[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
2017 Acura NSX Supercar Claims Class Victory in North American Racing Debut at Pikes Peak
More.......................
BREAKING: Hondata releases reflash for L15B7 (10th Gen Civic 1.5 Turbo), and we tested it
More.......................
Refreshed 2017 Acura MDX Launches Tomorrow (June 22, 2016)
More.......................
All-New 2017 Honda Ridgeline Launches Nationwide
More.......................
Acura NSX-Inspired EV Concept Ready to 'Charge Up' Pikes Peak
More.......................
Neal's Fantasy Factory Tantalizes with the Acura TLX "2020 Vision" Concept
More.......................
2017 Acura NSX Supercar to Make its North American Racing Debut at 2016 Pikes Peak
More.......................
American Honda Reports May Sales Results
More.......................
NSX --> Re: Reasons
Join Discussion......
Professional Motorsports --> Re: Assen MotoGP - spoilers
Join Discussion......
Today's Reading Links --> Re: VW to install BEV and FCEV charging network as part of settlement
Join Discussion......
Today's Reading Links --> Re: Particulate filters for gasoline cars coming by 2017
Join Discussion......
Civic --> Re: 06 Si and Takata
Join Discussion......
Civic --> Re: 2017 Civic Hatchback
Join Discussion......
General Talk --> Hemi Under Glass Rolls, and Jay Leno is the passenger
Join Discussion......
Strictly Technical --> Re: Mazda G Vectoring
Join Discussion......
General Talk --> Re: Shipping a Vehicle
Join Discussion......
Today's Reading Links --> Re: Honda/Acura below average on quality? WTF?
Join Discussion......
Today's Reading Links --> Re: Greatest commercials of all time! Hyundai!
Join Discussion......
General Talk --> Re: Vehicle Dependability and IQS
Join Discussion......
Civic --> Re: 10th Gen Civic 5-Door
Join Discussion......
Civic --> Re: 2016 Honda Civic problems, error messages & warnings
Join Discussion......
Strictly Technical --> Re: C&D: Turbo vs N/A transient response
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:
TOV Video: 2017 Honda Ridgeline ride along
Read Article....................
2017 Honda Ridgeline PR Photo Gallery
Read Article....................
First Drive: 2017 Acura NSX(!)
Read Article....................
2017 Acura NSX PR Photo Gallery
Read Article....................
TOV Video: Guy Melville-Brown talks about the 2016 Civic Coupe design
Read Article....................
TOV Video: John Hwang introduces the 2016 Civic Coupe
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