Does anyone know if they have done any testing to date on those engines yet on an Allison? Would love to know results if so.
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Does anyone know if they have done any testing to date on those engines yet on an Allison? Would love to know results if so.
I know of a 250 4stroke but nothing smaller.
The weigh 455, 470 and 505lbs. I thought the 200 pro XS being a 4.6L v8 would be too heavy and figured someone might mount up the 3.4L 225hp V6 or are the softer mounts not ideal for high speed?
Light that shiny new XTB up with some big HP Rick!
What's the blow out speed of the lower unit on the 150/175 models? Had heard they're good to ~78mph with the 200hp G2 TM being good to 85mph?
I am really interested in the 150 Pro, because it's light enough, and has plenty of torque. It just needs better gears. We may be trying it soon on a Grand Sport.
The V6 is interesting for the 21 hulls, but would need mounts and a better gearcase. I don't think the sportmaster bolts up on the V6? Although it might on the 150. The V8 is very heavy, and would need a Sportmaster, the 250R is 570 Lbs with oil and lower unit on.
I'm really wanting to put one on my XTB and see how it does.
Rick, the new 250R runs awesome on an XB21. That is the only boat I have personally seen it on, and have run it on. You have to set the motor a good bit higher than normal. The lower on these new motors is huge compared to a standard Sporty. The cav plate is about 1" thick. But the torque is extremely good and they run as well or better than a 2 stroke on top end. I put Woody's on the limiter with no problem running a 29 Hydromotive, and was right at 90. There was at least 2 to 3 more mph in it with a worked prop or maybe a 30".
That's pretty awesome Johnny but I just worry about the weight of the V8 on my light XTB.
I don't think the weight is an issue. It weighs the same as a 3.0 liter 505 pounds.
The V-6's are 470lbs.
Initially I read the standard 4-strokes used different mounts than the Pro XS versions though when I looked at the parts catalog only the R models had a different part number listed and all the other V6/8 models had the same part #.Quote:
Originally Posted by Wave to Wave
Does a 20" V8 Pro XS with G2 TM not weigh 505? I can see the SM lower unit being a little heavier and the R models have oil coolers, though not an additional 59lbs. Do those figures include prop and was your 570 with or without?
Good point all the V8’s weigh the same as the 2 Stroke Pro XS engines at 505.Quote:
Originally Posted by K-DAWG
https://www.mercurymarine.com/en/us/...75-300-pro-xs/
Without oil?
Last weekend, we weighed the new Mercury 250R V8 engine with calibrated digital scales suspended from an overhead crane. The engine was filled to the required oil level; however, no battery cables, harnesses, or cowling were attached. The engine weighed 534 lbs and the cowling (weighed separately) was 30 lbs. That's a grand total of 564 lbs when fully configured and a bit heavier than Mercury's advertised weight of 505 lbs. Given this, it is suspected that Mercury was weighing the engine minus the lower unit which would most likely result in approximately 505 lbs. It appears this is the same weighing process Mercury used for the 2.5 race engines years ago. Lee Sanderson has more knowledge than I on that particular issue.
The XTB-21 weighs approximately 400 lbs less (with a smaller beam and smaller rear pods) than the current XB-21 models. For those reasons and due to the engine weight increase, we do not recommend the 250R V8 for the XTB-21 models.
:sweating: Now we know... 564
Would it be fair to say the torque of the 3.0L I4 is ~ the same as 2.0L 2-stroke, 3.4L V6 is like the 2.5L V6 2S and the 4.6L V8 is on par with the 3.0L V6 2S?
If they were doing the same weight process with the 2 strokes then I imagine it would be the same. Also how such does the added oil weigh for the old 2 stroke since they both use some type of oil. I believe oil weigh approximately 7.5 lbs per gallon.
the OLD two strokes did not have an engine mounted oil tank -- mixed it with the gas.
My Pro XB has a separate oil tank for the 2 stroke oil. But yes, the old ones didn’t. Lol.Quote:
Originally Posted by fishnfireman