Helmethead

I went to a Toyota dealer some days ago. I was talking to a salesman there regarding engine reliablity. What I found I out is high-rev N/A engines are hard to modify with tubo/super charge kit. Also, they don't last long (like 5 years) if they keep getting high rev. So my question is how reliable a NA engine is? Said like Celica GTS, Honda Type-R and WRX's turbo? :thinking:

What's BMW VANOS system? And what is the different between Double VANOS on 760 and normal VANOS? Is that very different than our VTEC/iVTEC?

ThanXXX~

qtiger

Cleaning house. This will get more action in the Basement, where it belongs.

Nightshade

High rev engines are susceptible to damage because of the RPMs with which they are able to run at....from the factory and driven responsibly they last just fine...abused they are as reliable as any other abused motor out there regardless of manufacturer.

As for boosting a high rev motor the main thing that would come into play would be the compression of the engine (I just dealt with this question). If from the factory it runs a standard compression rate (generally 9.5:1 up to 11.0:1) then it can be boosted. These engines coming from the factory are capable of being built to a certain degree before fuel requirements make it prohibitive because of detonation issues and tuning as well as having to run 100 octane or higher ($60+ for a fill up isn't fun) on a daily car is not in most peoples budgets.

Boost adds compression to the cylinder chambers...an average being (example only) 5lbs of boost would on average add 2 - 3 points to the compression ratio. Some engines are more than capable of handling this for extended periods and never see a problem from it. When you get into the higher compression engines the problem becomes a fuel air issue which causes detonation...to solve this a stand alone management system is usually required and lower compression pistons are probably advised at this point as well as upgraded head bolts to keep it from popping off etc.

If the engine was originally intended to run as an NA application then the most important thing you can do is talk with your engine builder in detail about potential risk to the engine from a boost application and what can be done to solve this problem.

Boosting a 12:1 compression engine can and has been done but it is done with a lot of care and lower amounts of boost than you could push into a 9.5:1 compression engine but yield the same or in some cases better results...but a lot of mechanics don't like to do it unless they are extremely experienced at this sort of tuning.

RB

I don't recommend getting all your engine tech info from a dealer.