Durability opinions?
 

Over in another thread, some of us made reference to how long the GMC Vblocks would last, so thought I'd open this thread for your opinions.
Most of the motors I'm thinking of are those used as stationary power for irrigation wells.

Many of us locals have wondered how any engine, regardless of make or size will last much longer doing stationary duty than in cars, trucks, or such.

Is it the constant load, rpm, temp, and lubrication?

Why?

What do you guys think?

Re: Durability opinions?
 

Absolutely the duty cycle is important. GMC took an onroad design and applied it to a stationary source. Running at a steady rpm with steady load removes the acceleration & deceleration stress of street driving. Having a fixed load (water pump) removes the variable of accelerating different loads, too. Finally, the operators were trained to maintain the pump engines; as opposed to junior trying to get dad's ole farm truck to beat his buddy at the stop lights (provably not a huge issue for the GMCs).

Re: Durability opinions?
 

That's been about the majority of conclusions most of the guys could come up with here.
I know it's amazing how long even a 292 Isix Chevy will run a small well compared to in a vehicle.

The guys that had Vblocks were really ticked when GMC discontinued them, in spite of the heavy natural gas consumption.

Re: Durability opinions?
 

The Toyota Prius hybrid power system uses the 4-banger as a generator. Since it operates at two rpms, the engineers made the block thinner that a conventional motive engine. They haven't been in use but a decade, but it is a practical demonstration of the difference in stress levels.

Re: Durability opinions?
 

Greetings Club Members!

Engine durability has a lot to do with operating conditions. Engines such as the ones we are talking about here will last much longer pulling a steady load, and operating at a temperature that will disperse condensation from the engine. On another note, can you imagine if GM had decided to build these engines out of aluminum just how much shorter their useful lifespan would have been? I'm not a big fan of aluminum engine blocks, especially after hearing the horror stories from mechanics about GM's "oh so great" Northstar engines!

Re: Durability opinions?
 

I guess that's the reason they used so many tranny gears, and narrow rpm spread on the engines in the early days in over the road trucks.

Back in the early 60s, I drove over the road, with GM Detroit Diesels, 220/250 Cummins, and they used 10 and 15spd trannys/w an even shift of 300rpm from top to bottom, so if you shifted right, the motors always turned 18-2,100rpm.
Mack trucks used the same principle with their tri-plex and duplex transmissions. I always like to ride with a driver that was good on-the-box, but never got the hang of split shifting them very well.

My son runs a Peter-built with a big cat and he said the torque curve is 1,400-2,200/w much more hp, so not near as much shifting. So they've improved them a lot over the years, so I guess they still use the same principle to hold a near constant engine speed as we've talked about above.

In my younger years, I sometimes wished I could have studied to be a mechanical engineer, and somehow landed a job in research and developement to understand the workings of this type of stuff.

I loved the old Detroits, but hated sleeper time, as they'd pick up a resonate vibration in the cab at a certain rpm, and would almost hurt your ears. Other wise, was a easy engine to shift behind. Also, quiet a power house for their day. I drove the old '66 CO4000 Internationals.

Thanks for your replies, and interesting, too

Re: Durability opinions?
 

GM's LS V8 engines are all aluminum and they've seemed to have good success with these powerplants to the point of superseding the Northstar engines.

Re: Durability opinions?
 

It's not the materials. It's how you make it.

I'm sure many of us remember the throw away 140 CID aluminum Vega mill. How many remember when it first came out that the engine fabrication involved new materials and processes developed with Reynolds Aluminum?

It took a while for Detroit to look at a aluminum again, thanks to the Vega.

Meanwhile as all those "push 'em out the door as fast as you can" Vegas were burning gallons of oil, oxidizing away, and generally self-destructing, a German car maker was planning a new V-8 luxury sport couple and the engine would use the Vega's Reynolds materials technology.

THe Porsche 928 was a great success. More often than not it's all in the execution...

Now as to how long my V6 will last... I'll just say I'm not planning to ever get a truck to replace it. (That's why I bought the V6!)

Re: Durability opinions?
 

Like 'Yote said, the torque range is the key to performance and longevity expectations in all engines.
If a guy was to monitor an engines emissions and performance in both stationary and mobile duties, he could clearly see why stationary duty is much more conducive to engine life.
Once a stationary engine is dialed in under load, not much changes inside the combustion chamber or the crank case.
Of course, in a motor vehicle app, from 750 rpms to 5K rpms....constantly under change...in a nasty state of turmoil.....temp changes and so on...etc.
And of course, a stationary is usually under the direct care of a mechanic, not missing out on any PM issues....thus much happier for longer.

Blah Blah Blah...
I kinda rambled on there for a minute.