ToMorrow44

Apparently the Max lower has helped handling on a lot of big power single engine Vs. I guess the shape of the cone along with an extra long skeg help reduce lateral movement (chinewalk). I did not hear about the extra support of the vertical shaft in the Max lower though, I'll have to check it out. Do you know how much Max charges just for the lower case? If I remember right, the IMCO's were like $1700. Also, how far below the keel is the centerline of your prop? I'm in the same boat as you (no pun intended) as far as getting my boat to run faster and handle better.
-Tom

CB-BLR

Have any of you guys looked at the IMCO SCX drives? What are your thoughts on that?

Chris

Superbabi

I was looking into them price wise not bad, but I have yet to hear of any oso member using one. I did read on a thread that they were off 3-5 mph over an xr.

ToMorrow44

Ive seen a couple of them on various boats tested in Magazines. I think they probably work very well, but I'm not sure if anyone has tried one after running any other bravo style drive for a comparison.

articfriends

The prop c/l on my boat is 7 1/2 " ,the max worx billet lower case is 3600 or 3800$ bare w/ a vert shaft. Its billet though,not sand cast aluminum. They tell me it has a double set of lower vert shaft bearings and that gears seem to last longer because of this. Gary taylor is the only guy I know running one other then whirlwind (oso screen name) on his twin engine cig. B-max,max worx and Imco all claim their lower is faster then the competition by a few mph so i don't know who to believe. If I can get the imco to do something positive on my boat I will upgrade to the max worx lower and sell it (for the extra bearing support)Smitty

ToMorrow44

Damn thats expensive. The prop c/l on my boat is currently at 6" below the keel. I've been told by a couple people that these types of boats like to run somewhere in the 3-4" range so I will be trying some shorter lowers here soon. Gary told me his boat is at like 3-3/4" but some other Bullets are at 5". I dont know, maybe your boat likes to run really deep like that. Try the IMCO and see what happens and keep us updated.
-Tom

CB-BLR

My 28ft Nordic Heat came set up with the prop at 3.5 below the keel, and I could not get it to pick the nose of the boat up at all. it did the best of 78mph and looked like a jet boat going down the lake. Thirty foot rooster tail and all. I put on a one inch spacer (making it 4.5" below the keel) and picked up 2 mph. I put four ladies in the back seat, and both fuel tanks full, and picked up another 2mph. When I trim up to try to carry the nose, (without all the weight in the rear), the point on the nose of my IMCO lower shadows the water pickup, causing the Smartcraft to put the motor into guardian mode. I think I need to go down another .5 or 1 inch to make the boat work, but Nordic says that I am already deep enough, and that they think that my IMCO lower is slowing the boat down, and that I should switch to a Bravo XR lower (non-sportsmaster). I have the only 600sci, open bow, Heat in existance. There have been only two 600sci heats made. The other 600sci Heat is a closed bow, and I am already faster that he is, and he has a Bravo XR drive. I have a IMCO SC drive, that I provided to Nordic. The only other Heat that Nordic has built that is faster than mine stock, is the 700 Illmore boat. He is running a IMCO SC drive also, and is doing about 88mph. His prop depth is at 4.5 inches, just like mine is now. I think that my prop needs to go down not only because it is now running faster with weight in the rear, but also because I have extra weight in the nose of my boat due to the open bow.

Any thoughts?

Chris

masher44

Man I bet this can get expensive.... I think all brands will operate differently, only showing different results on different boat with any signifcant increases. Spacers are a better way in my opinion and my wallet's to mess with the speeds and set up.
I had a buddy in TN that had a nordic heat with a 750 Sterling in it. He tried every drive known to man at the time and it didnt change much at all. A spacer and prop tweaking eventually was the winner. Took him all summer to get it running with the right attitude and speed. Singles are hard and you can have a certain set up run a big number and handle like crap etc etc. Or you can strive to get the best all around set up. I would get a drive that wont break! and then worry about dialing it in. Much cheaper IMO and experience.
I cupped my props as much as possible and the boat got better bow lift and woke up big time.

PS. I think there are a few of the new IMCO drive running in OPA this year. May want to post there.

CB-BLR

What is OPA?

Chris

relaxalot

What prop are you running? It sounds like you may be able to get the stern down with a prop change. I have a five blade maximus which seems to lift up the stern. The four blades do not as much. I also have a 600 in a Howard deck boat. I have had many cooling issues with it. Eventually, I separated the intercooler and motor water intakes. I added a separate pickup for the intercooler only and ran the motor off the drive after I blocked off all but the bottom three vertical holes. It quit sending the motor into guardian mode. Merc has a problem with this that they won't admit. Many boats with the 600 have this problem.