who has broke a scx imco drive?
08-21-2010 | 01:11 AM
#81
Chris
Joined: Sep 2005
Posts: 1,426
Likes: 1
From: Snohomish, WA
KAP,
Have you ever checked the prop slip numbers with your benchmark prop with both the SCX upper, and the SC upper?
I think you are going to see that your slip numbers are lower with the SCX upper, which is costing you some rpm and speed. This is due to the fact that the SCX moves the outdrive back nearly 3/4 of an inch due to the larger diameter upper gear set, and the fact that the SCX is about 41 lbs heavier than the SC upper. Both of these add up to your prop being lower in relationship to the water coming off the back of the boat... thus reducing slip numbers and speed.
I have now done back to back testing with a SC upper, and my SCX upper... they are nearly identical in speed (1 mph)... when I raise the lower... up 1/2 inch while using the SCX upper.... ie... go buy yourself a 1" shortie & a 1/2 inch spacer , and go do some more testing.
I think you will be pleased with the results.
Chris
P.S. I still dont think the gear ratio is exactly the same in the SC upper and the SCX upper. ( I think the SCX gear ratio is slightly lower)
Have you ever checked the prop slip numbers with your benchmark prop with both the SCX upper, and the SC upper?
I think you are going to see that your slip numbers are lower with the SCX upper, which is costing you some rpm and speed. This is due to the fact that the SCX moves the outdrive back nearly 3/4 of an inch due to the larger diameter upper gear set, and the fact that the SCX is about 41 lbs heavier than the SC upper. Both of these add up to your prop being lower in relationship to the water coming off the back of the boat... thus reducing slip numbers and speed.
I have now done back to back testing with a SC upper, and my SCX upper... they are nearly identical in speed (1 mph)... when I raise the lower... up 1/2 inch while using the SCX upper.... ie... go buy yourself a 1" shortie & a 1/2 inch spacer , and go do some more testing.
I think you will be pleased with the results.
Chris
P.S. I still dont think the gear ratio is exactly the same in the SC upper and the SCX upper. ( I think the SCX gear ratio is slightly lower)
Last edited by CB-BLR; 08-21-2010 at 01:17 AM.
08-21-2010 | 09:32 AM
#82
Registered
Joined: Feb 2005
Posts: 4,333
Likes: 5
From: USA
I saw in the classifieds that Tres Martin has a Spectre cat for sale with "x power internals" in a bravo drive. Does anyone know about xpower offering a bravo upgrade??? It may be better for me because I'm thinking of swapping my SC uppers for either the SCX or Bmax uppers. Or if anyone knows of someone that wants some SC uppers let me know please.
08-21-2010 | 08:00 PM
#85
Registered
Joined: Aug 2006
Posts: 350
Likes: 0
From: Casa De Kappy
KAP,
Have you ever checked the prop slip numbers with your benchmark prop with both the SCX upper, and the SC upper?
I think you are going to see that your slip numbers are lower with the SCX upper, which is costing you some rpm and speed. This is due to the fact that the SCX moves the outdrive back nearly 3/4 of an inch due to the larger diameter upper gear set, and the fact that the SCX is about 41 lbs heavier than the SC upper. Both of these add up to your prop being lower in relationship to the water coming off the back of the boat... thus reducing slip numbers and speed.
I have now done back to back testing with a SC upper, and my SCX upper... they are nearly identical in speed (1 mph)... when I raise the lower... up 1/2 inch while using the SCX upper.... ie... go buy yourself a 1" shortie & a 1/2 inch spacer , and go do some more testing.
I think you will be pleased with the results.
Chris
P.S. I still dont think the gear ratio is exactly the same in the SC upper and the SCX upper. ( I think the SCX gear ratio is slightly lower)
Have you ever checked the prop slip numbers with your benchmark prop with both the SCX upper, and the SC upper?
I think you are going to see that your slip numbers are lower with the SCX upper, which is costing you some rpm and speed. This is due to the fact that the SCX moves the outdrive back nearly 3/4 of an inch due to the larger diameter upper gear set, and the fact that the SCX is about 41 lbs heavier than the SC upper. Both of these add up to your prop being lower in relationship to the water coming off the back of the boat... thus reducing slip numbers and speed.
I have now done back to back testing with a SC upper, and my SCX upper... they are nearly identical in speed (1 mph)... when I raise the lower... up 1/2 inch while using the SCX upper.... ie... go buy yourself a 1" shortie & a 1/2 inch spacer , and go do some more testing.
I think you will be pleased with the results.
Chris
P.S. I still dont think the gear ratio is exactly the same in the SC upper and the SCX upper. ( I think the SCX gear ratio is slightly lower)
Always good to hear from you!
You know we were watching a video of the SCX upper combo on the boat and it seemed our boat was riding a lot flatter as well i.e... less bow lift. I could be wrong as I rarely if ever get to see the boat running unless I am in an event.
I will get a shorty SC lower and see what happens I'm gonna go up about an inch and see what it does. Got any leads on anyone selling a used one if so call me.
We discussed the gear ratio and the IMCO people assured me the gear ratio is the same. I happen to agree with you on that one going up on the lower will help make up my mind.
Thus, far I am very happy I can get a shorty and keep my existing lower as a backup spare.
KAP
I saw in the classifieds that Tres Martin has a Spectre cat for sale with "x power internals" in a bravo drive. Does anyone know about xpower offering a bravo upgrade??? It may be better for me because I'm thinking of swapping my SC uppers for either the SCX or Bmax uppers. Or if anyone knows of someone that wants some SC uppers let me know please.
X-Power people in the past were selling XR gear sets which have been treated either by heat, cryo or vibration but allegedly they are supposed to be stronger. I have no data on this pro or con.
KAP
09-13-2010 | 01:16 PM
#87
Registered
Joined: May 2009
Posts: 6
Likes: 0
From: Kintnersville, PA
SCX Update
We have a 96 Cigarette Cafe Racer, a heavy flat bottom boat! Running appr. 800 HP each motor with blowers. Blew 5 Imco SC's in 1 season! This year put on 2 complete Imco SCX's with 1.34 gears 2" extensions. We have put on 90hrs this year, NO problems or issues! Strong drives, very smooth shifting. Lost about 8 MPH but all worth it! Tried numerous props, can't gain it back! Well worth the investment!
09-13-2010 | 01:51 PM
#88
Frank's Marine Service
Joined: Sep 2002
Posts: 11,959
Likes: 142
From: Elkton, MD
We have a 96 Cigarette Cafe Racer, a heavy flat bottom boat! Running appr. 800 HP each motor with blowers. Blew 5 Imco SC's in 1 season! This year put on 2 complete Imco SCX's with 1.34 gears 2" extensions. We have put on 90hrs this year, NO problems or issues! Strong drives, very smooth shifting. Lost about 8 MPH but all worth it! Tried numerous props, can't gain it back! Well worth the investment!
Installed BMax HT's and lost 3 mph (mainly due to the gear ratio change) then went 250 hrs on 800+ engines, in the ocean without any failure. I had one upper fail at 250 hrs but I later learned the upper bearings need to be replaced every 150 - 200 hrs.. I know this now!
09-13-2010 | 02:10 PM
#89
Chris
Joined: Sep 2005
Posts: 1,426
Likes: 1
From: Snohomish, WA
We have a 96 Cigarette Cafe Racer, a heavy flat bottom boat! Running appr. 800 HP each motor with blowers. Blew 5 Imco SC's in 1 season! This year put on 2 complete Imco SCX's with 1.34 gears 2" extensions. We have put on 90hrs this year, NO problems or issues! Strong drives, very smooth shifting. Lost about 8 MPH but all worth it! Tried numerous props, can't gain it back! Well worth the investment!
Chris
09-13-2010 | 06:26 PM
#90
Registered
Joined: Oct 2007
Posts: 468
Likes: 0
From: Union, NE
Sounds like similar results I had with my Apache a bunch of years ago. Blew 2 Extreme SC's in 20 hrs and threw in the towel.
Installed BMax HT's and lost 3 mph (mainly due to the gear ratio change) then went 250 hrs on 800+ engines, in the ocean without any failure. I had one upper fail at 250 hrs but I later learned the upper bearings need to be replaced every 150 - 200 hrs.. I know this now!
Installed BMax HT's and lost 3 mph (mainly due to the gear ratio change) then went 250 hrs on 800+ engines, in the ocean without any failure. I had one upper fail at 250 hrs but I later learned the upper bearings need to be replaced every 150 - 200 hrs.. I know this now!
Just curious what weight of oil you were running when you lost the upper bearings. My rig had 300 hrs when I changed the gear set and my bearings looked good and the gears were starting to pit.
