CC contributor/commenter dman passed along an (expired) for sale ad link to a very rare beast: a 1950 Cadillac Series 61 Coupe, just like our official CC mascot ’50 Caddy, but with a big difference: it has a diesel engine under the hood. Given that it’s a Cadillac, one might assume one of the smaller “Jimmy” Detroit Diesels. But according to a badge on the hood and the ad, it’s a “RARE” P&H diesel. Well those are rare, an aluminum block and head two-stroke diesel engine that came in 2, 3, 4 and 6 cylinder versions, not unlike the DD.
But there’s something a whole lot rare yet under its hood.
As I looked at the engine compartment shots, the engine looked distinctly different than any images I found of the P&H diesel engine. It took a bit of Google-diving, but I’ve finally come up with what it has: an ultra-rare Cerlist V4 diesel. It’s a valveless loop-scavenged two stroke that was designed by Austrian Dr. Hans List and built by a small North Carolina firm called Cerlist, between about 1956 and 1963.
Never heard of it before, but then this is what CC is all about: proving clueless For Sale ads wrong and learning something new.
First, the text from the ad, a classic in the art of understatement (“just clean up and drive…“) and which tells us very little except for how RARE it is:
You are bidding on a 1950 Cadillac RARE P&H Diesel powered 2dr Sedan. The car is original and black in color. Original stainless. Does not run at this time. The interior is original and has wear. This is a rare car that would be good for restore or just clean up and drive a rare survivor. I will be going to Norfolk, Ne after the 12th and will be adding more pictures and info to catalog. RARE car. I bet you this car gets awesome mileage!!!! Rare one for the collection or shows. This is part of the E.J. Christiansen Collection auction and is online only auction .
I bet it gets awesome mileage too, if it ran, which I would be highly surprised if it did.
A bit of a hole in the floor, but that’s minor. The ad did say: The interior is original and has wear.
Does this count as “wear“?
Enough nitpicking. Let’s get to the good stuff under the hood, which sports an authentic P&H Diesel Power badge.
Here it is, ensconced quite nicely in the Cadillac’s engine compartment. At first glance, I saw nothing out of sorts here, as the P&H diesel is not exactly a familiar sight to me.
But when I got to this side, I started scratching my head? What am I looking at? Looks like two cylinder heads, tilted this way.
This didn’t look at all like the P&H diesel engine in the ads and some others on the web, which are all inline, and look pretty conventional.
I cropped the shot to get a better view. That’s certainly what those are (cylinder heads), although it seemed a bit odd to see the injector right on the center of each cylinder.
I cropped the other side too, and sure enough, there’s two more of the exact same cylinder heads here too. This is a V4 diesel!
I had no idea who made V4 diesels so I just Googled that term, and soon enough I found it: the Cerlist diesel, also made in two and three cylinder forms. Here’s some info from that website:
The Cerlist Diesel Co. was incorporated in North Carolina in 1956 by Peter Cerf. The name of the engine company was derived from the names of Cerf and Dr. Hans List of Austria, who designed the engine.
The 2-cycle, high-speed, aluminum, supercharged diesels were unique in that they had no valves, and were “loop-scavenged”. Multiple intake and exhaust ports were cast through the cylinder wall near the bottom of the piston stroke. The intake ports were angled upward so that the incoming rush of supercharged air was directed up and over the top of the cylinder and then back down in a looping fashion to the exhaust ports, carrying exhaust gases with it and filling the cylinder with a fresh charge of air.
Cerlist Diesels were originally manufactured in the Cerlist Diesel plant in Burlington, NC until the company went bankrupt. Peter Cerf had estimated that several thousand were manufactured. Although the engines were used primarily in military applications, they were used in some industrial and marine applications as well.
During the Vietnam War, the Air Logistics Corp, of Monrovia, CA used the 3-cylinder Cerlist Diesel (above) to drive the jet fuel pump of their Boondocks Air-Transportation Fueling System. The system was a portable unit that included the engine driven pump, two huge flexible fuel bladders along with all the piping and valves that could be towed to the airfields built out in the boondocks.
In 1963, Waukesha acquired the rights to build the unique Cerlist Diesels.The Waukesha Cerlist Division was located in Waukesha’s Clinton, Iowa plant under the direction of Peter Cerf, Sales Manager. Cerlist Diesels were discontinued in 1973. All the WEHS knows for sure about the fate of the Cerlist’s Diesel is that in 1980, the entire inventory of Cerlist Diesel parts were sold to Engine & Equipment Co., Salt Lake City, Utah.
The Cerlist models involved in Waukesha’s acquisition were:
Model Cyl. Bore x Stroke CID. HP@ RPM Years 2
4.000 x 4.250 113.1 50 @ 3,000 1963-73 3
4.000 x 4.250 169.6 75 @ 3,000 1963-73 V4 V4 4.000 x 4.250 226.2 100 @ 3,000 1963-73
So this Cadillac has 226 cubic inches and 100 hp. That’s a bit less than the original 331 gas V8, but it would have been interesting to hear this at full chat.
The Cerlist diesel’s two-stroke loop-scavenging system was not exactly new or unique.
Detroit Diesel made a similar loop-scavenged engine series back in the ’50s, from 1950 to 1959, designated 2-51 and 4-51. Starting in 1957, the more conventional -53 series started replacing them.
Here’s a 2-51 being run. Apparently they were very reliable and rugged little engines. Of course they were noisy, as Jimmys (and all two stroke diesels) are wont to be. But putting mufflers on them with anything than minimal restriction caused exhaust back pressure which resulted in poor performance, not surprisingly, given their loop-scavenging system. This was the main reason they were replaced by the -53 series.
This bin with five cylinder liners is/was also included in the deal. But they don’t look like the Cerlist cylinders; there’s no ports and they look quite different. Could these be for the missing P&H diesel? Did this Caddy first have a P&H diesel, and the Cerlist replaced it? Inquiring minds want to know.
Unfortunately, we’ll probably never know. This fine diesel Cadillac sold for some $1800 back in 2018. I’m sure it’s been cleaned up and being driven regularly, and getting great mileage.