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View Full Version : Drop on 2.5 EFI powerhead



Boatmaster
10-30-2002, 05:05 PM
I have a buildable drop on powerhead, it can be bought in the box for you to build or I can build it to your specs. Anyone interested call or post a price. Open to all offers. This was a spare for my old boat and I no longer need it. 925-828-5775

TOBTEK
11-04-2002, 08:00 AM
Boatmaster:
I have a buildable drop on powerhead, it can be bought in the box for you to build or I can build it to your specs. Anyone interested call or post a price. Open to all offers. This was a spare for my old boat and I no longer need it. 925-828-5775Drew....maybe a dumb question BUT can that be put on a 95 225promax efi? My bro has that on a 20.8 Lavey seabring and its atotal toad! he NEEDs some more ponies!!!!!

HavasuDreamin'
11-04-2002, 08:31 AM
TOBTEK:
Drew....maybe a dumb question BUT can that be put on a 95 225promax efi? My bro has that on a 20.8 Lavey seabring and its atotal toad! he NEEDs some more ponies!!!!![/b][/QUOTE]
Yes, pro max is a 2.5L block and will bolt right up. Problem is that hull needs torque, not rpm's. I might suggest a 300X. :D What do you think about that motor? wink

TOBTEK
11-04-2002, 08:48 AM
HavasuDreamin':
TOBTEK:
Drew....maybe a dumb question BUT can that be put on a 95 225promax efi? My bro has that on a 20.8 Lavey seabring and its atotal toad! he NEEDs some more ponies!!!!!Yes, pro max is a 2.5L block and will bolt right up. Problem is that hull needs torque, not rpm's. I might suggest a 300X. :D What do you think about that motor? wink [/b][/QUOTE]
I hear its not real bad! wink Interesting though, was down looking a another being built last week, and his lower end was off the brandnew 300x, so I inquired why...They put 1:75 gear cases on the single motor boats and 1:62 on twin's...Ya think it makes that big of difference out of the hole,and what about top end? Im sure THEY know whats the hot set-up, just curious how different it could be.

HavasuDreamin'
11-04-2002, 10:39 AM
I really don't have any experience with the 300X gearcases or the differing gear ratios, but I think it has something to do with props and prop choices. For example, you put a 300X on a small tunnel.......if you had 1.87 or 1.75 gears, the rig would need a tall prop (32" or 34", etc.). However, if you get a 1.62 gear you could run a 28" prop which is much more readily available by multiple manufactures.
Does anyone know any type theory regarding prop pitch and slippage. Do you get more slip with taller props? I have no basis for my answer, but I think you would get more slip with a 34" prop vs. a 24" prop?
My confusing $.02 wink

TOBTEK
11-04-2002, 11:09 AM
I will inquire about the "non current" motor, but it better not be! Dave was saying with the wimpy single 300x (KAB wink ) it NEEDs the tourqe of the 1:75 gearcase, and with the right prop it will still do high 80's to low 90's....will se soon :D

Boatmaster
11-04-2002, 12:03 PM
Tobtek yes that powerhead would bolt right up. I took a 225pro maxs off Tunnel T's buddies 20.8 last March, boat went from 79mph to 91. We also added 8inches more set back at the same time and played with alot of props to get there. As far as gear ratio the 1.75s will give you a better hole shot and mid range but you will loose alittle on top end. No question about it a higher pitch prop in most cases has a higher slip factor. My feeling is if you can pull the higher gear do it, just my .02