Mercury V8 FOURSTROKE Engines

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2MATTANZA2
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Mercury V8 FOURSTROKE Engines

Postby 2MATTANZA2 » Mon Nov 23, 2020 7:23 pm

[Give me your] opinions or [your actual] experience with the new Mercury V8 FOURSTOKE engines.

I may put a Mercury 250 ProXS [that is, NOT the FOURSTROKE 250] engine on my OUTRAGE 25.

I previously had really good experiences with Mercury OptiMax engines (which are no longer in production).

jimh
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Re: Mercury V8 FOURSTROKE Engines

Postby jimh » Thu Nov 26, 2020 12:30 pm

I assume you are asking about the 4.6-liter V8 250-HP model. That 4.6-liter displacement for only 250-HP sounds like a very conservatively tuned engine so there should be plenty or reserve power available at lower engine speeds. The 505-lbs weight does not seem to be too burdensome for an OUTRAGE 25 to handle.

My opinion about these newer Mercury FOURSTROKE V6 and V8 engines which have supplanted both the VERADO FOURSTROKE and the OptiMax The Next Generation models is based not on any real experience with the engine or on random comments from others or from reviews in the boating press about them. Instead, I base my opinion of them on the career path of Mr. David Foulkes.

Mr. Foulkes spent 17-years with the Ford Motor Company before he joined Brunswick in 2007 as head of product development for Mercury Marine. In that role he lead the development of these recently introduced V6 and V8 outboard engines--including the engine you are planning to purchase. From there he was promoted to president of Brunswick Marine Consumer Solutions and to corporate vice-president and Chief Technology Officer, and in 2018 he was again promoted, this time to become the President and Chief Exeutive Officer of Brunswick corporation. On the basis of the extraordinary success of Mr. Foulkes career with Brunswick, I infer that those V6 and V8 outboard engines that were developed under his leadership must be selling very well and producing excellent profit for Brunswick. Strong sales of those engines is a good indicator of good performance. I don't think someone could go from lead engineer to CEO in 11-years without demonstrating very good product development and very good returns on investment for the corporation.

ASIDE: I had not noticed the the Mercury OptiMax has gone out of production. That is an interesting observation in itself, and perhaps worthy of its own thread.

2MATTANZA2
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Re: Mercury V8 FOURSTROKE Engines

Postby 2MATTANZA2 » Tue Jan 19, 2021 1:52 pm

I got my new [Mercury 250-HP ProXS engine in January 2021.]

jimh
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Re: Mercury V8 FOURSTROKE Engines

Postby jimh » Tue Jan 19, 2021 4:45 pm

I would like to see a photograph of a Boston Whaler boat in the water, showing the whole boat and a Mercury V8 FOURSTROKE or ProXS engine. In this way it will be possible to assess the size of the engine relative to the hull.


Why buy the 250 ProXS instead of the 250 FOURSTROKE model?

sraab928
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Re: Mercury V8 FOURSTROKE Engines

Postby sraab928 » Tue Jan 19, 2021 8:52 pm

Here are two views of my 1976 21 Revenge with its new Marcury V8 200 ProXS engine:

Mercury200FOURSTROKE.jpg
Fig. 1. Mercury 200 ProXS on 21 REVENGE.
Mercury200FOURSTROKE.jpg (65.08 KiB) Viewed 452 times


Mercury200FOURSTROKE_SternView.jpg
Fig. 2. Mercury 200 ProXS on 21 REVENGE
Mercury200FOURSTROKE_SternView.jpg (46.98 KiB) Viewed 450 times


As you can see the hull handles the weight quite well.

The gearcase comes from the factory painted that way. I am not quite sure why.

https://hosting.photobucket.com/images/v472/sraab928/IMG_5883.jpg
https://hosting.photobucket.com/images/v472/sraab928/IMG_5885_(1).jpg
Scott
1971 Boston Whaler Outrage 21 - under restoration
1974 Boston Whaler Revenge 21

jimh
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Re: Mercury V8 FOURSTROKE Engines

Postby jimh » Wed Jan 20, 2021 10:13 am

SCOTT--thanks for the nice views of your new Mercury V8 engine, a 200-HP ProXS model, on the boat with the boat in the water.

With the 21 REVENGE hull there does not seem to be any tendency at all for the static trim to be down-by-the-stern.

The engine height looks a bit tall, but one must consider that the 21 REVENGE hull has rather low freeboard aft, so that perhaps exaggerates the engine cowling height somewhat.

I am sure the 21 REVENGE must give very good performance with that big 4.6-liter V8 engine. If you have recorded some good data about boat speeds, engine speeds, and fuel flow rates, you could post an article in PERFORMANCE about this re-power. I think many readers will be interested to hear the numbers and to know what propeller you are using.

Also, I see you chose the ProXS model instead of the FOURSTROKE model.

Why did you choose the ProXS over the FOURSTROKE?

What is the difference between the FOURSTROKE and the ProXS in specifications?

I think they are using the engine block and mostly the same components. Is the gear case the difference?

biggiefl
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Re: Mercury V8 FOURSTROKE Engines

Postby biggiefl » Wed Jan 20, 2021 10:54 am

The ProXS comes in 20-inch shaft. I am not sure the [FOURSTROKE] 200 does. The ProXS is designed for lighter bass boats. The Revenge is pretty light.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).

jimh
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Re: Mercury V8 FOURSTROKE Engines

Postby jimh » Wed Jan 20, 2021 4:35 pm

biggiefl wrote:The ProXS comes in 20-inch shaft. I am not sure the [FOURSTROKE] 200 does. The ProXS is designed for lighter bass boats. The Revenge is pretty light.


Mercury seems to have created four product lines from the same engines:
  • FOURSTROKE
  • ProXS
  • SeaPro
  • VERADO

For example:
  • FOURSTROKE 250 is a V8 4.6-liter
  • ProXS 250 is a V8 4.6-liter
  • SeaPro 250 is a V8 4.6-liter
  • VERADO 250 is a V8 4.6-liter

How do you make four different engines from the same 4.6-liter V8 block, other than with marketing? Whatever Mercury is doing, it must be working because we have two instances here where guys bought a 250 ProXS, not a 250 FOURSTROKE, a 250 SeaPro, or a 250 VERADO.

There must be some FUNDAMENTAL element of the engine that changes in four different ways to create four different product lines--or is just marketing?

sraab928
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Re: Mercury V8 FOURSTROKE Engines

Postby sraab928 » Thu Jan 21, 2021 6:20 am

Jim, I recently changed propellers and haven't gotten back onto the water to test as my dock is currently being rebuilt. When I get some good data I will be sure to create a post.

I chose the ProXS model as the 200hp version is a V8. The standard Fourstroke 200 is a V6. I did not need the extra two cylinders but the sound of the engine is what sold me. When you start it, it reminds me of an old muscle car.

The VERADO models starts at 250-HP, and the Seapro is a commercial engine.
Scott
1971 Boston Whaler Outrage 21 - under restoration
1974 Boston Whaler Revenge 21

biggiefl
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Re: Mercury V8 FOURSTROKE Engines

Postby biggiefl » Thu Jan 21, 2021 10:43 am

SCOTT—does the V6 come in 20" shaft?

What is the weight difference between the two?

Usually the ProXS, like the Yamaha V-Max, is the only model offered in 20-inch shaft, has a high performance gear case, and has different [engine control computer] mapping for more engine speed compared to more torque.

Is this correct with the new ProXS models?

PS: you can leave your boat on my lift while your dock is being fixed. I'll refill the tank after every use as well.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).

sraab928
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Re: Mercury V8 FOURSTROKE Engines

Postby sraab928 » Thu Jan 21, 2021 3:24 pm

biggiefl wrote:Scott...Does the V6 come in 20" shaft? What is the weight difference between the 2? Usually the ProXS, like the Yamaha V-Max is the only model offered in 20" shaft and has a high performance gearcase as well as different mapping for more speed compared to more torque. Is this correct with the new ProXS models?

PS...you can leave it on my lift while your dock is being fixed. I'll refill the tank after every use as well.


Both 200-HP FOURSTROKE and ProXS models are available with 20-inch shaft length.

The 200 ProXs is V8 and the 200 FOURSTROKE is V6.

The battery charging output is 85-Amperes [on the 200 ProXS V8] and 30-Amperes on the 200 FOURSTROKE [V6].

And [the ProXS 200 has the] Torque-master gear case that I believe allows bigger [diameter] propellers, but I am by no means an expert. [I am] just sharing what I have learned in my research.
Scott
1971 Boston Whaler Outrage 21 - under restoration
1974 Boston Whaler Revenge 21

2MATTANZA2
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Re: Mercury V8 FOURSTROKE Engines

Postby 2MATTANZA2 » Thu Jan 21, 2021 7:13 pm

The Pro XS models:
  • [are rated for] higher RPM [than other models],
  • have a Torque Master gear case,
  • weigh 20-lbs less [than other models],
  • are available only in 20-inch or 25-inch shaft, and
  • are all [4.6-liter] V8 blocks except the ProXS 175-HP.

I was told [the ProXS model engines will] get better mileage [than presumably some other V8 4.6-liter models using the same engine block].

jimh
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Re: Mercury V8 FOURSTROKE Engines

Postby jimh » Fri Jan 22, 2021 10:17 am

Thanks for the nice summary of the principal differences between the ProXS and the VERADO, SeaPro, and FOURSTROKE versions of the 4.6-liter V8 Mercury engines.

I am skeptical that Mercury would only offer improved fuel economy in the ProXS model and provide inferior fuel economy in the VERADO, SeaPro, and FOURSTROKE models. The desire for optimum fuel economy actually seems to be LEAST likely in the ProXS model, which seems to be oriented to maximum speed outcomes. Generally boaters trying to maximize speed would be willing to forgo a bit of fuel economy to attain the higher speed.

If Mercury could simultaneously produce more speed and better fuel economy in the ProXS, I would expect they could deliver the same fuel economy in models not designed to optimize speed.

As a general rule, in order to go faster you need more power output. To get more power output you need to burn more fuel. Perhaps the ProXS is using a different fuel mapping, and runs the engine with a leaner fuel:air mix, while the other models use a richer fuel:air mix. But lean-burn mixtures create higher combustion chamber temperatures, which might produce shorter engine lifespan.

Again, it just seems counter-intuitive that the engine with more power output would use less fuel.

Perhaps all the improvement in fuel economy in the ProXS just comes from the gear case being more efficient and having less drag, or permitting higher engine mounting height.

To verify the claim of improved fuel economy is going to be difficult, as we would need head-to-head comparisons with the same boat running the ProXS and the VERADO or FOURSTROKE versions, with each optimized for engine mounting height and propeller. I suspect that any difference in fuel economy is going to be small.