I heard that the first oil change interval in a lot of german cars is something like 30,000 kms. Not sure if thats right but that is a long time to go without an oil change. Will do some research now anyways. --- Post updated --- Says here that non AMG and V12 variants are to be serviced every 25,000km's. http://www.mercedes-benz.com.au/con..._parts/service_repairs/service-intervals.html
I jumped my El Camino over a bridge support once. It was hammered. So, a couple buddies and I took some metal scrap and a sheet of steel and propped it up against a bridge support that was lying in the road, during construction. Banana'd it.
I'd argue the contrary. I have a friend who just sold off his 250,000 mile 528i, and it was perfectly reliable... apart from the time the time the rad blew... or the alternator failed, but I'd argue that come with mileage. You'll never see me in one, though. $1500 spark plugs from the dealer, or a special tool to do it yourself is a big turnoff.
Help me out here, guys. I'm trying to figure something out. I've read a little about why you would or wouldn't want a high-revving engine, some of which indicates that high RPMs are only really useful in an environment where your engine displacement is hard-limited (such as in a sanctioned racing series), and that otherwise it's all about average power and getting the gearing right. However, I'm starting to wonder if that's always true. Double however, actually figuring that out would require doing things like math that my lazy brain doesn't feel like doing right now. So, in an environment where you're starting with an engine that someone else built and sold a long time ago, but have no hard limits on displacement or outright power except how much displacement increase is physically possible with your chosen engine block and how much power said block can withstand, is there any sense in increasing the engine's maximum RPM (and optimum power RPM to match) for more power or is it better to add more power within the car's existing safe RPM range? In other words, is it cost-effective to go for RPM in a street build?
Think about how often you go near the redline in daily driving. High revving engines are cool, but it's nice to have power in lower revs to keep daily driving interesting. Plus, higher RPM means more wear on the engine, and more problems down the road if something goes wrong
Part of the Euro and Japanese styles to opt for high revving engines was tax. Many EU countries tax on displacement, as did Japan. And so if an entire could make more power for less displacement then it was always worth it. And so yes. Revs were worth it as we could achieve power goals and correct for torque in gearing. It's also why turbos with high boost levels were popular in Japan, turbo engines counted as non turbo engines with 50%more displacement. Yet throw 14psi on an engine and you've effectively doubled is displacement, working around the tax. Americans have the old adage no replacement for displacement. Whereas Europe and Japan always took the American "just make it bigger" attitude as lazy. It wasn't viable in our counties so we were always about doing more with less. Higher rev limits. Turbocharging as forced psuedo displacement. Increased compression ratios over American counterparts.
But that exactly what I'm getting at. When you're modifying an already-built engine, in a regulatory environment that doesn't place hard or soft limits on displacement, does it make sense to go for more revs?
Revs and displacement are both always good. The major reason to add Rpm beside making more power per foot pound, is the ability to take advantage of gearing. My current 1.6 with its 9200 Rpm red line makes around 195bhp and 115 foot pounds. The 2.0 I'm replacing it with makes around 160/140 or maybe even 150 foot pounds. The car will probably feel faster, but it won't be because that 2200 rpm I'm missing means I'll on average always be in a higher gear with less mechanical advantage for a given speed. Touring car racing is case in point. 2 liter gas engines up against diesels with the same power rating and one makes way more torque but has to shift at 5k instead of 8500. They run almost identically. 200hp at 3k rpm with tons of torque and long gears is the same as 200 between 6700 and 9200 once the gear ratios come into play. Horsepower is horsepower. Thrust is thrust. The reliability argument is for sure valid, low revs means less piston ring wear among everything else. If you take care of them however they tend to last. My friends daily driven gsr has almost 240k miles on the clock and sees 8200rpm every day. The golden rule of your scenario yes please I'll have more of both. Nascar engines last 1 race because they Rev like my honda, but they make stupid all motor power. Always spin it faster if it still breathes and can take it. Also don't forget cylinder bore is limited by bore spacing. My b series couldn't be sleeved out to more than 86mm tops.
If your building up something for the street, you want something that has enough power to pull away in higher gears without downshifting. My excel is nice but it could definitely do with some more power down low as I live in a very hilly area and have to often use 3rd gear to get up hills that most other cars can easily do in 4th. Factory it makes 99hp (engine) but that figure is at 6000rpm and it the power starts to come on at about 3,500 rpm and it fairly useless anything below about 2,000rpm. Its a light car but with me in it, the wieght would be just over 1000kgs and the engine size is only 1495cc/1.5L/93CI and rev limiter is at 6500rpm. Not sure how this helps but it gives another perspective.
He had a bit of luck my uncle has a 09 520d and its more in the dealership for repairs than at home and it just has 60000 km done. Also a friend of mines mum has a 218 or so and its engine failed after 20k km
It depends on your engine design quite heavily. A low displacement dual cam engine can probably do better with increased RPM and airflow (just look at all the ITB'd toyota and honda motors), however a bigger, older engine (such as a Chevy 350 or a Ford 302) would benefit more from increased displacement, cam(s), and prehaps supercharging or turbocharging (although I'd go with the supercharger as it's easier to do, cheaper, lighter weight and provides better throttle response which is of utmost importance in a car you're actually going to drive IMO)
http://pauter.com/shop/rods/acura-honda/b16b-rods/ Mid 10k rpm up shifts all day. It's the valve train that you need to really think about, and actually making power up there.
Maybe I should try to get the redline on my genesis higher. With no mods except an ECU it goes past 7k.
