Technical Engines that like to be worked: fact or fiction

Build two engines the same. Put in the same vehicles for tow. Use one to tow to its limit, other to commute with.

Stands to reason the vehicle that didn’t tow, engine would last longer.

Finn said why

 

I guess it’s all relative to design.
That’s why we have so many of em.
A straight 6 or 8 behaves differently than a V8 or V6. Bore and stroke combos. Some combos make torque on the low end, some like lots of RPMs.
Not driving them is as bad as abusing them in my worthless opinion.
My aunt had a mid 70s LTD. 351w. She may have averaged 1000-1200 miles per year. Hardly ever came up to temp. She lived in town and drove it about a 1.5 mile round trip to the store.
My cousin bought the car in the late 80s and started driving it to work. Typical 18 year old driving.
The engine started having issues, engine was gummed up. We removed valve covers, cleaned what we could and ran some “cleaners” through it. Got a little better but we ended up pulling the engine. Less than 25k miles and had tear it down. Bores were good but the crank had some scratches and some pits in the bearings and was almost stopped up oil drain wise. I guess it never could remove the condensation out of it.

 

I started this thread in hopes to make some good car related conversation and to get some people away from the election stuff. There is some really interesting studies explained above. In my opinion the proper application for an engine makes a difference in it's longevity (obviously maintenance and operator play a bigger role). One engine in mind (don't shoot me as it's not HAMB friendly), are Detroit 2 strokes..... I've heard it said LOTS that they last longer if they get driven hard. But I also know those engine have a narrow power band and kind of need to be driven hard. Longevity wise I honestly can't conclude either way. I would say there are 4 driving types and results of them....1 baby them as grandma did and lead to problems from sludge and condensation buildup and collapsed pistons from not reaching expansion before shutdown too much. 2 driving as dad did and have an overall good life with good maintenance and no carbon buildup. 3 driving as brother did and likely throw a connecting rod out the side. And 4 driving like an fleet employee where they get driven pretty hard but not quite to the point of blowing up. These I suspect are worn out badly too. These are general descriptions with discrepancies noted....little old lady from Pasadena.

 

So many variables, both in the engines, and in the drivers.
All engines when properly tuned and set up, have a "sweet spot" where everything works just right.
The key when building an engine is to choose cams, carbs, compression ratio etc. and not to forget gear ratios and tire size, to end up with that "sweet spot" at the speed where you want to drive it. It's about having all of the components working together in harmony.
Some get there by accident, others are just lucky, some should start again.

 

I dated a woman that liked to be worked hard and she could go on forever. If she were an engine I'd say she was built for low end torque. Get her warmed up and hang on. Had great compression. Oil pressure good. Had points but never a timing problem. Wasn't bad on gas.

 

I am 66 this year. Suffer from post polio syndrome. My neurologist says that I should have never done physical labor for a living, but I am able to do what I do because I did. On a good day I am in more pain than most of you on a bad day but I am functional because I worked instead of driving a desk.

Do I feel better because I worked for a living? That I cannot answer but I am able to get around better than other people with my condition because I did.

Now on to mechanical things. You run an engine in its power band. If you build a mill that pulls between 3500 and 5800 (just nominal numbers here) that engine is never going to be happy running @ 2200.

 

My first car was a 50 Ford 6 cyl. Needed a rebuild & the "old timer" who did the shop work said : make it work during break in. There were hills near by & he said go there & lug it up hill....after 100 miles, run her up hard once in a while for another 100, then change the oil. I did that and that 6 outran many V8s and never used oil while running fairly quiet & cool....two owners after me drove crap out of it and it was sold away from here. .02 cents or nonsense........

 

Two Stroke Detroit’s are an anomaly. Due to their design, they sound like they are working harder than they are. On the top end, they might have 500-800 more RPM than a Cummins or Cat, but since they have a power stroke twice as often as a four stroke engine, they make more noise. To a diesel guy like Blues4U or me, their sound is music. The old drivers used to say, To properly drive a Detroit, slam your hand in the door real hard, get good and mad at it, and drive it like you hate it.


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Engines have a sweet spot where they like to run! It’s not good to let an engine loaf, but it’s not good to overwork it either. This is more true with our old engines,than the new modern computer controlled fuel injected engines. It is not good for any engine to idle! Period! Running an engine too slow, especially an engine with a hot cam, causes the cam to be “ impulsive “ . Also carburetors engines don’t really run “ right” at low speeds and dynamic compression is also low at low speeds. This all add up to problems , down the road.






Bones

 

80% nitro and the highest rear gear ratio you can get and it will work for you!

 

My uncle owned a machine shop for years. He showed me a little 4 cylinder Datsun pickup that an old man owned. The old man bragged that he never drove it over 55. The valves looked like they had been hit with a hammer. Lugging an engine does as much damage as WOT at every stop light.

 

In many instances you are correct, but I know a few guys that are on disability with bad knees and backs from doing concrete work for 30+ years. They are in their early 60’s now and struggle to get around. Very well your ability to do things now was overcoming your disability you had/have.
I didn’t mean to imply that a body or engine, would last longer sitting at rest doing nothing, my last reply I made was I was inferring to and probably should have made that reply first

 

Funny you should say that , in colder climates ,diesels , especially OTR , never shut them off , they let them idle while they're sleeping , I'd guess the short run delivery trucks have more idle time than running ??

 

Cause they're so hard to get started!

 

That too !

 

Is this why engines that have run on LP look new inside?

I have a pal with a hemi that came off of a pump, running natural gas for ages. After inspection, he put it back together, popped in a new cam and a set of gaskets and right into his car.

It looked incredible inside.

It's been flogged on for 5-6 years with no issues.

 

That's because propane burns so clean, gasoline & diesel are very dirty in comparison. Natural gas is not the same as propane, but it too burns much cleaner than gasoline. It burns at a very high temperature though, so it can cause nitration of the oil leading to sludge.

 

The reason they can do this and get away with it is, the very next day that engine is worked at 100% capacity for 16 hours!
I fought this battle with my drivers! I told them to never idle an engine! Either shut it off or grab the hand throttle and turn the engine at about 1500 rpm.
That way the alternator will work, the fan will work, the dynamic compression would be high enough to clean the combustion chamber clean.








Bones

 

jaracer has it right... lug a diesel and you will see white smoke pretty soon! Even though they max out at around 3000 rpm you have to keep the pedal to the metal. That's why they have 15 spd boxes in them.

Gasoline engines, IMHO, last the longest when they are properly matched to the weight of the vehicle - put 1.8L 4 banger in a 7000 lb. caddy and see how long it lasts, but the 472 will cruise all day at 1800 rpm. That 472 wouldn't be the best choice for a Honda Civic (not to say people haven't done it).

I have a 2.5L, 4 cyl Toyota Camry that has been designed to run at 1500 rpm on the highway, it gets incredible gas mileage (8 spd automatic), yet it redlines at 6500. I will bet that it is still going strong at 250k miles - why: 1) most engine wear happens at startup (bearings) and nowadays, engines have excellent oiling systems designed for synthetic oil (adding an accusump is the old fashioned cure for this); 2) modern engines run extremely "clean" due to advanced engine fuel management, variable ignition and valve timing - oil change intervals are up to 10,000 miles; 3) the most destructive thing for a gasoline engine is "pre / late" ignition which has been virtually eliminated.

 

LOL we all speak or think in generalizations and for the most part it flies. I am way worse at that than most of us I am ashamed to say. There are almost always exceptions to the rule.

@Budget36
When I fall into a generalization especially if it is a dangerous one it would not hurt for you to remind me. Your alright and smart enough to get it right.

 

the newest vehicle I have ever owned is a 1998 Blazer. 2000 RPM's @ 70 MPH. 3.40 gear, overdrive and 235 75 15 tires.

perhaps the GM engineers have fixed this terrible problem of low RPM at cruise speed in newer vehicles... or could it just be that the entire premise of this thread is just plain wrong.

 

You are right on, jaracer! I couldn’t have said it any better. But it’s hard to convince people, because everyone has an “ uncle “ that lets his diesel idle all night to keep warm!
I fought this problem for 33 years on the Fire Dept. The guys would let the engines idle all the time. Most runs were balls to the wall out of the station with a cold engine, reach the fire scene, park the engine at an idle, check out the usually false alarm. Drive back to the station.
And any time they were on stand by, the engine idles.
This all contributes to what I called Fuzzy injectors , gummed up rings, dirty valves. I had one triple nickel Cummins that smoked like a freight train! Got put out of service because of it. Boss said overhaul it! I told him to let me try something. I changed oil and put in some of my miracle snake oil and got on out stretch of four lane and drove that engine wide open for two days. Ten miles up turn around and ten miles back.
Brought the engine back and had the state of Oklahoma puff it, it passed!
Same engine operated in different ways, with different out comes.
Two tanks of fuel and an oil change vs a $5000 overhaul!

Just my experiences.








Bones