What is the best engine?

[Oleo-Mac 999]

Good afternoon everyone, I would like to see the different opinions on the 2-stroke engines, the old and these new, the strato engine.
Who do you like more of the old engines and who like more of strato engines?
What have a favor, which have no other basically what strengths that distinguish both.

 

[Conquistador3]

Personally I am very partial to non strato-engines. Less parts, simpler to work on (see carburetors) and quicker to start.
Obviously a brand new strato engine will make more power than a fifteen year old non-strato engine in the same class, but I do not plan entering any contest any time soon.

 

[Oleo-Mac 999]

In short, your opinion is this; not strato engine is simple, practical and effective.
Am I right?

 

[Chris-PA]

Personally I am very partial to non strato-engines. Less parts, simpler to work on (see carburetors) and quicker to start.
Obviously a brand new strato engine will make more power than a fifteen year old non-strato engine in the same class, but I do not plan entering any contest any time soon.

A new strato has zero additional parts. Look at a 543XP.

 

[CR888]

Closed quad transfer port cylinder, piston port induction, strato is good for many reasons, not so good for a few. EPA carbs and mufflers are done away with to some extent with strato engines which is good. Fuel efficiency is simply amazing with strato's, I wish this tech came out 15 years ago and saved the two stroke in the world of bikes and outboards and it would have prevented cat mufflers and restricted carbs on saws. The modern two stroke seems to favour shorter stroke and wider bores and produce a power curve high in rpm. There are definately trends among high output two strokes these days, problem with a saw is size and room and the importance to minimise it. Saws are pretty basic low output commercial style engines IMO with low BMEP's in comparison to what's out there, but they are fun and serve their purpose well. I would love a factory water cooled rotary valve tuned intake saw with a well tuned expansion chamber, in a small light package but I doubt for many good reasons my wish will come true.

 

[beentown]

I'll take my Autotune saws everytime.

Sent from my SM-G900V using Tapatalk

 

[Conquistador3]

In short, your opinion is this; not strato engine is simple, practical and effective.
Am I right?

Yes. I know more recent strato engines have improved things somehow, with less parts, but the simpler, the better. We are talking about farming/forestry tools here, not the aerospace industry.

Closed quad transfer port cylinder, piston port induction, strato is good for many reasons, not so good for a few. EPA carbs and mufflers are done away with to some extent with strato engines which is good. Fuel efficiency is simply amazing with strato's, I wish this tech came out 15 years ago and saved the two stroke in the world of bikes and outboards and it would have prevented cat mufflers and restricted carbs on saws. The modern two stroke seems to favour shorter stroke and wider bores and produce a power curve high in rpm. There are definately trends among high output two strokes these days, problem with a saw is size and room and the importance to minimise it. Saws are pretty basic low output commercial style engines IMO with low BMEP's in comparison to what's out there, but they are fun and serve their purpose well. I would love a factory water cooled rotary valve tuned intake saw with a well tuned expansion chamber, in a small light package but I doubt for many good reasons my wish will come true.

Two stroke motorcycle engines were doomed anyway because the Japanese (meaning Honda) had decided so and lobbied without mercy. Honda is one of the top lobbysts here in Europe: they are second only to German automotive giants VAG and Daimler in their lobbying activities and by far the largest lobbyist when it comes to motorcycles and power equipment.
Funny thing is two stroke have refused to go away. Apart from chainsaws, where four stroke are impratical to say the least (I dare you Honda: build a four stroke chainsaw! ), two stroke managed a spectacular comeback in dirt bikes. FIM has sanctioned an European two stroke MX championship and we have many smaller scale manufacturer such as Ossa and Sherco manufacturing FI two stroke dirt bikes.
And even Honda appears to have finally discovered two stroke aren't that bad... but that's another story for another day.

 

[7sleeper]

For me the best engine is the one that works reliable. Don't care about any speed single cut orgasims, that are so important to many members here. Any pro with a hobby class saw will have felled & bucked more trees than me at the end of the day with any MTronicAutoTuneQuadportStratolooseproofnut saw... So I find quite a lot of this talk EDIT not futile.

7

 

[Oleo-Mac 999]

7 sleeper, I when I started this thread, was intended to discuss the pros and cons between the two engines conventional times and strato. As you see, there are different opinions, which I think is good and opinions that have to do with the thread are always welcome, now called idiots who gives opinion, no longer seem right. Here it is not intended offenses, nor was with this intention that I opened this thread, so if you want to participate in something constructive to the subject under discussion, well, if you do not want, do not need to participate.

 

[jdvsn83]

Only old, simple and reliable engines for me!

 

[Oleo-Mac 999]

It is also my opinion, but then also argue that we must evolve, but for me the evolution only change for the better. If not the case, it is better the old 2-stroke engines.

 

[7sleeper]

7 sleeper, I when I started this thread, was intended to discuss the pros and cons between the two engines conventional times and strato. As you see, there are different opinions, which I think is good and opinions that have to do with the thread are always welcome, now called idiots who gives opinion, no longer seem right. Here it is not intended offenses, nor was with this intention that I opened this thread, so if you want to participate in something constructive to the subject under discussion, well, if you do not want, do not need to participate.

Sorry no offense meant! I have misunderstood your intentions.

It is also my opinion, but then also argue that we must evolve, but for me the evolution only change for the better. If not the case, it is better the old 2-stroke engines.

I still see the engine as being hardly a problem, irrespective if strato or conventional. The rest of the saw, as is typical of most motorized equipement, tends to deteriorate earlier. Further if we look at what some modders are doing to saws to improve performance, removing the strato function looks like one of the important things. So that strato per se doesn't seem to be the holy blessings everyone was awaiting. And if fuel savings through strato technology is important, then why do we have examples that a conventional engine (dolmar 421) is more fuel efficient than the strato (husqvarna 450)? So obviously we donot have the whole picture yet.
Personally I am still disappointed that dolmar ditched the 4 stroke dolmar 500V. Of course it would be heavier and more costly than conventional two strokes, but I still see it as an extremely promessing development for a homeowner/firewooder!

7

 

[Oleo-Mac 999]

Ok. A good constructive response and according to the subject of the thread, this is what is intended
I have also seen people here that modify the strato for conventional, it is because their experiences with strato engines must not have been very good.

 

[Chris J.]

Totally not answering the original question(s):

Mopar 225 CID "Slant Six"

 

[jdvsn83]

Totally not answering the original question(s):

Mopar 225 CID "Slant Six"

Yeah, and here 188 or 221 CID Inline 6 Ford... Indestructable!

 

[CR888]

Sorry no offense meant! I have misunderstood your intentions.


I still see the engine as being hardly a problem, irrespective if strato or conventional. The rest of the saw, as is typical of most motorized equipement, tends to deteriorate earlier. Further if we look at what some modders are doing to saws to improve performance, removing the strato function looks like one of the important things. So that strato per se doesn't seem to be the holy blessings everyone was awaiting. And if fuel savings through strato technology is important, then why do we have examples that a conventional engine (dolmar 421) is more fuel efficient than the strato (husqvarna 450)? So obviously we donot have the whole picture yet.
Personally I am still disappointed that dolmar ditched the 4 stroke dolmar 500V. Of course it would be heavier and more costly than conventional two strokes, but I still see it as an extremely promessing development for a homeowner/firewooder!

7

You obviously have little experience with strato saws, the amount of work done per tank is greatly increased. I have a stock ms261 & a strato gutted ms261.....the stock saw will do double the work per tank. People gutt strattos to get more air/fuel in to obtain more power. It comes at a cost though.

 

[Toyboy]

I guess I'm just an "old school" type guy. For me, the "can you look at my saw" saw repair guy to my friends, I find the older saws easier to work on. I messed with a strato carbed saw once, and it left here running good, but I just don't understand the the whole concept. I've watched a Utube animation on how it works but I'm still perplexed with it. Most of you guys probably do more saws in a week then I do in a year.
Give me the good old basic two stroke and I'm happy. I don't know how much shelf life I have left, let alone start trying to sort out all this new fangled stuff on today's market.

 

[Chris-PA]

I like fast saws, but I like fuel efficiency and clean air to - especially when I'm standing next to it breathing the exhaust. Many years ago I read that Ford removed a rice grain sized divot used as an alignment mark on one of their pistons. Why? Because the engine ran so clean that the unburned fuel hiding in that feature had become a significant source of HC. Yet here we have engines that blow a large portion of the fuel they draw in right out the exhaust, and fuel systems designed to run so rich that puking raw fuel is used as a speed governor!

I also like elegant design solutions, and it turns out that huge improvements can be made in both these defects with hardly any additional parts (moving or otherwise). I'm not sure where is this additional complexity that is discussed? An additional throttle plate (newer stratos don't have this)? An H screw replaced by a fuel solenoid, a wiring harness and a stone simple microcontroller?

I read all sorts of claims about strato, like the pistons are too heavy to rev and they get too hot and don't lube. Yet I see an elegant solution with no moving parts that improves performance while reducing emissions and increasing fuel efficiency. Now that's heads-up engineering I can respect. I know some builders get good gains on some stratos by gutting them, but it isn't the only way and adding fuel to the strato air path is not what gives the benefits. Here is a strato I ported by increasing the duration of the air-only inlet and enhancing the strato effect - it's cutting a small branch to show that the strato design does not prevent it from revving (that's 12,700rpm):


I've been a fan of carbs for a very long time and have spent many hours figuring out how they work and tuning cars, but never paid much attention to 2 strokes. When I finally figured out why my saws were all misfiring so badly I was amazed - they were designed to do that! While the engines are small, people don't realize just how much unburned fuel is coming out in comparison to most any other modern engine. And you are holding it, breathing that stuff - sure, we're all young and invincible, until we're not. There's real nasty stuff in exhaust fumes. Feedback carbs use almost no sensors, and finally solve that problem. A proper mixture saves fuel, reduces emissions and improves performance. The system is so simple that Husqvarna could easily put an AT carb on every cheap Poulan sold, but clearly the regulations are too lose and they don't have to.

The manufacturers that have not invested in technology development or paid to use what others developed will try to promote what they sell. Sure, you can reduce scavenging losses as best you can with careful porting and stuff a cat on it, but the performance will be compromised and the cat just turns the lost fuel into heat. And if you mod it all the improvements are lost - you can improve the performance of an AT strato saw while keeping both functions.

 

[Toyboy]

Don't get me wrong Chris, I never said strato was bad, it's that I've only been around one, and it was a WTF moment when I pulled the air filter. First and only time (so far) that I've encountered one. I'm not the wiz bang saw guru like most of you, so anything that comes along that I've never seen before throws me.
It would be nice if the local college offered a course in two cycle engines but they don't. Most of what I've learned about the in's & out's of chainsaws and repair, I've learned from all of you on this forum. I do agree though, I've got a long way to go.

 

[Chris-PA]

Don't get me wrong Chris, I never said strato was bad, it's that I've only been around one, and it was a WTF moment when I pulled the air filter. First and only time (so far) that I've encountered one. I'm not the wiz bang saw guru like most of you, so anything that comes along that I've never seen before throws me.
It would be nice if the local college offered a course in two cycle engines but they don't. Most of what I've learned about the in's & out's of chainsaws and repair, I've learned from all of you on this forum. I do agree though, I've got a long way to go.

And my comments were not meant as a shot at you or anyone else, just the background on why I like the newer engines. Others have different views which of course is fine.