bored passages.












Still have not checked the small diameter tube on top next to the large one. Probably will need some cleaning out to.
I am still happy with the one I got and also glad I checked it and drilled it fully open too.
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Agreed, Having now 10.72mm from the (2) inlet legs flowing to the (1) outlet (13mm) port to the heater matrix then thermostat housing. Is better than the 6mm original bore of the inlet legs.

The vent port which I measured as 5 or 6mm bore was soldered into the outlet port header. Which I dress up on the 3.0SC manifold.

Header manifold port areas.

Inlet legs.78.5mm x 2 = 157mm
Outlet to heater.= 132mm
Outlet to vent.= 28.26mm

Total flow areas

CW Inlet in square mm 157mm
CW Outlets in square mm 132 + 28mm= 160mm

so no restrictions to CW flow through/by the Alloy header. (if the water flows through the heater matrix at all times to the thermostat housing.)


The only other thing I would change is to improve the inlet flange sealing to the cylinder head by replacing the original seals (AJ811600) as give a more deeper seal compression between sea,l leg flange face and the cylinder head.

The raised face of the seal on the Alloy manifold legs were 0.5mm rather than the 1mm on the original type plastic manifold leg port seals. see photos.

Given the sealing force is by 2 x M6 screws per inlet leg, and given the poor sealing effect of the thermostat housing seal overtime. (Also minimal 0.5mm seal compression.)

The 1mm raised face of the original seal between inlet leg and the cylinder head would be beneficial over time.

Some close up seal photos and part numbers.

https://www.aliexpress.com/i/1005004438399411.html

https://parts.jaguarlandroverclassic...tlet-seal.html

or JLR LR Pt, LR010793




Plastic OEM inlet leg with noticeable prouder raise seal face from flange face.

Plastic OEM inlet leg with noticeable prouder raise seal face from flange face.

Seal removed



So, my comments from post No.13, Alloy 3.0ltr SC manifold mostly, hold true for the 5.0ltrN/A & SC V8 Alloy manifold,
, and we waiting the findings of the solid once piece Alloy manifold.



Summary.

The blocked LH leg on the manifold pipe would have prevented any water flow from the LH cylinder bank.
The restricted RH/LH leg outlets would have restricted CW flow.
The outlet pipe was partly restricted.
The QA of the manufacture, was, / is non existent.

The narrow section of LH/RH leg pipe to the manifold header would appear to be less than Dia 10mm, and blocked/ restricted with Chrome flashing on all ports to some extent.

I would highly recommend anyone purchasing an Alloy rear heater manifold pipe , from any supplier, test it fully and confirm water flow from/ to each orifice.
Prodding with a 10mm drill or rod of suitable length 155mm to proved open and unblocked.

( Why 10mm?? The original header manifold pipe and the new plastic spare(copy) were measured and both found to be 10mm internally to the manifold.
The pipe Inlet is 13mm dia. from the cylinder head outlet.


Is it safe to use?

Not without inspection and testing before fitting.
Well it is strong, and if you ensure the ports are opened to the correct size and unblocked /restricted.
Then it should last longer than the plastic rear manifold header.

Funny as I had the same idea since I have the plastic version I purchased first. After working on the alloy version I wondered if swapping over to the factory seals would be better than using the seals that came with the metal version?

I was not sure if they would work in the after market metal manifolds? They appear to fit?
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And sit proud of the flange face, by more, say 1mm. and they are original (ish). More room to compress before the flange is hitting the cylinder head.
Check the seal recess size.

Thats the option I am going for on the 3.0lts sc Alloy header, when it comes time to fit.

The original JLR rear plastic pipe I replaced, had the seals flat to the flange face after 65K. Not leaking but since I was doing preventive, changed with another plastic.Before the Alloy header arrived.

Plus you know what material they are. I changed the O rings on the Alloy front Coolant water pipes, out with Viton O rings. I did ask the vendor what material the Alloy CW pipe O rings were and the response, was Rubber? I am sure they were brown Viton O rings. But better safe than sorry. My Viton O rings are doing well.

I put the Jaguar factory seal in the Euro-Amp metal water manifold. I think they fit better than the fat, square rubber seal it came with.



After drilling out the passages and using the stock seals now all I need to do is put the two halves back together (RTV?) and it's ready to install!
Thanks again for your help.
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Yes I used RTV on mine.
I would also check the temperature sensor O ring seal, one of the guys on the XE board had a damaged seal found after fitting.
But I expect you have already.

Since you brought it up?

How does that sensor come out? I thought I could rotate it but the two plastic tabs appear to be solid? Felt like I was gonna break some plastic so I stopped twisting.
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With a small flat screw driver.Lift/pull the Tab at the 12 O clock position on the sensor, back toward you away from the Header.

That unlocks the Sensor, and now you can twist anti clockwise, to remove.

46 to 53 K Ohms on the ones I tested.

Got it and again a difference between the stock plastic manifold and the aftermarket metal one? No problem taking the sensor in and out of the factory plastic manifold. The metal one is much harder to turn and it did come out fine. Also a good bit tougher to turn the sensor back in too.
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May be a slight reduction in port housing diameter, with the chroming. Lubed my O ring for refitting. The plastic Manifolds temperature sensors do come out slightly easier.

Hopefully we are all good to go, and we get some feed back from Nansan21 on the solid casting port sizing.

Sorry to keep this going BUT one last tidbit?

After drilling the passages out I decided to check the small diameter one. Turns out that port is a steel tube pressed into the Aluminum casting. So it's straight and clear all the way thru. Surprised but checked it with a magnet and it is steel.



Now time to get all this stuff installed!
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any update Nan?

I Fear Not!
The one piece casting does not lend itself to internal inspecting and finish machining to the correct sizes, easily.

The two part Alloy heater manifold would appear to be the way to go. For both the V6 and V8 (two different manifolds) Both with the same defects.
Because it is accessible to check and clear all orifices to the manufactured sizes.( fairly easily!)

Having bought, eventually the one for the V8 AJ133S, `They would all appear to have all the same defects,
namely:

• Flashings over the orifices,
• RTV over spill, and
• Under sized intlet pipes compared to the original two part plastic JLR parts.
• Also replace the sealing rings with known correct sized parts. JLR or OEM.
• .............................................and Check the temperature sensor and sensor sealing ring.

Again, I suggest opening inspecting, and confirming all openings are clear and of the correct sizing for the correct CW flow, engine longevity and the keeping of your funds safely in your wallet.

From whoever you purchase them from.

Some more entertaining photos from the album, for your entertainment, shock and amazment.


















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My mechanic advised against the 2 piece version and fitted up the plastic version again. I am yet to show him the one piece option to consider as a replacement as the car is now in the hands of my son driving it. I'll likely do something in the coming months and keep you updated

Can he explain why?
The plastic will fail that is a fact?
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My take is that he has reservations on the casting and coolant flow as everybody has seen
Everybody knows the plastic will fail, so I'll give the one piece version a trial if it test's with no flow restrictions

OK thanks. So a mechanic with zero experience using the metal versions has reservations?
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