Slightly off topic; but this is an important point to note in the Jaguar V12, which Grant Francis explained to me.
If the heater is bypassed, then hot coolant from the A bank heater feed is sometimes connected directly to the heater return feed, effectively cutting out the heater stage of the system. The effect is that the hot coolant is then fed directly into the radiator exit pipe feeding the water pump and thus straight back into the engine, uncooled. Result, immediate overheating.
If the heater on the V12 is to be cut off from the coolant circuit, the A bank feed must be blocked and the return from the heater also blocked.

 

Thank you for bringing this topic back. It appears that the Camaro's/Firebird's that had this motor did not have a heater valve at all. There was a flow restrictor (#13 in the picture below) that prioritized keeping the engine at operating temperature by partially blocking off coolant flow to the heater core at low engine speeds and allowed more coolant flow at higher engine speeds. Regulation of interior temperature was controlled by vacuum flaps in the HVAC box that let air either flow through the always-hot heater core or by-passing it completely.




Since my use case is primarily summer driving and maybe some cool spring and fall mornings, I am going to use the Vintage Air heater servo to regulate coolant flow to the heater core. I will also make and add a flow restrictor in the heater hose coming out of the engine. With the exception of the restrictor this is the same setup I had in my XJ6 with the same engine and it worked well.

 

It was a struggle keeping myself busy tonight while waiting for parts to arrive but I did knock a few items off the list. I filled the transmission up with fluid and worked some more on the air filter. I also scoped out a spot for the PWM fan controller.

 

I did not do any actual work tonight but I did hit a major milestone. With the batch of deliveries that were received today I now have all the parts on hand that are needed to drive the car around the block. The goal over the next few days is to finish the exhaust, test the fuel system for proper function and leaks, complete the plumbing of the cooling system and run the engine. It feels good to see the light at the end of this tunnel.

Additionally the covers from Lseat.com arrived. I kept the driver's seat fully skinned so installing the new covers are not a required part of driving the car around the block. I expect to start working on the seats in the next couple of weeks.

The covers arrived in two vacuum packed packages.


This is a front seat bottom in black leather...


This is the front seat back...


I am overall happy with how these turned out but the real test comes when I fit them to the frames.

 

I got a large portion of the exhaust system done this evening but I am not done yet. The left side to the merge pipe is done and only needs final welding, and the right side to the merge pipe is about halfway done. I still need to do the full weld on the merge pipe and resonator but I hope to finish the exhaust tomorrow.

 

Today I was able to finish up the exhaust, with the exception of a few hangers I need to add to prevent the exhaust pipes from rattling against the frame rails. But those are easy enough.

At lunch today I spent some time making a flow restrictor for the heater. I started by drilling a 3/8" hole in a piece of aluminum rod and turning it down so it would fit inside the hose from the water pump to the heater valve.

Here is the final product:


Here it is in the hose going to the heater valve. I will trap it between two hose joiners so it does not move through the system.


After that I put the tires back on, took her off the jack stands, and pushed her out of the garage. This is the first time in almost 6 months that she has been back on her feet and outside. It felt good to get to this point.


I was able to clean the floor where she had been sitting all winter which was much needed. Tomorrow we test the fuel system and finish plumbing the cooling system.

 

It is going to be a lovely car, Thorsen!

 

Nice to see it moving forward.Good to see another classic Jaguar being rescued. Looking forward to the updates.

 

Better than it was new, performance wise when your done.

 

Today was a busy day. After breakfast I filled the left tank with gas and ran the low-pressure pump to fill the surge tank. After the surge tank was full I ran a jumper wire to the high pressure pump and checked for leaks. I found 4 fittings that needed to be snugged up, but after I was sure there were no more fuel leaks it was time for the moment of truth...


I only let it run for 30 seconds because there is no coolant yet but I am pretty happy to see it runs off the fuel tanks. I also verified the clutch is working too.

After that it was time to get busy with finishing the plumbing of the coolant lines. I am a big fan of using silicone hoses, aluminum hose joiners, and Gates PowerGrips hose clamps. This is part of the line to the heater valve; you can see how the Gates clamps are much more attractive than normal hose clamps. In the 5 years I have been using these I have never had a leak.



Here is the top radiator hose, upside down. The aluminum section with the 3/8" hose barb connects to the steam vent line, which allows air that is trapped in the heads to vent out.


Here is the top radiator hose in position, minus the clamps to hold it to the radiator and water pump.


After building all the hoses I needed it was time to mount the accessories.


I debated if it was time to fill up the radiator, but I decided it would be easier to run the AC lines without the radiator in the way. So I made up a list of fittings I needed and moved on.

@Haalex - this part is for you. I decided to take your advice about re-using the stock air cleaner on top of the engine.

The key to making it work was finding a 3" silicone U-bend air tube that had the proper centerline distance between the legs. Most of them would put the middle of top leg right where the belt is. After some in-depth searching I found one that would work.



Next up was shortening the filter housing so I could mount it longitudinally. I marked the cut line with tape and cut it into two pieces.


My air filter fits in the can with plenty of room for airflow.


I removed a couple inches of this piece so it does not hit the firewall.

 

Picking up from where I left off yesterday, today I welded a strip of metal inside the filter can so I would be able to join the 2 halves.


A couple of screws hold the two halves together.


I am reusing the stock brackets, I just had to move them closer together.


I removed the original filter packing and left two layers of the metal gauze in place for appearance.


I drilled a 4.5" hole in the bottom of the can so the actual air filter could peek out. You can see the hot wire air flow meter and a rubber coupler. I need to shop for a 3" diameter flex hose to connect this to the large silicone U-bend from yesterday. I like how this incorporates some of the original parts from the car but also modernizes it.


After that it was time to put the front brace back across the front of the engine bay. I had cut it last fall to make it easier to get the engine in/out. It wasn't the first time someone had removed it as there were weld marks from when they put it back together.


I'm hedging that the engine might have to come out again so instead of welding it back in, I welded two pieces of 1/8" steel to the part that was removed and bolted that back to the body. This brings the rigidity back as well as allow for future removal - "just in case".


I'm not sure why all the pictures today have a gritty look to them but they look much better in person.

Next up is working on the transmission tunnel cover and mounting the AC evaporator unit.

 

Pictures look fine to me, as to why the numbers.
I M H O your proud of your accomplishments.
As you damn well should be.

 

After trying to rationalize the size of it and trying to make it fit without drawing too much attention, tonight I decided that the large evaporator I bought for the car last summer was just too big.
In the picture below, the black evaporator on the bottom is the twin dual-fan unit I wanted to use and on top is a generic single dual-fan unit I had on my shelf.


The view from the top shows just how much larger the black evaporator is. I did not realize when I purchased it but these are sized to cool mini-vans.


To make the black evaporator fit, it would have encroached on some of the driver's leg room and a fair portion of the passenger's leg room.
The smaller unit will fit nicely in the middle of the dash.


At the end of the day I decided I would rather save some leg room and accept the fact that the smaller unit will still keep the car cold but I won't be able to quick-freeze meat in the car. Such are the compromises we make on projects.

While the grey unit is the right size it's not the right color and I don't think I like the small round vents on the edges. I need to find one in black and preferably with the fan and temp knobs on the face of the unit.

Finally, I was able to complete the intake plumbing but forgot to take a picture. I will get one tomorrow.

 

I'm on-hold out in the garage until I get the AC fittings, so I decided to do some work in the basement on the seats. I am starting with the passenger seat and here's how it looks after for the last 4 months after I pulled the covers off and sent them to Lseats.com



The burlap look rough and there was no chance I was going to reuse the stuffing.


After stripping it all off I got to a solid foundation.


I purchased all my supplies from DLT Upholstery. I re-wrapped the springs with a new layer of burlap and used hog-rings to attach it to the frame.


The seat base has 3" foam as the cushion. I cut it to the shape of the seat bottom and then slit it for the U-shaped pleated section. I got into a groove and forgot to take pictures but I'll do better the next time.


It was a slow process of making sure everything was lined up and hog-ringing it into place, but I got the front and sides done and it looks pretty good. When I get the back edge tacked down the leather will smooth out.


I was pretty impressed with the Lseats.com seat covers. The leather appears to be nice and the craftsmanship is much better than I could have done. Waiting for them to finish was a pain but in the end it was worth it.

 

In anticipation of being able to do a test-drive soon, I put the driver's seat back in the car today.



I also finished extending the wires for the air flow meter and decided that a strip of self-amalgamting silicone tape around the seam between the two halves of the air filter will greatly improve the look.


For the bad news, I realized that my clutch master cylinder wasn't pushing enough fluid to properly engage the clutch. When I purchased the clutch master I bought the same diameter (.700") as the factory clutch master thinking that it would be a good match to the factory slave cylinder I am using. With the different pedal geometry it wasn't enough so I have a master cylinder with a larger bore size on the way.

 

Thorsen
I do hope that is the unrecovered driver's seat!!
I do want to say, too, that your skills are just amazing, that leatherwork and upholstering is really top grade-looking.

Final question, what is supporting the airflow meter?

 

Greg,
Yes, the driver's seat has not been re-covered yet. I left it untouched because I did not want to be in a situation where I wanted to test-drive the car and the seat needed to be re-covered. It would make me want to hurry up and there is no hurrying up when you are doing upholstery.
I will say that split in the vinyl gets bigger every time I look at it! The nice thing about cars from the desert is they are generally rust-free but the upholstery dries out very fast. It's a trade-off I will take.

Right now the air flow meter is supported by the filter, but the filter is free to move around in the "can" within the constraints of the hole. When I take the can off to make the seam look better I will secure the filter to the can so it does not have any movement.

Thomas

 

It's getting really hard to contain my excitement. As soon as the weather dries up over the next few days I will be able to get my first test drive in.
Tonight I got the radiator in and filled it with fluid.



I also able to finish all the AC hoses forward of the firewall.


This receiver/drier was used a long time ago but I saved it as a place holder to mock up the hoses to/from the drier.
Once I install the new under-dash unit I will need to build the hoses from the firewall to the evaporator. When it's time to vacuum down the system I will un-cork a new receiver drier and put it in place so it is not exposed to the atmosphere any longer than necessary. This will keep the desiccant from saturating.


Last night while I was asleep I figured out the issue with the clutch. On every other clutch I have seen in my life, the slave cylinder pushes down on the center of the clutch pressure plate forcing it to move to the front of the vehicle. On the LT1/T56 the slave cylinder pushes a fork that pulls the center of the clutch pressure plate towards the rear of the car. I did not have the fork installed correctly but luckily GM made it easy to correct that and I was able to fix it in about 10 minutes.

The goal for the next day or two is to get a few test drives in. After that I need to put a few mounts on the exhaust system and then tidy up a more things like installing the fan controller as well as installing the grill and the hood.

From there the big thing is the interior. I still need to finish the front passenger seat as well as get started on the front driver's seat and the rear seat. There are also a few trim panels I need to make but the first thing that needs to happen is new carpet.

 

Today I was able to drive the car for about 10-15 miles, which is the first time she has moved under her own power in 6 months. I did have one small water leak from the water pump but I was able to correct that easily. The engine is incredibly smooth and the torque makes it easy to drive the car. The disc brakes need some more breaking in but are already an improvement over the drums. I am happy with where things stand and hope to get the hood put back on tomorrow.

No pictures today but I do have one video, which is not the greatest as the camera was mounted outside the car and wind noise quickly swamped the microphone.
Also, I had the radiator fan wired to run full speed all the time and that is most of the noise you hear at low speeds.

 

Amazing progress, Thomas! I can't wait to see the remaining details come together.

Where will you source the new carpet you mentioned?

Cheers,

Don