Re: single v bottom with #6
 

Last I heard from the crew at gun lake was that Earhart is thinking of putting a #6 on his eliminator, don't know if he will for a fact though.

Re: single v bottom with #6
 

johnny at TNT said he did a 3a on his 28. He didn't know of a #6 on a Pantera

Re: single v bottom with #6
 

Well usually and engine and drive package are 1200 lbs per side. So your along ways from the weight of having twins in there. :D


Cougarman

Re: single v bottom with #6
 

He WAXED my azz good in my blown Bullet at Alumn Creek shootout....Very cool ride !!
4 footers tho....??

Re: single v bottom with #6
 

Yup...

Re: single v bottom with #6
 

Post 78 #

Re: single v bottom with #6
 

I agree

Re: single v bottom with #6
 

Gotcha.....The whole Checkmate "clan" are a class act...
Always look forward to seeing them at Alumn.

Re: single v bottom with #6
 

Thanks for all the kind words Cougarman. As you know if I had to do this project over again, I wouldn't hesitate do go the same route with the #6. This package has been bullet proof. I think that with the drive so far back from the transom the boat acts and handles like to was a couple feet longer. I've run in 4 footers and have gone over 90 in 3's.

Bill

Re: single v bottom with #6
 

Seem to work OK on a certain 100mph 18' Donzi.

Re: single v bottom with #6
 

You are correct it works well on that particular boat, but that is apples and oranges to an offshore boat.
That and the boat I know of has a big pad, and is switching to a Konrad.
I am sorry if i offended anyone.

Re: single v bottom with #6
 

No offense taken, fast fun 2, I just thought to mention it.

Re: single v bottom with #6
 

Bill,

Great to have you chime in, did Checkmate build the hull differently knowing your plans for the boat, such as stronger transome etc. ?

Jon

Re: single v bottom with #6
 

bigger tabs should make an improvement as well....

Re: single v bottom with #6
 

Why not the NXT1 before the #6 for a 30' single (assuming under 800hp)?

Re: single v bottom with #6
 

Because currently Mercury will not sell you the NXT1 drive.
You can only get it as a package with there 700hp.




Cougarman

Re: single v bottom with #6
 

I know a 3A takes about 90hp. What about a dry SSM #6?

Can we re hash this thread 10 years later !? I have a Warlock 29' World Class 1994 with a straight bottom. I've broke my bravo's too many times to count . Got a hook up for a #3A and a spare . Really leaning to go this route. Not interested in Nay sayers. I've seen plenty of surface drives , arneson , #6 , and #4 on boats that work great . Clearly it's in getting the drive height and prop correct . How has had success !? What prop shaft height did you run? What prop did you run?

Nordic 21 @ Nordic factory owner Randy Davis ski race boat 1350 6 drive .

Jg1000,
no nay sayer here, go for it
however the 3a is 24 1/4 shaft to shaft,
4 5 & 6 are like 18 5/8 , 18 11/16,
i'm not saying a 3a would or would not work for you, nor am i trying to queer any deal you may have going w/ another member or who ever.
just throwing it out there you'd be deep 18 x = 6 1/4 prop depth as example,

there are some # 4's in the swap shop now that i have nothing to with nor would i gain from there sale.
i'd like to grab one for my boat, (a 26 foot single) and i don't have big power, 496 h.o.
it was originally rigged w/ a 5 on a box w/ a big blower motor

the big bonus is they are driveline w/ extension boxes (as explained pics aren't up yet), means you can mount the engine forward to compensate the cg from weight gain (if you have room in front of the engine), move the box up and down, and i think try it without to get the boat dialed in.

i have the room (at 17 inch x from the transom to the firewall is 64 1/2 inches ) so for me, cg, smooth shift, reliability and the cool factor !
but i just don't know, it's easier to pick a girlfriend and lotto numbers than what drive and what x, at least the first 2 can be changed on a whim w/o the boat being taken all apart.

and again another thread i didn't have to start but was losing sleep over, thanks oso

speaking from first hand experience drive height is absolutely critical to get it to perform, too low and it's going to be a dog. Period. Dragging that giant case through the water is like dragging a boat anchor. I've been there done that and wasted more money then I'd like to talk about. On the transom even with the bottom. If it's on a box I'd set the box so you can go even 1 and 2 above. I've ran my 28 2 below 1below even and 1 above. night and day difference in speed and boat attitude all around. The higher it went the better the boat felt and handled and drastically started to go faster. Planing ability never changed much. 1 above slips a hair more getting up but even in Point pleasant testing Saturday it planed in 4-6s. If I wasn't racing it I think I would fill the transom and try even higher but I feel I'm at the point of diminishing returns.

if you're still planing on racing the boat. (Procharger guys right?) I would also go straight to a crash box. It'll help recoup some of the parasitic loss in the drive. I went the transmission route at first and saw solid gains everywhere by eliminating that.

As far as props my boat planes with pretty much any of them. I would be willing to let you try some that I have in various diameters and pitch assuming you are running a RH drive. I have the some of the smallest pitch big shaft props.

there are many ski race boats here in Australia with #6 behind 1350s, 1650s and custom built turbo motors. Most run a 2 speed powerglide transmission to get some low down launch and then shift gears for high speed

#6 on a 21
 

I was just at the Catalina Ski Race and saw a 21' hull with a Merc 1550 and a PAIR of #6 drives on the back

Check out Aussie ski racing. They run 21' hulls with #6 drives to 120mph sustained down the river while pulling a pair of skiers.

I'll try and post some pics when I get back

Dragging the boat anchor, that’s exactly how my 25 outlaw felt with an imco SCX 2-1/4” below on a 12” ext box. Whippled 509 just didn’t really feel like it had nearly double the 496ho hp that it replaced. So now it looks like Scx-4 is my only option to go higher without transom work. Scx-4 would put me at 1/4” below, on a 12 ext box.

Any ideas on how this might work with a #6 prop? Could I still get bow lift/ trim reaction? Would this be too deep for the scx-4 case and or a #6 prop? I was told planning would be my issue with the scx @ 2-1/4” below but I could jump outta the hole if I wanted to.

It feel would work with a 6 prop. Even at 1/4” below I would bet that it would work with a bravo style propeller in the 5 blade variety. If you choose to run a 6 prop you might need to have the diameter in the 16-16.5” range depending on how the boat feels. I have quite Afew smaller pitch 4 blade 6 props that id be willing to let you try or sell you if they work for you. Obviously it’s a big financial decision to buy a Scx4 on a guess but I think going up is going to gain you speed. It’s Just a matter of do you want to redo the transom or do you want to buy another drive.

Unless Konrad has figured out how to make their drives live I’d stay away from them in high hp applications. I installed a pair of konrads in a center console with twin 480 ta mars and they wouldn’t stay together. If they can’t handle that application there is no way the will live in a high perf application with 1000 hp
if I am not mistaken there are some number 6 drives on some
of the Australian ski race boats. I thing those are under 25’

Talk to pro27 here on the boards, if you haven't already. He has a 27 Progression with a whippled 525 and an SCX4 running a #6 prop. He can probably get you going in the right direction. I believe he's running an extension box too.

I’ve talked with Pro27 a few times and he has been helpful and given me some pointers. Most that I’ve talked to about insist that I should step up to the #6 props otherwise gains could be minimal.

Where are the Australian ski racer x-dimensions or prop shaft in relation to the bottom of there hulls?

Mickeymcclgn
Have you ran your 28 with a #6?
Was it a non stepped or stepped hull? With notch?

What do you think about a #6 on 27ft hull. Propshaft 2" above bottom too? Hull is non stepped but with 8" deep notch.

Chris12 sounds like over kill unless your putting big hp through it,#6 drive + transmission very heavy, imco scx4 wrked great for me 1" above bottom 8" notch 12" stand off, @ 800 hp 108 mph 5blade 6 cleverhttps://cimg3.ibsrv.net/gimg/www.off...e48013858.jpeg

I believe scx4 can handle up to 1100 hp

No sorry,workimg on thathttps://cimg3.ibsrv.net/gimg/www.off...8fd9bff305.jpg

not at all,also have big k plains
0

I started out with the drive much higher but I couldn't get the bow out of the water. We did end up with the drive much deeper which gave the boat trim leverage.