What are Blackhawk drives worth?
02-28-2002, 12:00 AM
#22
I think you guys have it a little wrong. The blackhawk drive has a very short vertical distance between the input and the prop shaft. It also is a surface drive that is designed to run with the bullet only slightly submerged when on plane. The transom cutout for the blackhawk drive is LOWER than the bravo cutout.
Also the blackhawk drive creates tremendous transom lift and almost no bow lift so the boat has to be built with a lot of natural bow lift and a rocker in the bottom. If you remove the blackhawk drives I feel you will not be happy with not only the performance but the handling. The bravo drives will be so low in the water that triming the drives may not help much.
Also the blackhawk drive creates tremendous transom lift and almost no bow lift so the boat has to be built with a lot of natural bow lift and a rocker in the bottom. If you remove the blackhawk drives I feel you will not be happy with not only the performance but the handling. The bravo drives will be so low in the water that triming the drives may not help much.
02-28-2002, 11:01 AM
#23
Charter Member #94
Charter Member
Tinkerboater,
I agree, and disagree.
True, the Blackhawk does have a shorter lower case so it does have a shorter distance between the input shaft and the prop shaft.
True, it is a surface drive with twin props, and as such does provide a buttload of stern lift and minimal bow lift.
I disagree on the Mercury spec X dimension. I may be wrong, but I was pretty sure that the specs were that the Blackhawk was mounted higher than the Bravo 1 &/or the Bravo 3's. Indeed, the Challengers I played with that had Blackhawks, did in fact have a higher X than the Bravo 1 & 3 boats. I used to have the Mercury bulliten on this. I'll look for it, but I've moved since then.
The hull design we are discussing here is a step bottom, which normally runs pretty flat anyway. The Challengers I played with, (swapped Blackhawk for B-1), seemed to like the extra bow lift.
As Mr. Offshore noted, having surface drives means less prop/drive in the water which means handling may suffer. I think it's a given that this boat will loose speed, but since Chris's CFO, (Mrs.283checkmate/ Cyndi), will be driving this boat, I'm thinking they won't mind giving up a few mph for a more stable better handling boat.
I agree, and disagree.
True, the Blackhawk does have a shorter lower case so it does have a shorter distance between the input shaft and the prop shaft.
True, it is a surface drive with twin props, and as such does provide a buttload of stern lift and minimal bow lift.
I disagree on the Mercury spec X dimension. I may be wrong, but I was pretty sure that the specs were that the Blackhawk was mounted higher than the Bravo 1 &/or the Bravo 3's. Indeed, the Challengers I played with that had Blackhawks, did in fact have a higher X than the Bravo 1 & 3 boats. I used to have the Mercury bulliten on this. I'll look for it, but I've moved since then.
The hull design we are discussing here is a step bottom, which normally runs pretty flat anyway. The Challengers I played with, (swapped Blackhawk for B-1), seemed to like the extra bow lift.
As Mr. Offshore noted, having surface drives means less prop/drive in the water which means handling may suffer. I think it's a given that this boat will loose speed, but since Chris's CFO, (Mrs.283checkmate/ Cyndi), will be driving this boat, I'm thinking they won't mind giving up a few mph for a more stable better handling boat.
Last edited by Gordo; 02-28-2002 at 11:09 AM.
02-28-2002, 11:22 AM
#24
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I have a electronic copy of that document that you are refering to Gordo. Unfortinatly, it's .pdf so I don't know how to post it. I does list the x-dim being "2-1/2 inches higher than the standard dimension".
