Alan's RCR40

My friend stopped by over Christmas and commented that I have gone backwards! It certainly looked that way as the car was pretty well torn apart. In actuality, work over the break consisted of trying to sort some of the issues found in the first few short drives.

I had coolant leaking at the water pump and replaced the gaskets. Unfortunately I ordered the wrong gasket between the pump and the timing cover as it leaked worse than before. Correct gaskets will be here for this weekend. I am hoping that the original issue is gasket related and not something else...

I also had oil leaking out of the mechanical fuel pump port, so pulled the plate and installed a new gasket with RTV. I am pretty confident that this should address the issue.

I had water leaking at the radiator and since it was not obvious that it was coming from a hose, I took the opportunity to pull the radiator while the system was drained and have it pressure tested for leaks. It checked out fine, so I replaced the 90 degree hose that through process of elimination, should be the issue.

I learned at the first start up that the radiator fan was installed as a pusher AND only had a manual switch. I spent the last day installing and wiring in a thermostatic switch at my intake manifold. This took some time getting the wiring hidden into the braided wire wrap from the engine bay, up through the cockpit, foot well and front. Once there, I wired it so that I have both the thermostatic switch and the manual switch operational. I also reversed the fan blades but still need to reverse polarity to get them 100%.

Finally, I didn't like how the mufflers hang in space as it seems the pipes would fatigue and break over time. I built this simple bracket off the gearbox to support them.

All in all, considering how much time I spent in the garage over the holiday, it doesn't seem like a lot to show for it!

Next up after water pump is fixed is seat, wheel an pedal ergos, heat shield for the rear clamshell, and installing the rear cockpit window. IMG_2852.jpgIMG_2853.jpg
 
I lost a couple weekends do to travel, but today was able to get the water pump re-mounted and coolant filled. I successfully completed 2-3 miles in the neighborhood with no more leaks at water pump or oil leaks. The engine seems to be holding a steady temperature now that I have the fans sorted. The shifter worked great (this was really the first test since Chris Kouba helped me adjust the shifter). All in all a great day!
 
Big day - car is registered and tagged. Remarkably easy in Oregon. Took my first real fun drive on the way home on my favorite local “mountain road”. All seems good, but I think the alternator belt is slipping at about 4K rpm. By the way, still haven’t had it above 4K and I can’t imagine what it will feel and sound like as I go higher....

Here is the list of what I have been up to over the winter. As usual, the list seems short by comparison to the amount of time that has passed.
- Moto-Lita wheel installed. (Took some time to machine the right five hole to 6 hole converter hub)
- Heat shield for rear clamshell. This is both material applied directly to the clam as well as a standoff of aluminum and heat shield material directly above the exhaust.
- New air cleaner as the old one interfered with my cockpit rear window
- Applied bed liner to the wheel wells to help prevent stones star bursting the paint
- Made headlight access panels
- Had VIN nameplate made and mounted it on firewall
- Seats and belts mounted
- Mounted side mirrors (these are convex and the widest that I found in the “formula” style and seem to offer very good visibility (relatively speaking)
- Mounted a fire extinguisher

Next up big jobs are getting the AC working and installing a fire system.
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Absolutely Dave. Hoping to take it to WOS Sunday to see their Mario Andretti display. (I think they have a MKIV there.) Will let you know when I can get out for Cars and Coffee as it would be great to coordinate. Also hope to meet up with you again this year at the historics. For now I need to get confidence in my reliability, set up, etc.
 

Udo

Supporter
Alan, quick question: did you bolt the rear mirrors directly into the side screens? Any reinforcement done? Udo
 
Just aluminum backing plates. I have seen others who build a bracket that also bolts to the door sill. Mine seem fine from a vibration point of view and vibrate less than my center mirror.
 
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It has been almost three months since I last posted. I have about 500 miles on the car… not exactly trouble free miles! Sorting and development was always expected, but I have lost time to a couple issues that I would not have expected. All that being said, the experience when driving is fantastic and I learn something every time out.

The CV boots failed on both sides at 100 miles. This issue has been well documented on the forum, but I was expecting at least 500 miles. When replacing them with the longer 930 style boots, I had interference between the boots and the brackets that the rear clamshell turnbuckles mount to. I had to make new brackets to get clearance (see pic). I am lucky that I saw this before driving or I would have destroyed my new boots immediately.

I found out that I either did not calibrated my fuel gauges/senders correctly or they are faulty when I ran out of fuel with my boss! This needs to be corrected, but I have deprioritized this for now and simply pay attention to the miles between fill ups and fill up frequently.

I had a lot of play in my steering and found that at each point that the steering shaft mates to the universal joints that there is play at the milled “valley” that captures the mounting bolt. As there are at least three of these points, the slop stacked up significantly. I added two set screws at each junction, 90 degrees to each other, to clamp against the steering shaft (see pic) and the problem is eliminated.

I had noticed that my voltmeter on my dash was reading 12 volts. I checked my alternator by reading the voltage at the battery and got 12 volts and not 14 – my alternator was not “working”. As I kept thinking about it, I couldn’t remember actually connecting the alternator after mounting it many months ago. Sure enough, I never connected it. I had driven 100 miles this way but always put the battery on charge after each drive, so never actually had the battery die. To make matters worse, I have a Powermaster one-wire alternator and when I eventually connected it, it still didn’t work. It turns out that the one wire alternators will fry the rectifier if you spin them unconnected. As I drove 100 miles in this condition, the rectifier was well and truly fried. Embarrassing. Alternator works fine with a replacement rectifier and when you actually hook it up!

I made a couple additions. I bought wire mesh grilles for the rear clamshell from a member of the forum and I think they look great. (see pic) Although I haven’t seen this on other 40’s, I think I will make a similar mesh frame for the top elongated opening. Also, as I haven’t connected my air conditioning yet, I added helicopter vents to my windows (pic). This turns out to be a very easy and effective mod for increasing airflow to the cockpit.

The major issue I found, and one that took a lot of time to diagnose and repair was a leaking left side fuel tank. I always smelled more gasoline than I should. At first I found a leak at one of the filler tubes at a hose clamp junction, but upon fixing this, I still smelled too much fuel. Then one day, after lifting the rear of the car, I smelled fresh fuel and found a puddle on the floor coming from the front of the left sponson. I first found a leak at the AN fuel pickup line at the back of the tank, but this seemed small versus the flow of fuel coming out with the rear end lifted. Finally after pulling the fuel tank, I found the leak by shining a flashlight into the tank and seeing light shining through a hole at the top corner weld of the tank! Essentially whenever the tank was full, or going downhill, fuel was leaking. On a positive note, I had noticed a squeaking when turning my steering coming from the left side of the car. While removing the suspension to remove the fuel tank, I found that my left bottom ball joint was never lubed. Upon lubing, squeaking is gone.

I got this all corrected just before the July 4 holiday and was able to add 100 very enjoyable miles over the weekend. I went to some scales not far from my house and it weighed in at 2,450 pounds with both fuel tanks essentially filled.

I also am attaching a pic with my friend’s new Corvette. It never ceases to amaze me how big sports cars have gotten over the years. The Vette looks like an SUV by comparison to the 40.

Next up things to work on is a slipping compressor/water pump belt at 4k-5k RPM, and a slight grinding when grabbing reverse when the transmission is warm… and adding miles…
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I thought an update was in order as I now have over 1,000 miles on the car. My last post ended with a mention of working on gearbox selection issues (grinding when I grabbed reverse and difficulty getting 1st) and chasing (what I thought was) a slipping belt. It has taken some time, but I had a breakthrough test drive this week where I resolved the shifting issue and identified the contributor to the “slipping belt” noise.
Chris Kouba was able to stop by last weekend and quickly identify what was out of adjustment with my shift cables and was able to set me straight. The car now shifts smoothly into first and does not grind when engaging reverse.

The “belt noise” was always strange as it both sounded like a belt slipping around, 3,500-4,500 rpm, but also could be heard as a vacuum/air noise similar to a turbo pop off valve. I replaced belts as well as drove without my alternator and was able to prove it was not the belts. I chased various other potential culprits, but on mentioning that I didn’t get the noise if I went through the same rev range without full throttle, my father suggested that it could be my vacuum-assist secondaries activating.

I spoke with Holley tech services and although they said they have not heard of this issue, suggested some things to test to see if it is related to the secondaries. I adjusted the secondaries to the slowest setting and drove the car. At this setting, the secondaries never kicked in and I did not get the noise. So I have proven that it is the secondaries but do not know the cause.

Has anyone heard of the carb making this type of noise when the secondaries are activated?

My next steps are to take apart the secondary diaphragm housing and see if there is any obvious tears or holes in the diaphragm or any gaskets. Holley also suggested squirting starter fluid into the secondaries at idle to see if there are any leaks in gaskets.

Finally, I found another leak in my fuel tank. My left hand fuel pickup tube was leaking at the NPT fitting due to being cross threaded at assembly. I hope to get a new pickup tube welded together and get the tank back in the car in the next two weeks. Driving on one tank at 8-11 MPG is somewhat limiting!

Despite these issues, the car is an absolute blast to drive and I never get tired of looking at it or simply sitting in the cockpit. I hope to add some miles this weekend before the winter rains come to Portland.

Any advice on the carb noise is appreciated.
 

Ron McCall

Supporter
Alan,
What a gorgeous GT40 you have!! Looks amazing!
A few questions though... Why did you choose to use a vacuum secondary carburetor instead of a mechanical secondary version?
Also, why would you not mount the license plate in the recess that was added specifically for this purpose?? It looks like a bit of an afterthought mounting it anywhere else. That's one thing that has always bothered me about Superformance cars.
Anyway,I It'sgreat to see you driving and enjoying the car!
Ron
 
Alan,
What a gorgeous GT40 you have!! Looks amazing!
A few questions though... Why did you choose to use a vacuum secondary carburetor instead of a mechanical secondary version?
Also, why would you not mount the license plate in the recess that was added specifically for this purpose?? It looks like a bit of an afterthought mounting it anywhere else. That's one thing that has always bothered me about Superformance cars.
Anyway,I It'sgreat to see you driving and enjoying the car!
Ron
Ron,
I got the engine from Keith Craft. It was already built for a Cobra customer with an automatic transmission who backed out. I got a good price on an aluminum block engine, but it had vacuum activated secondaries. I expect that I will be switching soon to mechanical...
Thx.
 

Brian Stewart
Supporter
Chris Kouba was able to stop by last weekend and quickly identify what was out of adjustment with my shift cables and was able to set me straight. The car now shifts smoothly into first and does not grind when engaging reverse.

Hi Alan. Could you please detail what adjustments Chris made? My shift has the same issues (i.e. difficult to get into first and graunches going into reverse). My setup (ZF DS 25-1) has solid shift linkage, as per original, so adjusting options may not be the same as yours, but any suggestions welcome.
 

Louis

Supporter
Very nice Alan!

I will check my tanks with a light too to make sure I see no holes in the tanks.

Louis
 

Chris Kouba

Supporter
Hi Alan. Could you please detail what adjustments Chris made? My shift has the same issues (i.e. difficult to get into first and graunches going into reverse). My setup (ZF DS 25-1) has solid shift linkage, as per original, so adjusting options may not be the same as yours, but any suggestions welcome.

Brian- Check your PM's.

Chris
 
Brian.
I believe that Chris reached out to you. The principles may be the same even with a linkage (although I don’t know your adjustment options). But essentially, I didn’t have my shift lever aligned to engage the reverse lockout correctly - the shifter was hitting the wall of the shift lever housing and not finding the lockout groove. The result was that I was essentially forcing it into reverse. We adjusted cables to align the shift lever for and aft to align with the slot in the gear lever housing for reverse.
 
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