KENALI JENIS-JENIS ENJIN KERETA

Azhargoth

OHV engine design
OHV means OverHead Valve - an engine design where the camshaft is installed inside the engine block and valves are operated through lifters, pushrods and rocker arms (an OHV engine also known as "Pushrod" engine). Although an OHV design is a bit outdated, it has been successfully used for decades. An OHV engine is very simple, has more compact size and proven to be durable.
Downsides: it's difficult to precisely control the valve timing at high rpm due to higher inertia caused by larger amount of valve train components (lifter-pushrod-rocker arm). Also it's very difficult to install more than 2 valves per cylinder or implement some latest technologies such as Variable Valve Timing - something that could be easily done in a DOHC engine.






OHC or SOHC engine
OHC in general means OverHead Cam while SOHC means Single OverHead Cam.
In the SOHC engine the camshaft is installed in the cylinder head and valves are operated either by the rocker arms or directly through the lifters (as in the picture).
The advantage is that valves are operated almost directly by the camshaft - easy to achieve the perfect timing at high rpm. Also it's possible to install three or four valves per cylinder
The disadvantage - an OHC engine requires a timing belt or chain with related components - more complex and more expensive design.





DOHC or Twin cam engine
DOHC or Double OverHead Cam - the setup used in many today's cars. Since it's possible to install multiple valves per cylinder and place intake valves on the opposite side from exhaust vales, DOHC engine can "breath" better meaning that it can produce more horsepowers with smaller engine volume. Compare: The 3.5-liter V6 DOHC engine of 2003 Nissan Pathfinder has 240 h.p, similar to 245 h.p of the 5.9-liter V8 OHV engine of 2003 Dodge Durango.
Pros: High efficiency, possible to install multiple valves per cylinder and adopt variable timing.
Cons: More complex and more expensive design.



Okeh aku excerpts dari samarins.com..(nampak menarik sebab di format .gif) untuk tambah pengetahuan pada jenis-jenis enjin. SOCH, DOHC etc...gambaran yang lebih jelas macmana beza satu jenis injin dan parts dia itu berfungsi...(eg cam shafts, piston, crankshaft...)

Credits to or more info :  http://www.samarins.com/glossary/index.html

[ Last edited by  Azhargoth at 7-12-2006 09:44 AM ]

bulletbiru

bro...
yang mana ingin kereta malaysia...
just nak tau larr contohnyer Proton WAJA Campro model...

Azhargoth

Illustration takde ler...tapi sefaham dan setau aku, enjin campro nih mcm basic DOCH engine...jap aku pi carik..

B_ii_L

Originally posted by bulletbiru at 7-12-2006 09:46 AM
bro...
yang mana ingin kereta malaysia...
just nak tau larr contohnyer Proton WAJA Campro model...

Proton Waja Campro.....DOHC Double Overhead Cam, MPI System (Multi Point Injection System)

Azhargoth

ada pun from : WIKI

Basic DOHC engine
The basic Campro engine coded as S4PH is a basic DOHC 16-valve 1.6 L engine that produces 110 bhp (82 kW) @ 6,500 rpm of horsepower and 148 N-m of torque. This is the engine that powers the Proton Gen-2. The S4PH engine can be fitted with Cam Profile Switching (CPS) and Variable Inlet Manifold (VIM) technology. Besides this 1.6 L engine, Proton has produced the 1.3 L version of the Campro engine.

Even though the S4PH engine seems to be quite powerful at higher revs, its performance is reportedly sluggish at lower revs and this is proven by driving the Gen-2 uphills where drivers who drive the manual transmission version have to shift a lot between 2nd gear and 3rd gear. This is due to its torque dip between 3,000 ~ 3,500 rpm where the torque decreases slightly before picking up back to the maximum torque at 4,000 rpm.

Before the engine is ready to be installed in the Gen-2 cars, Proton installed the engine in the Waja specialized for on-road tests.

Currently the Campro engines installed in the Gen-2 has none of the promised cam profile switching (CPS) and variable inlet manifold technologies. No date nor any information has been known as to when Proton will equip its models with the promised full-spec engine.

Another engine option for the basic DOHC engine is a 1.3L engine coded as S4PE. While the power output of S4PH engine can't be considered as impressive, the S4PE engine produces 94 bhp (70 kW) @ 6,000 rpm and the torque of 120 N-m @ 4,000 rpm, much powerful than most 1.3L rivals, even with variable valve timing technology.

The bore x stroke dimensions for both engines are as follows:-

    * S4PH (1.6L): 76 x 88 mm, resulting the displacement of 1597 cc.
    * S4PE (1.3L): 76 x 73.4 mm, resulting the displacement of 1332 cc


more info : http://en.wikipedia.org/wiki/Campro_engine

sedondon

Best le pulak animation tu, aku jadikan avatar aku ler, boleh tak azhargoth?

sedondon

Kenapa camshaft ada 4 valve bagi satu piston?

nizam_syah82

enjin magma xde ke..kekekekke..4G13Px super charger..

Fast-N-Furious

Originally posted by sedondon at 7-12-2006 10:43 AM
Kenapa camshaft ada 4 valve bagi satu piston?

tak semestinyer.. ader gak yang 3 jer..

Kilokahn

Citer pulak pasal engine Wankel.

Fast-N-Furious

wehh.. sesaper citer pasal rotary enjin plak.. haku malas nak citer walau pong haku tau.. hehehe

Squall-Leonhart

Originally posted by Azhargoth at 7-12-2006 09:42 AM

OHV engine design
OHV means OverHead Valve - an engine design where the camshaft is installed inside the engine block and valves are operated throu ...

Sebenarnya ada lagi jenis yang lebih primitif drp enjin pushrod, iaitu L-head engine. Enjin camtu diguna pada model2 keter dan motor terawal. Design dier sempoi giler tapi pasal injap dier kat part bawah dan ditolak terus oleh camshaft, maka enjin tu takleh hasilkan compression ratio yang tinggi, so kurang cekap la. Sebab tu la sejak tahun 1950an dah tak pakai enjin L-head lagi.

Squall-Leonhart

Originally posted by Fast-N-Furious at 7-12-2006 11:59 AM
wehh.. sesaper citer pasal rotary enjin plak.. haku malas nak citer walau pong haku tau.. hehehe

Bleh, tapi kasi credit lebih sket tau...? :bgrin:

Okey, enjin rotary aka enjin Walkel ni dapat nama daripada pencipta dier, Dr. Felix Wankel. Tak masam enjin piston biasa yang bergerak secara naik-turun piston dan ditukar ke gerakan membulat oleh con rod dan crankshaft, enjin rotary memang berfungsi drp putaran rotor. So 4 jenis lejang pada enjin 4-stroke biasa dapat dilakukan oleh enjin rotary dalam masa serentak.

Tapi kelemahan dier ialah kuat makan minyak sebab kedudukan intake dan exhaust port yang bleh terbuka dua2 once in a while. So, kuat makan minyak la. Tapi time tahun 2000 Mazda dah siapkan enjin Renesis yang banyak improve fuel consumption dengan ubah kedudukan port dier jer. Satu lagi kelemahan dier ialah rotor tip dier mungkin bleh pecah pada rpm tinggi, so rotor tip dier kena dibuat dengan bahan2 yang betul2 kuat dan tahan haus la.

Tapi kelebihan dier ialah power-to-weight ratio besar walaupun cc kecik. Enjin RX-8 tu baru 1.3L tapi bleh hasilkan sekitar 238 ~ 248 bhp tanpa guna turbo, padahal enjin piston 1.3L biasa - katakan enjin Campro 1.3L - baru dapat hasilkan 94 bhp. Satu lagi kelebihan dier ialah bleh pakai minyak merah, maybe pasal pergerakan air-fuel mixture dalam combustion chamber la.

Azhargoth

Originally posted by Squall-Leonhart at 7-12-2006 12:43 PM

Enjin RX-8 tu baru 1.3L tapi bleh hasilkan sekitar 238 ~ 248 bhp tanpa guna turbo, padahal enjin piston 1.3L biasa - katakan enjin Campro 1.3L - baru dapat hasilkan 94 bhp. Satu lagi kelebihan dier ialah bleh pakai minyak merah, maybe pasal pergerakan air-fuel mixture dalam combustion chamber la.

betuii..baru aku nak sentuh bab RX8 tuh RX7 pon sama gak actually rotary engine..cc kecik road tax murah lari cam roket..anyway aku dah tengok sendiri rotary enjin nih..kat satu rx7 masuk bengkel, bengkel biasa je tah tau tau la pomen tuh reti buat ke idak..ada org kata kalau nak tau berapa cc dia actually kali gan 2..so 1.3x2? betui ka?

Fast-N-Furious

Originally posted by Azhargoth at 7-12-2006 04:44 PM


betuii..baru aku nak sentuh bab RX8 tuh RX7 pon sama gak actually rotary engine..cc kecik road tax murah lari cam roket..anyway aku dah tengok sendiri rotary enjin nih..kat satu rx7 masuk bengk ...

tak silap haku, rotary enjin road tax dier lain sket, tak sama dengan enjin in-line..

t@t

Originally posted by Azhargoth at 7-12-2006 04:44 PM


ada org kata kalau nak tau berapa cc dia actually kali gan 2..so 1.3x2? betui ka?  ...

itu mcm kaaa...???

patut la Rx8 power gak wlaupun 1.3,maknanya double la...

Kandos

Melihat dari sistem rotary nih, lebih kurang mcm sistem motor 2 lejang kan?
Soalan.: berapa biji rotor kah yg diperlukan bagi sebuah enjin rotary. Mcm enjin piston ada 3 - 4 piston dalam satu enjin. V6 ada 6 bijik piston.

Squall-Leonhart

Originally posted by Azhargoth at 7-12-2006 04:44 PM


betuii..baru aku nak sentuh bab RX8 tuh RX7 pon sama gak actually rotary engine..cc kecik road tax murah lari cam roket..anyway aku dah tengok sendiri rotary enjin nih..kat satu rx7 masuk bengk ...

Satu rotor dalam keter RX-8 tu displacement dier 654 cc, setiap enjin RX-8 ada 2 rotor... so kalau kali dua dapat 654 cc x 2 = 1308 cc laa...

sixfullbar

perghh.. cantik ler rx-8 tu..



iklan jap.

the_trooper

ff:

fullamakkkkkkk bro...lawa abatar....:bgrin:
lama betoi x melepak sini...