shorty lower or extension box?
 

to raise x-dim on an old single engine v hull what is a better route? Shorty lower or an extenmsion box with a lift in it?


what are the pros and cons of each setup?

Puder,
I'm in the same situation. The shorty lower is the easiest and should be the first thing to try. It is an easy bolt on and if it doesn't work then you can go to the next step.
An extension box is a pretty serious project. If you don't have full hydraulic steering you will have to , and you might have to pull the motor out to get the inner transom plate off. Save the tough stuff for the last thing .
Just my opinion

I would go with what 26 say's, you don't see many ext. boxes on single eng boats? but you hear of shorter drives, try 2'shorter, what are other people doing?

engine is out. current transom assmble is on. but it is very easy to change.

So you can't run the stock steering huh??? That is what i was affraid of.

why don't single engine boats run extension boxxes? Any particular reasoning? I would thing teh extension box woudl set the drive back further and give it mroe leverage when trimmgin in addition it hough extension boxxes allowed the prop to be in "cleaner" water. PLus teh added benefit of the raised x-dim

I've seen X-boxes on several singles.

AND I've seen them on every fast outboard I've ever been around (they call them jackplates).

With the DRAMATIC difference you get on an outboard, I'd expect an X-box to help an I/O as well.

(for the record, I've got ONE +3 IMCO box and am looking for another for my 311).

yes, you have to run full hydraulic dual ram external steering.

Ive been told that if you put a neutral ext box on, it's like lowering your X dim 3". So if you put a box on that raises the X 3", you are back where you started from, except your boat will run like a longer one.

engine is out. current transom assmble is on. but it is very easy to change.

So you can't run the stock steering huh??? That is what i was affraid of.

why don't single engine boats run extension boxxes? Any particular reasoning? I would thing teh extension box woudl set the drive back further and give it mroe leverage when trimmgin in addition it hough extension boxxes allowed the prop to be in "cleaner" water. PLus teh added benefit of the raised x-dim

Puder, extenson box is a winner. Boat will handle better and yes you get more leverage. Now, if you can do both the short lower and the box you will see some real gains, the box will give you back some of the bow lift you lose with the short drive. Less drag as you have less lower unit in the water should give some speed.

Puder,

your box is full.

its been emptied

hmm why is it my "cheap" ideas for the boat always wind up being very expensive???

tis could easily become a $10k project. used extension box $2500 min, external steering and helm $3500, shorty lower (cheap one from totalmp) $2000

thats 8 right there!!! :(

crappola!

I bought my IMCO +3 for $1,200.
It's like brand new.
No shorty lower needed.
X-steering went for $3000 on ebay recently, and Maxx & Assoc will be pricing their system soon.

Sounding more like $4500 should be close for a doityourselfer.

hmmmmm

PM me i'll give you eth detail on that pair i found.

makes sense, probley why all the big dogs run bolth

Hey puder I know where you can get a steelings box for 500 bucks but it has know drive shaft or carrier.

Unfortinatly, your wrong. It's really a factor of your transom angle and the box design. Draw a line perpendicular off the transom and you'll see that the further you go back, the lower the line goes. If your transom is at 13* (I think that's the standard angle) then the additional setback will push the drive in deeper. If the angle is steeper than 13*, say 15* then the drive will go even deeper. If it's less, say 11*, then the drive won't go in quite as deep. All told, we're only talking about an inch or so.

The second factor is the extension box. The stellings for example compensates for the additional depth by raising the gimble face up. But this only works if you have a standard transom angle! More or less will throw the height off. You could actually end up being a scootch higher than what you started with!

Another factor that comes into play is the angle of the boat when it's on plane. This will set the drive into the water even further. It's this reason that people are actually able to set the prop centerline above the bottom of the boat. When the boat is running at speed, the angles will have the prop running close to the surface-even though it's technically above the running surface.

I currently have my prop set 3/4" above the running surface. It planes out with absolutly no slippage and I could go even higher if I wanted. I'm also running a shortened lower. But that was more a necessity of the application. If I wanted to run a high drive height, I would have to raise the engine up 2". This would have put the valve covers above the gunnel creating both an appearance issue and a high center of gravity.

I agree with Cord,
You do get more leverage but you might end up buying a shorty lower in addition to the box. Why not try the easiest and less costly thing first. If you pick up 3-4 mph with a shorty lower ($2000) as opposed to $4500 for maybe 5 mph . Which one is more cost effective ? I'm just guessing on the speeds but I'm hoping to get 3-4 by just adding a shorty lower on my particular set up.

my engine is out and needs to be remounted anyway becasu ei am goign to use an offshor emount instead of the stringer top one. SO i figured if i was ever going to do it now the time. I think that perhpas a shorty lower might be be a bette ridea and save me some $$$$. Hell i have enough in this project as it is.

The $500 Stellings sounds good. You can run an Imco driveshaft in it. The driveshafts are around $350. That makes $850 for an extension box. That ain't bad.

Course this will be a NEUTRAL box. Not exactly what youre after.

As far as the out and back rule, it's not out 12 and up 3. It's out 12 and up 1.

A 12" setback and a 1" lift will give you the same amount of prop in the water (of course this is just a rule of thumb and many factors come into play but it is the closest comparison I have heard.

All mfrs use a 13 to 15 degree transom angle to build their extension boxes to. Nobody makes a "square" box, they are all kind of "rhombuses" or whatever...

Cord I never thought of it that way,

Yea, sometimes this stuff will give you a head ache.

puder,
put the time in . goe with the extension box and a sportmaster lower. this will raise your x dimension really high and give you good speed but you will still maintain control with the new sportmaster because it has a 2 inch longer skeg and a wedge in it like the speedmaster six. if you want to go all the way plug up the holes on the drive and get external water pick up. i don't know what boat you have but if it is somthing decent you should gain about 10 mph. have to get a good prop a;so like a herring 5 blade. and yes it works awsome on a single engine application. look at it this way it is the cheapest speed you will find. and when your ready to put a killer engine in the boat then you already have all the stuff. any questions just ask. did this a hundred times.

Treadwell

lol

the boat a 1987 26' scarab excel. Its never going to be speed demon and the engine i just had biult is the biggest engine I will ever put in that boat. I was really hoping ot get her back together play with it for afew hours and sell her. I figured a shorty lower might be some cheap MPH. So far all speed predictions are getting me into the mid to high 60s. 70 is relaly here i'd like it to be. Its and old sinle engien v hull so i figured the x-dim is WAY conservative.

your x should be at 15 3/4. thta's how they come from the factory. yes the shorty should help it out quite a bit. but if your selling it just do the shorty and walk away. only do the work i mentioned if your going to keep it for awhile.

Treadwell

i'm proly gonan keep it for a bit BUT not a long while hopefully i'll sell her this season. BUt i do want to put afew hours on her. Hell after all eth work i did i have to play with it for a little while!

15 3/4??? FYI it had an alpha with 1.32 gears and the BBC before. I put the bravo on, so does't that lower it an additional 1/4". I was seeing very low speed before. And eth only thing i can think it wicked conservtative X-dim or ridiculous amoutn of hock or rocker ine th hull. It has soem hook in it extending fromt teh transom up abtou 12" (approxatamliy) on both side. But you can only see it witha straigh edge on the hull.

Hey Puder...

Lost your e-mail... Yes, I still have the box.... its a 3" Imco rise with a 12" setback. Its in really good shape. I have the box & the internal transom plate. The rest of the parts, (steering wings, driveshaft, long alignment tool), were supposed to come from Cobra Marty, but there was a UPS screwup, and they are currently MIA. UPS is investigating, and Marty hasn't gotten back to me as to what we are going to do about it. Its been a few months... I'll give him a buzz. Marty, if your reading this, I'll be calling, be prepared!! LOL! Anyway, it is still for sale. You are going to need external steering, but I might know where a set can be had for about $2K+ or so. It will work AWESOME on a single engine V-hull. Make sure you have the room for the engine to go up 3". I don't have that room in my Donzi. If your still interested, send me another e-mail & we will chat!

Woodsy:D :D

for a single in. v bottom you should use a 3 in box.. it;s a little more work but that will give you the best performance and if the drive is still to low you can go with a shorter lower unit to get it even higher if need be.it does require a full hydrolic steering system,it will cost about 5,600 for a complete system,not including the shorter unit.it will increase the handling,performance,and the boat will think it's a foot longer!! If you have a lot of horse power in this boat the torsional drive shaft will help the drive except this power. for more detailed info. call IMCO NV.

Yikes!

I had talked with Cobra Marty about the +3 box right around the time you were dealing. Seems like there was some sort of swap where you guys were switching a +3 for a Neutral box. Anyhow you guys had a done deal so I left with my tail between my legs.
I copntinued to see Cobra's thread in classified and occasionally checked back in to see what was up, but he told me that all was sold.

Jolly-
If Puder doesn't want your box, be sure to give me a holler.

Puder, you got the offer, so you feel free to go first. I prolly ain't gonna get around to turning wrenches this season again anyhow - looking like it'll be NEXT fall that the good parts get put on...

how about i'll give you the box and you get that 56 pred from me instead ;)

Send me info on the Pred.
56 Hardtop, 800's, thruster, hydraulic platform, full electronics and plasma upgrades. Blue hullsides.

Prefer well-maintained used boat, but will entertain new one for right price... Fax or email (fax: 615/860-2869)

You know I'm kinda sweet on 'em...
(course there's a SeaRay 560DB on the market that some poor sap needs to dump - you've prolly seen the ads, about six different brokers all have it listed simultaneously.)

oh 6 brokers on a sea ray scramblin for a little bit of a tiny pie!!!who would a thunk it!

leeme see what i can dig up for you.