What is normal oil consumption of a 276 Flathead. My flathead runs cool even in 100 plus, yet seems to use more oil than those I had 50 years ago. Just wondering if it is my memory ?
My flathead is a 255, not rebuilt with new parts but just all internal oilways cleaned and new gaskets all around. It does use a little bit of oil, around 1 quart per 1000 mls.
I remember my flatheads using a quart of oil about every 1000 miles. That was over 60 years ago, and pretty normal.
I have one that drinks as much oil as gas. Not positive what is going on with it since it doesn’t smoke. It was rebuilt about 10,000 miles ago, but it has NOS early valves and split guides. We reringed it about 5,000 miles ago and it didn’t make a difference. I’m sure it’s those guides now. I have a nice new L-100 cam to put in as soon as I spring for a set of new late style valves and guides.
The .030 over 255 in my '41 Merc uses about a quart in 1000-1200 miles. I've put 26,000 miles on it since I replaced rings, bearings, valves and guides and it's been steady at this consumption rate. Seems normal to me.
A flathead is supposed to leak about 10 drops a minute at 30mph. So it leaks ~20,000 drops --- a quart --- every 1000 miles.
off topic a bit but crazy question. Why do older model year engines use so much oil while newer ones do not? If it is not leaking what causes older year engines to use oil?
The fit and tolerances are much tighter in the newer designed engines. The loose tolerance allows oil to be ****ed into the combustion chamber. Every flathead leaks and marks its territory. My flatheads use about a quart every 1000. even the newly rebuilt one.
It is primarily related to the quality of the seals, gaskets and poor emissions systems (especially in the 32 - 48 engines). The road-draft system in 49-53 was better than the earlier ones (where the oil-pan frequently dripped out of the front pan breather). The rear-main and front timing-cover that used the original rope-seals always tended to leak a bit . . . which is one reason Ford but that big ole' cotter key in the earlier oil pans (underneath the flywheel). Also, as other's noted - manufacturing tolerances were nowhere near as uniform and consistent as we see in today's engines. Lastly, a lot of today's higher-performance engines are 'sealed systems' - with vacuum pumps and dry-sump oiling systems - they have no emissions that vent to the outside world.
Here's something interesting. On the last engine I built (a 258 ci 8BA with the attendant "speed equipment") I was very careful in fitting the rope seals, using the gauges and even the knife supplied with the Fel-Pro gasket set. Unfortunately, I suc***bed to the "newer is better" syndrome and installed a new replacement oil pump from Speedway Motors. The engine did not leak a drop, but had what I considered lower than expected oil pressure. I very carefully removed the oil pan and replaced the pump with a tested original one. After carefully replacing the oil pan, I was gratified to see that the oil pressure was up to my standards.. However, the engine had developed a slight leak at the rear seal. I may have done something wrong, but I sincerely doubt it. With the price of gaskets these days, I guess I'll live with it, but damn, it seems the seals are "one and done"! On my DD '51 Ford coupe, I installed a good running '51 Merc I had come across. It has satisfactory oil pressure and operating temperature. If I drive it locally and keep the speed down around 50 mph, I'll go 3 or 4 tanks of gas before it need a quart of oil. I usually drive the car to my high school reunion every year (a trip of 180 miles one way over some good highways). I have to run 70-75 mph to keep up with traffic. During these trips, it takes a quart of oil every gas stop.
The early 2 piece guides will let the intake valve **** oil up through any gap between the mating surfaces and can do the same if the guides or the guide bores are not fitting tight. Use the later one piece guides and modern valves. Don't neglect to put the rubber seals around the guides. Also, in the good old days, chrome rings had a problem seating in old engines. Bad crankcase venting in the older engines didn't help, either. I have always had the best luck using Hastings cast iron rings. My rebuilt 8CM engine has about 5K miles on it and does not use any oil. My 8BA engine sat in a barn for 30 years. It needed a valve job on the left bank, Modern guides and seals, new valves and I resurfaced the seats. It doesn't use any oil. A little oil use is to be accepted. A quart a thousand used to be considered good.
Just as off topic and jokingly (Based in reality though), you must have never owned a late 90s to early 2000s Cadillac northstar motor, any gm eco-tec motor or a 15 to newer Kia/Hyundai. All lose a quart every 1k miles it seems. I'd say Pete & Bored nailed it though. Better machining, tighter tolerances, better quality sealing materials.
The manufacturers knew how to make engines not burn any significant amount of oil. Then came the modern times and fuel consumption became important, manufacturers looked for ways to reduce engine friction and we got things like piston rings with less tension, so now we're burning more oil to save fuel... Great.
Hello, For all of the 5 years I owned my first hot rod 1940 Ford Sedan Delivery, I had a wonderful, but surprising experience. Previously, we had a lot of SBC motor experience, Chevy/Ford builds/rebuilds, repairs, etc. But no Flathead work. The only thing we knew was that it started and ran every time we got into the seat to go to the beach. It never faltered, ever. I could never use the “My car did not start…” if I was late to my first cl*** in school. Everyone saw it daily as it was always in parking spot number 1 to three in front of the high school. It was the replacement Flathead motor in what was once one of the coolest powerful hot rods in Bixby Knolls during our time there. A new build in 1960 and it was very cool when the 348 Chevy motor rumbled into the parking lot of the drive-in restaurant for all to see and hear. An old junior high school/high school friend had spent the last half year building this sedan delivery. I instantly liked the looks and sound. Others, the sound, yes, but a sedan delivery? For a teenage cruiser hot rod, for the weekly Cherry Avenue Drags excursions? That would have been nice, but for 90% of the young folks there in that parking lot car show nightly, a sedan delivery was for the neighborhood TV repairman, the milk delivery guy, and the myriad of local plumbers. Not a teenage hot rod. Jnaki I bought the sedan delivery with a Flathead motor as a replacement. The owner’s asking price was way above my pocket book. So, he put in the Flathead motor and it still had the LaSalle floor shift transmission. It ran and powered us all over So Cal coastal waters from Santa Barbara down to San Diego and even across the border checkpoint to the mysterious Baja, Mexico surf spots. The amazing thing was, it never leaked any oil on our mom’s pristine concrete garage floor. (she mopped the concrete floor as it was also her laundry area next to the cars usually parked in there) Or the concrete driveway or parking area. It was a solid running motor. There were no leaks, did not burn oil or smoke white or any color coming out of the tail pipes, other than early morning mist. Underpowered, yes, but so reliable it was overlooked when chugging uphill on a Coastal Highway grade to get to our favorite traveling surf spots. But, it did start taking a quart here and there. Then it was more quarts on long road trips, etc. Puzzling to say the least. No inkling of any drips or burning oil. So, the local Flathead mechanics took a look and were also puzzled at what was happening. It sounded great, ran great and gave me nothing but security while driving anywhere from coastal waters to downpour drives to our high school. Note: The can of oil usage was getting well beyond what my teenage pockets could afford. So, I started using reclaimed oil from our local gas station. The oil was good used oil, recycled many times to get “stuff” out and then resold as used oil. The color was similar to the oil coming out of the quarts of Valvoline. The motor ran cool, and for our long road trips, had a stash of gallon oil containers full of the low cost reclaimed oil. We never found out why it did what it did with the oil. But, it was a fine running motor and the memories of always starting with the first turn of the key was important, when hundreds of miles away from home in deep empty Mexico beaches… When I sold the sedan delivery to another young guy, I told him of the oil usage and he did not care. As long as it started and did not leak oil, he was a happy camper… YRMV
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