Ghia Race Prep for the Mitty at Road Atlanta

[FJCamper]

Race Prep for Road Atlanta 20-23 April 2017

In 1939, humorist James Thurber wrote The Secret Life of Walter Mitty, about a mild mannered man who had secret fantasies about doing exciting things. It was made into movies in 1947 and 2013. "The Mitty" is a classic car event held annually at Road Atlanta. Since the first running in 1978 it has grown to become one of the largest classic car events on the East Coast of the United States.

We ran our Historic Sportscar Racing Ghia in the Mitty last year and was doing great until we had oil pressure problems, self inflicted by excess sealant blocking the oil pickup. Here's a one-minute video clip where we run down two restored BRE Datsuns ... and if any of you reading this remember the reputation the 510's had back in the day, you know passing two of them is no small feat.

https://www.youtube.com/watch?v=Tng5ReSc2wY

We got back to the Mitty this season with some changes. First, no oil gallery sealant problems. Second, we're using a center-mount fan shroud with our own design internal ducting, and dual 40 IDF Webers rather than our customary Solex-Kadrons. The reason is simple. The Kad linkage won't fit because the center mount fan housing requires a different alternator stand.



Our IRS Ghia chassis has ATE/VARGA calipers at all four corners, a 20.6mm master cylinder, a 3-gallon dry sump oiling system, stock torsion bars front and rear, adjustable Konis all the way around, a 19mm front sway bar and no rear bar (promoting understeer), a 3.88 final drive, 8-gallon FIA fuel cell, and dual Facet fuel pumps in parallel.

We run 185mm 60-series radial tires on 5.5" steel stock wheels, and for the Mitty, we're going back to Hall-effect breakerless ignition after using points and condenser for a couple of seasons. We experienced what we considered early wear on the points rubbing block.

The engine is redlined at 7000, very carefully balanced, and has a brand-new aluminum bubble-top race case. We have a 74mm counter balanced crank, chromoly rods, 85.5mm hypereutectic pistons, and straight-cut cam gears rotating a Bugpack 4063-10 cam.

The exhaust is a 4-into-1 header, with a sideways-ducted exhaust pipe (passenger side) under the aluminum rear bumper. We use 40x35mm AJ Sims heads, dual valve springs, chromoly pushrods, 1.25 rockers, and a modest 9:1 compression ratio.

A nose-mounted battery, plastic rear window, and lightweight six-point roll bar (not cage), aluminum driver's seat, and many other weight-saving tricks gives us an excellent 45-55 front to rear weight distribution and a low 1800 lbs dry weight.

Ghia were made to be beautiful. They also make great race cars We mild-mannered Walter Mitty's never had it so good.

FJC

[Jadewombat]

Great stuff FJ, love the video.

[FJCamper]

40 IDF Webers (Chinese copy of the EMPI Chinese copy) Ready for Sunday Track Test

40mm throttle bodies and 1600 engines go well together, one of those natural mathematical matchups. Way back in 1952-53, Solex developed the twin-choke 40 PII (that's p-eye-eye, not p-eleven or P-jay-jay) for the anticipated four-cam 1500cc Type 547 engine, and kept it in service for street cars up to the 1600 912.



Above: Solex used a gold anodized carb body finish on the last of the 4-PII's to designate them as smog models on the final 1968-69) Porsche 912's.

Today, the younger VW enthusiast might refer to them as the ones that look like 40/44/48mm Webers. But the opposite is true. In the early to mid-1950's, downdraft Webers did not yet have the 40 PII look they have today. The Weber 40 DCN was soon recognized as superior to the Solex in racing for one reason. A wider range of tuning options. The DCNF model soon followed, which could accept velocity stacks and larger venturis.

The center-mount blower housing we use on our Ghia does not allow for a Kadron-style crank type linkage, meaning we can't use our trusty 40mm Kadron/Solex single barrel carbs. So, we have to run Webers.

We go to the test track Sunday with 36mm venturis, F11 emulsion tubes, 200 airs, 135 mains, and 55 idles installed. This combo is running fine on the parking lot and sideroad outside our garage. We'll have a box full of Weber vents and jets with us at the track.

We have a love-hate relationship here with Webers. Our last two treks to Sebring were fouled by Weber problems.

We want to be ready for Road Atlanta this time.

FJC

[FJCamper]

Above: The weather was perfect for a combo friends and family outing with some test and tune thrown in.

We take advantage of a Rezoom Motorsports track weekend at Barber, our world-class hometown track, to sort out our new ChiCom Weber 40 IDF copies for our Historic Sports Car races at Road Atlanta on the 20-23rd of this month.

The Ghia has been in storage since Sebring in early December last year, and to get ready required bleeding the 4-wheel disk brakes (dual 40mm piston caliper ATE copies by Varga), resetting the Holley fuel pressure regulator to 3.5 psi, and replacing a slightly leaky plastic fuel filter.

The Sunday weather couldn't be better, sunny, with an expected spring high of 80° F, so we make a friends and family outing of it. Today, my son Barret Camper drives and mechanic/driver Jamie wrenches, keeping preteen pit apprentice Dale Miller close, showing him the right way to do things. Dale would be Trunk Monkey but our trunk is full of engine.

I take the Ghia through tech, and we are placed in Red (full race) Group, which is anything that came in on a trailer, a mix of formula cars, racing 911's, and Corvettes. They are all more powerful than us, but Barber is not a top-speed track. Its corners and uphill-downhill layout favors "quick cars" about equally with "fast cars." There is a big difference.

The Porsche guys like the Ghia and want to know all about it. They take photos. A little girl and her mother walk by, the girl smiling and pointing at us. The Ghia's classic beauty touches another generation.


Above: RetroRacing Driver/Mechanic Jamie schools young racing apprentice Dale on tow bars & chains.

We top up with Sunoco 104 octane race fuel. I've actually given our high-revving 1699cc (85.5x74) a conservative 9:1 compression ratio, so we don't really need the Sunoco, but I like having my gas 100% gas, not 10% ethanol filler.

Barret takes the Ghia out in Red Group, screaming around the track, but sticking with our plan to give the big cars lots of room, not to race with them. We're just here to tune carbs. One thing on Barret's mind is we've shown up with the rear 19mm sway bar on, and he doesn't like it. He says it adds too much oversteer to the normally understeering IRS chassis, and not good fun oversteer like a swing axle, but scary at-the-limit oversteer.

Barret is soon turning 6000 RPM in 4th on the back straight from the turn exit just before the midway dip that seems to intimidate the novices so much, which with our 185/60-15 tires and wheels and 3.88 final drive, was approx 115 MPH. This is a good speed for anybody. The Webers are not exactly right yet, and we are still fast. The carb setup is 36mm venturis, 135 mains, 200 airs, F11 emulsion tubes and 55 idles.


Above: Jamie checking valve cover drip. At Barber, oil leaks are a zero-tolerance issue.

We deliver a minor oil leak that happens to spatter on the header, making visible smoke. The leak is from the right hand side valve cover, and the steel oil pump cover plate. We reseat the valve cover gasket and tighten the oil plate nuts, but discover we are getting high case pressure leaks around the distributor. We need better venting.




Above: Center-Mount air duct insert. We depend on it for the Ghia's engine survival. Oil temps today (80° F ambient) never exceeded 240° F. Case temp normal (you can touch the dip stick with your fingers)

Back in the paddock, a plug read shows sooty rich all the way around. We rejet down from 135 to 130 mains and just test driving around the paddocks, get lean exhaust popping, but we quickly discover the popping problem is the ground wire on the braided steel 2-4 cylinder bank spark plug wire clamp has broken. We fix that, and Barret does another round of paddock testing and reports the 130 mains feel too small. We rejet back to 135's and clean the plugs. I suspect the 55 idles are causing the excessive richness. Jamie had been idling the Ghia for a long time this morning to warm up our 3-gallon dry sump tank.

We'll swap to 50 idles the next day and get a soot-free idle.


Above: Jamie busy changing carb main jets

Barret goes back out for another track session and the power, brakes and clutch are good, but we again have minor oil smoke. Back in the paddock we determine we cannot fix the oil problem with the few hand tools we brought, but we are delighted with the plug reads - clean burning on all plugs almost to a lean situation.


Above: This is how it starts. Almost 13, Dale is a serious racing apprentice, carrying tool boxes and as of today, able to rejet Webers and know why. Katie, his girl friend, tags along to make sure he is not distracted by track tramps.

We are finished by noon. The Ghia is fast and with 140 mains potentially faster at Road Atlanta.

We pack up, move out, and head for Olive Garden.

FJC

[Fiatdude]

Sounds like a great day at the track..... A vent on the fuel pump block off might be in order

[FJCamper]

Hi Fiatdude,

We went from a 3/8" ID alternator stand vent line to a 1" ID line by making an adapter to replace the oil filler cap.

We'll be at Road Atlanta Thursday the 20th. I see by the tech sheets we'll have four other cars in our class, all high-dollar full race historics.

MGA
Austin Healey "Sebring" Sprite
Triumph Spitfire
MG Midget

FJC

[VW&MGman]

Hi FJC,

Glad to see you and the team are having fun with the Ghia.

I had a similar issue last year with one of my engines misting oil in corners. I installed breathers with 3/8" AN fittings on both valve covers, which stopped the leak on the 3-4 side, added one to the fuel pump block off plate, and another two on the generator stand. This helped reduce the oil mist, but it turned out to be mist from the front pulley. I installed a slip-in sand seal and the corner workers no longer call me in for smoking.

Here is a video of when "Herbie" was smoking Fast forward to the 3:30 mark.

https://www.youtube.com/watch?v=c1ZvnFjG1YI&t=540s

Regards

[FJCamper]

We are up against some Brit competition at Road Atlanta. Our class is VP5 (vintage production).

A 1959 MGA, a 1962 Austin Healey "Sebring" Sprite, a 1500 Spitfire, and an MG Midget/Spriget. are listed as VP5.

To recap, we're running an 85.5x74 (1699cc) sprint engine, DRD L5 heads, 3-gal dry sump, 40 IDF's on 36mm venturis, 3.88 final drive and 60-series street radials even though we're eligible for racing tires.

I've sandbagged our compression down to 9:1, and estimate we're running about 130 hp at 6500. The engine is built to turn 7000. We saw over 6k in 4th during our tests at Barber.

We expect mixed rain and dry days, Friday to Saturday.

FJC