“They found the wear on the engine was quite accelerated”
I hope the one or two fellows that think old engines should be run without a thermostat are reading this.
I have a neighbor with a '90 Accord 5-speed. Every morning he starts it up and heads right out to work, revving high and heavy throttle. Now he leaves a faint trail of blue smoke. I don’t care enough to point out the error of his ways.
This test could have been conducted in 1955 when engines needed rings a 30K even when treated gently.
We must seperate “automotive lore” with the enginnering in use today,in both materials, design,tolerences and inprovements in oil additive packages.
I am not commenting on why the Accord smokes as the possibilites are numerous.
Years ago, Consumer Reports, in the automotive issue, listed the feet per mile of piston travel in each of the engines of the cars it tested. A car with less piston travel per mile would theoretically have a longer engine life. Consumer Reports hasn’t provided this statistic for at leat 20 years, probably because it is now irrelevant.
One feature that was offered on many cars was the Borg-Warner overdrive in the 1930’s through the early 1960’s. This option was particularly popular on 6 cylinder engines. The overdrive could be engaged at about 30 mph and reduced the rpm of the engine. While increased fuel economy was the selling point, I always thought reduced piston travel per mile with the lower rpm of the engine was the real benefit of the overdrive. The Willys Jeep station wagon introduced after WW II came with the Borg-Warner overdrive as standard equipment. I’m reasonably sure that the overdrive was provided to reduce the rpm and hence lengthen the life of the four cylinder engine.
I conclude the Forum is not in agreement on the benifits of operating at reduced rpm,hence all the disagreement about getting better mileage at higher speed,as some claim the lower rpm is not the engines “sweet spot”.
“In theory the engine that spins less revolutions over the years should last longer. Yet, this is only one variable of many that determines how long an engine will last. Other variables are much more significant and have greater impact on longevity. The frequency of oil changes, number of short trips from cold starts vs lots of highway miles, etc. are all much more important than the difference in rpm in top gear.” This Is all true, however why would one take better care of a 4 and neglect a 6? The OP is probably assuming each one would get the same care, thus the 6 would have the advantage.
one other thing, why do you think a 4 will warm up faster than a 6 or 8? Is it because it has to work harder?
Joe, why didn’t they test it at 70 mph (higher rpm) and see if the bearings were still as good as the car that went 60 mph? If higher RPMs don’t harm an engine why do most race cars have to be rebuilt before every race?
Triedag, you are RIGHT-ON!!
Right-on about piston travel not being the main input on engine life of a modern 4cyl or v-6 engine.
What are you saying Triedag is right-on about Elly?
Haven’t we already been through this? A smaller engine warms up faster because it is smaller, holds less oil, and holds less coolant. With fewer cylinders, there is less metal to warm up. I have two 750 CC motorcycles. One is a V-twin and the other is an in-line four cylinder engine. Both are not fuel injected, so I have to warm them up using a manual choke. The V-twin is ready to ride after 30 seconds. The I-4 takes at least a minute with the choke on, and even then it runs better if I let it idle for another 30 seconds with the choke off. The I-4 takes longer to reach operating temperature than the V-twin.
As to why they don’t put four cylinder engines in the Fords, Chevys, and Dodges you mentioned, you should ask the engineers at those companies. Perhaps it is a marketing thing, because the people who buy those cars want more cylinders.
Instead of rehashing old arguments with me, you should start a debate with one of the other people in this thread who think a four cylinder engine will last just as long. Take your pick. There are many of them. You can choose from:
Please pose your questions to people who have not already answered them.
Because they are hand gernades with the pin pulled just waiting to explode.
What is a “4 cylinder thinker?”
I think driving a 6 is more fun than driving a 4, but I think they will both last just as long. Reliability stats show it. Cars that come with both 4s and 6s have roughly the same reliability ratings. Both will last just as long. Does that make me a “4 cylinder thinker?”
Exactly. Race engines are heavily modified to get the most power, not for longevity. Modified timing settings and racing cam shafts are two modifications that come to mind.
I agree. Triedag is right about engines made 45 years ago. I also agree with Triedag that the amount of piston travel per mile in today’s cars is “irrelevant.”
The Ford company tests I referred to in this thread occurred in the late 60/early 70s. I mentioned it because it supports the common replies that “piston travel amount” is not a dominating factor of engine wear.
In high RPM race cars, the amount of piston travel is much more relevant. I’m fairly certain the forces on engine parts grows non-linearly with engine RPM.
I would believe that far more important than the number of cylinders is the maintenance received and the design. You can make a very durable 4 cylinder or a very short lived one.The biggest influence on engine life is driving and maintenance habits because most engine problems are owner-inflicted.
You see both long stroke V-8s and short stroke 4-bangers reaching 300k miles so in my opinion it’s a wash.
I have to respectfully disagree that engines in cars made many decades ago needed to be overhauled at a low mileage. Some of the older cars both my parents and I have owned had no engine problems even with high miles on the odometer.
Both my 58 Thunderbird and 59 Impala had close to a 100k miles on them when I bought them and neither used a drop of oil. Even an old 120k+ miles 60 Chrysler New Yorker had zero engine problems; and I bought that car for 10 bucks.
Then, as now, people thrashed their cars. Given the carburetion, leaded fuels, and motor oil technology, failing to religiously take care of their cars could cause engine problems at an early age. Sign of the times I guess.
Look at it this way,how many mechanics in Dealerships or even Independants have heavy line (internal engine repair experience?)The number has dropped quite noticably even in my lifetime. At a time it was very common for many if not all mechanics to have internal engine repair experience,why,because so many engines needeed internal engine repair,almost so frequent it could be considered maintiance.
No arguing going on,we are discussing different experiences, viewpoints.
I wasn’t wrenching in the 40’s and 50’s but I asked my father (he is 79) and he does recall early (in comparison to today)valve and ring jobs on cars from the 40’s and 50’s.
For me in my era I do remember a standard that is not true today. When you were told as a mechanic that the car you were working on had 100,000 miles on it no one criticized you for concluding just about anything could be wrong with the engine. Today when you hear the 100K figure it hardly raises a eyebrow and justifibly so.
My dad bought a 1954 Buick in 1955, the year I started high school. I then bought the car from him nine years later when I was in graduate school. A couple of years later, the car went to my brother. When we sold the car, it had 160,000 miles on the engine and had never had the heads or pan off the engine. It didn’t burn oil and ran well. People at the time thought it amazing that a car could travel that many miles without engine work. Today, we expect engines, with reasonable maintenance to go at least this far without internal problems.
One problem that seems to have come back is engine sludging problems on certain cars. I remember in the late 1950’s through the mid 1960’s that the internal oil lines would plug up on some overhead valve engines and there were outside oil lines that could be installed to the rocker arm shafts to bypass the internal lines. I had faithfully changed the oil every 2-3000 miles in my 1965 Rambler and had problems with oil getting to the rocker arms. I couldn’t find an outside oil line kit, but I did find an independent garage that pulled the cyliner head and cleaned out the oil passage in the block for $38 including a new head gasket. This garage did a lot of work on light and medium duty trucks and apparently the same engine was used in some International trucks. Appperently, there was a bend in the oil passage in the block where sludge could collect.
Whitey, allow me to ask one question, is both or either one of your bikes water cooled? Also a 4 cylinder has less to warm up but a 6 or eight has much more to warm it up, namely more cylinders firing, and larger displacement
Right, high RPMs and longevity just don’t mix.