Haha, it's all good BB, I guess my sense of humour was also lost in the single dimension that is text only.
I am also a bit iffy with my thoughts on the longevity of the motor though, but there aren't too many complaints about it around the place. I did find a "service bulletin" that was issued to dealers in the 'States concerning the EXi series of motors. Here it is for those whom are interested:
Check and Add
A few years ago, Briggs & Stratton’s smallest lawnmower type engine, the L-head 90000 Classic series, was phased out. The same fate awaits the 120000 Quantum L-head engine family. Neither engine would be capable of meeting ongoing government emission standards.
A new 9 cubic inch OHV engine was designed and built to replace the Classic engine and a 10 cubic inch engine has just been introduced to replace the Quantum.
Most of the product the company sells comes from these two engine families so it was important to meet current and future customer needs and expectations.
After extensive market research, a list of features most desired began to take shape. It probably comes as no surprise that the engine needs to start reliably and the starting procedure must be simple. The top 4 or 5 comments fell into this category.
That the engine needed to have sufficient power was the next most popular requirement.
The 3rd most important concern highlighted the consumers’ dislike of having to change the engine oil. This is perhaps not too surprising as it can be a messy procedure and somewhat intimidating to those with little mechanical experience.
Armed with this information, the engineering departments went to work to see if we could make an easy to start, powerful and reliable engine that you never have to change the oil.
Now, if you’re a technician that’s worked in this industry for more than, oh, shall we say 2 weeks, you’ve seen the damage done to an engine run with low oil, maybe no oil and possibly the wrong oil. It isn’t pretty and it’s more often than not a fatal error.
If you’ve made a career in this business, you may have come across a customer that has actually admitted to never performing maintenance on their lawnmower other than adding a little oil now and then. These engines generally fair better than the no or low oil crowd but often exhibit premature wear. This is generally caused by the failure of the lubricant and wear particles inside the engine.
To make a long story short, engineering found that the oil most often failed from molecular breakdown caused by high temperatures and foreign material.
Some of the wear particles inside the block were left there by the manufacturing process, others were machining asperities from the break-in process and still others from outside the engine due to poor maintenance issues, usually in the air intake system. Regular oil changes generally keep these items to a minimum.
The task of building an engine that would function well without oil changes boiled down to:
· Reduce the oil temperature
· Clean up the inside of the engine
A big help in allowing oil to survive without being changed is that modern day oils are far better than they were 10 or 15 years ago.
The EXi engine design reduces oil temperatures in several ways.
· The OHV design of the EXi runs 10° F cooler than the L-head configuration. Cooler oil means a slower decay of oil properties
· EXi design sheds external debris such as chaff better so cooling fins remain exposed to airflow
· The flywheel scroll and flywheel fan focus air on the fins for improved cooling ability
The engine design also reduces oil consumption and internal debris by tightening up internal clearances.
Before manufacturing began for the EXi engine, the Poplar Bluff, Missouri plant was completely rebuilt with improvements to provide better control over the manufacturing process. The cylinder, sump and cylinder head machining lines are new and a state of the art piston machining line was added.
As a result of efforts to tighten up the manufacturing process, engine oil consumption dropped off significantly.
Typical oil consumption comparisons:
- 675/725 Quantum averaged an oil consumption of .3-.4 ounces per hour
- EXi Series consume an average of .1 ounces per hour.
– At .1 oz/hour it takes 40 hours to get to the “add” mark on the dipstick
– Adding 4 oz of fresh oil replaces 25% of the oil
One of the first elements of engine lubricating oil to deteriorate is the additive package. By adding oil as needed, these critical materials are refreshed.
We still count on the customer’s involvement in that they have to check and add oil when necessary. In fact, the concept of not changing the oil only becomes feasible if the customer rigorously performs other maintenance such as a yearly air filter change, replacing the spark plug, keeping the cooling fins clear and of course, keeping the oil full.
Like you might be thinking right now, “I don’t know, this still doesn’t sit right with me” the same thought will be had by many customers, particularly those that have diligently cared for their own equipment over the years.
Don’t worry; they can still change the oil if they want to! But, if it helps, we did do our due diligence by sending oil samples to an outside lab from multiple EXi engines. These each ran for 600 hours without an oil change [only adding] and the oil was still reported as serviceable.
Bear in mind, the Check and Add feature only applies to the EXi engine.
Seems reasonable. And to be honest, marketing aside, I think Briggs has maybe put some engineering work into accepting that almost no one will change the oil, but will top it up from time to time.
Last edited by Mystyler; 24/08/19 01:53 PM. Reason: Formatting
