Raise or Hold?
05-21-2017, 09:57 AM
#2
Registered
Thread Starter
05-22-2017, 08:22 AM
#4
coolrunning racing
VIP Member
Safety, steering and water pressure. The only way to know it to test. You need to maintain control at all aspects of operation. As the engine height increases the amount of usable trim decreases. Safety first!
05-22-2017, 08:52 AM
#5
Registered
Thread Starter
I think that's why I've been lazy about raising it thus far. Water pressure and steering are fine, but I almost feel like it hits the sweet spot for trim pretty quick as it sits. With the hull level on trailer, the motor comes from fully tucked in to level position in about a "5 count". On the water, I don't feel like increasing the trim much beyond that point yielded much result, but that might change with a prop swap and increased motor height.
Last edited by Speedracer29; 05-22-2017 at 09:11 AM.
05-22-2017, 12:17 PM
#6
Gold Member
What prop are you running? Is there a nose cone on the lower? Where is the propshaft in relation to the Pad (bottom). By the looks of the video it looks like it could go at least one hole up. There's little spray off the prop until the motor becomes over trimmed. There also didn't appear to be hardly any cavitation at takeoff.
As for safety, if a motor is too low it can also adversely affect the handling. Even more so if you have to over trim the motor to get the boat out of the water.
As for safety, if a motor is too low it can also adversely affect the handling. Even more so if you have to over trim the motor to get the boat out of the water.
05-22-2017, 01:38 PM
#7
Registered
Thread Starter
What prop are you running? Is there a nose cone on the lower? Where is the propshaft in relation to the Pad (bottom). By the looks of the video it looks like it could go at least one hole up. There's little spray off the prop until the motor becomes over trimmed. There also didn't appear to be hardly any cavitation at takeoff.
As for safety, if a motor is too low it can also adversely affect the handling. Even more so if you have to over trim the motor to get the boat out of the water.
As for safety, if a motor is too low it can also adversely affect the handling. Even more so if you have to over trim the motor to get the boat out of the water.
05-22-2017, 01:57 PM
#8
I would definitely try going up a hole. As long as you have water pressure, you should be good. At 18" of setback, I don't think that will be an issue though. Good luck with it!
No nosecone, but the 3.4L lowers are anchors and it only runs low 60's. Prop is a 23p Tempest (not plus). I can't remember if the propshaft was 3.5" or 3.75" below pad, but it was around there. 18" setback bracket. 1.65:1 ratio. Zero cavitation when tucked, the prop never gets loose from a dig. Same characteristics with a Mirage Plus, except the Mirage plus runs 2-3mph slower. A Mazco HP4 runs 1-2mph slower than the Tempest as well and it will loosen up on take-off, to the point that I won't run it when I know I'm going to be loaded down because it takes a bunch of effort to get on plane and isn't any faster. The day that video was shot it was 70*, about 50gal fuel, and 3 guys over 200lbs aboard. GPS showed a best speed of 61.7 and if the tach ever went over 5100rpm it wasn't while I was looking at it.
