quote:
Originally posted by aex125
Over the years I have seen leaf spring Cobra Engine #s that have always been 4 numerals which I assumed was a engine assembly # of some kind. Recently I saw that CSX2337 has an engine # of PA4041. Does anyone know what the PA designation stands for? Production Assembly, Pure Adrenalin, Post Adolesence,Plenty (of) Acceleration or?
TIA
Jay Peterson
Jay,
Regarding the serial numbering of 260/289 engines in Cobras (leaf spring chassis) finished at Shelby American in California. I can’t tell you what the “PA” means in your inquiry. I have tried to find a reference or knowledgeable person for many years. I will share my other findings and observations. It is getting harder and harder to find original details as people forget and cars continue to get modified.
Dan Case
CSX2310
CSX2551
If any of the HP260 engines other than the first two (which had hand painted serial numbers on their valve covers in early pictures) Shelby American installed received serial numbers I have never heard of it. Those early engines are strange combinations of production Ford parts and experimental (SK- and XE- Ford engineering number prefixes for rods, cylinder heads, distributors, and intake manifolds) development pieces.
The information I have accumulated so far is more than I want to type out here (casting numbers, date codes, model numbers, different versions of parts 1963-65 as Ford designs evolved as seen during examinations or reported by Cobra owners) but for HP289s as installed in Cobras new there are three types of HP289 engines I have documented, examined, owned, or had owners share information on.
1) Most HP289 powered cars received HP289 engines taken out of the stock of Fairlane production engines. These were standardized assemblies. Shelby American added the Cobra specific details. (exhaust system, oil and water temperature sensors, charging system, throttle linkage ancillaries, in at least 1964-65 production modifying the fuel pump <rotate the valve body forward> modifying the fuel pump to carburetor metal tube line installing the Eelco® brand elbow installing a jumper hose and Murray® hose clamps) These were all five bolt bell housing engines. There were some Fairlane model year or design revisions of individual parts differences between the 1963 and 1964 model years but each production HP289 engine block (not the engine assembly) received a sequential number in the alpha numeric AAXXXX form. Mr. Bob Mannel has a registry he maintains of these block serial numbers for Fairlanes. A few of us Cobra owners have supplied him with our engine block numbers. For example on my black car the complete block number is PA4537. Mr. Mannel has excellent Ford documentation and published an excellent book on the 260/289/302 engines. He is not sure what the alpha characters (PA on my engine) mean. ‘PA’ and ‘PB’ are common in Cobras but there are other combinations. The numeric characters are the sequential serial number of the engine block (4537 on my block). On the engines themselves all the alpha characters I have seen have been stamped on the front left tooling boss and all the sequential serial numbers on the left rear tooling boss. The sequential engine number was also usually hand painted on the rear of the block in white. Shelby American adopted the engine block serial number as the engine serial number. I have only seen a few copies of invoices from Shelby American to the selling dealer but so far all the street cars had complete engine block numbers listed on that document. My car’s invoice does. When the cars started getting supplementary identification plates riveted to the right side foot box Shelby’s shop included the ‘engine number’ in the field provided on the tag. Most cars’ tags that I have seen to date received the full number as shown on the invoice but it is not uncommon just to find the four numeric digits. (A Cobra that a friend owns now was originally titled and registered by the car’s complete ‘engine number’ and not the CSXxxxx chassis number when sold new. )
2) Cars finished after approximately August 25, 1964 received Shelby American assigned engine numbers. I am still gathering information here but as Cobras are some of the most modified cars of all time, finding cars with completely intact original engines is being difficult. Based on what Mr. Mannel has told me about Fairlane engine production that operation ended for the 1964 model year as summer 1964 started and by around July 1964 the new for the 1965 model year six bolt engines were being built. Based on what little has been found in print and what I have found through my inquiries roughly sixty Cobras still required engine installation when the supply of production five bolt 1964 Fairlane HP289s ended. Roughly half of these cars received five bolt engines and manual transmissions and the balance received new six bolt engines and automatic transmissions. These engines did not come from Ford with any type serial numbers stamped into them it seems. These engines got serial numbers in the form of “000XX” stamped on or just above the left rear tooling boss on the block. The lowest number I that I currently know what chassis it was fit into is 00004 and the highest is 00060. These numbers appeared on invoices to dealers and foot box tags. I have a car with this type numbering myself. (Researching this car started my investigation.)
a) The post 1964 Fairlane production five bolt engines Cobras received don’t seem to be normal 1964 or 1965 engines. The engines examined so far contain mixtures of 1964 and 1965 specification parts. The engines that have been checked contain blocks that were both cast during the 1964 Fairlane production time frame but not finished then; both were machined August 25, 1964. The lone intact engine found so far (Shelby engine number 00010) with its Ford identification tag still in place has information on the tag that indicates that the engine was a 1964 Fairlane HP289 for a manual transmission assembled in August 1964 (which was during Ford 1965 model year production).
1964 specification components identified so far engine block (five bolt)
block plate (five bolt)
bell housing (five bolt)
cylinder heads (rare C4OE versions cast in March 1964)
harmonic balancer
fan belt pulley on crankshaft
fan belt pulley on water pump
fuel pump
1965 specification components identified so far timing cover
oil pan (location of drain moved for 1965 and later models)
ignition distributor
carburetor (manual choke model instead of previous automatic choke)
intake manifold
b) The six bolt engines used in automatic transmission cars are believed to have been a Mustang configuration. (Finding one intact with its engine assembly line tag would tell us for sure.) The only Cobra that I am personally acquainted with that still has its six bolt engine original drive train was hot rodded (aftermarket induction, headers, and lots of small details) in the usual manner so it is impossible to tell exactly how it left Shelby American. Its engine was assembled August 28, 1964.
