2.0 vs 2.4 fuel consumption (modded)

[Pray-2-miss-logs]

i'm getting ready to put the boat the boat away for the winter, and under the knife, but one of the things that I want to establish is which motor to use for my build. my decision of which motor I will be running ultimately will take into account top speed vs fuel consumption. . .

I currently have a 2.0 175 max that I will be doing a full build to sell or building to hang it off the back. build will consist of full porting, shaved heads and re-jet/tune. i'll be doing the exact work to a 2.4 if I was to acquire one.

with all that said, does anyone have any experience going from a 2.0 to a 2.4 that could enlighten me on fuel consumption difference?

if it's a tangible difference between the two (especially both built), that will give me more fuel (pun intended) for a decision one way or the other.

i'll be adding a jackplate to the equation also, max speed is my goal regardless of the motor that's hangin off the back but I understand there's a compromise between fuel consumption and top speed and i'd like to address it before I start collecting blackmax's.

 

[corey331]

Do you mean fuel consumption just cruising around the lake or at WOT? I'm just guessing here, but my thought is cruising around the difference between the two would be minimal. If anything the bigger motor would do better since you would be swinging a larger prop and wouldn't have to push the motor as hard to obtain cruising speeds. At WOT I would assume the bigger motor is going to drink more fuel, but to me, the power and speed difference would be well worth the extra fuel burnt. Plus, how much of your time on the water do you spend at WOT? I know I spend 95% of my time just cruising.

On a side note. If you are worried about fuel economy, my guess is performance boating might not be the hobby for you.

 

[Pray-2-miss-logs]

Do you mean fuel consumption just cruising around the lake or at WOT? I'm just guessing here, but my thought is cruising around the difference between the two would be minimal. If anything the bigger motor would do better since you would be swinging a larger prop and wouldn't have to push the motor as hard to obtain cruising speeds. At WOT I would assume the bigger motor is going to drink more fuel, but to me, the power and speed difference would be well worth the extra fuel burnt. Plus, how much of your time on the water do you spend at WOT? I know I spend 95% of my time just cruising.

I should have specified this, im talking WOT only. cruise speed will def be comparable between the two, no issues there. I spend 90% of my time WOT as the bodies of water I boat in are inherently smooth, and the way i see it, there isn't much point in owning a boat like this if the hammer isn't kept down.

but, i also boat on the Chesapeake. . .i could rip all day in one direction. with that said, it might be worth it to sacrifice a few mph to save a gph - - -if of course there is a substantial fuel saving of a 2.0 vs 2.4.

On a side note. If you are worried about fuel economy, my guess is performance boating might not be the hobby for you.

thanks, but spare me of this guess. im looking for range and an efficient setup. not looking to make sure my next paycheck will be enough to fill the tank for one more outing. . .


this reminds me of the guys who say to me "if you have to ask, its too much". then I say "right, I have to ask to make sure youre not asking too much".

 

[Ramifications]

I have a built 2.0 150. Mine has milled heads, bored .015, milled reed cages, Chris Carson reeds, removed exhaust can, 200 tuner and rejetted and tuned. I'm not sure on the exact difference between the 150 and 175, but I get great fuel economy. I can easily run 100 miles on one tank (32 gallons) at varying speeds, including a few full throttle runs. This is on the same boat with a 10" hydro jackplate. I have seen a best of 69.xx with this setup and a 25p Tempest plus.

 

[Pray-2-miss-logs]

I have a built 2.0 150. Mine has milled heads, bored .015, milled reed cages, Chris Carson reeds, removed exhaust can, 200 tuner and rejetted and tuned. I'm not sure on the exact difference between the 150 and 175, but I get great fuel economy. I can easily run 100 miles on one tank (32 gallons) at varying speeds, including a few full throttle runs. This is on the same boat with a 10" hydro jackplate. I have seen a best of 69.xx with this setup and a 25p Tempest plus.

I was hoping you'd chime in. im basically going to have the same setup as you. with all the mods you've done, there will be less emphasis on the difference between the 175 and 150 (im also not sure what they are, but at the same displacement it cant be much after modded). that is good fuel economy, next to see what the guys with the 2.4's are getting (hopefully a 2.4 exciter will chime in).

I ran in the upper 50's and could crest 60 on a good day down river. that was with the tired 175 and 6000 rpm, so there was more room there. im excited to see what it'll do with fresh rebuild, more power, and a prop to match. going to jump right to a 27 and if theres room for more, going further.

 

[DropTop5.0]

Sorry for the old adage but...there's no replacement for displacement. I really can't see a 2.0 propelling you to 70 mph being far superior in efficiency than a 2.4 bringing you to the same mph with a drastic change in efficiency. I'd be more worried about parts if 90% of your time is WFO. I'm not a mechanic just an enthusiast.

 

[corey331]

If I rememeber right, ndaniels had an exciter that he put a stock 3.0L 225 on and I believe he hit a best of 79.9 on GPS. If you got an EFI version of that I would imagine that would be as fuel economical as it gets for the speeds you are wanting. And If you left it stock (maybe mod the exhaust so it sounds cool) It would be very reliable. I'm not sure how much all the mods cost that you are planning to do, but I bet for the same money you could find a late 90's, early 2000's 225 or 250 EFI. Unless you have a love for the 2.4 blackmax, that might be an option to get the best of both worlds.

 

[Pray-2-miss-logs]

If I rememeber right, ndaniels had an exciter that he put a stock 3.0L 225 on and I believe he hit a best of 79.9 on GPS. If you got an EFI version of that I would imagine that would be as fuel economical as it gets for the speeds you are wanting. And If you left it stock (maybe mod the exhaust so it sounds cool) It would be very reliable. I'm not sure how much all the mods cost that you are planning to do, but I bet for the same money you could find a late 90's, early 2000's 225 or 250 EFI. Unless you have a love for the 2.4 blackmax, that might be an option to get the best of both worlds.

i'll be doing all the work, so it wont cost that much, only parts cost. also im not in love with any particular motor at this point per se. . .but I try to always allow the situation to dictate decisions. the situation is, I have a 175 that needs rebuilt and a boat that ill be restoring in the off season (its going under the knife soon). my goal is top speed, but the 175 is worthless as parts, so whether I ultimately run it or sell it . . .its getting built. another variable in the equation (the 2.0 vs 2.4 debate rather than a later model) is that I can acquire a 2.4 for rebuild prices locally without problem. I am not putting a motor on this boat that I haven't built, allowing me to maximize my chances of it giving me at least a few seasons of trouble free use. the rest of the boat will be fresh, I want the motor to be as well.

the 2.0's and 2.4's are abundant, whereas the later models are not. at this point, i'm not spending thousands on a motor that some other guy ran the piss out of, or pay thousands more for a motor that will perform like the built max. if I find a late model powerhouse for a "rebuild price" i'll jump all over it, but deals like that are few and far between and not really worth planning for because of that fact. if I were to pull the trigger on a local 2.4, i'd build both, run the 175 for the tuning stages and list it for sale for what it is. with it tuned/running on the boat, ill be able to offer sea-trials. a lot of the total restoration cost could be recuperated with that sale, and then goes on the built 2.4 for tuning and rippin.

the 2.0 vs 2.4 consumption debate just adds (potentially, if there's a tangible difference) another defined variable to the equation, which will aid in the overall decision making akin to such a project (at least for me).

 

[strehl]

I'm assuming you mean an old 70's era 175 if its a 2.0L. I had one of those on my enticer and it seemed extremely thirsty compared to my 2.4 200hp on my exciter.

I never checked mileage on either boat but I remember the enticer only being able to go a couple times around the lake before I had that little 16gal tank empty. The exciter has a 24gal tank and I can use it the whole weekend doing the same messing around.

BTW. I'm still playing around with the setup on the exciter and I've got it up to 72mph. The only things not stock on the 2.4 is 1 steel sleeve, g force tuner and 2L heads to give me 145psi compression. The 2.4 has a ton more down low power than that 175 2.0.

I know I'm comparing apples to oranges with different boats but I hope it helps you a little.



With my 5.5 cmc jackplate my favorite setup so far is a worked 23" trophy plus with pvs blocked 1/2" below pad. I let this engine spin up to about 73-7400 rpm with that setup before backing out of the throttle. Holeshot is good and midrange is awesome. I know I should go to a bigger prop but this setup is really fun. I haven't had a chance to put my 26" laser2 on gps but with the same engine height it still pulled up to over 7k.

 

[Pray-2-miss-logs]

I'm assuming you mean an old 70's era 175 if its a 2.0L. I had one of those on my enticer and it seemed extremely thirsty compared to my 2.4 200hp on my exciter.

I never checked mileage on either boat but I remember the enticer only being able to go a couple times around the lake before I had that little 16gal tank empty. The exciter has a 24gal tank and I can use it the whole weekend doing the same messing around.

BTW. I'm still playing around with the setup on the exciter and I've got it up to 72mph. The only things not stock on the 2.4 is 1 steel sleeve, g force tuner and 2L heads to give me 145psi compression. The 2.4 has a ton more down low power than that 175 2.0.

I know I'm comparing apples to oranges with different boats but I hope it helps you a little.



With my 5.5 cmc jackplate my favorite setup so far is a worked 23" trophy plus with pvs blocked 1/2" below pad. I let this engine spin up to about 73-7400 rpm with that setup before backing out of the throttle. Holeshot is good and midrange is awesome. I know I should go to a bigger prop but this setup is really fun. I haven't had a chance to put my 26" laser2 on gps but with the same engine height it still pulled up to over 7k.

thanks for the input! mine was kinda soft out of the hole, but I attributed it to tired old age and the prop. I think i'll keep my eye out for a 2.4 and pull the trigger on it and build both at once. itll actually give me a rather interesting comparison myself, both in power production (out of the hole and WOT) and fuel economy since ill have to mount the 175 in order to tune it for sale.

i'd like to hear your speed numbers with the 26p also once you document the speed.

 

[strehl]

Just remember that most 2.4s are chrome bores so you can't really port them without the chrome flaking. If you want to mess with porting a 2.4 I would look for a xr4 which are steel sleeved blocks.

 

[Pray-2-miss-logs]

Just remember that most 2.4s are chrome bores so you can't really port them without the chrome flaking. If you want to mess with porting a 2.4 I would look for a xr4 which are steel sleeved blocks.

great point, i guess that is one advantage of the 2.0 no matter how else i look at it. i can only imagine a 2.4 resleeve to standard bore material to be costly outside the realm of worthiness. noted.. .xr4 or better it is