[home][rumors and news][model release matrix][dealer network][desktop calendar][exhaust notes][tov forums][links][search][sponsors][garage][login]

Tire Rack Upgrade Garage
 Search for a Dealer:
 Canadian Flag US Flag
 Honda Acura
 ZIP  
Acura
There are currently no active Acura promotions
Honda
There are currently no active Honda promotions
Strange Civic Type R(?) based mule spied testing in Europe.
More.......................
New 2016 Civic Coupe Spied Up Close
More.......................
Honda reports August 2015 Sales Numbers
More.......................
2016 Accord Raises its Game with Dynamic Styling, Chassis and Body Upgrades, Available Honda Sensing
More.......................
Acura NSX Features and Options on Display at The Quail, A Motorsports Gathering
More.......................
Performance Manufacturing Center: Precision Craftsmanship
More.......................
2016 Honda Odyssey expands availability of HondaVAC with more affordable SE model
More.......................
Honda reports July 2015 sales numbers
More.......................
HR-V/Vezel --> Re: Ad
Join Discussion......
General Talk --> Re: When Honda Ruled...
Join Discussion......
TLX --> Re: Exterior Styling: TLX vs. C300
Join Discussion......
Today's Reading Links --> Re: End of GM and US Automotive industry?
Join Discussion......
Prelude --> Re: Holy Prelude
Join Discussion......
TOV Asia --> Re: S660 nice little toy; if only I could fit in ...
Join Discussion......
Professional Motorsports --> Re: Honda Formula Lites
Join Discussion......
Today's Reading Links --> Re: Automotive News: Acura's new boss wants sedans 'that people get excited about'
Join Discussion......
Videos --> Re: Hill climb Accord Type R GoPro
Join Discussion......
Professional Motorsports --> Re: F1 - 2015 Italian Grand Prix
Join Discussion......
Ridgeline - General Talk --> Re: Ridgeline Spy Shot
Join Discussion......
TLX --> Re: Ready to be dissapointed
Join Discussion......
Today's Reading Links --> Re: Is this the Emperor's New Clothes?
Join Discussion......
RLX --> Re: Acura RLX Reviews
Join Discussion......
Strictly Technical --> Re: Driven to Kill - Wow
Join Discussion......
Jump to:
i-VTEC
Civic Si: Engine Block/Crankshaft
The Civic Si engine features a compact aluminum block with cast-in iron liners-a design known for its lightweight, high rigidity, and excellent durability. The block has a one-piece aluminum crankshaft carrier, which has ferrous-carbon inserts in the bearing caps for additional strength and incorporates a stiff, cast-aluminum oil pan. The crankshaft is a highly rigid, forged-steel design that uses a special micro-polished surface finish for reduced friction and increased durability. In addition, the engine uses high-strength connecting rods and crankshaft as well as high-compression cast-aluminum pistons.

Civic Si: i-VTEC Concept
The innovative Variable Valve Timing and Lift Electronic Control (VTEC) system delivers abundant low-rpm torque, exhilarating high-rpm power, and outstanding fuel efficiency. The Civic Si features the latest version of this remarkable engine system: i-VTEC. The "intelligent," i-VTEC system adds VTC (Variable Timing Control) to VTEC to provide continuously variable camshaft timing taking the concept of variable valve timing to new heights. In the Civic Si, i-VTEC = VTEC + VTC. Not only does i-VTEC provide a substantial performance increase across a broad power band, it boosts fuel economy while also reducing engine emissions.

Civic Si: i-VTEC Valvetrain
The Civic Si engine uses an aluminum cylinder head and a dual overhead cam, four-valve-per-cylinder valvetrain incorporating the i-VTEC system. High performance camshafts are used that allow for aggressive intake and exhaust valve openings to boost the rate that air moves into and exhaust moves out of the cylinder. At high engine speeds, valve lift phase on the intake side is increased by five degrees and on the exhaust side by 10 degrees. The camshafts increase engine breathing and help deliver enhanced top-end horsepower. The camshafts are operated by a silent-chain drive that helps provide smooth, refined performance while also being maintenance-free.

The VTEC component to the innovative Civic Si i-VTEC system adjusts the lift and opening duration of the valves to help the engine produce both abundant low-rpm torque and excellent high-rpm power. At low rpm, VTEC provides valve timing and lift for optimum cylinder filling. In addition, the timing of the intake valves is staggered and their lift asymmetric-creating a swirl effect within the combustion chambers. The result is increased burn speed with improved combustion stability. As engine rpm builds, VTEC transitions to a high-lift, long-duration cam profile for improved high-rpm engine output.

The Civic Si uses a high performance version of VTEC that varies the lift and duration of both the intake and exhaust valves for maximum power output. At lower rpm, the valves follow low lift, short duration camshaft profiles to help boost low-end torque. Above 5,800 rpm, the intake and exhaust valves are operated by high-lift, long-duration cam profiles, for maximum high rpm horsepower. When combined with VTC, both versions help the Civic Si engine produce a remarkably broad and smooth power band with exceptional torque and horsepower.

Civic Si: VTC (Variable Timing Control)
The Civic Si's i-VTEC system adds VTC (Variable Timing Control) to VTEC for continuously variable camshaft phasing across the engine's entire power band. As engine rpm builds, a VTC actuator-controlled by an engine-control unit that monitors cam position, ignition timing, exhaust oxygen content, and throttle position-advances or retards the intake cam throughout the 50 degree range, optimizing engine output and reducing emissions.

During typical operation, the intake camshaft timing is almost fully retarded at idle to help provide more stable idling while reducing exhaust emissions (NOx). As rpm increases, the intake camshaft is advanced, opening the intake valve sooner and providing additional valve overlap. This results in increased fuel economy (by reducing pumping losses) and a further reduction in exhaust emissions (by creating a large, internal exhaust gas re-circulation effect). Also, to generate additional power throughout the rev range, the intake camshaft is continuously varying the amount of advance or retard, instantly adjusting to provide additional power as required by the driver.

Source: Honda PR



[Previous Page] [Next Page]

reader's comments
Click Here to Submit Your Comments

Viewing Threshold (What is this?)

[fancy] [flat] [simple]
Subject Thread Originator Replies Last Post
  Si: Balance shafts and whoa torque dip.
VTEC_Inside 11
  MT on HYBRID??
zapata 2
  6-sp tranny ratios?
fleadhfan 2
  New SAE rating?
ipribadi 1
  Insurance?
swmtam 1
  Weight and prices?
8000RPM 0
Jump to:
Product Overview : Honda HR-V
Read Article....................
2016 Honda Accord V6 Touring Coupe PR Photo Gallery
Read Article....................
2016 Accord Touring Sedan PR Photo Gallery
Read Article....................
2016 Honda Accord Sport PR Photo Gallery
Read Article....................
TOV Video: 2016 Honda Pilot walkaround with Marc Ernst
Read Article....................
TOV Video: 2016 Honda Pilot First Drive
Read Article....................
Contact TOV | Submit Your Article | Submit Your Link | Advertise | TOV Shop | Events | Our Sponsors | TOV Archives
Copyright © 2015 Velocitech Inc. All information contained herein remains the property of Velocitech Inc.
The Temple of VTEC is not affiliated with American Honda Motor Co., Inc. TOV Policies and Guidelines - Credits - Privacy Policy