New Honda 135/150

[Minnow]

Hi- I'm a new member with a CD-25 on order from Cutter in MD.
I need help deciding between the new Honda 135 or the V-Tec version 150. I've read the debates on different torque curves from the 40's and 50's, and wonder if the same concerns apply to the larger twins. Any insight would be greatly appreciated.

[Chuck S]

There aren't any "debates" about the torque curves on the Honda 40 and 50 -- no one has ever seen the curves, so we can't even make intelligent guesses or have debates about them. Torque on an engine like these is pretty flat, though. If anyone knows the torque of the Honda 50 at 3500 rpm I'd appreciate it!

The VTECs strength is good fuel economy when the engine is "off the cam." This could translate into economy cruising -- if we knew where the VTEC cam change happened. From driving VTEC engined Honda automobiles the accelleration really climbs fast once the engine changes at about 4,000 rpm. These engines are too new for the official Honda website, but several dealers have minor specs on them. This is the 4 cylinder Accord engine technology. 2.4 liters.

Both achieve maximum horsepower at 5500 rpm. The VTEC looks to be about $1000 more.

-- Chuck

[Minnow]

Thanks for the reply, Chuck. The 2 page Honda handout says the VTEC delivers more power, torque and efficiency across the powerband and say the high lift cam engages at 4500 rpm. There is a torque vs. rpm graph, but ist is not labeled for the torque values. Cutter has quoted me $1350 extra for the 150. I don't see any downside to the 150 except for the cost, but do I need, or can I use the additional power on the 25?

[Les Lampman]

I can't report on the curves per se...what I can give you is that the BF40 produces 43.8 ft-lbs of torque at 3500 rpm and the BF50 produces 47.1 ft-lbs at 4500 rpm. Given the wide spread (1000 rpm) between the peak torque rpms and the relatively small difference (3.3 ft-lbs) to start with it seems reasonable to expect that they're not very far apart at 3500 rpm (and it wouldn't suprise to find the BF50 slightly lower at that point). At any rate it's splitting hairs; the real world differences wouldn't be discernable in most cases. It's really a matter of horses for courses; it doesn't appear to me that there's any indication that the BF50's will outperform the BF40's in the rpm range where most CD22's spend thier time (with twin 40's in the 3500-4000 range). There is clear evidence that if you routinely run in the mid-4,000 range and up that the BF50 is a better choice (which is why it works best for CD16's and such). Also, the BF50's WOT (wide open throttle) range should be 5500-6000 (max hp at 5750); the BF40's 5000-6000 (a good indication that a BF50 shouldn't be "lugged"); it's max hp comes at 5750 rpm. This translates into being able to prop the BF40 a bit more aggressively and given the same 2.08:1 lower unit gear ratio on both the BF40's and BF50's, the BF40's should perform a skosh better in the lower rpm ranges (at least up to the low-4,000 rom range where the BF50 starts "to do it's thing"). The final decision usually involves the money difference (about $1400 at MSRP); whether or not the extra dollars spent translates to a good return on investment depends an awfully lot on where and how you run the boat and on what makes you smile. I usually opt for the less expensive option given that most CD22's in our area will not be operating in the range where the BF50's extra performance comes into play. Seat-of-the-pants operations validates the numbers.

The BF135/BF150 question is more easily answered since there is a lot more than minor information available. Here we do have published torque and horsepower curves and there is a lot of information in the new Honda Sales Brochure. The motors are also in stock now at many dealerships.

Peak torque on the BF135 comes at 4500 rpm @ 140.9 ft-lbs and the BF150 at 5,000 rpm with 145 ft-lbs. The torque curves closely mirror each other up to 4,000 rpm where the BF150 takes a dip and they're almost equal. This continues through 4,500 rpm where the BF150 changes over to VTEC and its torque starts to climb away from the BF135 (who's torque stays flat here); the BF135 then falls off pretty rapidly after 5,000 rpm. The BF150 falls off a bit after 5,000 but it's a very gradual decline. The horsepower curves are very, very close; in fact they cross at 3500 rpm. At 4,500 rpm they're almost together and don't really start to split apart until 5,000 rpm where the BF150 stays on it's linear path and the BF135 drops off from it's peak at 5,500 rpm. The peak on the BF150 is really at 6,000 with 160 hp; 150 hp at 5,500 rpm.

My assessment is that I'd be perfectly happy with a BF135 on a CD25; actually I'm very happy with the BF130 on the CD25. The BF135 looks great in comparison to the BF130's torque curve; the BF135 holds about 140 ft-lbs from 3,500 to 5,000 rpm (very flat!) whereas the BF130 is just over 120 ft-lbs at 3,500 with a steady linear increase to around 135 ft-lbs at 4,500 at which point it drops sharply. The BF135 hangs in there pretty well for another 500 rpm (to 5,000) and then drops quickly like the BF130.

Given the $1600 difference (at retail) between the BF135 and BF150 the BF135 looks like the better choice (especially given the torque and horsepower is all but the same from 3,500 to 4,500 rpm) unless you've just got to have the top end (on a C-Dory!?!).

[Chuck S]

Local dealer lists the BF135 at $8844 and the BF150 at $9992 or a difference of $1148.

Les has an excellent summary and access to the data for the 135/150 I wish we had with the 40/50.

Torque is king, horsepower is a mathematical calculation based on torque and rpm, and the higher the rpms you can generate the higher that number will be. Note that at 5252rpm torque and horsepower are identical. By defination: Horsepower = torque x rpm/5252.

Torque and horsepower curves are paper items, and experienced boat gurus like Les have the time on the water to know what's spec, and what's performance. And don't forget he's noted the "what makes you smile" factor, one reason we have a 50 on our 16 Cruiser and not a 40 (the major reason, of course, was it was in stock!).

Me? I'd get the 150 VTEC and not blink. Why? The smile factor, and the techie factor (VTEC). No one has ever wished for less horsepower, even if we never ever use it.

Or save the money, get the 135 and have the dealer order a set of the 150 decals for the engine cover! After a while you'll start to believe it yourself.

-- Chuck

[Minnow]

Wow! Great info. I really do appreciate the smile and techie factors, and I think I can afford it, so I will be going with the BF150. On my current boat, I have always regretted (7 years), not going with the largest reccommended HP. As I plan on having the CD25 for a long time, the additional cost per year in the financing shouldn't hurt much. Looking out my window now has almost a foot of snow on the ground. This site is a great way to help me through the boating jones till spring. My new CD25 will be delivered to Maryland this month, rigged, and then shrink wrapped awaiting liquid water in the Delaware river. With help from the Wallas heater, I'm hoping for a very early christining.

Brady H. on the near future Minnow

[Les Lampman]

Way to go Brady!!! And congrats on your "soon to be a C-Dory owner" status.

[DaveS]

A new 25'......the excitement is building. Congratulations!

[C-Puffin]

I have just recently purchased a 25 and went with the 150 but I am considering changing to the 135. I talked with the Honda rep briefly and was told the fuel use would be very close between the 135 and 150 due to the Vtec technology on the 150. He quoted me 12.7 and 12.5 GPH at 5500rpm for the 150 and 135. These are the only numbers he had so at lower rpms I would think the gap would get closer with the 150 even using slightly less fuel but still remaining fairly close to each other. So at 3000 to 4000 rpm range which engine do you think would be better on fuel ?

[My IRA]

For what it's worth, we checked the graphs at the SBS and talked with the factory rep. and he agreed with Les, that the 135 is better suited for the CD-25 hull. He also said that the 135 would deliver equal or superior fuel economy to the 150 at all RPM ranges.

In short, we selected the 135 and saved some cash (earmarked for a kicker).

[C-Puffin]

Thanks for the additional information. I think I am leaning more to the 135 now and will take the additional $ and possibly put it toward an autopilot that I have been thinking about getting. On a side note what size kicker are you thinking about using?