Stock or modded, what's better, lasts longer?

[srcarr52]

A healthy engine is a happy engine. Generally modifying a saw and releasing more of it's potential will help it's life, but it's really all depending on the operator and the degree of modification.

A general woods porting and getting the tolerances (like squish, port radius, and port chamfer) to more acceptable ranges will increase the life of the saw because tightening the squish will make the combustion less explosive which puts less stress on the internals. The cleaner burn will run less deposits through the engine which allow the oil to get to the parts that need it easier and the saw will run cooler (which is a big deal in an air cooled engine). Plus the little extra power makes it so the user isn't lugging the saw as much which greatly increases the life of the bearings and piston.

The only down fall would be increasing the maximum RPM of the engine, this will cause more stress on the internal but most people don't let them get way out of the working RPM range for long.

Obviously more extreme modifications like finger ports, port timing modifications for much higher max torque RPM and pipes may start to decrease the life of the saw.

 

[spacemule]

because tightening the squish will make the combustion less explosive which puts less stress on the internals.

Bull spittle.

 

[srcarr52]

Bull spittle.

That is what the combustion chamber/squish band is designed to do, but if there is enough room for the flame to travel into the squish band area before TDC or slightly after (before the crankshaft is at an a decent load angle) then you'll have higher force spikes in the internals then if the tolerance was at a tighter value. Most of the energy of combustion is wasted with forcing the crank down into the bearings instead of spinning the crank because the angle of the crank at the time of the mass gas expansion.

 

[parrisw]

Although I agree partly with what Tom said, I still don't think its 100% right. The taking a car over 100mph will reduce the life of the engine by 10,000mi, is bull crap, if that's the case how come the fast cars I've had and built are still running? I drove them like I stole it, raced them, you name it I did it, was hard as hell on them.

Lets take a EPA clogged up saw, run it stock, the saw is so backed up clogged up, it'll run hotter and reduce its life, carbon up quicker, open up the muffler, I'm pretty sure it'll last longer, isn't that a mod? Some new cars are the same, I've seen a new Mini cooper cylinder head, the car would almost not run anymore, it had so little power, finally they took the engine apart, the ports were almost 100% completely blocked off with carbon!!! Crazy, never seen that before on such a new car, so is the EPA clogged up saws really better?? I say not.

Lastly, people will do what they want, I'm still going to mod my saws no matter what anybody says on here, and so will everybody else.

I do agree that with producing more power will shorten its life, by how much, I don't think anybody really knows.

It would be cool, to say give a logging company 2 441's one stock and one modded, run them for a year, then take them apart and have a look in there.

 

[srcarr52]

It would be cool, to say give a logging company 2 441's one stock and one modded, run them for a year, then take them apart and have a look in there.

I afraid that wouldn't be a fair comparison. They'd beat the modded saw like a red headed step child and never use the stock saw.

 

[parrisw]

I afraid that wouldn't be a fair comparison. They'd beat the modded saw like a red headed step child and never use the stock saw.

ha ha. Ya I thought about that. I'm sure it could be done though, just have to have a willing party.

 

[thomasjf]

Apples vrs. Oranges

My personal reason for modding my saws has little to do with longevity, but rather production. A true measure of our tools is the work they do and the time it takes.
And a true measure of a saw is not how many hours it lasts in its life, but the amount of work it does during that life and the time it took to do its job. The big plus to me with modded saws is the time and energy savings on my tired old body. An all day job with a stock saw turns into an easy morning run with a modded saw. Mod that saw for increased torque and add a more aggressive chain and you have a tool that will get the job done quicker and save wear and tear on the body, and leave time for a nice long nap in the afternoon.
Now, which saw will last the longest, a stocker with a stock chain that spends 20-25 seconds in the cut, or a modded saw with an aggressive chain that can do the same cut in 15 seconds. It's not really the number of years the saw will last, but the number of cuts it will make in it's life and the time it takes to make those cuts.
I will say, my stock saws will undoubtedly outlast my modded saws. For one simple reason, the stockers never come off the shelf.

 

[MacLaren]

Well men, ill go with what Eric Copsey and Tom Hall has to say about, and that's pretty much the end of it Imo.

 

[nba123]

I was told by a saw builder on the west coast with a great rep that I or U would get about a year of commercial timber cutting out of a ported 372 xpw, he really only builds for timber cutters and mainly builds 372xpws. My xpw is stock exept for muff and I love it, its power to weight is great IMO if I need more power I get a 385 if that isnt enought I get 395 and so on. I have a 084 with the works done to it and I race and use it to work with. I would venture to say if u ran it all day next to a stocker the stocker would out cut it, I no thats a strech but it absolutly eats the fuel and u would be fueling and the stocker would be cutting and its hard to make up 4 or 5 min or more. I say if you dont smash it before your years up ur doing good. I think as far as it is for me more time could be cut with better planing beter work habitts and technik sometimes its easier to just get a faster cutting saw than to have a better plan. If U R allready at max efficiancy then a ported saw would probly benifite U. This is all just opionion I would love to see some real dyno test and longjevity test. Maybe we should ask mythbusters. Maybe if money was no object all mine would be hoped up but im in it to make money not spend it. Thanks James

 

[gemniii]

There's lots of types of mods.
I'm all in favor of wringing performance out of good equipment if it's cost effective to me.
I was into overclocking PC's about a decade ago, I'd run them at 150% rated speed and they would burn out in two years. Of course in 2 years all the CPU speeds went up 200%.

I run my VW TDI at high tire pressure, trying to get that last drop from the gallon. I'm seriously thinking of getting a $500 software tune to further alter it once it's off warranty.

I've "dremeled" my saws mufflers and put a DP on one 660, and bought a snellerized 660 w/ a mild muff mod. Both of my 660's seem to cut about the same, and they both SEEM to have a lot more power than the one DP'd 660 was "stock".

But I would hesitate to get the other ported for the going cost because I don't think I'd see the benefit, and there's no dyno around to really quantify the differences. Also the going costs for a port are about half the cost of my used saw.

And I DEFINITELY disagree w/ those that write that the mfg does it all and does it right. Engineers do things, hopefully they try to do it right. But companies do things for profit, and many a corner has been cut to save a little change, meet a gov't rule, etc.

How many know the higher output oiler is now a REPLACEMENT on the 650 by a Stihl TI bulletin?
http://www.arboristsite.com/chainsaw/109369.htm#post2593011

Most of us know the DP muffler for the 660 is standard in Oz. Do they have some special atmospheric condition down there that requires a DP muffler so the saw will run like one in the US? Or does Stihl have to throttle the saw in the US?

Looking at some of the OEM exhaust ports posted in the mod threads do the mfg make them rough inside on purpose? Or is it just to save a penny?

And what is it with the carb limiters? That's GOT to be an engineer inside joke.
Engineer 1

Government says they have to keep the saw tuned lean

Engineer 2

BUT it won't run worth a darn

Engineer 3

Let's put a warning label on saying DON"T TURN THIS KNOB IT MAY ALTER PERFORMANCE, then when they turn the knob the saw runs well and our butts are covered

Engineers 1 and 2

Nah, that's too obvious, let's put a little piece of plastic on it and make them find it

 

[andrethegiant70]

My personal reason for modding my saws has little to do with longevity, but rather production. A true measure of our tools is the work they do and the time it takes.
And a true measure of a saw is not how many hours it lasts in its life, but the amount of work it does during that life and the time it took to do its job. The big plus to me with modded saws is the time and energy savings on my tired old body. An all day job with a stock saw turns into an easy morning run with a modded saw. Mod that saw for increased torque and add a more aggressive chain and you have a tool that will get the job done quicker and save wear and tear on the body, and leave time for a nice long nap in the afternoon.
Now, which saw will last the longest, a stocker with a stock chain that spends 20-25 seconds in the cut, or a modded saw with an aggressive chain that can do the same cut in 15 seconds. It's not really the number of years the saw will last, but the number of cuts it will make in it's life and the time it takes to make those cuts.
I will say, my stock saws will undoubtedly outlast my modded saws. For one simple reason, the stockers never come off the shelf.

Great post, as it illustrates that we are not talking about a simple "yes or no" issue. If you approached each saw with the notion of modding to INCREASE it's life span, there's no doubt that you'd slow some saws down and speed some up. For instance, you might turn down a Husky 242 to something more like it's brother the 42 and you might bump up a Stihl MS290's performance up by muff modding it to breath easier. All cat mufflers would probably come off. I suspect that most radical mods probably shorten the life of a saw and moderate mods on certain saws might just increase longevity. The only way to really address this would be on a saw by saw basis.

 

[pioneerguy600]

Modded saws are less likely to get straight gassed or run too lean as anyone with one will know how to mix fuel and tune properly. They will be better cared for and maintained better than the average saw due to the owner having more interest in the saw in general and how it is running. The chain will be kept sharper and tensioned correctly, proper bar oil more than likely used.
I see more saws destroyed by owners not maintaining the saws properly, they die a drawn out death from a malady of causes most of which I mentioned above.
Pioneerguy600

 

[Kevin*]

cooler is better

Heat is stress and friction on your saw. Take a infrared thermometer gun and see the temp difference between a moddified and stock saw. I have and the moddified saw will run 125 to 150 degrees cooler on the muffler. Seems like the cooler temp would lead to less friction wich means less wear on the engine components.

 

[indiansprings]

I agree with Thall and Eric Copsey also. The quality of the mod has alot to do with it like with anything else. I've seen threads were the port work is not that consistent, looks rough and can't flow near as well as some work done that is posted on another site where the work looks meticulous, polished out and extremely consistent.
Some modders even go to the trouble of doing bench flow comparisons and also use a saw dyno to validate the results. It's kind of like getting a paint job, take it to Earl Scheib and get a two hour special for 250.00 or take it to a custom painter and get a professional job for 2500.00. It's more than just cranking out the rpm's. It has always seemed like to me the leaner they are the less torque they have.
I plan on having my 460 done for one simple reason, increased production with decreased longevity as the trade off, just to see if it pays. I will test it in a log before it goes with several time cuts and save the log to do comparable cuts in when it comes back. I may attempt my first video, but I have to wait until wood season slows down. That will be the only timed cuts this saw ever sees as I personally see that as a waste of time and good firewood.

 

[wyk]

When it comes to a car at 100 mph, the power required to overcome the air resistance increases roughly with the cube of the speed. In other words, you require significantly more engine power at 100 mph vs 50. Depending on the aerodynamics, rolling resistance, weight, etc. of the vehicle, it can be up to 4-5X more energy necessary. Rolling resistance increases in direct proportion to speed, though(and so does the heat generated there from). However, a family car is designed to efficiently remove engine heat, transmission heat, wheel, brake, diff, etc etc up to 65-75 mph, and last a long time. Running a car at 100 mph regularly that wasn't designed to do that(like a minivan VS a sports car), and you very likely will not get as long a life from it. Adding 10,000 miles by doing it once may be a bit of a stretch, but you are not going to make your Chrysler Caravan last longer by running it at 100 mph often. And I would wager on the guy that keeps it at 60mph - ALL THINGS BEING EQUAL otherwise.

Which is sort of the point. All things being equal, the more wear = more wear. Hotter, faster, longer etc. Wear is wear. But, the thing is, all things are rarely equal. Whether it is maintenance, manufacturing, fuel, oil, additives, etc etc. There are few things one can really pin down and make sweeping generalizations or statements. But, all things being equal, the more wear on a machine, the less it will last.

 

[ScottWojo]

wyk,

Your comparison of a stock minivan and a modified chainsaw engine is like comparing A jet engine to a stick.

If the Auto manufacturers were producing a minivan that had a governor on it and would only allow you to drive 25 miles per hour max. But the minivan was fully capable of consistently driving 65-75 mph... Blah blah blah....

Not all modifications done to a two cycle engine will cause the life expectancy of said engine to be diminished. That being said, the technology between the auto industry and the two cycle engine are vastly apart, and virtually apples and oranges.

 

[Ambull]

How about cutting the trim tabs on a carb, and removing the catalytic converter? I can almost guarantee that those two mods will increase the life of a saw. Pretty soon all saws will probably have those two things.

Maintenance and proper operation will extend the life more than anything else. Putting too much pressure on the saw in the cut, causing it to lug at a low RPM, has to be very hard on it, mod or no mod.

 

[flyboy553]

Good thread. Was just going to ask this very question

I have been wondering if a minor muffler mod and perhaps a hot coil would help my 359 e-tech. And if so, why or why not. Would like to get rid of whatever it is that makes it an e-tech, as I am sure it takes power away. I only cut for firewood, if that makes any difference.
I don't want to shorten it's life, just get all of it's capabilities out of it. I know from racing snowmobiles and motorcycles, you pay for performance.
It also sounds as though you get X number of cuts from a saw, whether you mod it or not. Stock saw just takes longer to make that number of cuts. But in the end, both saws will have made the same number of cuts?

 

[wyk]

You've utterly missed my point, which was also that you can not compare them, and will find it difficult to compare chainsaws to one another as well. My auto industry paragraph had little to do with chainsaws; it was merely in response to THALL's original statement that was quoted by the OP. Had you read the OP's entire post instead of jumping blind, you might have understood that. In the future you may be better off spending less time being defensive and impulsive, and spending more time overcharging for your muffler mods.

wyk,

Your comparison of a stock minivan and a modified chainsaw engine is like comparing A jet engine to a stick.

If the Auto manufacturers were producing a minivan that had a governor on it and would only allow you to drive 25 miles per hour max. But the minivan was fully capable of consistently driving 65-75 mph... Blah blah blah....

Not all modifications done to a two cycle engine will cause the life expectancy of said engine to be diminished. That being said, the technology between the auto industry and the two cycle engine are vastly apart, and virtually apples and oranges.

 

[mdavlee]

I have been wondering if a minor muffler mod and perhaps a hot coil would help my 359 e-tech. And if so, why or why not. Would like to get rid of whatever it is that makes it an e-tech, as I am sure it takes power away. I only cut for firewood, if that makes any difference.
I don't want to shorten it's life, just get all of it's capabilities out of it. I know from racing snowmobiles and motorcycles, you pay for performance.
It also sounds as though you get X number of cuts from a saw, whether you mod it or not. Stock saw just takes longer to make that number of cuts. But in the end, both saws will have made the same number of cuts?

Getting rid of the cat muffler will help the life of your saw. I can't see all that extra heat it keeps in the engine better for it.