marine engine FI

[nhoj at cd.chalmers.se]

Espen Hilde wrote:
> > > I have 2  2.5efi high performance engines that I am reparing, line
> boring
> >
> > Are they any fun?
> Just problems so far,

I've heard that they require far too much rebuilding for a "standard" engine.

> but nice to look at with mahle forged pistons,
> lots of ports .aluminium Nicasil treated sleeves. Big reed blocks.
> and the v8 inspired trottle body. The loverunits are beauties, I have a
> slightly modified Yamaha 225hp with nose cone that I have to fill with
> padding all the time, I want to weld it but maybe it will change because of
> the heat.

What kind of filler do you use on the nose cone? (Mine is welded, and the  
paint is coming off, but the putty stays...)

What kind of boat do you run those beasts on? I have a Hydrolift CR22.

> Maybe the new lowerunits from Yamaha with biger skeg and
> low water pickups has the same gear and internals as the one I have .

I know someone who replaced the gears of a 150TRP gearhouse with the innards  
from a 225, or possibly 220.

> I have very modified Yamaha 200
> What modifications have you done?

Wayne Taylor heads and exhaust plate, HydroTec pipe (but that one is going  
to be replaced with a cut 225 pipe), ported front half, big intake and  
exhaust ports, shortened sleeves, cut pistons (forged from Wiseco), finger  
ports, dry stacked. I've also built a turboscope, but I've not had time to  
test and see if it makes a difference.

> that will get an EFI
> > system if it is still running when I can aford one (eg MADEFI) or find
> time
> I have looked at the mad efi myself, no I am hoping that 332 efi would
> do the trick.

If EFI 332 gets down to reasonable size;  an 8x8 inch four layer board +  
driver boards is rather ridiculous, IMHO. Something like the ECU6 or ECU7  
system would probably be good enough for an outboard, anyway.

> I would like to play with the ignition also...
> Do you have any info on recalibrating the ignition system on the Yamaha
> engine?

I don't, sadly. I know a Danish guy who may have the info, but I don't have  
his email address.

He has a lot of tuning info from Yamaha. You may consider contacting them to  
find out...

> > to build something... Performance below 4000 RPM is not exactly stunning
> when
> > using carbs.
> What hp does it make?

I don't really know. I had it tuned by a Swedish shop in Vasteras that have  
a DynaFlow, but they made a horrible mess of things. The porting they did was  
OK, but they made the heads totally wrong; the squish was going the wrong  
way, and the pistons kissed the heads. Then it gave 240hp from 6000 to 7000  
RPM. In the boat I never got it to rev over 6200. Due to the mess they made  
of it, the crank broke after about 20 hours. Needless to say, I stay away  
from them these days.

Now I have good heads, much larger ports and finger ports, and a modified  
exhaust system. 275-300 at 8000RPM is an educated guess. I don't wont to go  
much higher than 8000RPM, because that's how high Yamaha's own high output  
engine went. It used (or uses?) the same crank and bearings as the standard  
engines, but had longer rods and different pistons. (I don't think it used  
forged pistons, by the way.) The long rods make a huge difference I'm told. I  
think Hydrotec sells them, but I'm not sure. A bit too expensive for my  
taste, anyway.

> I read somewhere that the ox66 engine used GM corvette ecu.

Really? One would expect them to use Japanese components... That would be  
cool, though, because I bet there are lots of info on Corvett ECUs floating  
around.

Regards,
John Hornkvist