Author Topic: displacement versus HP engine basics? (Read 9059 times)

prysm · « **on:** August 07, 2006, 01:21:45 pm »

Hi

I was browsing through my newly installed autodata CD.

My current engine is a mazda R2 with 2.2L and 47KW, 64DIN hp @4000RPM

I found an RF engine with 2.0L and 52Kw, 72 DIN HP @ 4500RPM

my question is this figures correct? I have always thought bigger displacement meant higher horsepower.

thanks

MacGyver · « **Reply #1 on:** August 07, 2006, 02:43:05 pm »

Someone familiar with those specific engines & their technical info may offer more assistance, however:

What are their differences & similarities?
Do they both have the same injection system type & pressure, same number of valves per cylinder, same applications? Are they both about the same age or is the RF a newer 'improvement'?
Same compression ratios? Head & port styles? Air intake systems?

Without knowing both sets of specs, these & other factors can assist smaller lighter (newer?) engines to make more power per cubic inch.

prysm · « **Reply #2 on:** August 08, 2006, 11:56:02 am »

For The R2 here are the information I was able to get

Cylnder: 4/OHC
Capacity: 2184cc
Compression Ratio: 22.9
Pump Type: Kiki VE 104748-0151 Rotary
Nozzle Pressure New/Used: 135/116 bar
leak rate: 113/10 bar/secs
governed speed: 4700-4900

For RF

Cylinder: 4OHC
Capacity: 1998cc
Compression Ratio: 21.7
Pump Type: NP-VE4 Rotary
Nozzle Pressure New/Used: no data
leak rate: no data
governed speed: 5100-5300

so far thats what I was able to get

prysm · « **Reply #3 on:** August 08, 2006, 12:31:40 pm »

I guess the improvement in power output can be attributed to the
higher governed rpm.

zyewdall · « **Reply #4 on:** August 08, 2006, 04:06:58 pm »

In this case, it looks like the higher rpm is giving the higher horsepower. If you had a complete horsepower curve for each, I bet you'd see that the 2 liter would be a little less at the same rpm as the 2.2 liter.

Newer engines with their fancy gadgets definitely have a higher horsepower per liter though. For example, my truck engine is a 1984 mechanically controlled indirect injection, 2.3 liter turbodiesel, rated at 84 hp at about 4,500rpm, and 140 ft lbs torque at 2,400rpm. A 1999 VW TDI, with electronic controlled injection pump, direct injection, and variable vane turbo, and a performance chip, is rated at 110 hp at about 4,500rpm, and 180 ft lbs of torque at 1,800rpm.

prysm · « **Reply #5 on:** August 09, 2006, 05:55:06 am »

I was wondering if a turbo version of the 2.0L RF is strong enough to swap with my 2.2L NA without degredation in performance or overloading the engine.

the RF-turbo version is rated at 80HP

MacGyver · « **Reply #6 on:** August 09, 2006, 11:35:38 am »

Replacing 64hp engine with 80hp, and you're worried about performance? I don't get it :?
The turbo motor is 80hp @ what rpm? Unless it's far from the 4k peak of the 2.2L, it should offer enhanced performance. If I had to guess I would presume better low end numbers which would mean better acceleration off the line. Fuel economy could improve too unless you become addicted to the additional power & you're on the boost continuously.

You mention concern about overloading the engine. Is this engine known for being weak and/or problematic? If you're unfamiliar with it, do some research before procuring just in case...
Assuming the motor will take it, since it's turbocharged you could add an intercooler, increase boost & fuel for even more power like many of the VW drivers here do.

QuickTD · « **Reply #7 on:** August 09, 2006, 12:09:39 pm »

Quote

Is this engine known for being weak and/or problematic? If you're unfamiliar with it, do some research before procuring just in case...

The mazda 2.0 RF is what you would find (naturally aspirated) in a north american mazda 626 or ford tempo/topaz/escort/lynx. Pretty tough motor in 52hp naturally aspirated form, not sure how they respond to turbocharging. The water pump driven by the timing belt is the main killer, water pump gets loose or seizes and takes out the timing belt, the outcome is pretty predictable...

prysm · « **Reply #8 on:** August 09, 2006, 12:42:06 pm »

The RF is pretty common here along with the R2. They are also very cheap compared to isuzu and mitsubishi. They range in different version of the 626 as QuickTD said, but the most common is RF turbo version.

Macgyver
As based on my autodata CD the RF-turbo has the rating 66kW 80 DIN HP @4000 so I guess it's ok to swap it with my 2.2L NA.

Quick TD The R2 also has timming belt driven water pump, But I have never heard of seizing. It's pretty for the engine to be damaged through over heating, But based on what I have heard this were mostly due to years of neglect.

The RF was originally designed for sedans, so the NA versios would only make my slow pickup even slower.