jfor441 said:
Mr. OAM said:
The reason is just plain compression. If you've got 11.5:1 compression in your engine putting a blower on it is going to raise it higher because of forcing extra volume of air into the engine. This will lead to detonation which will beat your engine to death.
Please get a book on supercharging and read up on the basics so that you know what physics factors you are dealing with. It's not wise to go blindly into something like this.
Steve
That is why I am asking this question. I don't need to read a book. Compressing air raises the temperature. If the Rotrex blower achieves the same amount of power with lower inlet temperatures, then maybe it might be a good choice with a higher compression motor. Other factors to think about, if someone was running a water-methanol kit, that would also lower the air inlet temps significantly thereby helping to reduce the chance of detonation. Water-methanol makes the effective octane rating of 93 octane gasoline closer to 120 octane.
I am not going blindly into anything, I am asking a question.
You sound like someone that would build an engine without knowing anything about them when you say this (not saying you don't know how to build a normally aspirated engine, this is a comparison). How hard can it be to put the parts together, right? Well, there is a lot of physics that engines are designed and built around and to do these things correctly you need to know how these things work and what factors are involved.
Yes, you asked a question but I did not give you the answer you were wanting. Sorry, but there are physics and engineering involved that cannot be discounted. Supercharging engines started with supercharging fighter plane engines in WW II . Since then hotrodders have been adapting them to cars so there is a
very long history of trial and error as well as precision engineering done by real engineers, and to this day supercharged
street engines are not built with high compression for several real reasons that are all based on physics, and physics does not change.
So yes, you need to read a book to understand what is involved. There are no points to argue, only information to learn and understand. Nobody became a mechanic or engine builder because someone just told them once how to do it. You need to learn about these things, that's why not everybody can do it.
IF you were to build an engine this way you would need a race block, 4 bolt billet studded main caps, forged crank, rods, and pistons, studs for mounting the heads, the tops of the cylinders in the block would need to be machined for metal ring seals in the head gaskets, very high pressure valve springs, and life expectancy of the engine would still be shortened. This would take more money and last shorter on the street than most people have to waste. But don't take my word for it, the reason for this would become clear if you read a book on supercharging. Reading is not just something done in school, it's done when we want or need to learn about something.
Steve
