I have a Cat d-315 power unit serial # 9s7342 and was curious as to the year model and oil capacity. Thanks in advance for any help.
Hi gfixit - I have never seen any Serial #/Year of Build listing for industrial engines. Even Caterpillars records are confused and error-riddled. In the Cat Serial/Product ID Number Index, it states that 9S5001-up was a D315 Marine engine - and I can find no record of any D315 Industrial engine Serial #'s in that book. However, Cat list the D315G engine with two Serial # prefixes - 48B and 52B. Historically, Cat reserved different Serial # prefixes for Marine, Industrial and Genset engines. However, I'm not sure when that system started to be applied. I think earlier engines used the same Serial # prefix regardless of whether the engine was Marine, Industrial, or Electric Set application. Tractor engine Serial # prefixes were different. I have an operators manual for the "Diesel D315 Engine and Electric Set" - Serial #'s 9S5001-up. This manual appears to treat the engine as separate to the generator, as the book is essentially divided into two parts - so perhaps the 9S Serial # prefix ranged through Industrial, Marine and Electric Set engine applications. Despite a myriad of information in the operators manual, it staggers me to find no specifications for quantities of lubricants, anywhere in the book. I went to the Service Manual for the D315 and there's no quantity specifications there, either! However, I did find a sales brochure (!) that lists the engine lubricating oil quantity as "3.75 U.S. gallons, with oil cooler". I guess you're aware the engine oil cooler stands vertically to the LHS of the radiator. I'm not sure how much drains from the oil cooler when an oil change is carried out. The operators manual simply says, after an oil drain, to "fill the engine with oil to the high level mark on the dipstick, then run the engine for 2 minutes and recheck the oil level". The D315 went through repeated development/engineering changes and output/full load RPM changes during its 12 year lifespan from its release in 1947 to its demise in 1959. The HP was regularly increased, the full load RPM was regularly increased, and around 1953 or 1954 the engine was re-engineered for the fitment of a balance shaft which enabled higher engine speeds again. A relatively small number of D315 engines were offered in turbocharged form in the late 1950's. These were only ever used in Industrial or Marine applications, no Cat tractors were fitted with turbocharged D315's. As to year of build of your engine, I would hazard a guess at early 1950's build.
QzDozer, Thanks for the info. I was also found no info on oil capacity in the service manual that i have. It was just something that I have never found in writing and was curious. We have been using this engine to power a sawmill for the about 35 years and I have always been curious about the age. The plate on the engine states no load governor speed 1755 and full load 1600. Thanks for the info.
Yes, the first D315's ran at 1400RPM full load, the next upgrade involved a horsepower boost, and full load RPM was lifted to 1600RPM. I recall the HP increase was mentioned in a late Oct 1954 Service Magazine, so that places your engine build from at least that time. I'll get out my Cat rack setting book tomorrow, there should be a little more information in that.
I forgot to mention that you can utilise the Caterpillar casting codes system to assist in dating. Every major casting on Cat equipment has an initially odd-looking numerical code cast into it, besides the standard part number or casting number, which in Cats case is Number/Letter/Four numbers. This casting code system is called the NUMERALKOD dating system by Cat. Have a look on the engine block and you will find those NUMERALKOD casting letters, usually in a reasonably prominent position, and you can find the actual casting date, as indicated below. The NUMERALKOD can be interpreted by substituting the appropriate number for each letter as shown: N=0, U=1, M=2, E=3, R=4, A=5, L=6, K=7, O=8, D=9. The date sequence for the code is MMDDYY. For example: UMNDAR = 120954 = December 09, 1954. Actual shipping date for the Cat product would usually be around several months later than the casting date, as castings would have taken time to travel through the manufacturing system. I'm not sure if Cat blocks were aged for several months to relieve casting stresses before being machined and assembled, as some manufacturers used to do in earlier times. Later metallurgical research showed this ageing of castings wasn't really necessary, and even up to 9 months of ageing only released a maximum of about 15% of the casting stresses.