Versions. All versions have a bore of 84.0 mm (3.31 in), a stroke of 89.6 mm (3.53 in), a compression ratio of 10.2:1 and the redline is 7000 rpm.
Table of Contents
What are acceptable compression readings?
Healthy engines should have compression over 100 psi per cylinder, with no more than 10 percent variation between the highest and lowest readings.
What is normal compression rate?
Compression ratios usually vary between 1.05–7 per stage; however, a ratio of 3.5–4.0 per stage is considered maximum for most process operations. Quite often, the temperature rise of the gas during the compression dictates a limit for the safe or reasonable pressure rise.
How do you do a compression test on a BMW?
Is the N54 a good engine?
The N54 is a very highly regarded engine, for the most part. It’s received numerous International Engine of the Year awards and had thrice won the Ward’s 10 Best Engine Award. From an enthusiast standpoint, there are few engines today that can offer a similar return on the dollar in terms of modifications.
How much does a N54 engine weight?
e92 M3 will be about same weight as e92 335i. It will be heavier than the e46 m3. Its V8 weighs 445 lbs, while the N54 weighs 429 lbs.
What is a bad compression reading?
As a rule, most engines should have 140 to 160 lbs. of cranking compression with no more than 10% difference between any of the cylinders. Low compression in one cylinder usually indicates a bad exhaust valve. Low compression in two adjacent cylinders typically means you have a bad head gasket.
What PSI is low compression?
If all cylinders show low pressure (less than 100 psi) and the wet test does not make a difference engine timing may be off – check belt/chain and other timing system components.
Is 100 psi a good compression?
You should start to worry if one of your cylinders is getting close to 100 psi. Most new engines in good condition compress at around 175 psi.
What PSI is 10 to 1 compression?
10.0 to 1 = 200 psi etc.
Is 200 psi a good compression?
Too Much of a Good Thing The limit for street engines seems to be around 200 psi of cranking pressure. Numbers higher than 200 psi create excessive cylinder pressure at low engine speeds, which turns the engine into a detonating monster.
What is a good compression ratio for Turbo?
For the average street motor you should stay in the 8 to 8.5:1 range. If you have a fairly lightweight car you can probably get away with 9:1 or a little more, but watch your boost and detonation threshold.
What is a BMW compression test?
A compression test determines the relative compression between individual cylinders while a leak-down test determines the sealing ability of the valves, head gasket, and piston rings.
Do I have to remove all spark plugs to do a compression test?
“Compression pressures must be taken with all the spark plugs removed, carburetter throttles wide open, and the engine at it’s normal operating temperature.”
Can you do a compression test on a cold engine?
The compression test can be done either hot or cold. A hot compression test is done with the engine warm to ensure all the parts are up to temp and the clearances are as expected. If you suspect damage you might just want to perform a cold test instead of letting the motor sit and run to warm up.
How many miles can a N54 last?
The N54 can and often does last 200,000+ miles if you’re willing to spend enough money. If the repairs are done right the N54 can offer good reliability and longevity. You’ll just end up spending more money on repairs and maintenance than these 10-15+ year old cars and engines are worth.
What is so special about N54?
The biggest advantage of the BMW N54 is its power and potential. Sure, the twin-turbocharged petrol engine provides enough power as it is. Still, what truly makes it special is the ability to boost the output even more with a couple of aftermarket upgrades.
Are N54 internals forged?
Mahle Motorsports N54 pistons are forged for strength, light weight, and low drag to be a modest upgrade over the stock BMW pistons. Factory BMW pistons are cast aluminum, which is fine for the intended power output and durability.
How much HP does a N54 have?
BMW N54 Engine Specs A forged crank and rods deliver solid strength. Combine that with DOHC and variable valve timing and the N54 is good for 7,000 RPM redline. It also makes 300-335 horsepower from the factory.
How can I make my N54 reliable?
Regular fluid changes. Downpipes Intake and intercooler will all make the turbos work a lot easier and more efficiently. A proper tune and besides that, you should be prepared to change spark plugs and coils if misfires occur. N54 is pretty reliable besides a few misfires on old hardware.
Is the N54 aluminum?
Made from aircraft grade aluminum to ensure reliability. Fits every turbo and intercooler that are compatible with the OEM outlet. Includes everything necessary to upgrade from factory chargepipe. Lifetime warranty.
Is 140 good compression?
As a rule, most engines should have 140 to 160 lbs. of cranking compression with no more than 10% difference between any of the cylinders. Low compression in one cylinder usually indicates a bad exhaust valve. Low compression in two adjacent cylinders typically means you have a bad head gasket.
How much difference in compression is OK?
A variation of 10 or 15 psi between cylinders is normal. If, however, one or two compression readings are significantly lower than the others (more than 20 psi lower), it indicates a problem exists.
How can I improve my compression?
- By changing the flat-top pistons to high compression ones that curve upward to result in a higher compression ratio. However, since the air and fuel are both more highly compressed, there will be more heat.
- Turbocharging.
- Supercharging.
Is 90 a low compression?
As a general rule, a low compression ball should be used by golfers that swing the club less than 85 MPH, a mid compression ball is for swing speeds between 85-100 MPH, and a high compression ball is for swing speeds above 100 MPH.