1915-1918 Monroe Index


Gary Halford of Ohio owns a 1916 Monroe M-2 Roadster. The Car Number is 2958, which is stamped on the front side of the firewall, under the engine hood, in 9/16 high letters. This number 2958 is located on the top right side, about 3 inches below where the wiring loom goes through the firewall. Monroe also had the foresight to stamp the inside frame rail, just below the right hand headlight bracket, and Garyís car has a matching 2958 number stamped there. This frame number comes in handy years later, since the wooden firewall is often replaced during restoration.

Gary could not find any identification numbers on the engine block except a brass tag that is riveted to the front left crankcase that list it has a Model No. 16 with Serial No. 3012. The letter 2 is stamped more heavily over the number "0." Gary also has a spare engine that is stamped No. 3101.

On the top deck of the M-2 cylinder head, located under the rocker arm shaft, is the raised casting date. Garyís M-2 engine No. 3012 has a head date of 9 25 5, for September 25, 1915. I based my Estimate Production Chart on a Mason engine capacity of 250-275 a month, with Monroe car production based roughly on the same monthly percentages that Chevrolet used. Therefore the engine casting date preceded the Car Number by approximately ninety days.


Monroe owner Gary Halford reports that there is also a Body Number, that appears to be similar to the Car Serial Number, but isnít. This other number is stamped into the wooden board that runs the width of the seat, just beneath the driver (left) side, near the front. The physical size of the numbers is the same as the 9/16 inch number stamped on the firewall. This number on Halfordís 1916 Monroe M-2 Roadster is Body Serial Number 2454. Halfordís roadster is Car No. 2958, so this body number is 504 units lower than the Car No. The body number probably started at Serial Number 1, while the Car Number started at 501, explains the 504 number difference between the two.

There is also a Capital ĎMí located on this floor board under the seat in the very middle of the car. Since these roadster bodies were supplied to the Monroe Motor Company by the Monroe Body Company of Pontiac, the ĎMí must stand for the Monroe Body Company.



Gary Halford reports that the engine serial number 3012 is also stamped on the center section of the crankshaft and on each connecting rod right side. Each rod and rod bearing cap has a number 1 to 4 reading front to back. The rods also have a unique 3 digit number on each rod and cap as well. For example, engine number 3012 has the numbers 676, 648, 716, and 678, respectively for rods 1 to 4. There is an additionally internally stamped number for each engine. This is 3 or 4 digit number stamped on both main bearing caps and on the machined lower surface of the block near the main bearings. Engine number 3012 has number 952, while his spare engine number 3101 carries the number 1157 stamped as indicated above.


Several months ago I saw an ad in OLD CARS WEEKLY MAGAZINE for a 1915 Monroe Roadster, and wrote Gary Halford if he knew of this Monroe? Gary replied that he didnít, but was planning a business trip to where the car was located, was trying to make arrangements to visit the seller of this car, and would advise me of what he found. A few weeks later, Gary writes: "Iíve enclosed pictures of the 1915 production year Monroe M2 from the Rochester, New York area (near Pittsfield) in Monroe County. The engine serial number is 1657 and has a head casting date of: 6 9 15. This was exactly 82 years to the day of when I took the pictures! "


Gary continued his letter with a complete description and evaluation of this earliest know Monroe. "The body numbers are long gone, as the firewall was replaced and the rust pitting on the frame rail was too extensive to leave any evidence left on the stamped number there. The car has no top (but Iíve since located a set of bows and a body with both left fenders plus some other odds and ends in Jackson, Michigan), the wheels are incorrect (but look nice), the body has had a lot of rust that has been repaired with copper sheet metal, the hood is thin and jagged on the edges from rust, the upholstery has been redone, the steering wheel needs work, etc.

The head lamps look correct as does the dash instruments. It has the right gas tank and cap, and the rare spare tire carrier (was as option along with electric starter). It has a handmade wooden tool box on the back that looks just like the one in the Flint Museum (that also came from New York).

Actually, this car may not have come from New York, The current owner bought it a while back at Hershey. They were told it has spent 50 years on a car dealerís showroom floor. My guess is it also spent a lot of time in non-dry storage. It has been repainted a number of years ago, and a lot of liberties were taken in the engine compartment to get it to run. It needs lots of tender loving care, although from 20-30 feet, it looks decent, and properly restored, would look great."


Gary took 3 photographs of this 1916 Monroe M-2 Roadster. The brass Engine Model and Serial No. plate is slightly different on this early model. Itís length is longer but the height is less then the ones shown in the June and July 1997 REVIEWS. Engine Serial Number 1657 is the earliest known Monroe. I estimate this roadster is about Car Number 1602, since the car number seems to be approximately 55 numbers before the engine serial number. Car Number 1602 would have been completed about August 1, 1915. This would make the first 1916 model, Car Number 1501, finished on or about July 19, 1915 -- a Monday. The cylinder head casting date is 6 9 15 for June 9, 1915. If this is the original cylinder head for this block, this would prove that Car Number 1501 should of been built in the middle of July and not June 1st, as I first believed.

1915-1918 Monroe Index