Whats the difference between a v6 3.4liter SFI and a v6 3.4liter DOHC?

 

Check the below links for difference...EnJoy
1997 Chevrolet Monte Carlo -- Engines
A 3.4 Liter DOHC V6 SFI is standard in Monte Carlo Z34. This sophisticated, 24-valve engine is powerful, affordable and fuel-efficient. OBD II (On-Board Diagnostics Second Generation) is standard. ... 8mm cam belt and sprocket minimize noise...

249k - 36 sec @ 56k


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1996 Monte Carlo Specifications - (continued)
1996 Monte Carlo Specifications - ; Engine, Capacities and Transmission ... Type 3100 SFI V6 3.4 Liter SFI DOHC V6 ... Cam drive Chain Chain...

249k - 36 sec @ 56k


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Having Touble getting links to connect : ( Below is from above links)
1997 Chevrolet Monte Carlo Engines
3100 V6 SFI ENGINE (L82)


A 3100 V6 SFI engine is standard in Monte Carlo LS. This smooth-running, 60-degree V6 is teamed with the 4T60-E electronically controlled four-speed automatic transmission. OBD II (On-Board Diagnostics Second Generation) is standard.

• 160 horsepower at 5200 rpm
• 185 lb.-ft. torque at 4000 rpm.
  Additional 3100 V6 SFI features:
• Improved starter provides smooth, quiet and reliable operation
• One-piece flywheel improves quality and reliability, and reduces weight
• Increased coolant flow to the heater results in quick warmup time
• Powdered metal thrust plate and cold-formed steel camshaft journal (both features involved with opening and closing the intake and exhaust valves) improve reliability and durability of the camshaft
• Engine oil wear sensor informs the driver when the oil should be changed
• Powertrain Control Module (PCM) doubles the memory capacity over 1996 module
• Roller rocker arms are designed to minimize friction as well as engine noise
• Mass airflow sensor is designed to provide precise air metering and control of air/fuel ratio
• Sequential Fuel Injection (SFI) precisely matches fuel delivery to each cylinder’s intake stroke for a smooth idle, precise emissions control and impressive driveability
• "High-resolution" 24X ignition system provides fast ignition and smooth idle
• The 3100’s "assembled" camshaft is made up of individual lobes that are permanently locked onto a weight-saving hollow tube for outstanding durability and idle stability
• A structural oil pan adds strength and rigidity, and reduces noise. The die-cast aluminum pan is "cross-bolted" to the main bearing caps, similar to a race car engine
• An extended-life stainless-steel exhaust system (pipes, catalytic converter and muffler) resists corrosion and reduces the cost of ownership
• Oil level and coolant sensors alert the driver to check fluids to prevent engine damage
• Extended-life coolant has a scheduled maintenance interval of 5 years or 150,000 miles, whichever comes first*
• Extended-life platinum-tip spark plugs designed to allow first scheduled maintenance at 100,000 miles*.

*Maintenance needs vary with different uses and driving conditions.
3.4 LITER DOHC V6 SFI ENGINE (LQ1)


A 3.4 Liter DOHC V6 SFI is standard in Monte Carlo Z34. This sophisticated, 24-valve engine is powerful, affordable and fuel-efficient. OBD II (On-Board Diagnostics Second Generation) is standard.

3.4 Liter V6 power ratings:

• 215 hp @ 5200 rpm
• 220 lb.-ft. torque @ 4400 rpm.
  The following components are just part of what makes the 3.4 Liter DOHC V6 SFI engine’s performance so impressive:
• Upper and lower intake manifolds, cylinder heads, a discrete throttle body, a rear inlet duct and an exhaust manifold maximize airflow and contribute to the engine’s horsepower and torque
• Both intake and exhaust valves are designed for efficient and durable operation
• Camshaft timing and the 9.7:1 compression ratio provide even timing for the opening and closing of intake and exhaust valves. The 3.4 Liter DOHC V6 SFI is designed for quiet operation:
• Laminated oil pan and direct-mount accessories minimize vibration
• 8mm cam belt and sprocket minimize noise
• Composite covers surround the cam belt cavity and the direct-mount accessories for reduced engine noise and vibration. LQ1 technical features: Engine oil wear sensor informs the driver when an oil change is necessary Wide-open throttle has been increased from 6250 rpm to 6500 rpm for improved performance Powertrain Control Module (PCM) doubles the memory capacity over the 1996 module
• A low oil level sensor alerts driver to low oil levels to prevent engine damage
• Dual internal fan generator (DIF-130) provides high electrical output and low noise level
• Heated oxygen sensor provides quick emissions control at start-up
• Four-valve-per-cylinder, DOHC design gives excellent airflow and efficient high rpm operation
• Sequential Fuel Injection (SFI) optimizes combustion by precisely matching fuel delivery to each cylinder’s intake stroke, producing a smooth idle, precise emissions and impressive driveability
• Extended-life coolant has a scheduled maintenance interval of 5 years or 150,000 miles, whichever comes first*
• Extended-life platinum-tip spark plugs allow for first scheduled maintenance at 100,000 miles*
• Stainless-steel dual exhaust system with styled outlets resists corrosion.

*Maintenance needs vary with different uses and driving conditions.
ON-BOARD DIAGNOSTICS SECOND GENERATION (OBD II)

Standard on both engines, On-Board Diagnostics are sophisticated with OBD II (On-Board Diagnostics Second Generation). The Powertrain Control Module (PCM) monitors the emissions system and its components to detect deterioration or malfunction.

Enhanced evaporative emissions system (3100 V6 engine only) detects evaporative fuel system leaks between the fuel filler cap and the purge solenoid by applying a vacuum seal to the fuel tank. If there is a leak, the system will not achieve, or maintain, a vacuum. If a problem is detected, a Diagnostic Trouble Code (DTC) is stored and indicates the type of fault detected.

• The PCM stores and retrieves diagnostic messages to help technicians diagnose and fix problems quickly and accurately.
• The PCM alerts the driver by illuminating the "Service Engine Soon" light when it detects a deterioration in the performance of any of the monitored components.
• Unlike first-generation systems that signaled only system failures, OBD II alerts the driver to have the vehicle serviced before experiencing a possible breakdown or incurring more expensive repairs.

 

Couldn't ask to have a more detailed answer, the differences are right there in black and white.

great job Kidspace. (i feel like im role playing you, all i need are some :rolleyes, and maybe an animated .gif or 3 in my post, lol):p

 

which ones better?

 

Space did a great job compairing the 3100 V6 vs. the 3.4L DOHC V6....

I thought that I read: differnce between 3.4L V6 SFI and 3.4L V6 DOHC??? If this is what your asking then to the best of my knowledge, here are the differences:

3.4L SFI:
-Pushrod (cam in block) V6
-2 valves per cylinder (12 total)
-170-185 HP
-Found in 6th gen Monte's

3.4L DOHC:
-Double Over Head Cam V6
-4 valves per cylinder (24V total)
-215 HP
-Found in 5th gen Monte's

There may be more things different about the engines, but these are the big differences.....The 3.1L V6 that KidSpace was talking about was the base engine for 5th gen Monte's....The 3.4L DOHC V6 was the performance engine found in the Z34 (i'm not sure of exact years when engines were available, because I know at some point, I think maybe 1998 they replaced the 3.4L DOHC with the 3800 V6)....

The older 3.1L 3100 V6, 3.4L 3400 V6, and 3.8L 3800 V6 all use the same basic technology of 2 valves per cylinder, and pushrods. The 3.1L and 3.4L are 60 degree V6's and the 3.8L is a 90 degree V6.......

I know I went a little off the question...but I hope this helps...And If I read the question wrong then oops...you just got more information!

 

Thats too vague of a question to compare.

The 3.4 dohc engine hasn't been made in years and is far more rare because of it.

Conversely- the 3400 still exists today in various forms (as the engines like the 3100, 3400, 3500, etc are all very similar).

The 3400 is easier to work on, and more reliable- but I would think you could make more power with a 3.4 dohc in modding; the hard part is finding aftermarket for an engine that hasn't been made in 10 years. There are a handful of basic maintenance procedures on the 3.4 dohc that are significantly more difficult than on any normal engine.