Dock Holiday

I just spoke with Fred at IMCO in California and he says no problem using standard Bravo 1 4-blades or the Maximus 5 blades with the 1 inch and the 2 inch shorties.

boss252

Did he say were they take the 1" out at?

JaayTeee

The distance from the top of the lower gearcase
to the propshaft centerline is shorter than on a standard
unit.
If you were comparing the two, the strut area is where
you would see the difference ( the area in between
the cavitation plate and the area just above the propshaft
centerline)

I know on the 2" shorty, the cavitation plate area
above the prop is removed, I would imaging on a 1" it's
modifed somewhat also.

boss252

Thanks for the info JaayTeee.

Now what kind of performance can I expect from a 1" lower on my 252

JaayTeee

That's hard to say....If your drive is real deep, it
may help, if it's up, it may hurt.

I was able to borrow a set of 2" shorties, my
drives are high, they didn't work.

boss252

my drive height is very low. I would think it would help But would like to find someone who has tried it on a similar boat.

articfriends

iTrader: (1)

Your boat may like the plus 1" but plan on a 4 blade or even a 5 blade prop in your future. I know this isn't a perfect comparison but on my 272 with big power I had prop c/l to hull measurement of 7 1/2 to 7 3/4 with stock length drive,everyone told me that it was waaaay deep. Boat ran 89.7 w/30 pitch and fairly heavy load,ran 92.8 with light load and 32 pitch. Bought a stellings box and raised prop c/l 1" up,boat had no problem getting on plane but blows prop out at 2800-3200 rpm's when accelerating easy,porpoised like crazy,cavitayed and slipped like crazy,went 4-5mph slower for most part on top end. Added a 1"drive spacer (returned depth to stock) to get rid of most these awful charateristics but box is still slowing it down a few mph. I would buy the best labbed prop I could find if I were you and save your money for other mods. These Bajas like bow lift to go fast and shorties kill it. If you do buy one as long as your willing to buy a 350 to 500$ 1/2 " or 1" spacer to get your ride back if needed its the worst that could happen. If your boat has stock power and runs in the mid 60's now the nose cone built in the imco could create some wandering with stock cable steering and its extra surface area as it puts more stress on your gimble,just a heads up,Smitty

boss252

Thanks for the info Smitty, Did you every try the lower without the box?
I do have a 25p 4 blade Hydomotive prop QIV. It is not labbed. My motor has had a little work done on it but very little. The prop that I damaged was Labbed and Julie at Throttle Up figured it was running with only 3% slip. So something is definitley not right. Tach may be off. I am going to check it this weekend to see.

articfriends

iTrader: (1)

My box raised the stock length drive 1". A guy who works for CMI in r&d told me he tried a 2" shortie on a 96 272 w 850hp blower motor and that it wouldn't carry the bow,blew out,porpoised and cavitated. Your boat is 2 ft shorter though and your only wanting to go 1" so it may or may not work. I saw a 2000 272 for sale where the owner claimed the dealer ship (which turned out to be the same place I bought mine from) ordered all their 272's with a 3/4 " higher x-dimension from Baja but I have never seen or heard of this from any other source and I don't know if mine is the same as the one he was selling,Smitty

boss252

Thanks for the info Smitty. I am going to try to call Baja and see if they will give me any insight on this.