Blower ?

[Thunderbutt]

What realy happens if you put a Blower on a motor with to much compresson,and what is the max? Through the years I have changed the pistons twice because of the bad gas and I hate to change them agin.

[Craig]

Same thing as running a 12 to 1 motor on 87 octane. Bye bye pistons http://free.***boat.net/ubb/biggrin.gif Pump gas and 5# boost 9.3 to 1 max. Av-gas 8# boost, 9.3 to 1. Just from my experience.

[hulshot]

ran a small ci engine, 468 6:71 blower at 30 over on 118 octane and two 1150 dominators, kept the timing at 28 locked with, get this, 11.5 static compression. Yes it did stay together for over a year of NJBA and hard weekend racing. It finally quit after shearing the shaft in the lights and reving to 9600rpms and bending every valve I had.
In short low total timing and very good gas and fuel systems and always plug check.

[SPECTRABRENT]

JIm,
Are thinking about going to a blower?
Brent

[Infomaniac]

Switch to alcohol and do not worry about it. The max is different with every engine.
OK Detonation 101:
During combustion the air fuel mixture should burn smoothly (not explode).It should be a smooth release of heat energy. Even though it happens very fast. Every type of gasoline acts differently during combustion. If a gasoline reaches the point during combustion that the temperature or pressure in the cylinder exceeds the limitation of the gasoline. It will release it's remaining energy instantly (explode). It starts off as a smooth burn but when it reaches it's limit, the rest of the mixture explodes. Causing great shock to the engine. Especially the tops of the pistons. It should push smoothly on the tops of the pistons. Higher octane fuels can withstand higher temperatures and pressures during combustion.
Backing off the timing makes sure that peak pressure in the cylinder does not occur when the volume of the cylinder is at it's smallest. Not good for power but makes sure the fuel's limitation is not exceeded.

[Thunderbutt]

Brent, I'm not going to sell Thunderbutt, so I thought I'd do something to it, Like repaint or new motor. I wanted a Cat boat,but when I told my wife, she said the only cat your ever going to get will have a tail.(just kidding) When your retired you have nothing to do, but spend money.UOTE]Originally posted by SPECTRABRENT:
JIm,
Are thinking about going to a blower?
Brent[/QUOTE]

[picklefork1]

Infomaniac, that was very informative. Thank You. I'm new to blowers and info like that is great.