E-tec Gen 2 300hp

[kc]

On the homework I have done I am expecting an oil burn of about 1 litre per 3 hours cruising at 34 mph :: about 15 cents a mile or $5 an hour. I am expecting about 30 litres an hour fuel save compared to the Yammy 250 at cruise speed for the boat so $45 an hour fuel save offset by a $5 an hour oil burn = happy days. The 350 ml an hour oil burns number is a "running in" figure and should reduce after 20 hours, but, my previous etec experience on my 150 HO was an increase in oil usage as the motor got older.
As to the idiosyncrasies of the hull the biggest issues are slow speed wander and lying on their side under power, both a result of the very sharp entry V. It can be really alarmingly when under power if not trimmed properly or if weight is badly distributed with a big load up front. First few times I used the boat it scared the hell out of me but with a bit of time and practice it is just a matter of setting trim tabs and motor trim before planting the throttle. The boats are also sensitive to moving the weight around when running and need trim tab adjustment for even modest movement of weight (a bloke moving around for instance). I believe this is aconsequence of the very deep V but the trade-off is the softest mono hull ride in any sea conditions I have ever been in. It takes a sea head on like a boat 15 foot longer and 2 tonnes heavier and does it at twice the speed.

[kc]

Dealer sourced a motor interstate and will arrive next week . Fit out starts on 8th and should be sea trialling on 11th or 12th. Will post some photos and "numbers" as it moves along. Mackerel still on the chew and life is good.

[kc]

=( a sad tale of the refit. New motor arrived seriously damaged in transit. Now back to waiting for September 2nd shipment to arrive and mid September job. Bugger.

[kc]

The eagle has landed. Fit out starts Friday

[Chimo]

Looking forward to see how it goes.

Good luck with the fit up.

Cheers
Chimo

[kc]

Me too. I will post some pictures of the rigging and sea trial as well as the numbers. This is a big spend (in part because I had to buy the wife a new car to soften her up for the new motor) and I am expecting a very good set of numbers when it hits the water. I have 2 years of data from the 250 Yammy and want to see 30% better at least fuel burn and an extra 7 to 10 MPH top end speed. It is however all about fuel burn at cruise speed as well as shot hole for me, not about WOT.

Kev

[scottar]

not about WOT.

Kev

Who you kidding. It's always about WOT. If it wasn't...... you'd have bought a sailboat LOL. You must be like a kid licking the candy store window at the moment. Have you given your dealer the sh*t's yet? Pretty sure I probably would have.

[kc]

Yeah OK, OK, maybe just a little bit about WOT. My last etec 150 was sold with 900 hours and a total of 11 minutes at WOT. What I really want is range at decent speed. If I can get anything above 30 MPH and still be running in the order of 40 LPH I will be stoked. As to WOT. Thinking maybe 45 to 47 MPH (up from 37 with the Yammy)Attachment 114156

[gofishin]

... As to WOT. Thinking maybe 45 to 47 MPH (up from 37 with the Yammy)

Assuming both donks develop 'sticker HP', and setup, prop slip etc are all the same, your 300 won't give you any more than 40.5 mph kc, as per the speed-power square rule.

However, from memory the 3.3L V6's only put out around 240HP, so assuming that the G2 is 300 exactly that gets you to 41.4mpg.... still short!

That being said, 37mph does sound slow, even though those boats are hard to push. Maybe that ULS on an XL transom might be a factor. Did you ever work out the prop slip calcs for your 37 mph kc ? It just sounds too slow even for your boat (i.e. like something wasn't quite right with the setup/donk etc).... but I guess we will find out soon enough when you get that beast bolted on
Cheers
Brendon

[kc]

Thanks Brendon for your interest. Prop slip and the technical details are well above my "pay grade". I'm in the "pay the money to the experts and see what happens" class and tried everything with the Yammy to little avail. It was a dealer set up boat (in the US)and why on earth it was setup with a 30 inch leg on the Yammy I can't say. I lifted the motor (as you can see in the photos) put on a foil, went through 3 props and while the last prop was about the best overall, it achieved 5500 RPM and 37 MPH at full hammer, that said, always with pretty big gear loads. Factory specs say I should have been getting 41/2 MPH at WOT but think that was on a boat without the windage effect of the T-top, plus mine had a big min kotta plus the extra battery weight. At issue, in my unqualified opinion is that the boat was simply underpowered. Any motor having to work within 10% of WOT to get the boat cruising at a reasonable level is just not enough grunt. I am expecting, based on all I have read, that the additional tourque, coupled with the grunt of the RX4 prop will revolutionise the performance. Trouble is I have nothing to compare to and I can't find a single one of these unusual hulls married to an Etec 300 even in the USA, let alone Australia. I am hoping it will be a game changer, and I guess I will know in a week or so. Anecdotally the 300 Etecs are putting out 325 HP but without any hard data that I can find. They are outperforming 350 Verados, set up on identical Ranger 25's in apples to apples set ups, not only getting higher WOT speeds but killing them on fuel numbers.

[kc]

In she goes.

[myusernam]

Hulls not bent from sitting on a trailer wrong or something?

[kc]

No. Hull is fine and a factory set up trailer. On another note I just called in to see how it is going and the mechanic was just finishing lunch. Hope he washes his hands before starting back =)

[gofishin]

... went through 3 props and while the last prop was about the best overall, it achieved 5500 RPM and 37 MPH at full hammer, that said, always with pretty big gear loads...

Well maybe there is one or three of your mph there (due to short on rpm's). Do you remember what type/model/size of prop you got this with?

... Anecdotally the 300 Etecs are putting out 325 HP but without any hard data that I can find. They are outperforming 350 Verados, set up on identical Ranger 25's in apples to apples set ups, not only getting higher WOT speeds but killing them on fuel numbers.

If 325 is the number you are getting closer, now @ 43mph. Add on another 3mph to the 250's 37mph for a better matched prop, and with the new 325(?) ponies you're at 46.5mph .

Yes, i have read some pretty good numbers from the G2's on THT, so will be very interesting when you get some numbers from the new beast.
Cheers

PS. Nice looking lines on the hull, and looks like a very deep Vee from that transom pic too. I can see she would need some ponies to get her going.

[kc]

Thanks mate,
really appreciate your interest and expertise. My dealer is a great bloke and gives great service but I know propping is a dark art and we have never got the best out of either of my last 2 boats. On advice from a number of guys, including the etec owners moderators we are starting with RX 4 18's but also have an RX4 20 on standby.

Kev