The degree of compression and the compression in the engine.

Thank you;))) I have this car summer weekend, so that you can pour;)

That not everyone is perfect, in terms of the methanol to pour, and you pure methanol to deshmanu I wish valleseco motor.

And, well, maybe;) don't know for sure. Yes I think the hood should be. This motor in stock withstands 0.8 bar, and alive, and I have the methanol will. ;)

Well, the Germans like a blow to such a considerable degree well!

In what way?;)

Roman-Kuchinskij

It all depends on SJ I think. In General, I do not want to experiment — to destroy the motor due to such trifles hurt. I have read that it affects — I have the 10.5 LF. 1 bar is not enough. So I will hide behind wherever possible

Competitor BMW and Vag have been doing?

Thanks;) I will make every effort to that end;)))

Good luck.
Turbo motors are a different topic altogether.
I hope the motor is not collapsed.)))

It all depends on SJ I think. In General, I do not want to experiment — to destroy the motor due to such trifles hurt. I have read that it affects — I have the 10.5 LF. 1 bar is not enough. So I will hide behind wherever possible

Well, it's head must be like a hedgehog, what would this effect significantly appeared.
Electrodes of candles too higher temperature than have the whole plane of the combustion chamber and nothing, early ignition occurs. On the aluminum head heat sink what area of the combustion chamber, this is what we need to do something there locally overtempered.
Although I will not convince anyone.
All improvements private matter zarabatyvayu.

Any imperfections or rather acute angles, and so ignited faster and have higher temperatures. In consequence of that in these areas there is an early ignition. When tuning that all out

What makes you think that all sorts of irregularities and sharp edges promote detonation?
From these findings?
In fact everything is exactly the contrary, any imperfections break the blast front, and reduce the rate of burning of fuel and consequently increase the detonation resistance of the engine. To do this, and doing all sorts displacers on the pistons and in the combustion chambers.

well, I guess Yes, that it will not affect the LF, but at least it will remove the risks of additional appearance of detonatsii in the form of sharp corners and do all sorts of irregularities.

Roman-Kuchinskij

Rename already. Autopedia or something like this:) I'm still no mega calculations trying to predstaviti how I will change the LF if I remove all the irregularities around the valves, reducing the risk of detonatsii on the sharp edges and reducing LF.

Minimal. Get some dead head from cold flow the burette and see how much you have to whittle down to increase the volume at least on the cube. A lot need to whittle down.

Too lazy to renamed ) and boring what is the name you gave me

Rename already. Autopedia or something like this:) I'm still no mega calculations trying to predstaviti how I will change the LF if I remove all the irregularities around the valves, reducing the risk of detonatsii on the sharp edges and reducing LF.

Theorycraft always cool. Please go on.

Wellcome

For the analysis with formulae — respect!

Miller's cycle is the imposition of the Atkinson cycle to the Otto cycle
Only in the Atkinson compression stroke shortened by the geometry of crank, and in the Miller time open/close valves. Sobsna VVT is. Well esesno direct injection necessary as part of the air charge is drawn back into the intake
Dignity Atkinson wild efficiency and minus is the lack of torque at low rpm, so you can often see Atkinson in hybrids because the electric motor gives the desired traction on the bottoms. However, in my opinion, Toyota's hybrids is also not a pure Atkinson. Not going to argue, because at the time strongly did not go deep in this question. Could write about it in a simple language, but I think you can read about it in Wikipedia

here everything has fallen into place ))) and then they write everywhere that the transition to the Atkinson cycle, to lead people astray.
VVTi and it steers the same and in fact ? Only need another direct injection to the intake fuel is not left in the open valve.

Well Atkinson is in any case a derivative of the Otto cycle.
I really think that mentioned thee engine with the standard crank, not working according to the Atkinson and Miller cycle.

Just, available. Cool.
The optional question is.
due to what modern engines are moving to Atkinson cycle ? For example, the 2.0 Camry in the past . there's also the usual crank ? nothing special unlike the original idea of Atkinson. Just shorten the intake stroke due to the late closing of the intake valves ? And do it with VVTi ?

But if much higher — also it is time to get something filled in the combustion chamber reducing its volume.

Lifehack

Blah... I still hate all these "famous formula" the vestiges of past experience and empirical surveys of tatamotors. In which huge losses and low LF give the error formula is obtained empirically.

From above I cited a mathematical calculation, the most common physics course 9ого class.

I have personally measured on 2зз, engine Sz 11.5, compression 17, no variation in the cylinders, absolutely healthy kusasi not oil the motor.

And this formula is always the same as the factory maximum data compression. As tolerance -20% of this number. If a lower motor to get repaired.

I cut my way.

digree

The compression gauge good buy :)
My main experience is with BMW. Take kutovyi version of the M20 beginning of the 90s. Their SG of 9.0. The plant's maximum compression to 11.5-12.0. A minimum of 9.5. It all fits together. On besicovich szh 9,7-10,0. I had a perfect М20В25. 13,0 compression in each cylinder. And here the formula x1,3 works. No compression gauge he showed 15,0 :)

No GS, is, SS)

Yes OK ) I say let's agree to disagree )
From every point of view has the right to life )

Coincidences cannot be in a dozen motors BMW :) I had a lot of cars everywhere and I measured the compression. The formula works. Persuade anyone not going. Just expressed my opinion.

)) I knew that somewhere will emerge the theme of a normal compression gauge )))
So I wrote I'm not the only one and not on one engine )

I'm not going to argue. Just don't want ) the physical meaning of the dependence of the degree of compression and the compression is clear. And it is not linear. But coincidences always have a place to be. In the manuals the manufacturer often indicates underreporting to protect themselves. As is the case with oil burning 1 liter for 1000km according to the manual this is normal ))

In General, each will remain unconvinced )

Lifehack

)) I'm not alone and not one engine was measured 16.5-17 on сж11.5
Yes, by the way is the new motor most likely will not be high GS. To ride still needs to get used.

But in General. the polytropic exponent is taken approximate to 1.2. Loss, leakage and heat transfer with the walls in the actual motor more than likely. So I think 1.15 will be just right.
Dependence of compression from the compression is NOT linear.
And prove that your formula is not correct — very simple.

Take and count the diesel... your formula of CR*and CR 1.3 to the extent 1.15

The compression gauge good buy :)
My main experience is with BMW. Take kutovyi version of the M20 beginning of the 90s. Their SG of 9.0. The plant's maximum compression to 11.5-12.0. A minimum of 9.5. It all fits together. On besicovich szh 9,7-10,0. I had a perfect М20В25. 13,0 compression in each cylinder. And here the formula x1,3 works. No compression gauge he showed 15,0 :)

On the diesels and the turbo engine is also checked — all adequately factory indicators.

)) I'm not alone and not one engine was measured 16.5-17 on сж11.5
Yes, by the way is the new motor most likely will not be high GS. To ride still needs to get used.

But in General. the polytropic exponent is taken approximate to 1.2. Loss, leakage and heat transfer with the walls in the actual motor more than likely. So I think 1.15 will be just right.
Dependence of compression from the compression is NOT linear.
And prove that your formula is not correct — very simple.

Take and count the diesel... your formula of CR*and CR 1.3 to the extent 1.15

I read it's not Behind the wheel of the 80's :) And shows my great experience formula is true. Say, I have never seen on a fresh motor with an SG of 10.0 compression at 15.0-16.0 percent. Only if the compression gauge ass :)

Blah... I still hate all these "famous formula" the vestiges of past experience and empirical surveys of tatamotors. In which huge losses and low LF give the error formula is obtained empirically.

From above I cited a mathematical calculation, the most common physics course 9ого class.

I have personally measured on 2зз, engine Sz 11.5, compression 17, no variation in the cylinders, absolutely healthy kusasi not oil the motor.

Long-known formula of the LF is multiplied by the factor of 1.3.

From the figure? )

The new engine with the LF of 11.5 maximum compression will be of 14.95.

but the ) should be able to ))

I just do not understand one — as "to Use modern calculator" to the extent 1.2?! Okay logarithmically line, but the beads Papuan — it's aerobatics :)

Where added VC?
these formulas may not be the questions... Here everything is clear and accurate.
Either my medal after school red high school diploma — worthless... as my knowledge do not match with the existing reality

So in fact, to this added 1 VC, right up to infinity is possible, according to the formulas a lot of questions in school and University mathematics on top)))

Ah, someone at school badly studied? :)
we brought the left and right side of the equality to a common denominator VC (volume of the combustion chamber)
received an equality of the form 11.5*VC = 448658.9 + VC
When transferring from the right side of the equation the summand V in the left part, V s changes sign to opposite. Then we get the equation
11.5*VC — VC = 448658.9
well, or 10.5*VC = 448658.9

Yes

what kind of unity ? from 11.5 ?

And where in formula 5 unity gone?

the pistons saw — the best )
the main thing then the camera shed, and again drank to the unevenness of the volumes of the COP

Doesn't add up. Spent an hour of time. go pistons cut.

there was a time my compression was equal to the compression ratio, but it's already too sad to go

Diesel ? For diesel engines with such a degree of compression, 45 points it really possible compression.
Measurement at 30-32 shows, that many leaks that's all. You have of course absolutely live motor, but to perfect him away.
In ideal conditions, the polytropic exponent is 1.4, I used 1.2, but in fact it seems that 1.2 is still too much. The isolation system in the engine of course not the same.

People are interesting people... We live in a world where everything is served to the laws of physics, counting the missiles on the paper (at a time when there were not even computers ) and then they flew.

I showed You only the physical sense... He says that the relationship is not linear with a constant coefficient and the power function. You can accept it or not. Your right.
But the tendency of people to believe that they are fine and as it should be, I sometimes have to wear rose-colored glasses.
It can often be seen on measuring power when the power to the wheels is considerably below the nameplate capacity. The questions arise from what and why... and employees of the dyno, just "tweak" the wheel power up the passport, eventually based on the statistics they can give birth to an empirical conversion factor... )

the Holy I have compression turned 45 points, this despite the compression at 24.
in fact, 30 -32
when multiplying by 1.3 as it turns out more approximately

Measurement of compression for diagnostic purposes has several options, depending on situation, open throttle, closed throttle, hot, cold, with butter... etc for 5 minutes )

Yes, I am sealed. Meant to measure. How generally correctly to carry out the measurement of compression in the engine?

Yes, replace the candles of the first head( what's inside) with the removal of intake =(

Start with the fact that the compression doesn't change :) This is the measured characteristic for diagnosis.
to change or measure up? About measurement probably will not be able to tell. Plug replacement I understand with the removal of the manifold ? it's sad.

If you meant changing the degree of compression. What is the goal that is pursued?
Generally the right to change the compression ratio is the constructive change in the volume of the combustion chamber, such as the shape of the bottom of the piston.

Bookmarks. Really useful article, in which elementary chewed as a right and not guesswork, it's okay to count ; )

Big thanks to the author for the enlightenment of our minds )

The only question — I did not understand how to correctly change the compression. I have a 3.0 Duratec v6 engine manufactured by the Ford. The problem is that to the far row( 1 ) mind not to crawl without removing the intake manifold.

Thank you.

quickly... interesting. indeed, if you are satisfied, it may not be necessary — "dance with tambourines"

vanj72

rockoxhuis (maybe even older.)
maybe valve not configured.
or judging by the costume in the photo ...- phase shifted?(the food of course)

Raskatov has not changed or anything...

)

blah, can salyaru need? I spaz petrol pour )))

vanj72

rockoxhuis (maybe even older.)
maybe valve not configured.
or judging by the costume in the photo ...- phase shifted?(the food of course)

Yes, his campaign turbo diesel ))

wow...lenivye, then only panuati and remains...

Well, my 102 mad pony is the only way to raise it )))

Yes, in the red zone can certainly pogirai... but what is too much... still
to many it makes no sense to get to the redline — I have a duck on 4000-4500 torque starts to fade away — I see no reason to yell up to 6000-6500 — only time during acceleration to waste, but sometimes of course it is necessary to heat the soot to rip off ...so, once a month...

1 litre to 4 thousand in the red zone is not eating regularly? If the pensioner mode oil on the spot! Oil from the exhaust no smoke and no throws. Wonders what is. The autopsy will show until the ride...

But oil is eating...

The car goes fast! no deviations, no vibration motor behaves like a new one! All versions not the topic! Timing in the normal state, any motor-tuning has not been done except chipovka and removal of the cat 180 thousand km was Raskatova, the effect is ZERO!

PWO

But here a question! I have run 210 thousand Compression in that year has increased, now with under 18 kg./cm2! Zhor oil moderate 4-5 thousand km to 1 litre max but the red zone regularly five to ten times a day accurately track. The motor runs flawlessly, good speaker, neither of which is the speaker's fault, no! And the compression is crazy! Hu Izit?

rockoxhuis (maybe even older.)
maybe valve not configured.
or judging by the costume in the photo ...- phase shifted?(the food of course)

that's why you answer that with a simple replacement of the rings — the result is not the answer. che is there in the analysis — no one knows )

Well, H. with him. so I'll roll to the last. A and boring that no one canceled? The only question is whether REM rings for focus and perhaps counterbore...

You know, with mileage in the 200k+ might already have the ellipse in the cylinders, not even possible, and he's already just there. the question is how big it is. therefore, when new rings all can be even worse than it is now.

Lifehack

Oh ) apparently you have some sort of super motor ))
I don't know. one current option I have left. the combustion chamber is reduced with carbon, for example, resulting in the raised compression, with the result that trend has gone ) in growth )

Open until want, coming and going. Any autopsy will show. Again, I talked with the mechanics about to throw rings new. They told me that the result is not the answer, may be a bad motor and it will cease to go! In what way is not clear to me and the explanations have not heard any, we can only trust their "expertise". That's rolled while the behavior of the motor as not annoying!

))) here and compare it is ridiculous!

:))) Yes, I have the same oil burning. and very strong. But I have a forged piston, the motor is spinning up to 10,000 rpm, 400 forces, I have already scored and just pour once a week )

Well, the dynamics of the exact same or slightly worse than that by far. Most likely it is the oil compression, but due probably to the fact that the oil quality it is not belching from the exhaust and ugorayu on the sly )))

Oh ) apparently you have some sort of super motor ))
I don't know. one current option I have left. the combustion chamber is reduced with carbon, for example, resulting in the raised compression, with the result that trend has gone ) in growth )

G4EC 1.5 DOCH 16 valve. 3rd generation

So what is the model of motor?

Lifehack

Oh, wait... 5 seconds. Cha accent 3ьего generation?
Cha randomly on 1.5 diesel? For diesel such compression is not so much.

And maybe a diesel? And gasoline, I run 0_0

injector 1.5 16 valve. Automatic transmission 3-generation 14.5 the norm!

Oh, wait... 5 seconds. Cha accent 3ьего generation?
Cha randomly on 1.5 diesel? For diesel such compression is not so much.

So all these parameters should be the first thing to affect the deterioration of the dynamics of the engine! Or anything like that, no! The compression gauge checked for other accents 14.5! Zhor oil 1 litre for 4-5 thousand. (after replacing the MSC zhor oil gone, 10 thousand miles ago) a very active drive to the red zone. If you ride a pensioner that oil on the spot! The timing on the label place all the same. Reduction of the combustion chamber and timing down, the motor would not go! Here is a miracle! )))

The options can be sea
maybe the compression gauge is lying )
and there is such a thing as "the oil compression" — the oil seals the gaps. thereby reducing air leakage during the measurement. with the increased consumption of oil.
the fuel pressure was turned off when measuring?
maybe the timing marks are wrong, because the geometric compression ratio — how and compression, and actual (after the valve is opened taking into account inertia)
Maybe because of the increased oil consumption and carbon deposits on the valves, thereby decreased combustion chamber and increased compression where the gain and compression.

in General you guessing for very long

But here a question! I have run 210 thousand Compression in that year has increased, now with under 18 kg./cm2! Zhor oil moderate 4-5 thousand km to 1 litre max but the red zone regularly five to ten times a day accurately track. The motor runs flawlessly, good speaker, neither of which is the speaker's fault, no! And the compression is crazy! Hu Izit?

On my Mazda, engine derated, the compression ratio is reduced)
The turbine can be put quietly)

With the increase in compression ratio increases the peak pressure of the compression stroke (compression), the higher the pressure, the higher the temperature, and thus increases the chance of self-ignition of the mixture of detonation. It is logical to assume that you need to use a more high-octane fuel, which has a higher threshold for detonation is detected...
Homegrown mechanics, often don't like the findings, supported by theoretical studies based on the laws of physics, as they destroy their rose-colored glasses.

Yes, leaks a bunch, so as to pump the maximum pressure (compression) — turn 4 to do — well, not bolee5-ti — leakage is usually from 1 trafficking 8-10 shows.
partially oil slit overlap... (in rings)
by the way, you can perverati (empirically) the lower bound is valid, but there are still many other factors — the spark, the ignition, gasoline, etc, etc, etc...
but based on personal experience...
VAZ dvigun 08 — goes well until compression 10 11 - good 12 — very good— 12.5-13 — after the bulkheads — excellent.
compression 9 — it is impossible, but if in 2 cylinders 9, the horror, not the drive
classics 03 didak goes to compression -8 — 7 then it is impossible — it is hard to ride
9-10 — still going...
I have a degree in siute 10 don't know — did not measure, but if you think 14.5-15 is a very good result
conclusion... why is it always this conclusion doesn't like homegrown mechanics, but at higher compression ratios — it is recommended that a high-quality gasoline with a high octane — Hey mates, who are pouring in the car with a compression ratio from 10 — 92 gasoline — I just pity them. (and no matter what he is kind of better, while it is still 92)

yeah, I already wrote in the comments that most likely have to use less.
since 1.2 is the polytropic exponent is the adiabatic compression in imperfectly insulated system for 2 of the atomic gas. In a perfect 1.4
In the ice campaign is still worse, large leaks through the rings, through the valve, the heat exchange with the cylinder walls, not matching the geometric compression ratio and actual due to timing and account of the inertia of the mixture when closing and opening valves. etc.

so probably 1.15 where it is more similar to truth. however, this depends on the condition of the motor

Interesting, never thought about the connection, though of course your head then it's understandable, but not in precise terms and formulas ...and exactly the 1.2 factor should you use? — not less? ...
in my view — to 10-compression 14 compression — it is a working version on top of the bar, but no...a little wrong, but corrected

Wankie !

) without fuel and set — up was useless of course. and with the SJ ... 98ой not racked

to donate new staff prikladom for a hundred bucks to check it rushing, not really want to, and again, a suitable fuel no

BlackSilent

Gee))) it is interesting that you showed, would be the compression gauge in my current setup of GS 14.2 =)))

14 to 1 rushing at lower levels as the compressor... tin

estimated))) I this unit is stupidly nothing to feed))) we have only 98 and the two gas stations)))
today took 2mm spacer will end up with 11.5:1 under 98 go eclicto xylene and acetone — all of us! =)

you have a 14.2 ?! auet. 20точку something's gotta give!
gasoline then go and 115ый? :)

Gee))) it is interesting that you showed, would be the compression gauge in my current setup of GS 14.2 =)))

This is called the geometric compression ratio and actual. The closure of valves associated with the inertia of the air charge. I did not go deep enough. Because it will cause even more issues )

A small clarification. When measurements of compression by means of scrolling by a starter from the working volume of the cylinder... how can I put it?.. "subtracted" part of the piston stroke to intake valve closing. For example, on my 318 Magnum engine intake valve closes at 61 degrees rotation of the crankshaft after the BDC. Thus to the volume of the combustion chamber is compressed, not the entire volume of the cylinder. Roughly speaking, when the degree of compression of 9.1/1, the actual mixture is compressed only in the order of 7.5 times. Again, this is something that concerns measurement of compression when scrolling the starter.
Well, the pressure at the end of the compression stroke slightly differently calculated. In the training manual for thermal calculation engine to see. And so, in General, all right.

I have a diesel 1 KZ-compression ratio — 21 and perfect compression 30.5 bar hence gamma is approximately equal to 1.125. )

It's good )

Taught this, yeah)

The new generation is still very a lot of time and is still ahead )

I'm a new generation and me that unfortunately is not taught((( so thank you)!

Famously described everything!
Now I'm waiting for an article about the dynamic of the LF, its relationship to "broad" shafts and some benzo to pour!)))

this banal formula from physics. nothing more.
here it is possible long and hard to talk about the intricacies and overlaps of phases, the geometric compression ratio and actual, etc. you Can write a strange book... but who needs it?

A little bit about your argument about the ratio between the LF and compression:
In the calculation of the compression is taken to be the volume Vp is equal to 3/4 of the geometric volume of the engine (closing the intake valve area 45градусов after NMT), so substituting in the formula EGS/Ro values from the definition of CR in error(from the formula Vp CR Vp is not equal to the formula EGS).
And Ro unit is not necessary to take (remember the difference of compression at the closed and open throttle, filmed not filmed air filter).
In my opinion the picture of compression in a person's head will be better, if it is not the formulas, and the graphs of change of pressure in the cylinder watch the process.
In the net you can find a lot of waveforms with motortestera, with the comment of what is happening.

science is good but in practice, the compression depends on the overlap and valve timing, modern almost new motor the compression should not be less than 15kg, the turbo motors are smaller. Below 12kg already large wear and power loss. For me landmark is a classic with a SG of 8.5 is normal compression 12-13kg

I'm trying to explain complicated things in simple words
not complex things even more complex concepts.
So. No. Not decided )

One Expat decided zakosit? :)

I waited for a mathematical solution describing the thermodynamic process is not a high school kid. Not attempt to expose the theory with examples at the kindergarten level.
We are with you in principle, nothing to talk about, if you do not understand the words "compression in the best case may be" — meaning that it is theoretically possible compression with such a compression ratio in the cylinder. That is more it does not become. Less — Yes. The same — with the big stretch. Not anymore.
With all this, you probably are not able to take into account, that in the compression stroke of the classic Otto cycle, the compression continues from BDC to top dead center. In the real motor, due to inertial processes, the Intake valve needs to close later NMT that is already there it suggests that the process of their compression stroke the compression is not the full working volume. Oh and don't forget the leakage past the compression rings have normal working engine up to 40%... And this is not the difference of the adiabatic index is 0.2 units, which is usually considered in an isolated system.
If tn tried to pull a decision, he simply used the ratio of specific heats in the 1.13-1.14 and you would get most of the empirical examples of Tazo-of secerov.

I hope call for a brain break, VAZ 2106 Sz 8.5 compression 11-12, VAZ 21213 szh 9.3 compression 11-12, VAZ 21083 szh 9.9 compression 11-12. How to use the formulas from the article to come to such a result?

Not waiting for the decision from the student. ) is?

The tale about the student having the task of looking up the answer on her, tried to solve it, and draw his own interpretation to the desired number of answer.

completely agree. I then also said — "burn" a car with such a compression. eventually found a book on operation and have it all figured out

Great article! Just describes my case. 10.8 compression, after compression capitali 17 everywhere!)) And in manual Mazda says that is the norm. And all those who studied at the Vases (it's Russian brand) also kindly offered their services for Kapitalka No. 2, wypoczywa eyes from these values and scaring stuck rings (immediately after capitali)! Just do not forget that there are vehicles where all is not well customized, there and loss more and the less... (for example someone can shed 5W20, and who is only 5W40)