WildWolf
Active Member
Looks interesting? I found this video http://www.youtube.com/watch?v=zFCljQsAu40 trying to hear it run. Anybody else know of a good video?
WW
WW
Yamaha SHO 4-stroke 505 pounds
- Thread starter WildWolf
- Start date
K.Kiser
Well-Known Member
Like most all Yamaha's, it a sweet looking engine... I've been tring to stay updated on this engine for the last year or so and I see alot of promise for this motor in the future if they're not priced outta sight... I predict that sometime in the near future they'll turbo these things, and when they do We can all sit back and wipe tears cause it's gonna be over..
allison xtb
Active Member
I've read in another post somewhere that they can't be rebuilt. Does anyone know if this is true?
Gary
Gary
Darth VMAX
Well-Known Member
I have "heard" that if you score a cylinder than you have to get a new block because of the plasma fused walls (no sleeves) my question? When was the last time you scored a cyl in your 4-stroke?
biller31
Active Member
Looked at em at the Bassmaster classic. They've got low water pick up. Light enough for the XB-21... Gotta say I am curious what one would do on the back of my boat. Any body wanna buy my XS for a fair price? I'll guinea pig this motor and play with the set up If I could afford it.
GotMyAlly
Well-Known Member
How many hours on your 250?
whipper
Well-Known Member
Brian Harden on hear has used this motor an Allison owner and dealer. He is going to report back with his findings compared to a XS on a fast hull soon I hope. He mentioned this in another thread on S&F. Not shure on what hull he was going to try it next? So Brian have you had the SHO to a good number yet? Not trying to put ya on the spot or anything just couriose
Darth VMAX
Well-Known Member
I know C&O is doing the 250VMAX SHO/XB21 BasSport PRO performance bulletin for Yamaha's Website. Haven't heard any results yet.
Yamaha Specifications
Looked up the specs on the Yamaha website. Shows weight as 558 pounds. Only available as 25" and 30". OK, so someone needs to make a 15" or 20" mid for these and a turbo, then things will start to get interesting!
Looked up the specs on the Yamaha website. Shows weight as 558 pounds. Only available as 25" and 30". OK, so someone needs to make a 15" or 20" mid for these and a turbo, then things will start to get interesting!
Last edited:
BigRedAlli
Well-Known Member
Although a turbo would be cool, it would also be very dangerous (expensive) with a non sleeved block. One wrong calibration,or get boost happy, and your gona pay big time...:gasp
Yamaha would be my next choise if/when my merc self-destructs.
Yamaha would be my next choise if/when my merc self-destructs.
K.Kiser
Well-Known Member
Wrong calibrations usually get expensive regardless, but it gets done with success regularly in this day and age... The LS based GM engines aren't an over bore-able engines and turbo set-ups are common and make HP with reckless abandon... With the modern knowledge of turbo systems and the advanced engine management at the disposal of a disposable income it can be done and of that I have zero doubt, it's a 4 stroke and that is a very credible buffer... One of these Guy's are gonna put one on a custom short mid with a light race cowl and drop about 50-75 lbs. with about 10 psi of turbo boost and were all gonna be talking about "the way it use to be" and squabbling for 2nd place...
Last edited:
FFWD
Active Member
Whipper, its going to be a couple more weeks. The boat is not ready yet. It will be a 721 Phoenix Bass Boat. I know its not an Allison, but its not a slug either. Should run a tad over 80 light and high 70s loaded. I already have the same boat with a 250 Pro XS that I will be able to do head to head testing with. I'll post up the results and hopefully some video as well!!!Brian Harden on hear has used this motor an Allison owner and dealer. He is going to report back with his findings compared to a XS on a fast hull soon I hope. He mentioned this in another thread on S&F. Not shure on what hull he was going to try it next? So Brian have you had the SHO to a good number yet? Not trying to put ya on the spot or anything just courioseJames
Brian Harden
FFWD
Active Member
Its not really even going to take a turbo. This engine is WAAAAY under what its horsepower potential can be. Yamaha engineers told me that 400HP on this platform is easily done but in normal Yamaha fashion they detune it for the mass markets so it will run forever. I would think some good head work, custom ground cams, and a larger throttle body would easily get you to 350HP. Then you could always add a shot of the giggle juice just for fun. Everything inside the engine is forged so it will take it. This type of setup will be the future like it or not and they are only going to get lighter and higher in horsepower.
RedAllison
Well-Known Member
Is the gearcase completely new and specific to the SHO? The gearcase on the Vmax sucked and won't run on our rigs but I think Hydrotec made a conversion kit for their Maxs that allow you to bolt a Sporty on.
Knock on wood my 225 SportXS has been flawless but I'm quite interested in the prospects of the SHO. But like I said, the gearcase issue would have to be cured. I wouldn't drop an XS for a SHO if it meant it was 3-5mph slower because of the case and or it made for poor handling.
I cussed DFI 2strokes until I bought my deckboat which had one on it. At least for now Yammie has answered our calls for a lighter 4 stroke with an eye toward bassboat performance. I wonder what Merc is working on??? :twisted evil
Anything under $20k should keep it in the ballpark, :beer:
RA
Knock on wood my 225 SportXS has been flawless but I'm quite interested in the prospects of the SHO. But like I said, the gearcase issue would have to be cured. I wouldn't drop an XS for a SHO if it meant it was 3-5mph slower because of the case and or it made for poor handling.
I cussed DFI 2strokes until I bought my deckboat which had one on it. At least for now Yammie has answered our calls for a lighter 4 stroke with an eye toward bassboat performance. I wonder what Merc is working on??? :twisted evil
Anything under $20k should keep it in the ballpark, :beer:
RA
Darth VMAX
Well-Known Member
Thomas you looked at the wrong motor. The VMAX SHO is ONLY available in a 20" shaft and it IS listed at 505lbs. You must be looking at the 4.2L offshore motors.
I beleive the Lower is pretty much the same as the Series 2 VMAX HPDI's except the redesigned the screen intakes for better cooling. RA, Hydro-Tec has two options. They can mod the existing Yamaha Lower OR you can convert to the Sporty. The first option is MUCH less expensive. They have ran the mod Yamaha lower on Strokers well over 100 mph so they would work fine on our boats IMO
Merc, To me, a 2.6L that weighs 650 lbs vs a 4.2L that weighs 505 (Same as an 3.0L Opti) is too much to overcome. Maybe they will go back to buying their 4's from Yamaha and start painting the SHO's Black LOL ;-)
I beleive the Lower is pretty much the same as the Series 2 VMAX HPDI's except the redesigned the screen intakes for better cooling. RA, Hydro-Tec has two options. They can mod the existing Yamaha Lower OR you can convert to the Sporty. The first option is MUCH less expensive. They have ran the mod Yamaha lower on Strokers well over 100 mph so they would work fine on our boats IMO
Merc, To me, a 2.6L that weighs 650 lbs vs a 4.2L that weighs 505 (Same as an 3.0L Opti) is too much to overcome. Maybe they will go back to buying their 4's from Yamaha and start painting the SHO's Black LOL ;-)
Last edited:
biller31
Active Member
I'm just itching to see one of these on a 21 to see what it'll do. I really think there's a chance this could be a great all around motor for the big boats. If in fact it can be "turned up" horsepower wise with minimal cost and effort, and it is 500 to 600 hour reliable, and gets better mileage than the 2 strokes as claimed, then I could fill up once a year with the Allison fuel efficiency advantage and have a motor that'd last almost a third as long as my hull will hold up and stay pretty.
50 Horsepower For 53 Pounds
Oops, I did look at the wrong model. OK, let's look at the F300 offshore. Same 4.2L, presumably the same block, same compression ratio, same DOHC, weighs 53 pounds more than the VMAX SHO and has an additional 50 horsepower. Got to be a way to clone that additional 50 horsepower over to the 20" version and have a 4.2L 300 horsepower factory stock motor. Wouldn't take much (cam, turbo, small blower) to get that up to 400 horsepower and then who knows what's next?
Oops, I did look at the wrong model. OK, let's look at the F300 offshore. Same 4.2L, presumably the same block, same compression ratio, same DOHC, weighs 53 pounds more than the VMAX SHO and has an additional 50 horsepower. Got to be a way to clone that additional 50 horsepower over to the 20" version and have a 4.2L 300 horsepower factory stock motor. Wouldn't take much (cam, turbo, small blower) to get that up to 400 horsepower and then who knows what's next?
Darth VMAX
Well-Known Member
I see your point unless....
The 250 "VMAX SHO" is at the 10% allowance on the MAX side (275 hp) and the 300 Offshore is at the 10% allowance on the negative side. Then theoretically it could be the same motor with a different badging.
It has been mentioned that BRP did this with the Pre-ETEC 3.3L FichtRam 225HO and standard 250 when they 1st bought the OMC assets in 2002.
The 250 "VMAX SHO" is at the 10% allowance on the MAX side (275 hp) and the 300 Offshore is at the 10% allowance on the negative side. Then theoretically it could be the same motor with a different badging.
It has been mentioned that BRP did this with the Pre-ETEC 3.3L FichtRam 225HO and standard 250 when they 1st bought the OMC assets in 2002.