Weight, HP, pump/thrust, Size.... go!
Weight, HP, pump/thrust, Size.... go!
Ecotec 2.2 Supercharged 343 lbs
Hamilton 772 (7 1/2") 120 lbs 773 is 130 lbs
Total 463 lbs for 252hp 1.83 lbs/hp
Merc Sportjet 200 367 lbs for 200 hp 1.83 lbs/hp
Pretty close match there eh?
I know ill have a few more ponies next year, maybe 300...it depends how much it will cost me
I think it pushes a little harder in the midrange than the sportjet, but I dont have that much experience with them. Next spring we will have to do a comparison. We will have to get Wooldridge to build an Ecotec XL
09 River Wild, 3 stages, LS power
Is the ecotec, 4 stroke?
Yes it's a 4 stroke made by GM
"A reputation for performance, durability and adaptability has made the Ecotec the "small-block" of four-cylinder engines. It's a great engine for many applications and GM Performance Parts offers a production-trim Ecotec 2.2L in a crate engine package that satisfies the needs of all sport compact enthusiasts."
C-bolt, I'm going to assume the noise level is much lower than the SJ, have you ever measured your dB levels with the boat in use? There are a few harder of hearing folks from SJ use that are interested I'm sure. Oz
link that gives the power curve. I believe you said at WOT your reaching 5000rpm This is where the pump is stalling the engine. So your actually only getting about 225hp out of the engine. Do you have a pump absorption chart for your jet? I can see why you mentioned it doesn't have much in the mid range for thrust. Probably feels like the pump isn't putting out much at all until you get up past 3500. Even though your engine puts out more HP on the sticker it wouldn't be able to turn a standard 2.45kw impeller. Your probably at 1.75Kw just guessing. Attached is a 2.45Kw absorption chart. Where the engine hp matches pump absorption is where the engine will stall at WOT. Appears it could only turn up to maybe 3700-3800. If your getting 225@5000 that's where it matches up but your limited to most likely running high rpms to get any thrust from the pump. Before you sink serious money into extra ponies you may want to find out if the gain will give you a steeper hp curve throughout the entire range of rpms. If it only extends the graph in at the current slope you wont see any gain unless you want to run past 5Krpms. If the increase in power will get you to around 200hp at 4000rpm you could then switch to the equivilant of a 2.4Kw impeller. As it stands your pretty close to matching engine WOT with pump absorption it appears and more like 2.06lbs/hp. When it comes to a jet it doesn't matter what the sticker says on the engine, it's what the jets putting out a WOT.
Something to ponder.
we have built 3 boats now with the 252 hp super charged ecotec
we are getting 3 1/2 - 5 1/2 gph fuel burn rate
we have used the scott 752 pump on all 3 and turning 5400 rpm wot
they all have great hole shot and mid range
we are now buildind 1 with the next gen 2.4L ecotec and a scott 751
for those looking for more power in less wt. how about a 2.8L 400 hp V8 thats 200 lbs
The more important spec in the power curve is the torque, that is what really turns the pump. Look at the chart again and notice where the torque comes in. Does anyone have a chart for the sportjet torque curve ?
I'd be interested to compare some SJ torque / hp curves too... I've actually never looked at them, but I do know in real world experience what they will do and much as I love them, would like to have a higher performing setup that would allow me to stay nearly as lighweight as they are... forget the hp to pound ratio even, just keep the whole powerplant/jet combo less than 400 pounds and give me big pump thrust and I'll be all over it. They were just starting to play with the ecotec when I built my last boat and I didnt have the nerver to go first back then. It looks like they have them pretty well dialed in now. Might be time to spring for a new setup... (glad you went first C-bolt!)
I agree. I have a 22' FishRite powered by 351W turning a 773 pump, at 2000rpm I can really feel the torque come on through 3800rpm. I cruise it at 33-3400rpm at 30-32mph, at WOT 4000rpm and 40mph. That 600rpm in reserve is power on tap when needed. Not having some power in reserve can be a problem in a delicate situation.I hardly ever run WOT, mostly in that 50 to 80% throttle setting actually. We built most of the torque to come in between 3500 and 4800 rpms which is where I run most times and thats where you find the most thrust response. After you pss the torque curve with your rpms and the hp climbs, you still get incremental speed increase, but at a lesser ratio than down in the maxtorqu range. Its still great fun once in a while, but I dont think needing WOT to eperience maximum preformance out of your boat is the best way to set up things.
HG, I am not sure about the impeller absorption rate or anything like that. Ive never gotten that into it. I do know the engine has an extremely broad torque curve thanks to the forced induction. I highly doubt the 200 Opti SJ has that kind of torque. Most 2 strokes are great at building HP but not as much torque. I would love to see a chart on the SJ as I am very curious. I said earlier, and I think it pushes more in the midrange than a SJ.
The 772 does have a bit of a whine to it as well as the supercharger. I think it is quiter than a SJ but I havent spent much time in a SJ boat.
Toshiro, why dont you chime in and give us your opinion. He got to drive it a bit, although it was dark...hehehe.
I dont have a flow meter but I think I am in the 4-5 gph range when cruizing. For the cost of one of those sweet Floscan's I think I will just wing it for a while and do more averaging.
JBM has made some sweet purpose built boats and they look pretty capable. When RW built mine, they had an extra 772 in the shop so they used that one. They have since built one with the new AT pump and I believe they are happy with that as well.
If you look at the chart, you can see how broad the torque curve is. From 2500 rpm, the Ecotec has more than 220 ft lbs of torque peaking at 4700 rpm with 247 ft/lbs. Thats pretty impressive if you ask me.
09 River Wild, 3 stages, LS power
C-bolt the torque does look good but the problem is HP. If you don't have more hp then the pump is absorbing at a particualar rpm the engine will stall at that set rpm. Engine HP must exceed the impeller absorption for rpms to increase. I'm sure she spools up quick because there's not much pump absorption on the low end. Pump absorption follows more of an exponential curve rather then a linear curve. Your running a 1:1 ratio I assume and the SPJ is 1:1.25 and I'm guessing the SPJ has a larger kw impeller. The impeller is topping out at ~4300rpms at WOT. To get the same thrust and power out of the jet your upwards to turning the impeller @ 5000rpms. If you want to have a good thrust at the bottom end you need hp and torque down low so you don't have to wind out the engine at cruise. I'm not sure what jbm is calling midrange but didn't you say you cruise at 4000.
This is one reason the diesels are much nicer in this application. Attached are power curves and torque curves for the 190hp and 250hp. 1 Lb-Ft = 1.35582 Nm, Torque peaks at 2400/274 and 2600/339 respectively. HP say at 2000rpm on the HPEP250 is nearly 129hp where as it's 80hp on the gaser. I guess another way to look at it would be HP to weight ratio at a set rpm and jet thrust. Your still ahead but not by much.
If you look at the hamilton chart for different impellers you'll see the ecotec couldn't turn the 1.8 up to 5000rpm. It would stall at around 4200. This is why I imagine the pump impeller is probably less then 1.75Kw but without a chart it's hard to say. But just for demonstration purposes what's the jet abosorbtion and consquential thrust with 1.8kw vs 2.4kw impellers. At 3800rpm the 1.8kw produces 100kw and the 2.4 produces 130kw. So if you want to cruise at a lower rpm, with much less noise and extended life expectancy getting the torque and hp out of the engine at lower rpm is needed. Just food for thought.
im call mid range 3200-3600
at 3600 rpm we were running 32 mph up stream and at 3200 rpm we ran 36 mph down stream with full fuel [ 30 gl ] and 2 guys on board
this is the rpm we ran in a 15 1/2 ' 60" bottom in .190
we used a 18 front and a 18 rear impellers in this boat with 112mm noz ring
we try to set up our boats for out of the hole and good cruise rpm with wot rpm around the max hp rpm for that motor
we work very close with konrad to get the impellers to match the motor we are using in any given boat
with these smaller/less hp engines you have to get this dead on so you can use all the hp you can
we have 1 set up with a 143hp turbo and a scott 751 pump where we use a 9 pitch impeller that gives us around 7400 rpm wot
this set gives us very good hole shot and cruise speed of around 28 mph with only 30% throttle
which gives a very good fuel burn rate of around 3 gpm with little load [ full of fuel and 2 guys ]
if i was a little smarter on this computer i would try to attach the test run ecu log
but i am have trouble attaching it sorry
What was the weight of the boat? 15 1/2' boat couldn't have weighed much. What's the fuel capacity in that size boat? Not sure two guys and a moose quarter would even fit.
who has one of these motor in there boat
Just a comment, brought to light by a good friend in the know, anyone think about or realize that being turbocharged the EcoTec should be run on Premium fuel?? Availability is somewhat limited, especially anywhere resembling bush Alaska. Tell me I'm out of my mind, please. I'd like to look at perhaps using one of these in the future. Oz
C-bolt, what's required on the blown version? The link here indicates premium fuel is required.