[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
Honda HR-V Compact SUV to Join All-New 2015 Fit as Honda Expands Small Car Lineup
More.......................
Some thoughts, photos, and notes on the 2015 Acura TLX from the NYIAS show floor
More.......................
2015 Acura TLX Unveiled at the 2014 New York International Auto Show
More.......................
Video: TOV member catches a TLX prototype on dashcam!
More.......................
All New 2015 Honda Fit Designed to Top the Subcompact Class
More.......................
Honda set to show interesting new Concept at Beijing International Automotive Exhibition
More.......................
'HR-V' name confirmed for upcoming Fit-based 'urban sport utility'
More.......................
American Honda Announces Sales Results for March 2014
More.......................
General Talk --> Re: Some random NYIAS thoughts on auto interiors
Join Discussion......
Today's Reading Links --> Bloomberg: ASIMO gives Honda edge in driverless cars
Join Discussion......
General Talk --> Re: Honda set for a rocky road ahead in Europe
Join Discussion......
NSX --> Re: Acura NSX....How it's going to be sold in the US
Join Discussion......
General Talk --> Re: Place your bets-TLX. Fit, HR-V sales
Join Discussion......
HondaMobilia --> Re: Tenshodo RA273 Engine
Join Discussion......
Professional Motorsports --> Re: Any rumors about Honda F1 engine progress?
Join Discussion......
MDX --> Re: My review
Join Discussion......
Accord --> Re: Converting to HID lights in 13 or 14' Accord...
Join Discussion......
General Talk --> Re: If there was a TLX Wagon
Join Discussion......
General Talk --> Re: Acura Style Magazine - Out of touch?
Join Discussion......
Today's Reading Links --> Re: USA Today article about Acura
Join Discussion......
Civic --> Re: latest CTR details - megane 275r 7:45 minutes
Join Discussion......
Today's Reading Links --> Re: Honda FY14 production / JP sales
Join Discussion......
Accord --> Re: 9th Generation Honda Accord Reviews
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 Photo Gallery: 2015 Honda Fit
Read Article....................
PR Photo Gallery: 2015 Honda Fit
Read Article....................
TOV Dyno Test: 2014 Accord Hybrid
Read Article....................
TOV Video: 2015 Acura TLX design Overview by Jared Hall
Read Article....................
PR Photo Gallery: 2014 Acura RLX Sport Hybrid
Read Article....................
PR Photo Gallery: 2015 Civic Type R Prototype
Read Article....................
Contact TOV | Submit Your Article | Submit Your Link | Advertise | TOV Shop | Events | Our Sponsors | TOV Archives
Copyright © 2014 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