here's hoping it all works out properly and fun!
My Baby is BACK and better than ever, with a new heart (aka engine) and 5 speed. I am in love!
- Thread starter scottevest
- Start date
Hey guys, just wanted to give a quick update. I made it from Palm Desert to Phoenix over 250 miles without incident (averaging 20 mpg btw), and somewhere along the drive I think I finally figured out what has been causing the bizarre intermittent problem I described earlier. With help from @HB Chris and a few mechanics here at the event, the issue now appears much more likely to be clutch-hydraulic related rather than anything catastrophic in the gearbox or driveline.
On one occasion during the drive, I noticed the clutch pedal had dropped much farther than normal and was not fully returning on its own. I was able to hook my foot behind the pedal and pull it back up a few inches, after which the pedal feel returned to normal. That seems to fit a leaking slave cylinder allowing air into the system, or possibly another issue somewhere in the clutch hydraulics or release mechanism. In other words, the working theory now is an intermittent clutch slave / hydraulic problem, not a transmission failure.
The good news is that the car is otherwise running great. It made the drive here without incident, is pulling strongly, and generally feels excellent. The current plan, if the mechanic here has time, is to inspect the slave cylinder for leakage, bleed the clutch system thoroughly, and take a quick look at the master cylinder, hose, pedal return, and related clutch release hardware just to make sure nothing else is contributing.
At this point I think I’m probably fine for the rally, but I wanted to close the loop and share what now seems to be the real culprit. Thanks again for all the input here. I really do appreciate it. If anyone has anything else to add, I’m all ears, but for now I think I’m in reasonably good shape.
On one occasion during the drive, I noticed the clutch pedal had dropped much farther than normal and was not fully returning on its own. I was able to hook my foot behind the pedal and pull it back up a few inches, after which the pedal feel returned to normal. That seems to fit a leaking slave cylinder allowing air into the system, or possibly another issue somewhere in the clutch hydraulics or release mechanism. In other words, the working theory now is an intermittent clutch slave / hydraulic problem, not a transmission failure.
The good news is that the car is otherwise running great. It made the drive here without incident, is pulling strongly, and generally feels excellent. The current plan, if the mechanic here has time, is to inspect the slave cylinder for leakage, bleed the clutch system thoroughly, and take a quick look at the master cylinder, hose, pedal return, and related clutch release hardware just to make sure nothing else is contributing.
At this point I think I’m probably fine for the rally, but I wanted to close the loop and share what now seems to be the real culprit. Thanks again for all the input here. I really do appreciate it. If anyone has anything else to add, I’m all ears, but for now I think I’m in reasonably good shape.
Glad to hear all worked out. Perhaps relevant - just had a discussion with Don yesterday and since I am running an entirely new clutch, slave/master cylinder, lines, etc, he was cautioning me that when bleeding it, one should be careful with the slave cylinder. The bluebook walks through the technique, but essentially because you can’t easily reach the bleed screw, the slave should be dropped down off the bell housing and then he suggested pumping the piston by hand while having a hose attached to the bleed screw with the other end in a vat of brake fluid. He cautioned against using a pressure bleed on the slave since it could drive the piston out. So yes seems like improper bleeding could be the issue. He also told me that I should expect to have to bleed my brake/clutch system likely three times in the first month or so of driving just as the air bubbles that are inevitably there coalesce into larger air bubbles which can then actually be bled out.
That is extremely helpful. Hopefully the Mechanic servicing the rally can do that for me.
Made it through first full day of rally with no issues, although did consume some clutch fluid. Watching carefully. Car ran great!
No drips on the garage floor?
Another 212 miles and no clutch fluid used and no Drips. I think all is well. Car is running really well keeping up with all the fast Ferrari, Lamborghinis Porsche’s, etc..
Guys, I wanted to report back after completing the Copperstate 1000 in my 3.0 CS.
Overall, the car was excellent. Other than the transmission/clutch shakeout issue I dealt with right before the event, the BMW performed extremely well for the entire rally. Once underway, it gave me no real trouble at all. No overheating, no fuel delivery issues, no altitude-related carburetor drama, and notably, it did not use a single drop of oil over the trip. That alone made me very happy.
For those who have followed the project, this is Carl Nelson’s 3.5-liter high-compression carbureted build with the performance cam and 5-speed, and on this event the combination really showed itself well. The car pulled strongly everywhere. We saw major elevation changes, from essentially sea level to roughly 7,000 feet, and the carburetors behaved far better than I would have expected without any adjustment. No obvious loading up, no major flat spots, and no meaningful sense that the engine was down on power at altitude. It would pull uphill in fifth gear at speeds where I would normally expect more complaint from a vintage carbureted setup.
On the faster sections, the car felt genuinely strong. There were long stretches where we were running well over 100 mph, and at 100 mph the engine was turning about 4,200 rpm in fifth gear. That seemed to be a very comfortable place for the drivetrain. The engine felt relaxed, responsive, and very much in its element. Sound-wise, the car was exceptional. A number of people commented on how strong and how good it sounded, and in a rally filled with serious machinery from the 1960s and early 1970s, including some very special Ferraris, Porsches, and Maseratis, the BMW did not feel outgunned.
Fuel economy was also better than I expected given how the car was driven. On the all-highway portions, the car averaged almost 20 mpg. With highly spirited driving, that dropped to roughly 13.5 mpg, and for much of the balance of the trip it was in the 16 to 18 mpg range, with several legs right around 17 mpg. For a 3.5-liter high-compression carbureted E9 being driven properly, I thought that was more than respectable.
The one clear limitation I noticed was aerodynamics. Compared with my Alfa Romeo 1750, which feels much slipperier at speed, the BMW feels like it is pushing a lot more air. At one point a strong crosswind hit the car at speed and moved it around enough to get my full attention. That was a useful reminder that however composed the chassis may be, this is still a relatively upright early-’70s coupe with the aerodynamic properties of a handsome brick.
Still, the biggest takeaway is that I came away from the event far more impressed with the total package than I expected. The car felt fast, stable, charismatic, and surprisingly versatile across a wide range of conditions. I genuinely fell back in love with it on this trip, and at the moment it may be my favorite car in the garage.
So overall, I’m quite pleased with Carl Nelson’s build, even allowing for the transmission-related shakeout issues. Thanks again to everyone here who has offered advice, input, and encouragement throughout this project. I really do appreciate it. I thought the forum would enjoy the report, and I’ll attach the video clip below.
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Overall, the car was excellent. Other than the transmission/clutch shakeout issue I dealt with right before the event, the BMW performed extremely well for the entire rally. Once underway, it gave me no real trouble at all. No overheating, no fuel delivery issues, no altitude-related carburetor drama, and notably, it did not use a single drop of oil over the trip. That alone made me very happy.
For those who have followed the project, this is Carl Nelson’s 3.5-liter high-compression carbureted build with the performance cam and 5-speed, and on this event the combination really showed itself well. The car pulled strongly everywhere. We saw major elevation changes, from essentially sea level to roughly 7,000 feet, and the carburetors behaved far better than I would have expected without any adjustment. No obvious loading up, no major flat spots, and no meaningful sense that the engine was down on power at altitude. It would pull uphill in fifth gear at speeds where I would normally expect more complaint from a vintage carbureted setup.
On the faster sections, the car felt genuinely strong. There were long stretches where we were running well over 100 mph, and at 100 mph the engine was turning about 4,200 rpm in fifth gear. That seemed to be a very comfortable place for the drivetrain. The engine felt relaxed, responsive, and very much in its element. Sound-wise, the car was exceptional. A number of people commented on how strong and how good it sounded, and in a rally filled with serious machinery from the 1960s and early 1970s, including some very special Ferraris, Porsches, and Maseratis, the BMW did not feel outgunned.
Fuel economy was also better than I expected given how the car was driven. On the all-highway portions, the car averaged almost 20 mpg. With highly spirited driving, that dropped to roughly 13.5 mpg, and for much of the balance of the trip it was in the 16 to 18 mpg range, with several legs right around 17 mpg. For a 3.5-liter high-compression carbureted E9 being driven properly, I thought that was more than respectable.
The one clear limitation I noticed was aerodynamics. Compared with my Alfa Romeo 1750, which feels much slipperier at speed, the BMW feels like it is pushing a lot more air. At one point a strong crosswind hit the car at speed and moved it around enough to get my full attention. That was a useful reminder that however composed the chassis may be, this is still a relatively upright early-’70s coupe with the aerodynamic properties of a handsome brick.
Still, the biggest takeaway is that I came away from the event far more impressed with the total package than I expected. The car felt fast, stable, charismatic, and surprisingly versatile across a wide range of conditions. I genuinely fell back in love with it on this trip, and at the moment it may be my favorite car in the garage.
So overall, I’m quite pleased with Carl Nelson’s build, even allowing for the transmission-related shakeout issues. Thanks again to everyone here who has offered advice, input, and encouragement throughout this project. I really do appreciate it. I thought the forum would enjoy the report, and I’ll attach the video clip below.
The Copperstate 1000 was an absolute riot. Great roads, great people, great cars, and my 74' BMW 3.0 CS E9 came to play. In a field full of Ferraris, Porsches, Lamborghinis, Maseratis, Jaguars, and plenty of other rolling jewelry, the old BMW more
The Copperstate 1000 was an absolute riot. Great roads, great people, great cars, and my 74' BMW 3.0 CS E9 came to play. In a field full of Ferraris, Porsches, Lamborghinis, Maseratis, Jaguars, and...
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FYI