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new build 241 vs 912

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Re: new build 241 vs 912

Postby mgrant » Fri Mar 20, 2020 9:04 am

Agree, I learned the hard way that all that hp is useless if the pump can't utilize it, and the 241 is not even capable of using 500hp. With the 212 I considered the uncontrollable blowout as a frustrating predicament, not something to brag about or be proud of. Now my boat doesn't blow out at all :)
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Re: new build 241 vs 912 vs 231

Postby smitty » Fri Mar 20, 2020 10:00 am

Ok, performance people.

When a stick gets in, how do you fix it?

If I could build a new ride, I guarantee the cleanout will be on the wet side of the transom. Performance junkies and interwebbers - plug it and get back to me.

Thank - you AT 231 … Survival on the river outweighs performance every time, get me there and back without complication. 300 club
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Re: new build 241 vs 912 vs 231

Postby Riverjohn » Fri Mar 20, 2020 10:06 am

smitty wrote:Ok, performance people.

When a stick gets in, how do you fix it?

If I could build a new ride, I guarantee the cleanout will be on the wet side of the transom. Performance junkies and interwebbers - plug it and get back to me.

Thank - you AT 231 … Survival on the river outweighs performance every time, get me there and back without complication. 300 club

Sounds like you have picked your pump :Drink: :Drink: There are 2 used ones on Craigslist. Now's your chance to put your money where :Drink: :Drink:
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Re: new build 241 vs 912 vs 231

Postby mgrant » Fri Mar 20, 2020 12:06 pm

smitty wrote:Ok, performance people.

When a stick gets in, how do you fix it?

If I could build a new ride, I guarantee the cleanout will be on the wet side of the transom. Performance junkies and interwebbers - plug it and get back to me.

Thank - you AT 231 … Survival on the river outweighs performance every time, get me there and back without complication. 300 club


I've had sticks, grass, and seaweed stuck in the grate, that I had no idea was there until I hauled the boat out of the water. Some of the sticks made contact with the impeller, as their ends were shredded.
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Re: new build 241 vs 912

Postby Hell Yes » Fri Mar 20, 2020 3:34 pm

I understand the 912 has a clean out.
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Re: new build 241 vs 912

Postby smitty » Fri Mar 20, 2020 6:06 pm

smitty - kicking a hornet's nest since day one... <c:
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Re: new build 241 vs 912

Postby mgrant » Fri Mar 20, 2020 7:03 pm

Hell Yes wrote:I understand the 912 has a clean out.


It does, never needed to open it. I took the one off my 212 more times than I care to remember.
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Re: new build 241 vs 912

Postby akhunter67 » Fri Mar 20, 2020 10:15 pm

Mgrant Have you tested it with the cam swap ? That boat is awesome!
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Re: new build 241 vs 912

Postby chariotdriver » Fri Mar 20, 2020 10:22 pm

FlyLow wrote:
mgrant wrote:I do know the LT4 can actually blow the 241 out, like the LSA would do to a 212. I know a few boats with big Chev/Dart strokers and supercharged big blocks, their comments indicate that 4000 seems to be about the max usable revs, anything more didn't gain speed or thrust...which seems to be true of all the single stage axial jets.



I wonder how big the letdown is to a new LT4 and 241 owner that they just touch 500hp?


Should be getting this question answered soon; HCM is in the process of making an impressive looking 22 footer.

There is a forum member running a very big Bloodsworth with a 241/Haxby Custom engine. It is around 600hp at 4500rpm.

My LSA/241 has a very noticeable performance increase between 4000rpm and 4500rpm. Turning 4000rpm the boat lopes along at 42mph burning 25gph. Firewall the throttle...there is a noticeable acceleration, within a few seconds it's going 51mph spinning 4500rpm sipping gas at 45gph. Numbers from a few hours ago on a no wind lake, pre-season warm up with a 4.0T impeller. No idea what impeller the bigger engines are running. The 241 should provide much more holding power based on the 40% increase in intake/impeller size. They are not designed to absorb much power when static, look at their performance charts. They need 10-15kts forward speed to absorb even what they are rated for let alone over boosting them by 50%.
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Re: new build 241 vs 912

Postby mgrant » Fri Mar 20, 2020 11:38 pm

akhunter67 wrote:Mgrant Have you tested it with the cam swap ? That boat is awesome!


Yup, gained about 40ft lbs of TQ around 4500, WOT rpm went from 4500 to 4600 (verified with ecm datalog as Faria tachs are unreliable) with the jet configured at 4.05kw configuration according to Scott. Cam is a Comp custom solid roller grind from Dwayne Porter, 248/248@ 0.50 110lsa, .600 lift. Surprisingly enough, fuel burn at 3100/30mph went from 12.8GPH to 10.5GPH; we're thinking more efficient cylinder filling with higher lift is resulting in more dynamic compression and efficient burn...should go a ways further with its 140gal fuel tank. Also went with 2.25" primaries on new Hi-Tek headers, plus installing H-pipe before the exhaust passes through the transom. The motor is moving enough air that I had to switch out the Flowmaster mufflers with straight through Magnaflow, which gained 30 rpm WOT and even a touch quieter. ECM WOT datalog: fuel burn=35.3GPH(221lb/hr), BSFC=0.39-0.42, VE=105% max.

However the cam grinder is trying to talk me into a building a Bill Mitchell aluminum block 572 Wedge to better compliment the Indy cylinder heads and intake :p This engine runs just fine as it is, but all those cubic inches weighing less than 500 lbs is intriguing.
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Re: new build 241 vs 912

Postby akhunter67 » Sun Mar 22, 2020 10:05 pm

That is an awesome engine package!
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Re: new build 241 vs 912

Postby FlyLow » Tue Mar 24, 2020 7:56 pm

MGrant- are you running the same impeller stack as the LT4 boys? I was told second hand that Eric’s boat turns 4800rpm.
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Re: new build 241 vs 912

Postby mgrant » Tue Mar 24, 2020 9:50 pm

FlyLow wrote:MGrant- are you running the same impeller stack as the LT4 boys? I was told second hand that Eric’s boat turns 4800rpm.


No, in fact Eric went back to the same 19s/19p stack to turn 4800 in Granite's hole, not sure which nozzle he had in it at the time. With the 19p/19p Eric mentioned that it turned 4500ish with the 123 nozzle. Travis is currently testing his LT4 19p test bullet behind his Raptor 575. Travis and Scott Jet would like to see me try it, which I may, but it works pretty good as is with the 120 nozzle...in fact, it works even better with the 121 nozzle that I had machined out from a 117 when I first got the pump. The 19p test bullet was a mild steel test unit only, and once determined that works, they will be producing them in stainless.
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Re: new build 241 vs 912

Postby heyjpark » Thu Apr 02, 2020 10:56 am

I have a 25' Bloodsworth full hard top with a Haxby BBC producing 558 hp and 733 lb/ft of torque at 4,000 RPM. I have a 241. I wouldn't get rid of the 241 for anything.

I've thought about the 912, but to my knowledge not one single person has a boat similar to mine and exchanged a 241 for a 912. I'm not gonna be a guinea pig.

From my research, I'd probably gain a lot of top end with the 912. I do believe the 241 dies off at about 4,100 RPM and after that is just eats RPM without producing additional thrust.
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Re: new build 241 vs 912

Postby bondobreath » Thu Apr 02, 2020 11:25 am

Whats the average GPH with that Bloodsworth set-up ?
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Re: new build 241 vs 912

Postby wooldridge1 » Thu Apr 02, 2020 6:41 pm

heyjpark wrote:I have a 25' Bloodsworth full hard top with a Haxby BBC producing 558 hp and 733 lb/ft of torque at 4,000 RPM. I have a 241. I wouldn't get rid of the 241 for anything.

I've thought about the 912, but to my knowledge not one single person has a boat similar to mine and exchanged a 241 for a 912. I'm not gonna be a guinea pig.

From my research, I'd probably gain a lot of top end with the 912. I do believe the 241 dies off at about 4,100 RPM and after that is just eats RPM without producing additional thrust.


How about a picture of your boat and motor?

Thanks Joe
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Re: new build 241 vs 912

Postby FlyLow » Thu Apr 02, 2020 6:49 pm

heyjpark wrote:I have a 25' Bloodsworth full hard top with a Haxby BBC producing 558 hp and 733 lb/ft of torque at 4,000 RPM. I have a 241. I wouldn't get rid of the 241 for anything.

I've thought about the 912, but to my knowledge not one single person has a boat similar to mine and exchanged a 241 for a 912. I'm not gonna be a guinea pig.

From my research, I'd probably gain a lot of top end with the 912. I do believe the 241 dies off at about 4,100 RPM and after that is just eats RPM without producing additional thrust.


That’s a mean BBC! What do estimate the kw of your impeller to be? Top rpm? Do you have to be easy on the throttle to not blow it out? My boat makes 570hp and 985lb/ft at 3000rpm and the HJ274 with a turbo Impeller can’t be blown out at all. I’m surprised the 241 can hold your power.

A lot of top end is subjective, the 4 mph that mgrant gained isn’t worth anything to me.
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Re: new build 241 vs 912

Postby mgrant » Thu Apr 02, 2020 7:21 pm

FlyLow wrote:
heyjpark wrote:I have a 25' Bloodsworth full hard top with a Haxby BBC producing 558 hp and 733 lb/ft of torque at 4,000 RPM. I have a 241. I wouldn't get rid of the 241 for anything.

I've thought about the 912, but to my knowledge not one single person has a boat similar to mine and exchanged a 241 for a 912. I'm not gonna be a guinea pig.

From my research, I'd probably gain a lot of top end with the 912. I do believe the 241 dies off at about 4,100 RPM and after that is just eats RPM without producing additional thrust.


That’s a mean BBC! What do estimate the kw of your impeller to be? Top rpm? Do you have to be easy on the throttle to not blow it out? My boat makes 570hp and 985lb/ft at 3000rpm and the HJ274 with a turbo Impeller can’t be blown out at all. I’m surprised the 241 can hold your power.

A lot of top end is subjective, the 4 mph that mgrant gained isn’t worth anything to me.


Actually it does, meaning that the pump will take full power and give you thrust in return. The 212 I had prior would simply blow out over 3/4 throttle, lose suction entirely, and put you into one heck of a predicament if you're in hairy whitewater. The 241 would, and should give extra over the 212, and I had full intentions of swapping in a 241, until the news of the 912 development came out a week prior to when I had planned to call Hamilton in Woodinville and plunk down cash and start building an intake block to weld in.

As far as comparing the 241 to the 912, the LT4 guys would have to chime as that is a motor that can blow out a 241. However, Eric's trip up right up through and out the middle of Granite's dreaded hole at full power, does say a lot about his LT4/912 combo.

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Last edited by mgrant on Thu Apr 02, 2020 7:31 pm, edited 1 time in total.
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Re: new build 241 vs 912

Postby FlyLow » Thu Apr 02, 2020 7:29 pm

mgrant wrote:
FlyLow wrote:
heyjpark wrote:I have a 25' Bloodsworth full hard top with a Haxby BBC producing 558 hp and 733 lb/ft of torque at 4,000 RPM. I have a 241. I wouldn't get rid of the 241 for anything.

I've thought about the 912, but to my knowledge not one single person has a boat similar to mine and exchanged a 241 for a 912. I'm not gonna be a guinea pig.

From my research, I'd probably gain a lot of top end with the 912. I do believe the 241 dies off at about 4,100 RPM and after that is just eats RPM without producing additional thrust.


That’s a mean BBC! What do estimate the kw of your impeller to be? Top rpm? Do you have to be easy on the throttle to not blow it out? My boat makes 570hp and 985lb/ft at 3000rpm and the HJ274 with a turbo Impeller can’t be blown out at all. I’m surprised the 241 can hold your power.

A lot of top end is subjective, the 4 mph that mgrant gained isn’t worth anything to me.


Actually it does, meaning that the pump will take full power in the froth and give full thrust. The 212 I had prior would simply blow out, lose suction entirely, and put you into a heck of a predicament. The 241 would, and should give extra over the 212. As far as comparing to the 912, the LT4 guys would have to chime in as the LT4 can blow out the 241. However, Eric's trip up right up through the middle of Granite's dreaded hole, does say a lot about his LT4/912 combo.



FYI- this thread isn’t about a 212. The point of this thread is a new build and why to choose a 241 over a 912 or the other way around.
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Re: new build 241 vs 912

Postby mgrant » Thu Apr 02, 2020 7:33 pm

Don't you think I know that? Read the second paragraph...
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