Lawn Dart
Registered User
Las Vegas, Nv
I hear a lot about this modification of swapping out your 7:1 pistons in a stock WD-150hp-O320-A2B with 10:1 pistons and heavy wall wrist pins, and then calling it a 160hp-O320-A2B?.
I?ve read enough about it to know that I am thoroughly confused! :roll:
From the posts that I?ve read, no one has been specific about how to go about this.
I read that some people change the cylinders to choked barrels (cylinder bore is tapered up by TDC) and others don?t. I read that some just change the pistons, rings and pins, but I don?t know what the part #s are and I can?t find anything on Lycoming that suggests that they made 10:1 pistons for any O320.
I see that if you convert a 150hp to a 160hp you stamp a ?C? at the end of the model # (is that right?) but I still don?t know exactly what all is involved in the 160hp conversion (part #s, machining, log book work, etc)
And lastly, I?m totally mixed up about this whole 150 to 160 and 7:1 to 10:1 connection.
I?m no engine shop, but I?ve built enough to doubt that raising the compression 3 whole points in a 320 cubic inch engine is only going to raise the HP 10 horse?
I promise that if I blow the heads off of my stock straight barrels, I won?t hold you responsible!!
Anybody??
PM me if you?d rather.
I?ve read enough about it to know that I am thoroughly confused! :roll:
From the posts that I?ve read, no one has been specific about how to go about this.
I read that some people change the cylinders to choked barrels (cylinder bore is tapered up by TDC) and others don?t. I read that some just change the pistons, rings and pins, but I don?t know what the part #s are and I can?t find anything on Lycoming that suggests that they made 10:1 pistons for any O320.
I see that if you convert a 150hp to a 160hp you stamp a ?C? at the end of the model # (is that right?) but I still don?t know exactly what all is involved in the 160hp conversion (part #s, machining, log book work, etc)
And lastly, I?m totally mixed up about this whole 150 to 160 and 7:1 to 10:1 connection.
I?m no engine shop, but I?ve built enough to doubt that raising the compression 3 whole points in a 320 cubic inch engine is only going to raise the HP 10 horse?
I promise that if I blow the heads off of my stock straight barrels, I won?t hold you responsible!!
Anybody??
PM me if you?d rather.