My 1975 Sportwagon build - vintage rally support vehicle

Yesterday I actually worked on parts for one of my Opels. I got a batch of metal parts back from being zinc plated. Decided to put some of those parts to use, and finish up some projects that were in limbo.

First, I got to assemble the Quaife fast ratio rack-and-pinion guts into the steering housing for my Sportwagon. It was a Quaife rack I built in ‘93 or ‘94, and it had been raced hard, so it needed refurbishing. I polished the rack shaft and pinion gear, replaced the bearings, and some other incidentals (seals, etc).



Freshly cleaned parts.





Input pinion, rack boot clamps, dust cap, and locking ring back from zinc plating.





Freshly assembled with Red Line CV-2 synthetic grease.





Grease zerks have been fitted, and new input boot and needle bearing seal too.




I hate the way the locking rings get all chewed up with pliers, so I bought a spanner wrench and modified it to fit the locking ring without damaging it.

The other thing I worked on yesterday was assembling a custom vented hub/rotor assembly for the 1975 Sportwagon. It’s nothing fancy but it’s effective and not too expensive. The other thing I like about it is it fits under most of my 13” rims (but not all of them).

The rotors are 24 mm x 260 mm (about 10.25” OD), so there is not only greater heat dissipation from the vented rotors, but also greater braking torque from the larger rotor OD. I also use a 4-piston Wilwood caliper that provides good clamping and a larger brake pad.

The rotor/hub assembly weighs 3 lbs more than a stock 1975 Opel rotor/hub assembly, but the Wilwood calipers are over 5 lbs lighter than the stock iron calipers so it is more than a wash. So, a slight loss of unsprung mass, with a slight increase in rotating inertia.





Opel hub, custom spacer/adapter, center rotor, and the fasteners needed to make it all work.





First step was to bolt the adapter to the hub with new 10mm x 1.25 x 25mm grade-12.9 socket cap screws, I apply a light film of anti seize between the aluminum and iron parts, and thread locker to the bolts, and torqued them to 60 ft lbs.








Because there is some slop between the rotor bolt holes and the 1/2”-20 bolts that secure the rotor to the hub, I use a pair of countersunk bolts to draw the rotor centered to the bolt holes. No slop, and no radial run-out. Just snug them by hand, then fit two of the real bolts and tighten them to about 30 ft lbs. I then remove the locating bolts, and fit the last two real bolts to the rotor.





I used anti-seize again between the dissimilar metals, and thread locker on the mounting bolts. These are torqued to 90 ft lbs, being grade 8 fasteners.





Finished rotor/adapter/hub assembly.







The finished assembly is quite a bit larger than a 1975 ‘big brake’ setup

I put the inner and outer tie rods onto my rack-and-pinion today. The inners were originals, but very tight and in good condition. They got wire wheeled, Scotchbrited, and then got painted with satin black chassis paint.

The outer tie rods are NOS German items I’ve had since the early 1990’s! The dust boots were cracked, so I replaced them with aftermarket urethane boots, and got some new jam nuts. These outer tie rods got scuffed up, cleaned, and painted with the same satin black chassis paint.

The rack-and-pinion boots themselves are replacements from OGTS. I used my newly zinc plated inner boot clamps, but the outer clamps (stainless steel Oetiker clamps) I bought from McMaster-Carr didn’t fit. They fit standard OEM Opel rack boots, but not these aftermarket rack boots....grrrrr. Too small. Oh well.

A while back I was at my family’s business and I got the chance to cut down a set of front and rear ‘big’ bumpers (1974-1975 style) on the large bandsaw they have.

I ended up taking 2” out of the middle of the bumper. My original intent was to use the factory spring loaded bumper mounts and turn them sideways to fit within the narrowed bumpers. The aluminum adapter on the bumper was already removed, so this brings the bumpers closer to the body by about 2”. However, if the original spring loaded mounts are enacted, the bumper will hit the body.

So my idea is to solid mount them with lightweight chromoly tubing that bolts in rather than clips in like OEM. I figure I’ll save about 10 lbs per bumper total, and there’s less chance of body damage.

Anyway, in the quest to remove even more weight, I drilled holes in the bottom of each bumper. I took a router bit to the edges of the holes to smooth things out.

Next, using a spare front Ascona clip I own, I layed out my future auxiliary lighting. I have a new set of IPF H4 halogen headlamps with yellow film applied. Then a set of replica Cibie Oscar 7” driving lights. Further inward are a set of PIAA 80 rally lights with dual-element H4 bulbs, they are roughly 7.8” in diameter. These lights will be mounted on a custom steel bracket that raises them about 2” above the top of the bumper. This not only will provide the light pattern I desire, but it also leaves the grill area more open for airflow. Below the bumper, I will mount a pair of Hella 500 fog lamps with yellow film applied.

Yup, I like lights.

These are all for my 1975 Sportwagon.

Almost forgot another thing I collected.

Been buying gauges gradually over the past year. I have a factory Manta Rallye/Sportwagon center gauge panel, which I fitted with aftermarket gauges. It houses a mechanical oil pressure gauge, electrical oil temp gauge, and electrical water temp gauge.

Now, I also have an original and fairly rare Rallye A/C gauge panel. When A/C was fitted, the gauge panel below the radio can’t be used. So the solution was a vertical gauge panel to the far left of the dashboard.

I decided that in light of the rarity of the A/C gauge panel, I would make a mold of it to pop out cheap fiberglass reproductions.

I made this mold two years ago then forgot about it! It got put into a bin before my shop got built and was hidden until last week.

So, I removed the original part from the mold after two years. To say it was stuck in there was an understatement! I damaged the original part slightly when I removed it, but the mold looks pretty good. I need to sand some edges and touch up the gelcoat, but the mold is very solid.

The vertical gauge pod will house a voltmeter, a clock, and a turbo boost gauge.

Built a light bar to raise the center PIAA driving lights up 2.5” higher than the bumper itself for my 1975 Sportwagon.

Used some rusty 3/4” x 1-1/2” steel I had laying around. Not fancy, but functional and doesn’t flex.

I also made some brackets to bolt to the underside of the front bumper, they will be to mount the fog lights. I wanted them set back a bit to avoid curbs and such.

Got this radiator today. It was on sale so I couldn’t pass it up. VW Scirocco type double pass aluminum radiator for under $200. Last month I picked up the intercooler in the pics. Normally $199 but on sale for $66.

Anyway, this is for one of my tinkerings again. I wanted to see if I could stuff a radiator AND intercooler into the nose of an Ascona (Sportwagon to be precise). Very little room up front in one of those.

I think with trimming some sheetmetal and some of the bracketry it should fit nicely.

I’m toying with putting a small turbo on a stock 1,9 with ‘original’ L-Jetronic Opel EFI. I swapped the guts out an Opel 1.9E air flow meter into a 2.0E air flow meter. It’s 44% larger in area, so I will also fit roughly 40-45% larger fuel injectors. That should be easily tuneable for off-boost driving. Then, a higher flow fuel pump will be fitted and a rising rate fuel pressure regulator added to increase fuel flow under boost. With a modest 6-8 psi I’m hoping for decent driveability and power. On top of all this I have an old (never used) Jacobs turbo timer which retards timing under boost.

So, tinkered a bit with the EFI intake for this concept. Decided to direct-plumb a water/methanol injection system into the intake.

First I made a distribution manifold from a short piece of -6AN fuel rail extrusion. Next I chopped up some 1” OD x .125” wall thickness aluminum tube to make the spray nozzle adapters. They will have 1/4” NPT bungs welded into them.

The manifold wasn’t too greasy but it had some corrosion on it which made welding challenging. I had to adjust my TIG heavily on the ‘cleaning’ scale to get the welds to flow at all. Of course that means lousier penetration so it took a lot more amperage than I expected.

So, I found a 4th 1/4 NPT female weld-in bung, and decided to finish off that part of the intake.

I also blended the intake manifold ports to match a stock 1.9 head…the stock EFI intake necks down a lot near the injector plates.

The new injector plates I’m using are shown for posterity.

Then I proceeded to the coolant surge tank. I used what I had laying around. This included a scrap of 4” diameter aluminum tubing, an old aluminum filler neck off a radiator, a scrap of .062” aluminum sheet, and some random tubes for the fittings.

The welding of those random tubes went about as expected. Horribly. The 5/8” tube was actually fine as that tubing is also .062” to match the flat sheet.

But the 3/8” tubes are only .030” thick, and when I went to weld them, it pretty much had the same effect as Hershey bar left on a hot sidewalk. So I melted the first one into mush. Decided I will weld in some 1/8” NPT bungs instead. My skills are seriously lacking.

I played plumber yesterday. Bent up some 1/4” copper-nickel tubing, and flared the ends 37 degrees for use with tube nuts/sleeves. I still need to drill out the lower -4AN to 1/8” NPT fittings and tap the brass adapter bushings to accept the 1/8” NPT misting nozzles.

I ended up not using the distribution manifold I recently made. Instead, while searching thru a box of AN fittings I found the one depicted, which I built many years ago.

Here is what I’m doing for the spray nozzles. They’re just industrial high pressure misting nozzles. Threading them from the inside of the manifold wasn’t really an option, so this was my solution.

I enlarged the hole in the black fitting to clearance the spray nozzle. I ran an 1/8” pipe tap into the opposite side of the reducer bushing so that I could thread in a fitting from both ends.

Interestingly, the stock 1.9 EFI throttle body has an oddball diameter. The inlet OD is 66 mm. So trying to find a connector hose proved impossible. I found that I could use a piece of 2.75” aluminum tubing to slip over the throttle body, which then allows for a 2.75” hose to be fitted. I will just epoxy the piece of tubing in place, since welding might warp the throttle body.

The connector hose is a 90 degree transition from 2” to 2.75”. This will go to one end of the intercooler.

I threw together a long block so I can mock-up the turbo location on my Sportwagon cheapie turbo EFI build. I wanted to be able to weld a turbo oil drain tube onto a steel oil pan, so I need to know exactly where the turbo drain is located.

In order to do that I need the actual turbo I’m going to use on the final engine setup. In keeping with the low-buck theme I ordered a CX Racing T28 turbo with an 8 psi wastegate. I normally run away from the cheap Chinese knock-off turbos, but I figured I’d give it a shot. I may regret it when it comes to performance capability and reliability, but we’ll just have to wait and see.

I put a timing cover and valve cover on my mock-up engine. Still waiting on the turbo. Should be here in a couple days.

The workshop got a new refrigerator. My old one died while it was in storage. It’s been tough finding any under $500 lately, it seems like all the cheap ones (compact size) are all sold out and backordered. I found this one at a local appliance dealer for $100 off due to a dent in the door. Otherwise it’s brand new. I’ll cover it in stickers eventually.

The turbo came in today.

As expected, I had to re-clock the center section in order to orient the oil feed and drain lines correctly. When I re-clocked the compressor side of the turbo, surprisingly the wastegate actuator was pretty much just where it needed to be without binding. I may have to adjust the preload tension on the actuator, but it all JUST fits in there.

It did dawn on me that this setup won’t fit the early 1971-1973 engine mount brackets, only the 1974-1975 brackets. The waste gate actuator is nestled inside the engine mount practically!

Anyway, first impressions are that for $236 (delivered), this turbo doesn’t look too bad! I was expecting far more flawed castings and impeller wheels, but it didn’t look half bad. Time will tell however.

With the intake bolted back on. Everything is good and snug.

In my my anticipation for the turbo yesterday, I failed to even notice another package had come in. In it, I got my twin 8” cooling fans for the Scirocco radiator, and the Pertronix ‘Flamethrower HV’ 60,000-volt coil with .45 ohm resistance.

I still need to fabricate a radiator shroud from aluminum (or fiberglass…haven’t decided yet), and I need to order the Pertronix 2 igniter.

Recurving a factory distributor is another step I’ll need to take as well. I already have all the other needed components for the ignition…Standard Ignition distributor cap, non-resistor ignition rotor, o-ring seal for the distributor base (in lieu of a gasket), and a ratcheting distributor hold-down handle and stud. I have a Magnecor wire set I was going to use but the coil wire doesn’t work with my new coil so I may go with a full custom 10 mm wire set instead.

Today was mostly a housework day. Didn’t get into the shop until later. Didn’t do much either!

I did however pick up some closed cell foam, as I decided to make the fan shroud from fiberglass. So I need a buck to make a mold from. I would’ve liked to have made the shroud at least twice as tall as I did to improve airflow thru the fans, but in an Ascona that just isn’t happening! There simply is no room. A Manta would have had the space though.

Been a busy week. Mostly house work, but I managed to take 4 days off too, and attended the Mt Washington Hillclimb. Amazing weather and an amazing event!

Anyway, during my absence a few things I ordered came in. Mostly related to the turbo. As usual, when you buy something cheap you get what you pay for. In this case, I’m finding that the turbo has some non-standard features. Tracking things down has been interesting. And in one instance, I had no choice but to make it myself! All in all, I will probably have as much invested into the turbo plumbing (oil and water, and gaskets/flanges) as I do into the turbo itself.


First things first. While the oil drain bolt pattern is correct, it is in no way centered over the turbo oil drain hole! If I used a standard T25/T28 drain tube it would partially block the oil discharge on the turbo. Never good.






The solution, of course, was to make a custom turbo oil drain flange. I cut it out of 3/16” steel, and brazed a 5/8” steel tube to it.






I used my tubing beader to produce a raised bead on the metal tube for better hose retention. I’ll probably have it zinc plated.






Note that I had to put a bend and a slight offset in the drain tube in order to clear the wastegate actuator rod






Here you can see a 3/8” banjo tube fitting which is the feed for the water-cooled center section. It gets REALLY tight in here, so much that I had to order a small-head banjo bolt (M14 x 1.5 pitch) to clear the turbo mounting flange stud. Even still, I will be using a shortened mounting stud and a small-head (10 mm) copper exhaust nut for clearance.






Close-up at the banjo bolt. Very tight fit.






The black fitting in the center of the turbo is the discharge line for the water cooled center. It’s also M14 x 1.5 pitch.

At the top of the pic, there is the oil feed line, which is an oddball size. Usually a turbo will have an 1/8” NPT feed. Sometimes an M11 x 1.25. Sometimes M12 x 1.00. Sometimes M12 x 1.5. This turbo however, was M12 x 1.25. Weird. Hard to find and expensive banjo bolt too. The oil feed line will be a -4 AN (1/4”) copper-nickel tube with 37 degree tube nuts for attachment.






Then there is the turbo discharge flange. I tried a GT25/GT28 flange I had. Nope. I ordered a T25/T25 flange then. Nope. So then after some research I found out it matches a Nissan T25/T28 flange, even though this turbo is universal and not vehicle-specific. Not rare, but not exactly common everywhere either. So I now have one of those in order now, along with a gasket.

I also picked up a manual boost controller if I want to increase boost above the 8 psi baseline setting that the supplied wastegate gives. Nothing crazy, but a ball-and-spring regulator is arguably better than an air pressure regulator valve.