Reducing Horsepower on a 376 Canyon??

[Ronrog]

Hi and looking for any first hand advice on reducing the horsepower on a GW 376 Canyon. My current "376" has Yam 350's X 3 and now thinking about upgrading the same boat, but the one I'm looking at has Yam 300's X 3. I'm not a top end boater, but I am somewhat concerned about the HP and/or torque needed to get this boat up on plane asap, so I can see over the bow.

Have any of the GW members experienced a reduction in HP on this size boat with any positive or negative results? Any and all comments will be appreciated.

Thanks

Ron

 

[SmokyMtnGrady]

Ron, first I would change your name to Capt Ron and get an eye patch and red speedo ...That would be awesome! If it is going to happen it is going to happen out there.

As I understand your post, you have a 376 and it's powered with 3 350s and you are wanting a new or newer one powered with 3 300s? Correct? If that is the case sea trial that bad boy because you know what the 350s do so it should be clear on what the 300s do as you have intimate knowledge of how that model performs.

A friend of mine had a 330 powered by twin 225s I think. He hung the 300s on it and it made a world of difference. As you know Grady's are heavy . Maybe the extra 150 HP might not be missed but it might and sea trialing it I think is your best bet.

 

[Ronrog]

I agree on the sea trial before purchasing, but not so much on the red speedo.

Ron

 

[SmokyMtnGrady]

You're right. The red speedo will clash with Grady colors. You need a blue, yellow or white one. Lol. Captain Ron is a funny movie. One of my favorite Kurt Russle characters.

You know the 300s are lighter than 350s and maybe the weight on the stern saved might offset some of the power lost? The flip side and I don't know when that boat came out, but was it ever powered with 3 250s? If so the 300s are in the middle there . That is a sweet ride you have. If you take it for a spin post back . I am curious to see how it performs.

 

[Ronrog]

Yes ..it was a good movie..

and I will report back after the sea trial...

thanks again

Ron

 

[everwhom]

It will be interesting to see what you think of the sea trial. I suspect you may notice the drop in torque more than the drop in max HP. Simplistically speaking, Torque is proportionate to displacement, so going from the 5.3L V8 F350's to the 4.2L V6 F300's will result in about a 20% drop in engine torque. I'd pay close attention to planing time and how the vessel accelerates in the mid-speeds. The 150HP drop will probably only result in a few mph loss of max speed, but since most folks don't run flat out much (if ever) you may not even notice that.

 

[Ronrog]

i got this info from Grady white today..

the 350's get on plane in 5.06 seconds and reach 30 MPH in 7.28 seconds

the 300's get on plane in 4.78 seconds and reach 30 MPH in 7.10 seconds

that surprises me, but I got it directly form GW...supposedly the 3 X 300 HP engines will reduce the over all weight by 1100 lbs and reduce drag due to small gear housings, etc..

I am not a gear head or a techy, but passing on this info for what ever its worth..all I need is for the boat to quickly get on plane and handle as good as my 3 X 350 HP engines did. Probably if I was ordering a boat, I would stick with 350's only because I have no complaints with them, but now that I'm running out of time, I might take the 300HP and get on the water in the next month or so.

Thanks for the responses..

Ron

 

[everwhom]

Interesting. In addition to the weight savings and less lower unit drag on the 300's, it's quite possible that they have been able to shift the torque curve so that the difference at lower RPM's are not as great. It's too bad outboard mfg's aren't required to publish their dynometer graphs as it would take a lot of the guesswork out.

But it certainly sounds like the F300's are more than viable!

As you're probably aware, the F350's have issues with their flywheels and some winterization problems, but the early F300's also have issue with the thrust bearing.

 

[Ronrog]

Thanks for the response and the info on the Yam 300's.

Greatly appreciated

Ron

 

[beachbum]

Ron,

Comstock Boats in Brick, NJ has a 376 with trip 300's on their lot, saw it last summer and it is still there. They are great guys, might be a place for you to ride one and this boat might be a good deal. Also, I know they sold a 366 with trip 300's to a guy that lives near the Marina ( I looked at his boat when I was also looking at 366's) Maybe that's another opportunity for a ride or feedback.

I agree, if you can stay away from the 350's (even the C series) since they still have the winter freezing and flywheel issues and get acceptable performance, I would go 300's.

The performance numbers of 376 with 300'sand 350's on the Grady site look very close to each other.