Bringing a '74 back up to her intended glory.

[Bmachine]

Good grief... Soooo much has happened during the last year. I was kept away from any car activities by unrelated issues. Mostly a big personal change in our lives as, after living for 24 years in in the Los Angeles area, my wife and I decided to start on a new adventure. We sold our house in southern California and bought a new one along the coast north of San Francisco. Needless to say that was a huge undertaking which put everything else on hiatus. But I recently did come back down for work reason and took advantage to pick up my car from Carl who had installed a fully rebuilt '88 B35 motor with 10:1 pistons and Motronic 1.3 along with a Getrag 265.

Most of the mechanicals are now in place. The next job will be to start on the myriads of fine tuning, as well as interior and exterior cosmetic jobs. Because right now, this car is much more rat rod than classic coupe.

It was so great being able to finally spend some time driving the car again and I have to thank my friends Carl Nelson, Rey Rivera, Jason Lawrence, Gary Ibusuki, Gavin Arthurs, Chris Macha, Don Laurence and John Abelson for all the help and friendship they provided.

 

[Bmachine]

A few random pics of the oily bits:

 

[Gransin]

That's great, Bo! How does the new engine+trans feel like?

 

[Bmachine]

That's great, Bo! How does the new engine+trans feel like?

Thanks Robert. As with any major organ transplant, there were many hurdles to cross and then some fine tuning that needs to happen. There is still a lot of work to be done to increase the quality of the driver experience. The car is very noisy bc I am missing a lot of sound proofing bits, including the tranny tunnel foam pad and center console, most of the window seals are perished and lots of stuff rattles. The clutch was also very hard at first so Carl replaced the stock slave with an e23 one which made it much more enjoyable. Jason also modified the original throttle linkage for a much smoother fuel delivery. The stock seat padding is completely gone which means the seat is very uncomfortable.
That being said, the motor is fantastic, pulls very strong and the tranny is buttery smooth. The suspension and braking I had rebuilt are excellent I am really enjoying driving it again after 3 years on the operating table. And things will only get better from here!

 

[Bmachine]

When I was racing my Tii, one of the racing instructors told me "The cheapest performance improvement in a car is driver comfort". How true that is! So I added two items to implement that philosophy.

My back was never happy with the stock seats for long distances. Since I want this car to be as friendly to drive as possible, I have been looking at ways to improve driver comfort.

After much research, I decided that the e92 seat is the best compromise between style that is at least -somewhat- similar to original e9, (unlike the Recaros which, to me, look too "racy"), and they offer multiple adjustments for comfort. It is a coupe seat, so it folds properly for rear seat access and uses the original seatbelt system (in my case, a '74 with the shoulder belt anchored near the rear parcel shelf). Now I need to dye the leather to match the rest of the car and do lots of clean up and tidying. I made sure this mod is completely reversible since I am using the original seat rails and no mod needed to be done to the car itself.

The main challenge was to find a way to install the seat as low as possible because those later seats sit way too high when placed on the stock e9 seat rails. In order to achieve that while also retaining the full adjustability of both the lumbar support and the side bolsters, I had to use a manual sports seat from an e92 and transfer the lumbar adjustments from an electric sport seat. Then hack into the wiring harness to make it work in the e9. Then I made brackets to "sink" the seat in the available space.

The end result for me is a seat that is far more comfortable for long distances. But that is entirely a personal thing. Many are perfectly comfortable in the stock seat.

One more thing for long distance comfort: I added a center armrest from a '78 733i. I had discovered that those fit perfectly on the e9 with my first coupe many years ago. This works as long as you use narrower seats like the Recaros or these e92 ones. The stock seat is too wide. Those arm rests are VERY difficult to find as they only made them for the first two years of the e23. My plan is to re-cover it in leather matching the seats.

 

[Bmachine]

I've been driving the car more and more, including in traffic to work (an hour each way) and I have to say it is really coming together very nicely. And even if the seat and arm rest are not "period correct" they make driving soooo much more comfortable (for me) that it makes me want to use it that much more.

I'm still not at the level of working on cosmetics but I sure would like to start replacing all the dead rubber around the windows so as to lower the wind noise. Adding sound insulation between the cabin and the engine would also make things much more comfortable over longer distances.

 

[Peter Coomaraswamy]

That looks like a fast car- great shot with the famous Carl Nelson!

 

[Bmachine]

Today I finally installed the passenger side mirror. It's amazing how much we get used to those things and how difficult it is to change lanes on the freeway without one.

A bit of research on this site led me to buy a rivnut gun and this worked out great!

 

[Bmachine]

Lots of smaller things attended to:

Got the AC hooked up finally. The new Sanden compressor blows nice and cold but the engine temp climbs dangerously close to the red when sitting in traffic. Gotta figure out what that is. The condenser fan runs though...

 

[Bmachine]

Removing the overspray on the horns from the PO's misguided attempts at a respray and cleaning them up.

 

[Bmachine]

Taking apart the windshield wipers and freshening all that up...

 

[Bmachine]

Finally, my "sport CSi" original wheel's very thin rim was getting pretty uncomfortable over long distances. So, until I get something "better" I am using a "Turbo Style" Petri 38. It may not look period correct but I must say that the thicker rim is far more comfortable...

 

[HB Chris]

Lots of smaller things attended to:

Got the AC hooked up finally. The new Sanden compressor blows nice and cold but the engine temp climbs dangerously close to the red when sitting in traffic. Gotta figure out what that is. The condenser fan runs though...

View attachment 65661 View attachment 65662

Bo, temps that climb when stopped is usually radiator related, you may have a partial blockage, an infrared heat gun can tell you if this is the case. Hot temps at top and cooler at the bottom hose exit. Our 2800 would do this but we had the original mechanical clutch and putting a modern clutch solved our problem. Driving provides more airflow and sitting puts more stress on the system. Does the condenser fan kick in when temps get high? Your 74 has the radiator temp sensor which helps. I am going to add this to my coupe one day.

 

[Bmachine]

Bo, temps that climb when stopped is usually radiator related, you may have a partial blockage, an infrared heat gun can tell you if this is the case. Hot temps at top and cooler at the bottom hose exit. Our 2800 would do this but we had the original mechanical clutch and putting a modern clutch solved our problem. Driving provides more airflow and sitting puts more stress on the system. Does the condenser fan kick in when temps get high? Your 74 has the radiator temp sensor which helps. I am going to add this to my coupe one day.

Really good info. Thank you Chris.
The condenser fan kicks in as soon as the compressor kicks in.
Without the air conditioning the car runs cool, mostly at about 4 o’clock on the needle. Tstat is a 72 degree one. This would lead me to believe that the car radiator is working fine.

 

[HB Chris]

Bo, condenser fan should kick in with AC off when temp gets too high in your radiator, a feature of all 74s. At speed a rad can be fine, sitting in traffic not so fine, usually caused by a blockage.

 

[Stevehose]

And with the ac on, the engine works harder and the condensor is hogging the cool air that otherwise would be available to the radiator which can expose a weak radiator, especially in traffic.

 

[Bmachine]

The radiator is a new "Don Laurence special" one. The fan and cooling system are all new as well. And the condenser and fan are new from Nostalgic air also.

The condenser fan is wired using the original circuit so it is activated by compressor clutch turning on and triggering the relay above the battery. I'm not sure how it also gets triggered by the radiator temp however... I have not looked at that part of the circuit.

 

[Stevehose]

I think Don installs the fan sensor in the lower passenger side corner of the radiator, other places could be a dual sensor in place of the normal sensor by the t-stat housing.

 

[HB Chris]

Your original rad had a bung as Steve said above the outlet hose.

 

[Bmachine]

Thank you. Will check tonight after work.