Will Strato charged motors be less reliable long term?

[blsnelling]

Which has me wondering why anyone would send you a 461 or a 661 with their hard earned money to hop one up. You obviously do not understand how they actually work! I also question your instance that pop-ups are better than squish cut, and that one ring is better then 2. You have continued to refuse to compare your saws 1:1 against other types of modified saws in dyno testing that would easily prove things one way or the other. But noooooooo! You are above empirical testing and analysis!

And yes, I am aware that there are other engineers here. At least one anyway. You are certainly not one of them.

You're showing your ignorance on so many levels, in nearly everything you have to say. You obviously know basically nothing about me, my saws, or my work. The proof's in the pooding, right there buddy. I have no need to go into my professional credentials. I've also never said cutting squish bands is inferior. I simply don't find them necessary. Again, the proof's in the pudding. Cutting the squishband is a valuable tool when needing to lower the exhaust, or need more compression than a popup will get you. That's not very often IMHO. Different people skin cats different ways. What's it to you? The only thing you have in this is a bone to pick, and who knows why. I never had any dealings with you. The simple fact that you need to exploit your supposed credentials and tear down mine speaks volumes!

 

[bwalker]

You're showing your ignorance on so many levels, in nearly everything you have to say. You obviously know basically nothing about me, my saws, or my work. The proof's in the pooding, right there buddy. I have no need to go into my professional credentials. I've also never said cutting squish bands is inferior. I simply don't find them necessary. Again, the proof's in the pudding. Cutting the squishband is a valuable tool when needing to lower the exhaust, or need more compression than a popup will get you. That's not very often IMHO. Different people skin cats different ways. What's it to you? The only thing you have in this is a bone to pick, and who knows why. I never had any dealings with you. The simple fact that you need to exploit your supposed credentials and tear down mine speaks volumes!

Brad, respectfully, squish bands are very important and it has nothing to do with compression. And a popup piston has some serious downsides. ONLY in the chainsaw world is this be acceptable and then only because of the difficulty in properly machining the head of a saw.

 

[fordf150]

Not sure how this turned into a pop-up vs squish thread

 

[Moparmyway]

ONLY in the chainsaw world is this be acceptable and then only because of the difficulty in properly machining the head of a saw.

Soooooooooooooo NOT true

Think of the Hemi - it has a popup with valve reliefs

the only motor to be banned from NASCAR due to its rediculous winning history ............... leaving the others to having to resort to begging for rules changes so their motors could stand a chance

 

[walexa07]

When I first read up on the strato design, and the lower fuel consumption, I jumped on the bandwagon with the less lubrication line of thinking. This thread has opened my mind some in that regard. Take a 4-stroke engine in an automobile for example. If you remove the drain plug on the oil pan, and if you can pour engine oil in the filler cap fast enough to keep the oil level at the constant required level, lubrication is sufficient. So just because a traditional 2-stroke has more fuel mix through the engine does not necessarily mean it is lubricating the internals better - it's just wasting more - same as removing the oil drain plug on the automobile as referenced above. I know a 4-stroke engine in an automobile is way different than any 2-stroke engine, but I think the analogy holds true.

Waylan

 

[fordf150]

When I first read up on the strato design, and the lower fuel consumption, I jumped on the bandwagon with the less lubrication line of thinking. This thread has opened my mind some in that regard. Take a 4-stroke engine in an automobile for example. If you remove the drain plug on the oil pan, and if you can pour engine oil in the filler cap fast enough to keep the oil level at the constant required level, lubrication is sufficient. So just because a traditional 2-stroke has more fuel mix through the engine does not necessarily mean it is lubricating the internals better - it's just wasting more - same as removing the oil drain plug on the automobile as referenced above. I know a 4-stroke engine in an automobile is way different than any 2-stroke engine, but I think the analogy holds true.

Waylan

To an extent that is probably true. Individual engine design characteristics likely play a role too. Lots of things to consider from improvements in materials and machining tolerances to 3d modeling and computer programs to determine loads placed on individual components instead of just winging it on determining proper bearing sizes. Probably to many variables for anyone to give a definitive answer either way.

Something to think about with your auto engine line of thinking though. Just ten years ago a 4cyl engine held 4 quarts of oil and a v8 held 5. Today it isn't uncommon to see a 4cyl with 6 quarts of oil and 6 quarts is the minimum for a v8. Same or even better improvement in oil quality in auto oils compared to 2t oil

 

[blsnelling]

As engines are pushed farther and farther, developing more HP, and ever increasing the BMP, the demands on the oil continue to rise. One way to deal with that is to increase the capacity of the sump. Some engines are MUCH harder on oil than others, having to do with valve train design, etc.

 

[bwalker]

Soooooooooooooo NOT true

Think of the Hemi - it has a popup with valve reliefs

the only motor to be banned from NASCAR due to its rediculous winning history ............... leaving the others to having to resort to begging for rules changes so their motors could stand a chance

Except a hemi is a four stroke....Four strokes are not sensitive to piston temps like a two stroke.
Not to mention the fact that Hemi came that way and as such don't have part of the area above the ring removed..
AND what I said was "Soooooooooooooo true". You only find home made popup pistons in the chainsaw world.

 

[bwalker]

When I first read up on the strato design, and the lower fuel consumption, I jumped on the bandwagon with the less lubrication line of thinking. This thread has opened my mind some in that regard. Take a 4-stroke engine in an automobile for example. If you remove the drain plug on the oil pan, and if you can pour engine oil in the filler cap fast enough to keep the oil level at the constant required level, lubrication is sufficient. So just because a traditional 2-stroke has more fuel mix through the engine does not necessarily mean it is lubricating the internals better - it's just wasting more - same as removing the oil drain plug on the automobile as referenced above. I know a 4-stroke engine in an automobile is way different than any 2-stroke engine, but I think the analogy holds true.

Waylan

Your not considering several things.... it is a fact a strato engine has less lubricant available to it. The strato design from a lubrication stand point are the same as a traditional two stroke.

 

[fordf150]

Except a hemi is a four stroke....Four strokes are not sensitive to piston temps like a two stroke.

Even 4 stroke engines generally perform better with flat tops and zero deck heights. Exceptions do exist and sometimes it just isn't possible to get the compression that is needed/wanted with a flat top and the chosen chamber design

 

[svk]

Alright gents, there have been some complaints about this thread. Lets keep things cordial in here. Thanks.

 

[zogger]

Alright gents, there have been some complaints about this thread. Lets keep things cordial in here. Thanks.

Ya, no need to argue about this, just go old school! Add some zerk fittings to the crankcase, keep it pumped up with good old farm grease! Acts like crank stuffers, too...

 

[bwalker]

Even 4 stroke engines generally perform better with flat tops and zero deck heights. Exceptions do exist and sometimes it just isn't possible to get the compression that is needed/wanted with a flat top and the chosen chamber design

Your talking four strokes and engines pistons designed to be popups, jot garage made pop ups... totaly different kettle of fish.
No tuner worth a damn in the motor cycle, kart, or snowmobile world would make a pop up.

 

[Moparmyway]

And a popup piston has some serious downsides. ONLY in the chainsaw world is this be acceptable and then only because of the difficulty in properly machining the head of a saw.

You only find home made popup pistons in the chainsaw world.

Welp ........now yer changin yer tune again....... if'n ya would have written that in the first place, I wouldnt have had any need to single out yer words

This goes back to where I suggested that you take your time and think before you hit "post reply"

 

[Chris-PA]

it is a fact a strato engine has less lubricant available to it.

It is a fact that a strato has maybe 20% less fuel mix moving through the case per revolution. The rest of the claims are not as clear:

Because moving the fresh charge to the cylinder, that means it stays in the case for a greater number of degrees (=time) than a conventional engine.

Case bearings are not on the flow path of the mix, rather a side eddy where mix gets trapped. They get coated with the same mix, and I doubt they experience a 20% reduction in lubrication.

 

[bwalker]

It is a fact that a strato has maybe 20% less fuel mix moving through the case per revolution. The rest of the claims are not as clear:

Because moving the fresh charge to the cylinder, that means it stays in the case for a greater number of degrees (=time) than a conventional engine.

Case bearings are not on the flow path of the mix, rather a side eddy where mix gets trapped. They get coated with the same mix, and I doubt they experience a 20% reduction in lubrication.

The only thing doing the coating is oil, not mix. The fuel evaporates when it reaches the crankcase. Thus how long the vaporised fuel stays in the crankcase doesnt matter. The oils loiter time is dictated mostly by rpm.

 

[bwalker]

Welp ........now yer changin yer tune again....... if'n ya would have written that in the first place, I wouldnt have had any need to single out yer words

This goes back to where I suggested that you take your time and think before you hit "post reply"

I didn't change my tune at all, you just didn't think about what I said...

 

[the GOAT]

So since a ported saw is less fuel efficient wouldn't it make sense that they need less oil in the mix?

 

[Chris-PA]

The only thing doing the coating is oil, not mix. The fuel evaporates when it reaches the crankcase. Thus how long the vaporised fuel stays in the crankcase doesnt matter. The oils loiter time is dictated mostly by rpm.

That the fuel evaporates out is not relevant to my point that the oil in a strato spends a greater number of degrees of crankshaft rotation in the case than it does in a conventional engine. The rpm is also not relevant as each rotation is a separate event, at higher rpm more oil will be brought in sooner (the next rotation), and both the oil and the fuel are continually moving through.

I agree with you that there is some 20% less oil moving through the case, but I disagree that this translates to 20% less "lubrication" in all areas, as the situation is more complex than that. And with a variety of strato saws on the market for over 10 years I think we'd have seen evidence of some inherent problem with the technology if there were one (setting aside any possible design flaws on specific saws).

 

[Franny K]

So since a ported saw is less fuel efficient wouldn't it make sense that they need less oil in the mix?

To quote ChrisPa
It is a fact that a strato has maybe 20% less fuel mix moving through the case per revolution. The rest of the claims are not as clear:

This thread is about the longevity which the manufacturer uses as a design parameter. Adding in modified from stock brings in complication.