Bob Cahill, Chrysler Engineer

Bob Cahill with Carl Diehl and Bob KnowleRobert John Cahill attended the Chrysler Institute of Engineering, studying and working as a student engineer, starting in 1936. In 1938, he began to work for Bill Drinkard, head of engine development; Cahill later credited Drinkard with being the driving force behind the original Hemi engine. According to a 2008 interview with Mopar magazine, the hemispherical-head design was a tough sell for chief engineer Fred Zeder.

In 1953, Cahill moved from component development under Drinkard to being a motor engineer assigned to the Lynch Road (Plymouth) assembly plant. He transplanted a 1952 Chrysler Hemi into his 1950 Plymouth daily driver; the engine made the lighter car quicker than the big Chrysler, though cornering suffered. Cahill began to join special projects, including racing and the Mobilgas Economy Run.

Bob Cahill was one of the members of the engineering team that prepared a 1956 Plymouth Fury for the Daytona Beach speed trials [also see Chrysler 300s at Daytona]; the flagship Chrysler 300B had just set a performance record, but driver Phil Walters easily broke the new Chrysler record by driving the Flying Mile at a two-way average of 124 mph.

Cahill raced a 383-powered Plymouth hardtop in 1958 and 1959; he had fooled the production system into installing the engine into his Plymouth, which was only supposed to get a 350. He experimented with tuning the car across the street from the Plymouth plant, at the Product Planning garage.

Bob Cahill was promoted to Manager of Vehicle Performance Planning, moving to Highland Park. He ran Chrysler’s Pure Oil Performance Trials team and the Mobilgas Economy Run efforts, and led the racing group that developed the “Hyper Pak” powered Valiants for NASCAR’s short-lived compact car racing series. Tom Hoover led the creation of the Hyper-Pak — his first racing development project; he would eventually join Product Planning under Cahill. (Mopar quoted Hoover as saying that they’d gotten “just under 200 horsepower with 11:1 compression, tuned exhaust and a ram manifold ... with a Carter 2948 AFB carburetor.” Increased valve sizes and shorter intake runners were planned for the future. The car bodies were stiffened with extra welding, as well. The GM and Ford cars were subjected to similar modifications; presumably, so were the eight Volvos, the SIMCA, and the Nash which were also in the race.)

Cahill personally brought the Hyper Pak parts to the garage where the racing cars were being converted from standard Valiant sedans, with modified transmissions, axle ratios, suspensions, tires, and brake linings. Cahill and Ron Householder drove them on the city streets to check out the mechanical components, though being set up for racing, they were not especially “streetable.” The nimble Valiant essentially destroyed the series by being too far ahead of the competition for the end of a race to be in any doubt, a lesson learned all too well by NASCAR’s leaders. The racing series never continued past the first race at Daytona, and Cahill bought the blue Valiant HyperPak car which had been driven by Paul O’Shea. He pulled the racing engine, and put in a standard 225 slant six for use as a daily driver.

Bob Cahill personally preferred drag racing to NASCAR; according to Mopar magazine, he “dreamed up” the Max Wedge and HEMI® Package Cars Chrysler built from 1962 through 1968. Mopar wrote that Cahill “wrote the official Product Planning Letter to Engineering that kicked off the 426 HEMI project.” Bill Weertman, the design engineering leader on the project, was quoted as saying, “Bob Cahill had knowledge of the original 1951 HEMI as a development engineer.” By the mid-1960s, Cahill was Chrysler’s racing manager. From 1968 to 1975, Bob Cahill worked for Bob Rodger, who was in charge of oval track and drag strip racing; Rodger reported to Burton Bouwkamp.

Butch Leal wrote,

I later met a man named Bob Cahill, who was the director for Chrysler Factory racing. He wanted to hire me to drive a 1965 four speed Chrysler Hemi. I signed up and became a member of the Chrysler factory team. I had the first funny car that was ever built. Chrysler had built 6 Plymouths and 7 Dodges. They presented the cars to NHRA so a class might be established. The NHRA would not accept the cars because the rear wheels and front wheels were moved forward and their response was they “look funny.” ... This was the beginning of what we know today as funny cars.

One reason for the 426 Hemi’s success was the excellent engine breathing, which was partly the result of Cahill’s intervention: while he didn’t want to tell the engineers they might need help building a racing engine, he and Jack Charipar contacted one of the world’s chief experts in airflow, Harry Weslake. Weslake had worked on the heads for Bentley’s 1929 LeMans winner as well as those for Ford’s 1969 LeMans champion. He consulted on the 426 heads, as well as various other racing engines.

Along with Special Car Manager Bob Rodger, Robert Cahill — then Chief Engineer — wrote a key letter in 1965, outlining a detuned Hemi for the B-body cars. They suggested using two four-barrel carburetors, cast iron exhaust manifolds, cross-bolted main bearing caps, and tuning that would maintain power but be driveable in four seasons. They assumed that sales would be around 5,000 to 7,000 units. The Street Hemi appeared in model-year 1966, as outlined by Rodger and Cahill; while sales were never close to the modest sales the pair projected, the Street Hemi certainly bolstered Chrysler’s image and would help the company’s “street cred” for decades to come.

Bob Cahill also approached Vic Edelbrock to make aluminum intakes for the first 440 Six Pack cars, in 1969. These were later replaced by iron manifolds made by Chrysler, for cost reasons. Later in 1969, Bob Cahill was listed in Mike Doherty’s Drag Racing article as one of the top ten most important men in drag racing — the second person in the list, ahead of Jacque Passino (Ford), Andy Granatelli (STP), George Hurst, and a group of racers including Don Garlits.

John Wehrly, formerly Dodge Engineering Motorsports Manager, wrote,

I’m honored to be asked to comment on Bob. He was one of my boss in the early 1970s and always treated me with a great deal of respect.

I was in a motorcycle accident in 1972 and was in a full leg cast and also an arm cast. I couldn’t drive for several weeks and had difficulty getting to work. We had a weekly race meeting, where the all of the groups (engine, chassis, drag racing, etc.) got together and strategized our next moves. Since I had difficulty attending, Bob had the meeting at my house, until I could attend the meetings at work.

This is an example how down to earth and kind Bob was. He never "elevated" himself, just because he was the boss. He was a thoughtful and talented engineer and was steps ahead of our competition, whether it was in racing or a fuel economy contest. When the SRT Neon came out, Bob was, at 90 or so, trying to get a “good deal” on the Neon, not considering his age as an issue. Bob always tried to stay in contact with the guys he worked with — right up when he died.

I feel very privileged and honored to have know and worked with Bob.

Bob was inducted into the Society of Antique Modelers Hall of Fame in 1993 (his last modeling competition was in 1949). The Society wrote:

Bob is a top model designer, with an inventive mind, whose ideas were often recognized and used by many other modelers. Some of his designs appear in Zaic yearbooks. ... He won his first contest in 1929 with a baby ROG flight of 47 seconds ... At the '35 Nats in St. Louis, he set a national FF Class C record which stood for many years. Bob considers his greatest contribution to be what he believes to be the first use of folding props on rubber models. ... Bob also developed an indoor stick model with a balsa tube fuselage, which converted from stick to cabin by sliding a small fuselage over the stick. ... When he started building “gas jobs” in 1939, he pioneered the use of alcohol-based fuels. He also developed and built an electronic tachometer for engine testing.

Warren Steele added,

I recall a story about Bob who lived near us in Royal Oak on Vinsetta Blvd. Mel Brown was a block away, we lived a half mile distant, and Bob Knoll was a near neighbor too.

Chrysler Engineering had bought a new Citroen with an “Air-Oil” suspension system and some other interesting features. Paul Bruns and his group arranged for a complete vehicle tear down for everyone’s evaluation. Each concerned group was asked to tear down their stuff, as was stipulated each had to have the UAW provide this work. I think we had that car spread around various labs etc. until 3 or 4 years later it was decided to reassemble the car and sell it.

There the fun arrived, seems many of the UAW guys had moved on, retired etc. and no one could begin to know how to reassemble it!

They did have a service manual (in French) which afforded little help so Bill Drinkard (Executive Engineer), I think it was, said sell everything “as-is” in the baskets and boxes of parts at any price. No takers until Bob Cahill bought the remains at a ridiculously low price and did actually put the car together. Bob's wife helped translate the service manual.

After Bob retired they moved to Saint Croix in the Virgin Islands!  None of us could believe this, they bought property high up on the island overlooking at the beautiful beautiful Caribbean. They sent photos and stories of the house building (do I remember $40K?). Great vista but after a short time they got tired of being so far from civilization, family etc. and they sold out and returned to the US.

Bob Cahill retired from Chrysler in 1975, when he was head of their competition and racing department. He wrote this letter to fellow product planner Burt Bouwkamp about his post-retirement life:

Most of you have not heard from me since I retired in June 1975. However I did keep in touch with some, and Bill McNulty made me aware of Burt Bouwkamp's list of Chrysler retirees.

Since early this year I have planned to send out this message, briefly showing my activities. I hope that some of you will respond, telling me where you are and what is happening to you. ... In 1973, we started building a retirement house in St. John, U. S. Virgin Islands. On June 30, 1975, I retired and we moved everything to St. John. I do regret not taking more of my records at Chrysler with me, but I left them all for my successor.

For the first few years, we spent the time finishing the house, buying a used 36' sail boat (and repairing and maintaining it) and doing all the things necessary to establish a new location. We immensely enjoyed the fine swimming, snorkeling, sailing, and living in (for us) a fine climate. Our house on a ridge 400' above the ocean, enjoyed the trade winds to such an extent that we did now need air conditioning, or any heating. There were, however, some drawbacks. The almost third world conditions concerning health care, shopping for necessities, lack of real acceptance by the natives, and limitations of cultural activities made me tire of the island living. Our travel was somewhat limited by the expense of flying to the mainland before starting any trip. After seven years, we decide to move, but were still insistent on a warm climate.

We took a two week trip of exploration to Southern California, and travelled from Santa Barbara to San Diego. We wanted a place that we could afford, near Los Angeles and San Diego, but with no smog problem! We were fortunate to find such a place in the small town of Fallbrook , fifty miles north of San Diego, on the eastern edge of the large Marine Camp Pendleton. The prevailing ocean wind blowing over the Camp and over Fallbrook managed to eliminate the smog for us, and this was an important criteria for Marika. Although a town of less than 30.000, Fallbrook (The avocado capital of the world) did have a chapter of the Antique Automobile Club of America, and a chapter of the Experimental Aircraft Association! We found a pleasant three bedroom house, and settled into our new environment. The Senior Citizen building and tennis courts were only two blocks away, and the ocean a half hour to the west. From in front of our house we could see Mt. Palomar to the east. We settled in for some California living, and were quite pleased with our move. An outdoor Jacuzzi added to our activities, and we started a series of camping trips to explore the West. After a trip to Oshkosh, I decided to start on a home-built airplane. I chose an Avid Flyer, a high wing monoplane about the size of a Piper Cub, a two place plane that weighed only 900 #, with a two stroke, two cylinder air-cooled snowmobile engine of 64 H.P. @ 6000RPM, With all the major changes that I made, too numerous for this epistle, this turned into a multi-year project. Marika was very patient as I occupied much of my time (and all of our two car garage) building this flying machine. (The wings folded back to fit in the garage).

I made the first test flight in ’89, and after more alterations, flew it for some time in the nearby area. I put quite a few hours on the plane, but I found that flying a small plane in that area was a little like taking a Sunday afternoon car ride on a Los Angeles Freeway (25% of all the licensed pilots in the USA live between Santa Barbara and San Diego!) I had a little problem landing one day at the Hemet, California airport, and pretty well wiped out the landing gear. ... A friend and I tied the spread landing gear together, and towed it back the 30 miles to home.I decide (much to the relief of Marika and the neighbors) that I should give up my flying career. I installed a new nose gear, repaired the main gear, and sold the plane.

We stayed on in California until 1996, when we decided we were getting old enough (81 and 76) that we should be closer to our family. They lived in Virginia, the Virgin Islands, and England, so we located a retirement home in Charlottesville. Our daughter, son-in-law, and only two grandchildren live here,and we have just watched our grand-daughter graduate from VA. Tech. We are well established here in Thomas Jefferson's town, a very pleasant place to be. (But every winter we long for Southern California.)

I am fortunate to be in fairly good health after reaching my 91st birthday, can still drive and walk, and have challenged myself in getting rid of my six year old PC, and switching over to the Apple camp, for several reasons. Had I realized it would be this difficult to teach an old dog some new tricks, I might not have done it. ... My wife of 64 years is not so fortunate, and requires a walker to get around, and has been fighting the terrible scourge of Alsheimer's for some time. This requires some of my time, and severely limits our traveling ability. I find that most of my older friends from earlier model plane and University days have gone, and I'm reaching out to you younger associates to find out how time has treated you.

In fall 2010, Cahill broke his right arm. Then, on December 3, 2010, Bob Cahill and his wife were involved in a multiple-car accident (fourth in line). He later fell over backwards and broke his left arm, unable to use his walker, with both of his arms broken. The racing community rose to send him cards, visit him, and let him know he was remembered and supported. Bill Dedman wrote that he had an eight inch stack of get-well cards. At the time, he was 94 years old.

His wife, Marika (“Molly”) died on July 10, 2011, in Charlottesvsille, Virginia at the age of 91.

Bob Cahill died on November 14th in Little Rock, Arkansas, at the age of 96. He had a daughter, Judith, two brothers, and three grandchildren. Services were at Little Rock Funeral Home.

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