Willem Weertman, Chrysler Chief Engineer, Engine Design and Development
The legendary Willem Weertman worked on or led the creation of Chrysler’s most famed engines, including the LA, B and RB series V8s, 2.2 and 2.5 liter four-cylinders, slant six, nearly every V6, and the Viper V10. This interview is from 2007. See his professional life or buy his fine Mopar Engines book.
Q: Can you tell me about how you decided to back to the hemispherical heads and the plusses and minuses when you were working on that?
I would have to say it is an often told story. Chrysler was interested in supporting the racers, particularly the NASCAR racers because there was a good connection between racing victories and selling cars. We had been using the wedge-head big block V-8 engine and we weren’t doing very well with it, we were being outgunned by the very experienced and well-equipped Ford and Chevrolet teams. Our senior management thought it would be nice for us to win races. They asked the question “What would it take for use to win a race?”
After a lot of consideration, the engineering response was that we should go back and try to see if we can run our Hemi engine again because we did so well with the first generation Hemis that had come out in 1951 and had been raced in NASCAR and had a tremendous amount of victories.
The inquiry came to us in engine design, “could we put a Hemi head on top of a raised B (RB) engine?” That’s when the story started and ended up with our indeed being able to do that. We had engines ready for the 1964 NASCAR race in Daytona Beach and we did extremely well and continued doing well during that season. When the order came we assigned our best designer to it, with Bob Rareya and me looking over his shoulder. By making changes to the block we were able to do that job with a brand new set of cylinder heads having machined Hemi chambers that just happened to have the same included valve angle as the 1951 Chrysler Hemi and it worked. It was quite a program for us; it was a very rushed program and we were extremely happy when it was successful on race day and we blew the competitors off the track.
Q: Did you have anything to do with the carburetor choices over the years or was that development?
That was really development. I did not enter into any decision about which carburetor because the carburetor companies had pretty well standardized their attaching patterns and throttle bore spacing so they were interchangeable on top of the engines.
Q: Can you tell me about your first experiences at Chrysler?
I came to Chrysler in 1947 as a graduate engineer, I was recruited by Chrysler. I entered the Chrysler Institute of Engineering program, I was attracted to it because it was a two year program that led to a masters degree of automotive engineering. During that two years we went to classes and had work assignments that rotated, so we had a nice education and experience with quite a few of the departments of engineering and in some cases the production plants.
At the end of the two years the students were expected to find a permanent home, a department where they would start working just like a regular employee. After my two years were over in 1949, I was at the Plymouth assembly plant in an engineering group that was called the resident engineering staff of the Plymouth division. I was not actually working on engines at the time, I was working in the electrical section. That was my first permanent job assignment.
In 1950 my career was interrupted because I was called up for the Korean war, where I served until 1952, when I left the Navy service and came back to Chrysler in the same position that I had in the electrical group of the Plymouth division resident engineering staff.
Then, in 1954, a new engine plant was being planned where Plymouth would produce its own V-8 engine. The chief engineer of the Plymouth resident engineering staff, I’m pretty sure it was Bob Anderson at the time, asked me if I would consider becoming the resident engineer of this new plant that was just in the planning stage. I said “yes,” I said I don’t know that much about details about engines, we had engine work during our Chrysler Institute classes but I said I would be very glad to do it. And so I transferred and I became the first resident engineer of what would be the Plymouth Mound Road Engine Plant.
It was fascinating, it was exciting, and it was a great place to be in. We had so much to do and I was working really closely with the tool engineers and the plant engineers and all the staff that had to create this plant to build engines. It was like a brand new plant although we were using space that had been used to do war work.
I was located in the plant, but my engine information came from Central Engineering, which had the staff of the engine design department and engine development department. I was a daily visitor there, finding everything I needed to do my job at the engine plant. This was a very intense education about engines for me.
In the fall of 1955, there was a death in the engine design department. The assistant chief engineer, who was in charge of the department, was a fellow by the name of Mel Carpentier and when he died the fellow who had been his assistant, the manager of the department, Bob Rarey, was immediately promoted to the Assistant Chief spot. I had gotten to know Bob very well when the two were on the resident engineering staff of the Plymouth plant. Bob was the motor engineer. He was a great guy. Now there was a vacancy in the engine design for a manager of the design department. In casting about for candidates to fill the spot I was asked to take the job.
I was very pleased to be requested. I transferred from the Mound Road engine plant to become manager of Engine Design at Central Engineering.
My learning about engines started when I moved to the Mound Road Engine plant which gave me a lot of experience in how engines were produced. When I transferred to the engine design department my education started on how engines were designed. That went on for years and years and I was later promoted to Assistant Chief when Bob was promoted become manager of the Mound Road Engine Plant.
So I had wonderful years of experience in engine design, later I became Chief Engineer of engine design and development. All those years I was in design I was working closely with the development people so it was again a big welcome increment into my engine experience. That was the way I ended my career at Chrysler being in charge of Engine Design and Development. I officially retired in 1987. I went back to do some per diem work and that lasted for about five more years.
LA series V8s
Q: Did you work on the A or LA series V-8s?
Yes, as I mentioned earlier I was in the production plant when we were first building the A engine series and then I had been transferred to engineering when we were building the LA engine series. I was in charge of design for the LA engine conversion.
Q: I understand the main difference was the light casting. What else would be the fundamental differences between the A and LA engines?
The biggest difference between the LA and A engines is really the valve arrangement. We went from a skew valve type of arrangement on the A-engine which had the exhaust valve parallel to the bore, and the intake valve tipped toward the intake manifold giving what has been described as a poly-spherical chamber. That was the A engine.
When it came to the LA engine we made all the valves tipped to the intake manifold and inline, as viewed from the front of the engine, giving it a wedge shaped combustion chamber. The reason we went to such a change, which triggered totally new cylinder heads and manifolds for the engine, was that the engine was designed to go into the Valiant car.
The Valiant car was originally not designed to take a V-8 engine, so we were really limited in every which way about getting the engine in place, and the older A engine was simply far too wide at the cylinder heads in order to go into the car. So we put the wedge head engine, cylinder heads on top of the A engine and that was what we needed to do in order to get that engine into the Valiant.
In the process we also wanted to take a lot of weight out because the Valiant [engineers] wanted to have engines much lighter than what a conventional A engine would be. So we took as much as we could out of the cylinder heads and the intake manifold and the cylinder block which is the largest and heaviest piece of an engine. That triggered a new casting process for the cylinder block that allowed us to make all the walls thinner and we took a lot of the weight out of the block.
Q: Was there any performance penalty for this or was it a wash or an improvement?
It certainly wasn’t a penalty, it was really a wash. From going from our polyspherical chambers to the inline valve wedge chambers we found it was a wash. There was concern that it would be a loss but it was not.
Q: There were some strong variations in the power of these engines. How much did you work on the different variations and squeezing more power out of the basic design?
We had the design and development responsibility for them. We did the 273, and then next came the 4 barrel 273, and then we had the first 340 which was a single 4 barrel. Then we had the 6 barrel having three 2-barrel carburetors and then we went NASCAR racing with it with a single 4-barrel. We were doing development with the LA engine in the race cell so that work was going from our race cell into the engines that the Chrysler supported teams were using.
Q: Did any of the performance boosts that you developed percolate down to the standard production engines? So, if you learned something was important on the 6 barrel 340 would that have led to any changes on the pedestrian 318?
I don’t recall any direct hand down. We were engulfed in making these engines pass the emissions standards. So we didn’t do much work in trying to hand down the high performance stuff. Emissions were pretty well segregated to 2 barrel and 4 barrel engines and then later it was fuel injection and then we no longer had carburetors.
Slant six engines
Q: What were the first engines that you led the design of?
That would be the Slant Six, which I remember was like starting with a clean sheet of paper. The B-engines, which were our big block engines, both low-deck and high-deck, were also a clean-sheet new design. They were designed just before I arrived in the department so the designs were really firmed up but there was still a lot of work to do. So the first clean sheet engine that I had was the Slant Six.
Q: What did it have in common and where did it differ from the prior sixes?
Really, we never compared it to the prior sixes, which were all L-heads and considered quite obsolete when we put down the lines for the Slant Six. The fundamental engineering approaches as far as the power section parts, pistons, connecting rods and crankshafts were applied to this new engine. One of our biggest challenges was putting the tappets in place. Although we did not start with hydraulic tappets, they came in much later. Making it an extremely compact and lightweight six gave us plenty of challenges and we were pleased with the way it came out.
Q: Competitors were coming out with their own new straight sixes at that time. What made the Slant Six different from the others other than the obvious difference of it being slanted?
I think we may have achieved a more compact engine, particularly in the fore and aft directions, because of the demands of the installation in the Valiant car. The Valiant engineering team was really insistent about keeping the engine short. It was that shortness that led us to tilting the engine over on one side in order to make it a good deal shorter than it would have been with an upright arrangement of the engine. And then we took advantage of the slant location to do a good job with the intake manifold with the engine.
Q: What would you say you personally learned from doing this first clean sheet design in terms of what worked well and what didn’t work quite so well?
One thing was a very good feeling when that engine went into production. We were rewarded with having done a good job on it. It was a feeling that if we worked hard enough we would have success. We applied it to our thinking in the future; if we had a challenge and we worked at it we would have success. That was the way it was going to be.
Q: The various programs to modify the Slant Six that I have read include things such as a turbocharged version and a fuel-injected version, is there anything that you can tell me about those and what instigated them and why they were not pursued?
I think I mention both the diesel and turbo versions in the book. I really don’t have much to say about the turbo version, I remember it ran in the lab and there just wasn’t the interest in it because we had V-8 engines on top of it. The diesel version was a pretty neat program when we were working on that one. It was quite well developed; we had a 4-cylinder version of the Slant Six engine for use, it was a turbo-charged 4-cylinder diesel version of the Slant Six engine. It was no longer slanted though. I’m sure it was upright. But the diesel version of the Slant Six was slanted.
That program died when the interest in diesel engines in the U.S. died following the unsuccessful launching of General Motors diesel version of an automotive engine. That gave the diesels a bad reputation in the field and the market dried up and with that we quit our diesel program. That cessation of our own diesel Slant Six program was a decision by Lee Iaccoca. He figured the market wasn’t there and we shouldn’t be spending any money in that direction and he was right and we just stopped working.
Australian Hemi Six
Q: The only other straight-six engine that came out after that was the Australian hemi-six. Did you lead on that?
We were the lead on it. That was by arrangement and agreement with the Australian engineering staff and the company. The installation requirements were different and both the Australians and ourselves liked the upright arrangement for the engine for its simplicity and being maybe more acceptable in their competitive field. We had provision for a larger size of the same engine; it was a raised deck of the same engine, as a possible truck engine. We liked that idea of this being a good sized truck engine of about 300 cubic inches. There the factors and the requirements for the use of the engine that said we could use an upright engine so that was why we went for it.
Q: Was there any way that you approached the development and design process differently for this engine?
Yes, Chrysler Engineering in Highland Park was the lead off for the design. The development was started there and that’s where the basic development of the engine took place. Then the final engineering responsibility was transferred to Australia. They worked very hard at high performance versions of the engine that we did some consulting on but it was really their responsibility. I think they did a pretty good job on those versions.
Q: As far as I know it was never developed into a truck engine. Can you tell me anything about why or why not?
That is correct. It was a financial decision. It would have cost quite a bit of money to make a truck version of the engine including the engineering and the development and production costs. It was decided that the anticipated volume would not pay for the cost of it so it never got any further than design studies. We never built an experimental engine.
Q: Pete Hagenbuch said that they approached the Australian Six a little differently in terms of instead of making it heavy and then lightening it they started by making it as light as they could. Does that sound familiar?
Yes, in the design we did indeed try to make it a lightweight engine, even though it was all cast iron we wanted to make it a lightweight engine.
Q: Was there anything that came out of that that you were able to use in later designs, for example the 2.2?
Again the sequencing I’m unsure of. Our massive effort at reducing engine weight was really on the LA V-8 engine. I think those lessons carried over then into the Australian engine that was designed and into the 2.2. I think the LA came first. We sort of went through the lightening process once and then we applied those lessons to all of the future engines which would have included the Australian engine and the 2.2.
Q: In your book, do you go over the process from sitting down with the requirements to making the first lines on a clean sheet?
Really not, it’s there by inference on some of the stories of the engines but I don’t attempt to put down the process of designing an engine.
Q: When you first sat down what guided your initial architecture choices, things like would it be overhead valve, would it be dual overhead cam, single overhead cam, or the basic bore and stroke all the other key elements that need to be laid down?
Often we would have a number of design studies before we would go into the final design. That phase was when we played around with bores and strokes, and valve sizes and engine lengths and even estimates of engine weights. We would consult with the advanced chassis people who installed the engines and who were responsible for all the weight estimates that had to go into the vehicle so we would be in tune with what the engine was being designed for. Based on those many meetings where we would consider all these things a final design would emerge of the best combination.
2.2 / 2.5 liter engines
Q: I assume that you led the creation of the 2.2 and 2.5 engines.
Q: Can you tell me what was different about those compared to engines that went before. Size is of course obvious but what else would have been different and what planning did you make for future technologies? Were they planned with the idea that sooner or later they would have turbo charges or fuel injection or maybe dual cam?
Usually at the time we were not able to look into the future very far. I remember on 2.2 we knew what size we wanted, in fact we had prior sizes that weren’t as large as the 2.2, they were in the 2.0 liter range. But then in meetings with the other people in the Advanced Chassis and others, we would start to adjust the engines and it was adjusted up to the 2.2 liter size. That became the final size for the engine.
At the time of that engine we didn’t know enough about fuel injection to think that it was even coming. We were with carburetors and that seemed like what we were going to have forever, at least on the highest volume of our engines. There is always going to be the super-high performance fringes which will run almost anything. Likewise we had no idea we would be putting turbochargers on that engine.
We weren’t even too sure about future displacement changes from the 2.2 and it took some doing to get to the 2.5 when it finally came along. That required balance shafts that we had to put in place. We were very happy that we could add the balance shafts at the time and still get the engine into the compartment because that compartment was extremely tight since it was front-wheel drive and the engine was mounted transversely and we just didn’t have any room to work with.
Q: Were balance shafts an idea that you got from the Mitsubishi engines being used by the company?
The balance shafts had been around for years and years, Mitsubishi added them to their engine because their engine was so large at 2.6 liters; without shafts there would have been far too much unbalance of the engine to be satisfactory in a passenger car.
When they designed their engine they were able to build the balance shafts into the cylinder block. They had the room in the vehicle for the extra space needed to do that. And of course they hadn’t tooled up any production block machining lines yet so they were able to put provisions in their block lines. When our 2.2 liter engine was tooled up there was no provision in the block line to have any balance shafts added to the cylinder block as Mitsubishi did. When we decided to make a 2.5 liter version of our own 2.2 liter engine and we needed balance shafts, we had to add them. That started the creative juices thinking about “How to add those balance shafts?”
There was only one place we could go and that was down below the crankshaft because it was the only room available. The problem was that below the crankshaft were the oil and the oil pump. We came up with a housing that had provision for pumping the oil out of the housing so that the balance shafts would be swinging around through air and not thrashing through the oil which would have been unacceptable.
Necessity was the mother of invention.
Q: What were the key differences between the development and design of the 2.2 and something like the Slant Six?
Overall I don’t know if there was any fundamental difference in our approach. After we liked the design we brought in the prototype hardware and we just ran them through a large number of tests, both component tests and overall engine durability until we were satisfied that it had what we wanted. We used that approach almost like a cookbook to know when the engine is ready – once it passes all these tests and we are satisfied with it then it’s ready. We put the Slant Six through it, we put the 2.2 liter through it, and every engine goes through that process.
Q: The power ratings for the 2.2 seem disproportionately high in comparison to the slant six, given the difference in displacement. Is that just a factor of having a smaller engine or is that something fundamental to a design change?
The 2.2 was designed much later than the Slant Six and had more emphasis on performance, which it needed to be competitive. It had a big plus for that because it was an overhead camshaft engine compared to the pushrod engine of the Slant Six. It also had a better bore-stroke ratio than the Slant Six. The bores were relatively larger so that its valves could be larger and therefore had better breathing for the entire engine. It just was a higher speed, higher performance engine with better breathing so we would have expected it to have a higher specific output.
Q: Compared to most other engines of that time, the 2.2 has much higher torque compared to horsepower. The top Honda Civic engine had 125hp and 100 foot pounds of torque, whereas the base 2.2 had 93 horsepower and 123 pound-feet. Was that dictated by the development people or was that engineered in from the start?
Our performance engineers were very good at predicting what the engines’ performance was going to be. I just don’t have memory of specifics any more.
Q: Was any thought given to making a 4 cylinder engine in the 60s or 70s or any other time?
There was some thought about it and we made some designs of 4-cylinder versions of our Slant Six engines. I sort of recall that South Africa wanted an engine like that, but nothing ever came of it. We determined that “yes, it could be done;” the biggest thing would be to put in the production equipment to machine them.
Q: Can you tell me how the 3.9 came about?
The truck people wanted to bring out a new model that was smaller than what they had with the Ram [D] series and it would become the Dakota. It had a smaller engine compartment. They wanted to have both fours and sixes for it. So we had the challenge of taking the 2.2 4 cylinder engine which had been designed for only an East-West or transverse location and we redid it and installed it in what is called the conventional drive line or the North-South drive line for the Dakota small truck. And they wanted to have an upgrade power plant from the 4-cylinder so the V-6 was designed as a way of furnishing a V-6 for the least possible tooling costs.
Because of capital investment, we didn’t want to get into a whole new engine. We just wanted see what we could do with what we had and that caused us to look at the V-6 version of the Mound Road Engine [LA 318 and 360, or 5.2 and 5.9]. That was the way it was done. The engine had to be shorter than the V-8 in order to fit into the compartment. It was only in later years that enough space was found in order to be able to put the V-8s into place. But the first ones were powered with a 4-cylinder 2.2 and the 3.9 V-6.
Q: Did you have any particular challenges in the adaptation or anything you would have done differently once it was all set up?
We had a challenge on the V-6 because the crank-pins had to be split in order to get away from the very unequal firing if we had only 3 crankpins, each crankpin having two of the connecting rods as is V-8 practice. The reason is that the engine would be rather badly out of balance and would have not been acceptable even in a truck engine. So we had to do some redesigning of the bottom end in order to split the crank pins and make the firing order a little more uniform and it seemed to have worked out ok.
Q: Did you know why the 3.3 V6 came out fairly late in the game?
I think the reason it was not brought out sooner was because we were importing 3.0 liter engines from Mitsubishi. They were filling that slot in our plants that we needed particularly for the minivans. So with that slot being filled with our contract with Mitsubishi for engine supply we did not have a rush reason for bringing out our own engine which is a very heavy tooling expenditure.
We were often restrained from what we wanted to do because the company had to put available money into different spots.
Q: Once the 3.3 was out it took a long time before it supplanted the Mitsubishi engines. As far as you know was that because of production restraints or something to do with the contract still being out there?
I think it was a combination of both; we did have the contract that needed to be fulfilled so the need for our engine did not come into sharp focus until after the contract expired.
Q: I believe that was Chrysler’s first ever V-6, can you tell me what the primary influences were when you were building it?
One influence was the simple piece cost of the production engine and another was the cost of tooling the engine. We wanted to have an engine that was quite economical in both respects. Also, at the time we were hard pressed for space in the compartment and the engine had to fit where the 3.0 liter Mitsubishi fit.
Q: Why 3.3 liters as opposed to a smaller engine which might be easier to design to fit in those spaces?
I think even then we were concerned about giving room for expansion in the future. We wanted to match the power and performance of the 3.0 liter engine if not exceed it with our own 3.3 liter engine.
Q: What did the 3.3 have in common with the existing engines? Was it a clean sheet or did you base it on your V-8s?
It was essentially a clean sheet engine. I don’t recall if we used any of the hardware but I don’t think we did. Parts would have been designed to have been quite similar to the older V-8 engines with their overhead valve systems. As such it wasn’t any particularly difficult task for us to equip the engine with the overhead camshaft system.
Q: Did you deal with the tuning of the engines or just the basic design and architecture?
We were involved in the tuning because we had to come up with the designs that would agree with whatever the tuning was going to be. Our development people, our performance people were the ones who really took the lead on the direction we should go for the tuning of the engine.
Q: People handled emissions in different ways. Volkswagen went with multiple fuel-injection as early as 1979. Was that solution considered at Chrysler as opposed to the add-on systems and carburetor retuning and such?
I really can’t comment about that. The work for emissions was done by a separate engine qualifying group. Indeed the tide was turning toward the fuel-injection, first with the single-point throttle-body injection and then the multi-point fuel injectors. As the requirements became more stringent there was always a thought that we should be able to try to pass the test with the least cost increases. I think that led us to hang on to carburetors for quite a while.
Q: So carburetors, even when they were feedback carburetors, were cheaper than throttle-body injectors?
I had the perception that the single-point throttle bodies when they came out were more expensive than any of the carburetors but that emissions demanded that higher precision and therefore the carburetors were just abandoned almost en masse.
Q: Were you involved in the development of the new Hemi they are making now?
No, that was after I retired.
Q: Did you work on the 2.0 that was used in the Neon?
I did not work directly on it, I happened to be per diem (consulting on a day by day basis) and I did some slight assistance on the program. I was not truly involved in the design and development of that engine.
Q: Have you ever read Carl Breer’s book?
Oh yes, it was very interesting. I’m probably the only person in the world that knows of an error in the book [buy it]. When I read this particular statement I decided to check on it. I found the statement was incorrect. I then read the original transcript that Breer wrote. Breer had it right, but it was the [re]writer who inexplicably changed it to make it incorrect. So my respect for Breer went up.
Q: I’m impressed you checked the original transcript.
That’s because another fellow at the archives who I worked with when we were both active employees worked as an executive assistant to Breer and had a copy of the transcript that was the basis of the book.
The Chrysler Engines book
Q: What led you to start writing your new book?
The origin was a request through the manager of the Walter P Chrysler Museum, who had been asked to contribute information for a history of Chrysler. I understand that request originated after the merger of Chrysler and Daimler-Benz in 1998, and the leaders of the two companies thought it would be fitting to have a summary / history of each portion of the corporation.
Following that request I got a call to see if I would write up something on the history of Chrysler engines, to be included in the book. I started working on that and was visiting the Chrysler archives and the Chrysler museum, putting information together because I wanted to have a complete list of all the Chrysler engines that had been in production, and to give some specifications about each engine and if possible a picture of the engine, like a cross section or a photograph.
I was approaching completion of the engine material when the project itself, the entire book, was cancelled for reasons I am not entirely certain about. My own interest in engine histories was aroused, though. I spoke with the manager of the Walter P. Chrysler Museum and the manager of the Chrysler Archives saying that I would like to write a book about Chrysler engines myself.
Of course, when I’m writing about the engines it was going to be far more in depth than what I had originally assembled for the proposed Chrysler / Daimler Benz book. That in turn led me to a number of years assembling the information that I needed to make a book out of it.
Q. Did you write the book entirely on your own, or did you use an assistant or ghost-writer?
Oh, I wrote the entire book myself, every word. There were some very good suggestions from the SAE editor and reviewers relating to style; the first version was more technically stilted. I went back and changed some things so the book is easier reading. But as far as who wrote it there was nobody else. And I really do have an appreciation for the SAE editors and the reviewers for helping me accomplish that. I put it in the Forward of the book.
Q. Why did you choose to publish with SAE rather than a more mass-market publisher?
As I mentioned earlier, the museum manager was asked to support the Chrysler book which was to be written. He in turn contacted a fellow that I have a lot of respect for by the name of Al Bosely. Al Bosely was actually the one who talked to me about “would you be willing to volunteer for this task?”
When the first project folded and I was thinking about doing the book myself I went to Al Bosely and asked Al, I need your advice about getting this book published. Al recommended SAE because of the prestige that they have and he thought it was a book they should publish. That was what really triggered it. I wasn’t sure SAE would publish it, but Al thought they would. We were successful so I never went to any other publisher. SAE also had published an excellent book about the piston engines of the allied aircraft during the Second World War by Graham White. Having reference to this I read the book and thought that was really a good book. I thought if they could produce this book they would be a good publisher for my book. After they approved it I never looked back.
Q: Is there anything you would like to add?
The earlier days of the engines which I found rather fascinating. I was glad to find information about the very earliest engines that had the name of Chrysler attached to them. Also in writing the book I had a much larger appreciation for the contribution of the three original engineers that designed the Chrysler cars. Fellows by the name of Carl Breer, Fred Zeder, and Owen Skelton, they were really excellent engineers.