That's my thought too.
72 3.0 CS 2240344 Restoration
- Thread starter ScottAndrews
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Finally had a bit of time to poke around my coupe since moving her to the new shop.
Did a lot of inspecting with a bright light and a screwdriver.
Found only a small bit of rust around the round recesses in the middle of the driver's side floor. . Not sure if that is structural or not. There is a fair amount of peeling underbody coating in the way.
I did not get my scope into the shelf area, but I did inspect it from the wheel well using a bright light and a screwdriver. There is a haze of light surface rust visible on the vertical aft of the wall of the area, but nothing ugly and scaly. The bottom of that area is solid when poked and probed from below, so I think that area is OK. Nothing noticeable in or around the A-pillars. Front clip, fender tops, etc., all solid.
I'll go over tomorrow and get some pics with the borescope.
So currently it seems I have that small 6 inch section at the rear rocker (last few inches of the inner rocker) that are are rusty enough that there was some visible bubbling of the paint just forward of the rear wheel and below the rocker cover line. And whatever is up with the round recesses in the floors.
Body exterior is clean with no significant dings or dents. Shut lines are true, and trim is in good, if not pristine condition with no visible dings.
The interior is a mess, but I knew that, and it will all be replaced.
I did discover what appears to be some wonky wiring up near the battery. There are a couple of sections taped with plastic electrical tape. These have terminals that look like they are supposed to go to the battery positive terminal, and a set of inline blade fuses spliced in... Odd... But I was planning to redo the entire harness anyway..
I'm going to start by removing the doors and hood and putting them on dollys. Then I'll pull out the entire interior, and get under the padding to see what's up with the floors.
In the meantime, I am getting familiar with a 3D modeling software package, and plan to work out the design for a new intake manifold that, if possible will allow the three carbs with elbow trumpets and air filter to fit properly without interfering with the inner fender, the booster, the thermostat, and the hood.
Did a lot of inspecting with a bright light and a screwdriver.
Found only a small bit of rust around the round recesses in the middle of the driver's side floor. . Not sure if that is structural or not. There is a fair amount of peeling underbody coating in the way.
I did not get my scope into the shelf area, but I did inspect it from the wheel well using a bright light and a screwdriver. There is a haze of light surface rust visible on the vertical aft of the wall of the area, but nothing ugly and scaly. The bottom of that area is solid when poked and probed from below, so I think that area is OK. Nothing noticeable in or around the A-pillars. Front clip, fender tops, etc., all solid.
I'll go over tomorrow and get some pics with the borescope.
So currently it seems I have that small 6 inch section at the rear rocker (last few inches of the inner rocker) that are are rusty enough that there was some visible bubbling of the paint just forward of the rear wheel and below the rocker cover line. And whatever is up with the round recesses in the floors.
Body exterior is clean with no significant dings or dents. Shut lines are true, and trim is in good, if not pristine condition with no visible dings.
The interior is a mess, but I knew that, and it will all be replaced.
I did discover what appears to be some wonky wiring up near the battery. There are a couple of sections taped with plastic electrical tape. These have terminals that look like they are supposed to go to the battery positive terminal, and a set of inline blade fuses spliced in... Odd... But I was planning to redo the entire harness anyway..
I'm going to start by removing the doors and hood and putting them on dollys. Then I'll pull out the entire interior, and get under the padding to see what's up with the floors.
In the meantime, I am getting familiar with a 3D modeling software package, and plan to work out the design for a new intake manifold that, if possible will allow the three carbs with elbow trumpets and air filter to fit properly without interfering with the inner fender, the booster, the thermostat, and the hood.
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So I have been doing some measuring on my coupe, and exploring various options for intake manifolds using triple Weber 40 DCOE carbs.
The core issue with these, as most of you are aware, is interference with the brake booster. I am not super keen on having intake trumpets that almost interfere with the booster and the inner fender, and that are somewhat problematic relative to any sort of air filter.
My journey started when I bought a set of conversion manifolds from Pierce Manifolds. After measuring these, it appears they are about 18 degrees. They seems to be the same as those available from others (all made by Karsuntpartz), and I must say, they are really not very well finished.
I went over to the shop and set up a laser level to provide a datum in the engine bay. In this case I used the top of the firewall, which, while it may not appear so, sits even with the fender flange at the hood, right about where the shock tower is. Measuring down from there, I came up with a rough cross-section of the engine at cylinder 6 (the aft most one). The engine tilts up from there, rising about 31 mm from there at the front.
I then took dimensions from one of Tim Mason's beautiful billet air filters, and some rough measurements form the carbs, and tried various options and positions.
Using the 18 degree manifolds does not seem like a great idea. First off, since the engine sits at 30 degrees from vertical, the carbs are tilted 12 degrees back. While the carbs can tolerate some tilt, this is pretty extreme, and is outside the 5 degree limits that @Stevehose suggested. I can make it work with custom 78 degree elbows leading up to the air filter, and just miss the standard brake booster, but this approach seems to have a lot of compromises.
I then tried a 25 degree manifold. This places the carbs at a 5 degree tilt toward the engine (better). This also works using elbow trumpets and a standard booster.
It is pretty obvious that the critical points are: 1) the clearance to the under side of the hood, 2) the clearance between the air filter and the carbs, and 3) the clearance to the brake booster. This last one is very tricky because, since the booster is round the clearance is affected by both the vertical rise of the assembly, and the later al extent.
Some observations: The lower the angle of the intake manifold, the greater the tilt of the carbs (obvious), and the greater the vertical clearance (because the assembly is not rising up as fast), but the lower the angle the more the entire assembly moves laterally (because it is not rising up as much as it is moving sideways). So, there is a complex non-linear relationship between the manifold angle and the three clearance points (hood, carbs and booster).
I also found that there are some 90 degree trumpets made by Kooglewerks, which seems much cheaper than making special 78 or 85 degree trumpets. Those seem to really only work with a 30 degree manifold unless you are OK having the air filter tilted sideways.
I finally caved in and tried a design using the 90 degree elbows, a 30 degree manifold, and a Tii booster. That seems to be the best solution. The beauty this approach is not only do the carbs sit flat, but there's relatively little vertical rise, so the vertical clearance is easier to manage, and the 90 degree elbows work. I will still need to account for the fact that the front of the engine is about 30 mm higher than the back (it rises by about 6 mm per cylinder), so to keep the front of the filter from hitting the underside of the hood, I'll need a tad more vertical clearance.
I think once I get the dimensions nailed down more precisely, I'll make up a solid model, 3D print a prototype for fit testing, and start looking at casting my own manifolds...
Here are some diagrams representing these three options. There is a bit more to do in terms of precision measurements, but I think I am homing in on an optimal solution.
The core issue with these, as most of you are aware, is interference with the brake booster. I am not super keen on having intake trumpets that almost interfere with the booster and the inner fender, and that are somewhat problematic relative to any sort of air filter.
My journey started when I bought a set of conversion manifolds from Pierce Manifolds. After measuring these, it appears they are about 18 degrees. They seems to be the same as those available from others (all made by Karsuntpartz), and I must say, they are really not very well finished.
I went over to the shop and set up a laser level to provide a datum in the engine bay. In this case I used the top of the firewall, which, while it may not appear so, sits even with the fender flange at the hood, right about where the shock tower is. Measuring down from there, I came up with a rough cross-section of the engine at cylinder 6 (the aft most one). The engine tilts up from there, rising about 31 mm from there at the front.
I then took dimensions from one of Tim Mason's beautiful billet air filters, and some rough measurements form the carbs, and tried various options and positions.
Using the 18 degree manifolds does not seem like a great idea. First off, since the engine sits at 30 degrees from vertical, the carbs are tilted 12 degrees back. While the carbs can tolerate some tilt, this is pretty extreme, and is outside the 5 degree limits that @Stevehose suggested. I can make it work with custom 78 degree elbows leading up to the air filter, and just miss the standard brake booster, but this approach seems to have a lot of compromises.
I then tried a 25 degree manifold. This places the carbs at a 5 degree tilt toward the engine (better). This also works using elbow trumpets and a standard booster.
It is pretty obvious that the critical points are: 1) the clearance to the under side of the hood, 2) the clearance between the air filter and the carbs, and 3) the clearance to the brake booster. This last one is very tricky because, since the booster is round the clearance is affected by both the vertical rise of the assembly, and the later al extent.
Some observations: The lower the angle of the intake manifold, the greater the tilt of the carbs (obvious), and the greater the vertical clearance (because the assembly is not rising up as fast), but the lower the angle the more the entire assembly moves laterally (because it is not rising up as much as it is moving sideways). So, there is a complex non-linear relationship between the manifold angle and the three clearance points (hood, carbs and booster).
I also found that there are some 90 degree trumpets made by Kooglewerks, which seems much cheaper than making special 78 or 85 degree trumpets. Those seem to really only work with a 30 degree manifold unless you are OK having the air filter tilted sideways.
I finally caved in and tried a design using the 90 degree elbows, a 30 degree manifold, and a Tii booster. That seems to be the best solution. The beauty this approach is not only do the carbs sit flat, but there's relatively little vertical rise, so the vertical clearance is easier to manage, and the 90 degree elbows work. I will still need to account for the fact that the front of the engine is about 30 mm higher than the back (it rises by about 6 mm per cylinder), so to keep the front of the filter from hitting the underside of the hood, I'll need a tad more vertical clearance.
I think once I get the dimensions nailed down more precisely, I'll make up a solid model, 3D print a prototype for fit testing, and start looking at casting my own manifolds...
Here are some diagrams representing these three options. There is a bit more to do in terms of precision measurements, but I think I am homing in on an optimal solution.
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Some additional musings. To illustrate how small changes in dimensions can have significant impacts on fit and clearance, I tweaked the height of the air filter to gain a bit more clearance (needed at the front of the engine, which sits somewhat higher than the aft end). Here is a setup that hardly looks any different from the one above, but allows substantially better hood clearance...
Based on my post above, I whipped up a quick 3D model of the 30 degree manifold. Seems pretty straightforward. Need to figure out how to cast this. The flange holes are pilots. I'll also have to taper some of the bits and add fillets. Next step will be to 3D print this and check for fit. I may need to print it in several parts and glue them together.
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Spent several hours over in the shop working on the coupe.
Spent quite a while with a borescope examining the wheel wells and "the shelf". Other than a TON of dirt that I scraped and vacuumed out, the rust there looks to be just some surface rust. Nothing serious, although accessing it to clean it more and coat it to keep it from progressing will be a challenge. I'd post pics, but they are a bit like looking at your embryonic kid inutero via ultrasound.. more weather map than image..
Next I pulled the front and rear seats out, and pulled up the carpets and floor insulation. Looks like @Breiti was spot on about rust under the "tar panels". The fronts were rusty enough that the tar stuff just lifted off in sheets and bits. The passenger side is worse than the driver's side. I think this may be from condensation from the AC. Here are the ugly pics.
Passenger side:
The floor panel seems easy to replace, but I am concerned that the replacement panel may not reach far enough inboard or forward to fully patch this. I can't find any other trans tunnel or firewall patch panels on line, so I guess that means those areas will need to have patches fabbed. Looks like a small-ish section about 2 inches wide and about 5 inches past the firewall/floor joint.
The driver's side is not quite as bad. The circular recess is toast, and the accelerator pedal support is funky, but structurally OK.
And the rears are OK. The left rear has more rust than the right, but it seems to be surface rust in the channels. The metal seems sound throughout.
Notice that some joker cut speaker holes in the lower rear bulkhead (SMH...). I'll probably patch those..
Spent quite a while with a borescope examining the wheel wells and "the shelf". Other than a TON of dirt that I scraped and vacuumed out, the rust there looks to be just some surface rust. Nothing serious, although accessing it to clean it more and coat it to keep it from progressing will be a challenge. I'd post pics, but they are a bit like looking at your embryonic kid inutero via ultrasound.. more weather map than image..
Next I pulled the front and rear seats out, and pulled up the carpets and floor insulation. Looks like @Breiti was spot on about rust under the "tar panels". The fronts were rusty enough that the tar stuff just lifted off in sheets and bits. The passenger side is worse than the driver's side. I think this may be from condensation from the AC. Here are the ugly pics.
Passenger side:
The floor panel seems easy to replace, but I am concerned that the replacement panel may not reach far enough inboard or forward to fully patch this. I can't find any other trans tunnel or firewall patch panels on line, so I guess that means those areas will need to have patches fabbed. Looks like a small-ish section about 2 inches wide and about 5 inches past the firewall/floor joint.
The driver's side is not quite as bad. The circular recess is toast, and the accelerator pedal support is funky, but structurally OK.
And the rears are OK. The left rear has more rust than the right, but it seems to be surface rust in the channels. The metal seems sound throughout.
Notice that some joker cut speaker holes in the lower rear bulkhead (SMH...). I'll probably patch those..
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a lot of coupes have speaker holes there. not unusual. consider putting a passive radiator in the holes and mount a subwoofer under the seat.
2002s have a similar bulkhead. Out of the four 02s I owned, three of them had speakers in the same spot. I like Scott's idea.
rblongboarder
Well-Known Member
Very nice 3D renderings from Solidworks or a similar CAD program. Instead of casting those intake manifolds... why don't you have them milled out of T6061 billet by a shop like ProtoLabs or an equivalent machine shop? There are lots of web-based machine protoshops that will bid based on IGES files...
Yeah, I may do that. I also found some prototype shops that do 3D printing in sand (!!), for complex castings. So, several options seem to be available.
I did the drawing in Autodesk Fusion 360. Nice free version is available for personal use. Pretty steep learning curve, I have found. The drawings above would not render in a 3D slicer program because of the way I did the "tubes" (they were basically two meshed sleeves, with no solid material between the inside and outside surfaces...). I have since reworked the approach, and have a rough design that properly renders. I will do that with more precision over the next few days, and post the results. Fusion shows IGES files in the export menu, but they are greyed out. I have been exporting STL files for printing. I'll explore what's up with the other file formats.
Made more progress on the coupe disassembly today. Managed to work out how to disassemble most of the passenger side door. I am currently a bit stuck on how to remove the vent window handle. As I recall @rsporsche provided the trick in a recent post, so I'll go find that.
The door bottoms have no rust, which is good, but I did find some rust along the upper edge of the door, where the window trim strip slides on. The sandwiched joint where the outer and upper inner shell join has several fairly substantial rusty spots. All of these are on the inside piece, and do not perforate to the outer shell. Not sure if these are structural, since the rust scapes off, but it is a lot more than typical surface rust. I'll probably scrape and file it clean, and then see what's left
Here are a few pics.
The door bottoms have no rust, which is good, but I did find some rust along the upper edge of the door, where the window trim strip slides on. The sandwiched joint where the outer and upper inner shell join has several fairly substantial rusty spots. All of these are on the inside piece, and do not perforate to the outer shell. Not sure if these are structural, since the rust scapes off, but it is a lot more than typical surface rust. I'll probably scrape and file it clean, and then see what's left
Here are a few pics.
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small right angle tool like an allen key to access the hidden hole from behind, then push out the round plasti-chrome insert. Then just a screw.
Thanks to @Stevehose I got the wind-wing out, and moved to the other side of the car. That went much faster, since i know the various tricks after doing the passenger side. The driver's side upper door is also rusty, but not nearly as bad as the passenger side. Here are some pics of that. I think this can be cleaned up and treated without any heroics.
I then moved to the rear windows. Once I sorted out how to remove the trim strips, that was easy... I am pleased to have found no rust on the window sill area, and peering down into the rocker, it appears that the rust I found on the outside is only on the lower edge of the rocker, and only in the outer and middle rocker panels. So, that repair should be fairly easy.
Here is the rocker from the top side (inside the rear window area).
And, peering down the B pillar into the inside of the middle rocker, there is rust, but very light and not structural.
I then moved to the rear windows. Once I sorted out how to remove the trim strips, that was easy... I am pleased to have found no rust on the window sill area, and peering down into the rocker, it appears that the rust I found on the outside is only on the lower edge of the rocker, and only in the outer and middle rocker panels. So, that repair should be fairly easy.
Here is the rocker from the top side (inside the rear window area).
And, peering down the B pillar into the inside of the middle rocker, there is rust, but very light and not structural.
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