Amen! A 12:1 motor with 16lbs of boost is called "Driving a hand grenade"...


(with the pin pulled)

 

You can't have your cake and eat it too. NA means get as high compression you can get with pump gas before detonation. A blower needs low compression because the boost will make actual compression a lot higher. If you build an ideal NA setup with let's say 11:1 compression, and throw 10 psi of boost to it, you are looking at probably like 14-15:1 compression which will destroy the motor. You need to build the motor for what is going to be designed for: low compression=blower.....high compression=NA. Your cam must also compliment a blower or NA. A blower needs more exhaust duration and less overlap while a NA motor needs more overlap (to a certain point). Do some more research and talk to the guys in the forced induction forum....they are very helpful.

 

This motor was built as a blower motor, Je blower pistons and 9-9.5 CR Just trying to find ways to make more power.

 

Maybe I wasn't clear. On a street car, I wouldn't run boost with a high compression ratio, but it DOES depend on the application. To make a generalized statement such as "If you "build a decent (NA) motor" and put a blower on it you will not have a killer blower motor, you will have a dead blower motor." and "A 12:1 motor with 16lbs of boost is called "Driving a hand grenade" show that its not always as simple as high or low. If you are going to run race gas all the time, why NOT go for the 11:1 motor? You can make at LEAST 100 hp more, heck, usually that much N/A, and double that for FI. Also, you CAN build a decent N/A motor, with everything optimized, and then lower the C/R and apply boost. I would do that before choosing an unkown cam spec because its been called a "blower cam". Now, granted, I haven't built a blower motor yet, but I do research it, and try to avoid a lot of the FI forum regulars BECAUSE of the ingrained mentality. If you listen to the LT1 Tech forum, a lot of people will tell you that the 847 is too big for a 350. Looks like the contrary is true. Again, don't take this as a "gee guyz, i think a 12:1 race motor with 20lbs of boost would be the bestest street car in the world" post, because its not. There are a lot of guys that say not to run over 8:1 for FI, there is no set RULE for it, just as there is no set RULE for the cam specs. If you look past the blinders, you might see something new.