OMC general questions.

[HydraSports]

First off I apologize for the 'dumb' questions. I've searched the site a ton, but it seems everyone here already knows so it isn't discussed......

What years and models OMC's were X-flows, and what ones were Loopers. The MadEFI, and Brucato stuff is for loopers or x-flows? Web sites simply say OMC.

I have a 90 Evinrude XP150. I'd like to do a few things to it, but need to do it in stages due to $$$. I'd like this to be a really nice engine, that I keep when upgrading boats...

Ideas for a plan of action?

[BenKeith]

Your 90 xp is an X-flow

The first 90 degree V-6 looper came out in 1986 in 200 and 225hp

The 90 degree 150 and 175 hp motors were Xflows until approx 1992. Then they came out with the 60 degree looper for the motors less than 200 hp. Well, that's not totally accurate because they did make some commercial and jet drive motors that were rated at less than 200 hp but were still 90 degree looper block.

As for the aftermarket front ends, I think most of that is for the 90 degree 2.7/3.0/3.3 loopers but to be sure of that one, you'd best email or ask them.

As for modifying your 150, to me it makes about as much since as modifying a flat head Ford engine for a race motor. You can do it, it will make a few more HP, it will cost you a bunch of money and after you've finished, a slightly modified 3.0 looper will have much more hp and torque for a whole lot less money.

[BarryStrawn]

Agree with everything Keith posted.

The new aftermarket stuff is for loopers only. At least I don't know of anyone still making hotrod parts for crossflow powerheads.

What condition is the engine now?

[flabum1017]

To answer the first question, the first loopers were the three cylinder motors from the '60's :D

But that doesn't apply to your motor.

Your motor is a crossflow, and there are things such as porting and increasing the compression plus getting lager carbs and a different tuner that can boost your performance. But as said before, the loopers are easier to build up.

[EMDSAPMGR]

The 150 XP/GT engines already had upgraded components from the factory and would produce 10% over rated hp, or around 165. There are further bolt-on improvements you can make, such as the 78-79 small bore 235 heads, intake stuffers, composite reeds. These changes should get your engine just beyond the old 175 (flatback-low port) crossflow hp. If you want to get into machining changes, porting the engine will also help.

[Riverman]

Hydrasports, welcome to the board. At the bottom of my signiture is a link for OMC parts lookup. Use it, copy and keep the link, it's handy.

[HydraSports]

Also considering making small changes here and there and later swapping a larger power head on. Adding a nose cone w/water pickup, an exhuast dump or creating a dry stack exhuast, and solid mounts. Then add pryo's and egt guage, heads, reeds, velocity stacks, switche the louvers on the cowl around, a lighter flywheel, and some sort of ignition to rev the thing higher.

From my understanding with the adapter plate a 235 power head will bolt on. In which case I could find one of those and build it, and bolt er' on. I really would like to add EFI down the road though, and all the kits are for the looper aparently....

[flabum1017]

Also with an adapter plate you can go with a looper 225 and build on that

[HydraSports]

well after using the search feature a bunch I think that may be my best way to go.

One of the main things I don't like about building a crossflow is having to use premium......I would much prefer a realiable powerfull engine that isn't so octane sensitive.

Is this a factory adapter, or aftermarket?

[sharkcrazy]

Where is there a place to buy aftermarket looper parts?

[jphii]

Pro Marine, or here. Or Wayne Taylor or Monty.

[Action Dave]

well after using the search feature a bunch I think that may be my best way to go.

One of the main things I don't like about building a crossflow is having to use premium......I would much prefer a realiable powerfull engine that isn't so octane sensitive.

Is this a factory adapter, or aftermarket?


Ahh grasshopper...with raised compression comes need for premium fuel.
Actually, any performance motor regardless of brand make or model shouold be run on at least 93 octane.