Beda cc beda apanya?

[ediwarsito]

Membaca spesifikasi beberapa mesin Honda (Revo 100, Supra 125, Blade dll) yang beda-beda volume ruang bakar, ternyata diameter pistonnya tetap sama 50 mm. Ini artinya perbedaan volume tadi (cc) terletak pada jarak langkah TMA & TMB. Yang ingin saya tanyakan komponen apa saja yang mempengaruhi peda jarak TMA & TMB itu? Matur Nuwun.

[esh]

IMO, stang piston. CMIIW

[flexiblebil]

kalo nggak salah yang paling mempengaruhi itu panjang lengan kruk-as (crankshaft). ini yang mempengaruhi langkah piston. maksudnya, lengan kruk-asnya yang nggak sama antara mesin2 itu, jadinya panjang langkahnya juga beda. cmiiw.

[Prive]

ruang bakar kalo nggak salah khan pake ukuran bore & stroke, kalo beda cc tapi diameter piston (bore) sama berarti stroke-nya yang beda (panjang ruang bakar kira2 gitu) - cmiiw

[spin022]

IMO, stang piston. CMIIW

panjang pendek setang piston gak berhubungan dengan stroke bro...
stroke itu jarak antar poros bubungan(kruk-as/crankcase) terhadap pen setang seher
sepert ditunjukkan digbr : huruf "R"



cmiiw

[flexiblebil]

bener banget yang ditulis bro spin022. langkah piston itu kalo menurut gambar adalah dua kali R atau D. jadi bisa jadi piston ukurannya sama, tapi pabrikan maen2 di kruk-as (crankshaft), biar langkah piston (stroke) beda2.

[eNeR]

beda overstrok ama understrok apa ya?

[danangms]

understroke kayaknya gak ada deh. ada yang lebih tahu?

[ALTIMIT]

kalo borenya sama brarti strokenya yang beda bro karna cc dipengaruhi Bore x Stroke

slain overstroke klo ga salah ada square (bore=stroke)

[eNeR]

kayaknya gak ada ya, xe xe xe

[esh]

@ spin022: Thanks atas penjelasannya yang sangat akurat

[yoyoyo]

pernah dibahas juga disini
http://www.serayamotor.com/diskusi/view ... t=9578&f=4

[eNeR]

sori, sori, maksud aku beda oversquare ama undersquare apa?
trus berdasarkan link yg diberi ama mas yoyoyo td dikatakan bahwa oversquare lebih cocok untuk high sped (atau high rpm ya? cmiiw)
kalo diameter 53, 5 trus panjang 48,3 , termasuk oversquare ya?

[maxx]

sori, sori, maksud aku beda oversquare ama undersquare apa?
trus berdasarkan link yg diberi ama mas yoyoyo td dikatakan bahwa oversquare lebih cocok untuk high sped (atau high rpm ya? cmiiw)
kalo diameter 53, 5 trus panjang 48,3 , termasuk oversquare ya?

Stroke ratio, bore/stroke ratio and stroke/bore ratio are terms that are used to describe the form of a piston engine's cylinder when the piston is at the bottom dead center (bdc) point. The stroke ratio also gives a general direction of the engines characteristics. The bore is the diameter of the cylinder and the stroke is the length that piston travels, which is generated when pistons top dead center (tdc) and bottom dead center positions are compared, which is twice the crank throw. There are two different types of stroke ratios that are often mixed together causing confusion: Bore/stroke ratio and Stroke/bore ratio


Bore/stroke ratio
Bore/stroke is the most commonly used term, which is mainly used in the USA, Great Britain, Australia and some other countries.

An engine that has wider bore vs. stroke has a bore/stroke value of over 1.

For example an engine which has 100 mm (millimeter) bore and 80 mm stroke has a bore/stroke value of:

100 mm / 80 mm = 1.25

Such an engine is referred as oversquare or short-stroke engine.

An engine that has shorter bore vs. stroke has a bore/stroke value of under 1.

For example an engine which has 90 mm bore and 120 mm stroke has a bore/stroke value of:

90 mm / 120 mm = 0.75

This type of engine is called an undersquare or long-stroke engine.

An engine that has equal bore and stroke has a bore/stroke value of 1.

For example an engine which has both 95 mm bore and stroke has a bore/stroke value of:

95 mm / 95 mm = 1.00

This type of engine is called a square engine. Usually engines that have a bore/stroke ratio of 0.95 to 1.04 are referred as square engines.

Stroke/bore ratio

Stroke/bore ratio is generally more rare than bore/stroke ratio but is used in some countries, like in Finland for example. Stroke/bore ratio is similar to the bore/stroke ratio with the following exception:

When stroke/bore value is over 1 the engine is longstroke or undersquare and when the stroke/bore value is under 1 the engine is shortstroke or oversquare. However the square engine has a value of 1 in both cases.

For example an engine with 110 mm stroke and 80 mm bore, stroke/bore value 1.375, is an undersquare or longstroke and an engine that has 70 mm stroke and 100 mm bore, stroke/bore value 0.7, is oversquare or shortstroke.

Oversquare

A piston engine is oversquare or shortstroke if its cylinders have a greater bore (width, diameter) than stroke (length of piston travel). This is generally considered to be a positive trait, since (all things equal) a shorter stroke results in less friction and less stress on the crankshaft. An oversquare engine is generally more reliable, wears less, and can be run at a higher speed. In oversquare engines power low-speed torque tends to be lower since torque is relative to crank throw (distance from the crank center to the piston pin center) as well as the lowering pressure of the combustion gases as the piston descends. Engines can be modified by being "de-stroked", shortening the stroke to increase maximum rpms and top-end horsepower, at the expense of low-end torque.

Oversquare engines tend to be lighter and shorter than similar undersquare engines along the direction of piston travel, but they are wider in directions perpendicular to piston travel. As the length is not a large problem, these engine types are highly favored by many manufacturers because of their power and compact size.

Some Formula One engines have a bore to stroke ratio of approximately 2.5:1 and are capable of revving to 19,000 rpm.

Undersquare

A piston engine is undersquare or longstroke if its cylinders have a smaller bore (width, diameter) than stroke (length of piston travel). This can be a negative trait, since a longer stroke usually results in greater friction, more stress on the crankshaft, and a smaller bore requires smaller valves which restrict gaseous exchange. An undersquare engine usually has a lower redline than an oversquare one, but it generates more low-end torque. Engines can be modified with a "stroker" crankshaft, which increases an engines stroke from stock, increasing torque.

Undersquare engines typically are, proportionally, shorter in length, heavier, and taller than equivalent oversquare ones, which is one of the reasons why this type of engine is not generally used.

Many British automobile companies used undersquare designs through the 1950s, largely because of a motor tax system that taxed cars by their cylinder bore. Therefore, many of the most famous cars of that era use this design. This includes the Austin A-Series engine and many Nissan derivatives.

The Chrysler Slant-6, in the most common 225 cubic inch (3.7 L) version, is a massively undersquare engine with a 3.40" (86 mm) bore and a 4.125" (105 mm) stroke, producing most of its power right on the peak of its torque curve. The achilles heel of this engine, otherwise known for its exceptional durability, is being over-revved by inexperienced drivers. Red line for a factory engine is under 4,500 rpm; red line with aftermarket connecting rods is about 5,500 rpm. On the other hand, a well-maintained Slant-6 can be made to idle as low as 75 rpm (though this is *not* a recommended speed, neither the alternator nor the oil pump will function adequately). In some circles, the Slant-6 is nicknamed "The Stump-Puller" for its diesel-like low-speed torque. Appropriate gearing and driving skill is required for performance use.

Willys also used mostly undersquare engines, in fact the L134 and F134 engines, with their fairly small 3.125 inch (79.4 mm) bore and 4.375 inch (111.1 mm) stroke, are probably the most undersquare engines ever built (for Jeeps).

The Dodge Power Wagon, among other vehicles, used a Straight-6 Chrysler Flathead engine of 230 cubic inches (3.8L) with a bore of 3.25" (83 mm) and a stroke of 4.625" (117 mm) yielding a substantially under-square stroke ratio of 0.70.

Nowadays, undersquare engines tend to be quite rare, but this form of engine is still used in some applications. For example, a modern 8.4 liter Valmet 645 inline-6 tractor diesel engine is a longstroke/undersquare engine, but has an output of over 300 horsepower (224 kW) with turbocharger and intercooler. The popular Mazda Miata also uses an undersquare engine.

[danangms]

waduh...penjelasan teknisnya pakai english. ada yang indonesian? biar lebih mudah dipahami.

[ALTIMIT]

Bore/stroke ratio
Bore/stroke is the most commonly used term, which is mainly used in the USA, Great Britain, Australia and some other countries.

An engine that has wider bore vs. stroke has a bore/stroke value of over 1.

For example an engine which has 100 mm (millimeter) bore and 80 mm stroke has a bore/stroke value of:

100 mm / 80 mm = 1.25

Such an engine is referred as oversquare or short-stroke engine.

An engine that has shorter bore vs. stroke has a bore/stroke value of under 1.

For example an engine which has 90 mm bore and 120 mm stroke has a bore/stroke value of:

90 mm / 120 mm = 0.75

This type of engine is called an undersquare or long-stroke engine.

An engine that has equal bore and stroke has a bore/stroke value of 1.

For example an engine which has both 95 mm bore and stroke has a bore/stroke value of:

95 mm / 95 mm = 1.00

This type of engine is called a square engine. Usually engines that have a bore/stroke ratio of 0.95 to 1.04 are referred as square engines.

Bore/Stroke ratio adalah istilah yang paling sering digunakan, biasanya dipakai di U.S,England dan beberapa negara lain

Mesin yang mempunyai bore lebih lebar dari stroke (bore>stroke) mempunyai nilai bore/stroke melebihi 1

Sebagai contoh,mesin dengan bore 100mm dan 80mm stroke mempunyai bore/stroke value:

100mm/80mm = 1.25

Mesin seperti ini disebut oversquare atau short-stroke engine

Mesin yang mempunyai bore lebih kecil dari stroke (bore<stroke) mempunyai nilai bore/stroke kurang dari 1

Sebagai contojh,mesin dengan 90mm bore dan 120mm stroke mempunyai bore/stroke value:

90mm/120mm = 0.75

Mesin seperti ini disebut undersquare atau long-stroke engine

Mesin dengan bore sama dengan stroke (bore=stroke) mempunyai nilai bore/stroke 1

Sebagai contoh,mesin dengan bore 95mm dan stroke 95mm mempunya nilai bore/stroke:

95mm/95mm = 1

Mesin seperti ini disebut square engine. Biasanya mesin yang mempunyai rasio bore/stroke 0.95-1.04 disebut juga sebagai square engines

cukup bro?ato masih kurang?mao diitranslate yang mana lagi?CMIIW y klo ad salah2

[eNeR]

translatenya bagus mas, matursuwun terimakasih

[danangms]

thanx translate nya. lebih mudah dipahami. gw jadi lebih ngerti soal mesin.

[eNeR]

cara ngitung cc-nya darimana ya?

[yoyoyo]

....dikatakan bahwa oversquare lebih cocok untuk high sped (atau high rpm ya? cmiiw)
kalo diameter 53, 5 trus panjang 48,3 , termasuk oversquare ya?

oversquare berarti stroke nya pendek, sehingga utk 1 siklus lebih singkat, sehingga rpm nya lebih mudah naik, sehingga akselerasi lebih baik, tetapi pengorbanan di torsi putaran bawah.
Makanya dikatakan oversquare pd mesin ber-cc kecil kurang tepat krn torsinya baru "ada" di putaran yg tinggi..tinggi sekalski
Dan ya, yg ditanyakan diatas termasuk oversquare.

cara ngitung cc-nya darimana ya?

rumus silinder? 0.25 kali phi kali bore kuadrat kali stroke
= (0.25 x (22/7) x 53.5^2) x 48.3
= 108.5.... ml , sekitar 110cc

[ALTIMIT]

cara ngitung cc-nya darimana ya?

mnurut wiki

Code: Select all

Engine displacement is the volume swept by the piston(s) in a single movement. In the very familiar four-stroke piston engine (but also in the two stroke engine) this is the volume that is swept as the piston(s) move from top dead center to bottom dead center. It can be specified in cubic centimeters, liters, or cubic inches. An engine's displacement is a basic mechanical feature such that, all other factors being equal, more engine displacement means more power.

Engine displacement adalah volume yang dikompres oleh piston dalam sekali pergerakan TMB ke TMA pada mesin piston 4-tak konvensional juga 2-tak.Engine displacement bisa didefinisikan dalam satuan cubic centimeters, liters, atau cubik inches. Lebih besar engine displacement maka lebih besar pula tenaganya.

ini rumusnya : Engine Displacement



cnth : Bore 53.5, Stroke 48.3 silinder 1 brarti engine displacementnya
(phi/4) x (53.5 x 53.5) x 48.3 = 108.57

sori kalo salah,gw ga tau engine displacement indonya apa,juga baris trakhir agak ngaco

[eNeR]

wah thanks bro yoyoyo dan altimit, berarti untuk oversquare lebih ditujukan pada rpm tinggi ya?
pantesan smash kok untuk awalan masih kurang greng

[eNeR]

men, kalo liat dari rumus yg mas bro altimit berikan, kok mirip ama volume tabung ya...
r=53,5mm/2= 26,75mm
t=48,8mm (sori bro, kemarin salah tulis, kemarin nulisnya 48,3)
V=3,14 x (r x r) x t
=3,14 x (26,75 x 26,75) x 48,8
=109647,073mmkubik
=109,6cc
mungkin hasilnya akan mendekati bro altimit jika tingginya (t) sama,
just sharing bro

[Cloud]

men, kalo liat dari rumus yg mas bro altimit berikan, kok mirip ama volume tabung ya...

emang sama plek, kan emang mencari rumus tabung, bedanya disini disebut displacement, arti kasarnya kira2 volume silinder yang dilewati piston,
secara umum, makin oversquare, karakter mesin lebih bagus pada rpm yang lebih tinggi, begitu sebaliknya.
nah, kalo diameter piston diperkecil ato sama, sedangkan strokenya yang dinaikkan, tujuannya mengejar efisiensi thermal dan efisiensi langkah. makin kecil piston, maka penyebaran campuran bbm dengan udara makin cepat mengisi ruang, kemudian, luasan piston yang kecil akan memperkecil heat loss, yang berarti energi panas buat memuaikan fluida ketika meledak lebih sedikit yang hilang dibandingkan memakai piston yang besar.
jadi ketahuan dong, kalo mesin long stroke lebih mengejar efisiensi n torsi,

[flexiblebil]

mantep banget penjelasan dari bro cloud.. saya nggak kepikiran soal efisiensi panas yang lebih besar kalo pistonnya berdiameter lebih besar, kirain cuma masalah torsi lebih besar aja untuk mesin2 undersquare hehehe..