measuring X ????
11-08-2002, 04:53 PM
#21
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X dimension
If I remember correctly (it has been a long time) the standard X dimension is where a line extended from the engines crankshaft would pass through the transom when the drives cavitation plate is equal with the bottom of the boat. By moving everything up, placing the cavitation plate above the bottom of the boat, the X dimension (crankshaft centerline) is increased. This is a simple way to think of X dimension.
Higher X dimensions mount the drive up higher and out of the water decreasing the drag from the gearcase and increasing boat speed. This may come at the expense of cavitation in turns and acceleration cavitation from the prop sucking in air from above the water surface.
Please correct me if I am wrong!
Sincerely
Dennis Moore
FAMILY AND PERFORMANCE BOATING MAGAZINE
Higher X dimensions mount the drive up higher and out of the water decreasing the drag from the gearcase and increasing boat speed. This may come at the expense of cavitation in turns and acceleration cavitation from the prop sucking in air from above the water surface.
Please correct me if I am wrong!
Sincerely
Dennis Moore
FAMILY AND PERFORMANCE BOATING MAGAZINE
11-08-2002, 08:28 PM
#22
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Posts: n/a
Kaama, My boat - no steps no beaks, etc, etc . The higher you place the drive the Slightly more speed especially when the football is out of the water (Less drag) BUT a Dennis stated the trade off is cavitation etc.
I had spoken to Chris Sutphen today (knows more then 90% of the people...) Max speed is when the prop shaft center line is 1-1.5 inches above hull bottom (record setting speed junkies) only one blade is in the water at any time, and the skeg is the only part of the drive in the water. The negative is handling which depends on boat bottom,k-plane,drive skeg area and on and on.
This high X-d is for max speed only,Sutphen did set (HONEST) kilo records The last record I recall was 85.96 with F2-50/stock factory 502 ci motors. I will agree with you mark and give up the speed for better handling.
Cord think we are on the same page. presently i have one stelling box and standard bravo 1 mounted on my boat. If i get a chance i will mount the other without the box and take measurements from center of prop shaft to hull bottom, like Kaamas im on bottom holes(box as high as poss).
Dennis 100% correct , X-d is what most performance boaters want to know, which depends on manfu., application etc..
Wette Vette I read all your posts. Very knowlegable about motors. When I have a chance I have questions for you,mark, findme and Eddie/smittymarine
Dyno sorry if I deverted your post, hope some of this info will benefit you.
I had spoken to Chris Sutphen today (knows more then 90% of the people...) Max speed is when the prop shaft center line is 1-1.5 inches above hull bottom (record setting speed junkies) only one blade is in the water at any time, and the skeg is the only part of the drive in the water. The negative is handling which depends on boat bottom,k-plane,drive skeg area and on and on.
This high X-d is for max speed only,Sutphen did set (HONEST) kilo records The last record I recall was 85.96 with F2-50/stock factory 502 ci motors. I will agree with you mark and give up the speed for better handling.
Cord think we are on the same page. presently i have one stelling box and standard bravo 1 mounted on my boat. If i get a chance i will mount the other without the box and take measurements from center of prop shaft to hull bottom, like Kaamas im on bottom holes(box as high as poss).
Dennis 100% correct , X-d is what most performance boaters want to know, which depends on manfu., application etc..
Wette Vette I read all your posts. Very knowlegable about motors. When I have a chance I have questions for you,mark, findme and Eddie/smittymarine
Dyno sorry if I deverted your post, hope some of this info will benefit you.
06-13-2003, 05:06 PM
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Attn: Cord
Hey Cord,
I remembered your post when I found this:
http://www.performancemarine.net/bul...94/om94_06.pdf
Where did you get your information form? This is probably older (94?) than where you got your info from... what do you think?
I remembered your post when I found this:
http://www.performancemarine.net/bul...94/om94_06.pdf
Where did you get your information form? This is probably older (94?) than where you got your info from... what do you think?
