Rcr 40-31

The wife and I had a superb trip in the GT this week. The car now has over 3050 miles on the clock, and per the hand-held GPS we covered 975 this weekend, although the odo says we added ~1100. The car ran flawlessly with the exception of the oil pressure gauge which quit registering pressure. We made fine time going down with warmth and sunshine and the ventilation work to make the car more user-friendly paid off well. A/C is high on the list at this point though.

The car runs super-strong with 3k on the tach getting me 75 mph. It pulls very well and the ratios and the motor seem ideally matched for each other. My steering arms are in the closer (shorter length) setting and even with my basic string alignment, it tracked well and didn't seem nervous at speed on the highway. With the seat set up just the way *I* want it, the ride and driving position was remarkably comfortable. I also set up a foot rest for B and put it exactly where she wanted it as well, and she was comfortable enough to actually sleep in the car underway... Some of you may cringe at this but we went the entire way down with only one stop for gas after ~5h. And not that it's a real yard stick or anything to have your build be planned around but we got low 20's for MPG's as well (975m/46g = 21-ish). Not bad for having my foot in it whenever I wanted and as deep as I felt appropriate.

Weather on the way down was very warm, but I had recently installed some duct work to flow fresh outside air in through the brake cooling ducts and into the cabin. It worked extremely well. Copying an idea I saw on Ian Anderson's build, I added a switchable bilge blower and also a slide-opening gate in case it's too cool outside. The ducting worked great, with genuine flow coming through once I reach about 15 mph, so the blower is a little redundant. The outside air coming in is AWESOME though.

Once in Redding, it actually rained a bit and the work I did to weather-proof the cabin paid dividends. I will take additional pics and post them later, but I glassed flanges into the front clip to stop the unhindered flow of splashed water from the front wheels flowing into the cabin. I still have some work to do in that respect as at highway speeds, the spray flows in with the air. It was still MILES better than what it was previously and what I've done already is a good foundation.

As for the actual trip, it was a fun visit with Vaughn. His car is flat-out gorgeous. I helped him with a few detail items on it on Thurs and B and I went for a drive on Fri, stumbling on to a gem of a road for 110 miles. Sat we got the car down to the show early (Kool April Nights), went home for breakfast, and came back to check out the show for the rest of the day.

There were some astounding cars there, but only 1 GT40 (I didn't enter mine). It was absolutely magnetic- young, old, male, female, hippy, yuppie, red-neck, blue-blood... EVERYONE stopped to check it out.

Our trip home today was a mixed bag of weather. We left in sunshine, but were driving through some monsoons by the time we got to the OR border. It was pretty cold too and I think I even saw some slushy flakes as we crested one of the passes on the way home. It was a good reminder that I have a bit more work to do with the weatherproofing but the car still did remarkably well.

All in all, it was a very successful trip and as expected- good times with some great people and beautiful cars.

The "luggage" for a GT40- B gets a bigger bag than I do:

On the way, Mt Shasta in the distance:

Vaughn and me:

GORGEOUS road on Fri:

One pretty dirty, one just PRETTY!:

Heading into the show:

On the lawn:

Heading out this morning:

Typical Oregon weather on the way home:

Lunch in downtown Rogue River:

More pics in this album.


Ian Anderson

Lifetime Supporter
Great write up

I could not see your air ducts in that photo
Would you mind posting a couple of shots, always willing to upgrade to a neater system!


The ductwork is bonded to the underside of the front clip. After taking a poke through my build thread, I apparently didn't document its construction. I used foam to make a model of the path it needed under the clip (the pink, 2" stuff; shaped into the wide horseshoe shape), pulled that model off the clip, and glassed it up to make a part. I then glassed that part into the clip after opening the backs of the NACA ducts to connect them.

After cutting a hole in each bulkhead to let the air through, I did the same thing to connect the back of the headlight boxes (brake duct openings feed this volume) to the ductwork already installed. There may be a pressure imbalance which stagnates air somewhere, or flows it out one of the ducts unintentionally, but it works well enough to flow air INTO the cabin.

Stock underside, red outline shows duct path, NACA ducts not cut out yet:

This one shows the current state of things. NACA and headlamp box connections made, clip to chassis duct glassed in as well:

The chassis side of the system, blower and gate valve are on a bracket which is fastened to the visible bolt on the cowl. When the clip closes down the foam on clip seals around the intake on the chassis:

I neglected to take a photo of the blower and gate prior to install so you'll have to use your imagination. I haven't done finished interior ductwork yet and may end up just connecting it to the current HVAC ducts- or I may fab up something to have it as a separate system. Time will tell. It is incredibly practical in the absence of AC though. I am very glad I went through the effort.

Also visible in some of the pics are the flanges and "gaskets" I put in to try to seal the wheel wells. Here is the left side:

They need a little work, or maybe a second row added but they are reasonably functional already and kept a LOT of water out of the cabin on this trip.


Ian Anderson

Lifetime Supporter
Thanks Chris, that is really neatly done.
How do you do with tyre to clip clearance where you have the ducting?

And yes the spray off the tyres does cause havoc around the hinge area, mine still leaks!

I was nervous about the tire clearance when I was doing it, the car wasn't running and I was fairly well just guessing where it'd be "safe" to put it. Where I ended up with it does not rub at all, although the RCR chassis doesn't have massive amounts of lock in either direction. In all honesty though, I think for the tires to touch that area would require a rearrangement of the chassis- at which point I would have other things with which to be concerned.

If you have a better/different way you're sealing off your wheel wells, I'd be interested in checking it out!

Got out and played with the neighbors today:

(Disregard the Honda)

Mt Hood with its head in the clouds:

Dave connected me with a really nice bunch of people. Great drive on a gorgeous day.
3,4xx on the clock now. Another 4h behind the wheel with the Cobra guys today, although I had to bail early. Pic taken over the windscreen of the Cobra in line behind me, Dave just in front:

Car is still as strong as ever, although I have an electrical gremlin I need to track down now. Added that to my list...

Hope all is well in your garages!

Last post was over 2 years ago... Wow. Lots of distractions around here. Going to take some time off from the gravity car operation and catch up on life's other pursuits.

Car now shows over 4K miles, but up until last week, I hadn't run it in months. Crossing paths with a few local forum members here is a good motivation to get on with the to-do list. Got the cobwebs blown out and ran it around a bit. It's still as strong as ever and winds out very well, but I was never able to identify the offending circuit which was emitting the "hot wire" odor, so I'm biting the bullet and re-wiring the car.

I was never overly happy with my wiring job from the first time around- I was too chicken to cut out the circuits I didn't need based on thinking I might need them later, and some of them had way too much extra wire and some would benefit from a little bit more. So here I am:


Will get things tidied up a bit here as well:

After this, I may (FINALLY!!) tackle getting the AC working, as that would let it be much more usable in the summer months. I was staring at some of the components today wondering why I never completed the job at the time of install. The hardware is in place already, just need to verify it's sealed up and then wire up the switches, pump it down, and charge it. After that, a bit more work on the weatherproofing and I should totally be able to daily drive it.

There are a few more things actually on the to-do list, but my goal is to have it sorted and settled enough to actually really use it next summer-including a day or two on a track. We'll see how that plan shapes up!
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So it might not look like much but it's already coming back together.

Placed the dash back in and hooked it up, connected the battery, and checked a few systems. Fuel pumps fired up, injection computer and HP fuel pump primed, starter relay triggered... no smoking wires. Push the button, motor spins. Put the coil lead back on the coil, motor still spins. Whoops... Fully seat the weatherpack connector leading to the coil- magic, it jumps to life!!!

I am pretty happy to have fired up the car less than a week after I tore it down. It would be fully wired except that I wanted to run new, heavier gauge lines from the fan relay to the fans and I need to replace some conduit. Other than that, it looks encouraging and will hopefully have resolved the issue. In addition, I had forgotten that oil pressure gauge quit and the speedo reads erratically, so looking forward to seeing if those items are corrected as well.

So it's off to the store to pick up wire and see what else I can get done before I need to go to work tonight. Reassembly awaits!

The car is about an hour or so of work away from being mobile again, but since it was all torn down I decided to get the AC going as well. This did not go as planned. It all looked so simple on the internet...

I finished wiring up the compressor and the trinary switch and have everything set up to function correctly (I think).

Not remembering exactly where I was with all the hardware installation, I picked up an o-ring kit and re-sealed all the connections. The only one I didn't actually put my hands on was the compressor supply and discharge (very problematic access). The system pumped down and held vacuum well, so I was content to say the system was sealed and ready to charge.

I picked up a set of manifold gauges and associated stuff and set about charging the system. The system was still under vacuum, but I pumped it down a while again anyway, and then added the first bottle of refrigerant. The low side went up to ~60 psi but the high side never moved off ~28" of vacuum and the compressor never triggered on. I manually jumpered the compressor to engage, but there was still no pressure build on the high side and no movement on the low.

Although it was a Hot Rod Air system, I spent some quality time on the phone with Vintage Air tech support to troubleshoot the issue. The conclusion is a stuck expansion valve, so I ordered another one along with a new dryer as well seeing as the system wasn't under vacuum for the past 12 years and the it might be compromised.

All that stuff should arrive on Weds and if all goes well, it will be in before I call it a night on Thurs. Even if the AC isn't functional, the car will go back together and I plan on getting some seat time on Friday. I am heading down to see Vaughn next week and want to make the trip in the GT again so I'm looking to get a bit of shakedown time.

I just noticed in one earlier photo of your road trip that the mounting point of your shoulder harness is 6 or 7" too high. I'd strongly recommend revising it per the attached drawing. A safety harness is like a parachute- normally you don't need one but when you do, you need it BAD.