8.2 MAG H.O. - 430hp
 

Anyone have any insite on this motor vs the 496HO, it list as 5 more horsepower, is this the replacement motor for the 496?

Merc had one in their booth at the show yesterday. Didn't look to long. No blower or turbo on it. I believe it is a replacement for the 425ho mag. They had quite a display of all their stuff including all their new package's. I noticed that stuff they were not going forward with was not there like the 1200sc's, but I did not notice if they had a 496 on display or not.

Yes

GM is not building the 496 anymore, so Merc went back with the good ole 502

Does the new motor have a catalytic converter?

Yes but there are ways around that.

:coolcowboy:

1) They are kind of a ***** to rig with tailpipes and Captain's call as the manifold/cc exit is about a foot farther aft than any other engine.
2) The cc definitely makes the engine compartment VERY hot. Heat in the box slows you down; no matter what engine you've got.

Other than that, they appear to be great motors.

Yes it is Eddie!

I am hear that old 496 HO have 425 BHP, but new one have reall 430 HP on prop shaft.
This is much more than 5 HP if it is true.

Pretty sure all Merc motors have been rated at propshaft HP for quite a while now.

Is the CC required now? If you have a new boat built that is equiped with a CC are you required to always have one? Not that it would be easy for anyone to check up on you.

I don't think anyone has been able to remove them and change the computer program from Merc as of yet, I may be wrong but mu buddy has two of these engines and if they did come up with something he would have it. I know he has spoke to several compaines asking when? they said it will take time to get around the computer.

No.

All black merc's are rated a the prop shaft since the mid 80's at least, and all merc racing are rated at the flywheel after the introduction of the 600sci.

Thats what I thought ,but by reading this http://www.fullthrottlemarine.com/ ( left side ,vieuw our high perf projects) it let me believe that the output is crank rated ?
Or his dyno must be off ,but I found that hard to believe.

Very interesting reading for sure. The thing is. If you ask mercuiser, they will say it is prop hp. If you go to merc's website, they clearly state it is @ prop. Just cheked with the new 8,2. When you test the engine in the boat like that, there are a few variables. Engine and drive hours, air temp and humidity, drive oil ect. Now it gets interesting. If you go to merc racing's website, they have changed the rating on the 1100 and 1350 to transmission rating, It said crank shaft rating a month ago! The 1200 is still rated at the crank, thay claim. Confused? I honestly think they will change thier claims as they see fit. What you need to do, is to take a new engine/drive and replicate mercs testing to the smallest detail.

Another way of looking at it is. If the 425 is crank and the 8,2 is prop, the speed diff, would be rather noticable, but it is not. If the 8,2 is 430 prop, it should about 465-470 at the crank. That is a big difference. I asked formula about this some time ago, and they said, there where no difference on a 350ss with a set of 496HO's and the same boat with 8,2HO's. I would say that, a combined increase in hp of about 130 to 140 hp would be felt.

My bottom line is. I just don't think mercury is very accurate or maybe even honest about the hp claims.

Isn't the new 502 just a de tuned 525 I think? There is alot of power that can be made with this engine!

For accuracy in temp/humidity ,that should be taken care of using a correction table wich measures temperature and humidity and should be equal everywhere on earth.
My friend has 2 Superflow dyno,s ,using corrected horsepower ,he calibrate his dyno very often, cause he does use his dyno,s almost every day ,he received a new mercruiser engine from a P1 team that needs to be verified in Horsepower /torque ,the power was within 3 HP from what Mercury dyno,d ,so I guess they are pretty accured.
I don,t know what mercury said about prop or crank,cause I couldn,t find it on their website ..

Is Merc using any O2 sensor feedback on these engines yet?

Yes i think that is where the issue is. I also think they have two on each cat one before and one after. That is where the aftermarket companies are having trouble, getting around those. But I will say and it could be the boat, Matt's 32 Sunsation runs in the low 90's with those motors.

CMI already offers aftermarket headers for the 8.2 with catalytic converters so they are just a bolt on. It is just a matter of time before someone gets into the computer.

If you are truly looking at a boat, just pay the money for the 525's - It just isnt worth fooling with the 8.2's. By the time the warranty is up, someone will be into the computers anyway...

A picture of the 502's & the boat (It is for sale):coolcowboy: If your looking

I was unaware that CMI offered anything for the NEW 502.

Is there really a point of replacing the headers without a computer upgrade? I don't know but the 525 are a huge jump from the 8.2? I think with a computer change (someday) and headers those would scoot for less $$$

Any idea if those are narrowband or wideband sensors?

Well to tell you the truth I don't know too much or the difference between the two.

Narrowband sensors are only accurate very near the stoichiometric point of the fuel they are sampling (Lambda = 1.00). Wideband sensors are accurate over a much larger range. We regularly use the Bosch LSU 4.2 sensor which is accurate from .68 Lambda to 1.22 Lambda (roughly 10.0:1 - 18.4:1 A/F for petrol gasoline).

The quick check is to look at the number of wires coming out of the sensor. Narrowband sensors usually have 3 or less wires, where widebands have 5-6.

The Real Deal?
 

Just to let you guys know what I have learned about Mercury horsepower readings as tested by myself and other independents.
When we measure horsepower on Blue- Mercury Racing engines they always make more horsepower at the crankshaft than at the prop and that's why Mercury Racing rates them as propshaft horsepower, its accurate at the prop. On Mercruiser engines (black) such as the new 8.2L HO engine or the 496MAG or Mag HO the horsepower measures within 5 hp or so of the rated horsepower at the crankshaft and less at the prop and it seems to follow from this that Mercruiser is actually using crankshaft horsepower for its black engines. This is also confirmed by Volvo Penta, Crusader, Indmar, etc. in their measurements.
As for this new Mercruiser 8.2l (502) engine, yes the computer reprogramming will be difficult and extensive due to the Catalytic exhaust system and such. But the most important thing to consider at this point is the fact that Mercury must warranty the new engine and exhaust emissions system for three years to meet the new EPA requirements. Whats this mean, it means that if you tweak, modify or change the system, you automatically void the 3 year engine and emissions warranty and basically break the law from an emissions standpoint! After a few years when more of these new engines hit the water and are out of warranty it will probably be feasible to start thinking about looking into ways to up the power output but now its not economically justifiable nor a smart thing to do. When properly done in the future at its then expense on top of this engines $22K price tag its probably just a better idea to buy a Merc Racing HP525efi @32-35K and enjoy it for the next three or four years!, plus you get a stronger drive with the blue engine.

Best Regards,
RAY @ Raylar

Ditto... :) Jamie / Lakeside

Ray,
Are you sure the engine is warrantied for 3 years and not just the exhaust emissions system? That would be great cause I have a couple that are coming up on their 1st birthday in July. 2 more years of coverage would be great but I don't think that's the case.
Steve

Marine Emmissions sytems warranties?
 

If one carefully reads the EPA requirements on the new emissions engines it requires that the emissions system must be warrantied for three years to meet EPA requirements. If the engine quits working because the emissions system stops working or it damages the engine with improper operation then the warranty would apply to the whole engine. If the engine other than the emissions system alone breaks or fails due to any other proven cause beyond emissions or from misuse or mis-service, then the three year warranty would not apply as I read the EPA requirements. There was a lot of conversation at NMMA over the last several years about this very item and the EPA put out some pretty clear definitions for the manufacturers as to what had to be warrantied and since this is such a new area with such few engines of this type built and put in service so far the real problems and battles of this issue have yet to be fought! This will get ugly before its over and I for one am still not sure this whole catalytic marine emissions systems will ultimately work out long term, only time will tell.
Mercury marine is still the 800lb gorilla in the room so it will also be interesting to see how they handle this issue? Could get interesting!

Best Regards,
Ray @ Raylar

Has anyone tried o2 simulators on these engines yet? Headers are not an issue, it comes down to getting programming to bypass the cats. I've used the simulators on a few car engines with good luck.

Matt

All part of the government agenda to put mother earth before the safety of humans. Eventually we will all be driving around coke cans that will self destruct on impact, but it will get 100mpg because mother earth is first.

We saw this motor at the LA Boat Show and it does appear to have narrowband O2 sensors in it. That being the case, there is probably a relatively small area of the fuel curve that is monitored and controlled via closed-loop operation.

Narowband sensors are only accurate at/near stoich, unless their accurate "spot" has been moved. Stoich is ~14.7:1 A/F for most gasoline today. From air/fuel curves of other Mercury engines, I can't imagine Merc is running this engine in that range for very much of it's range. All one would have to do is to characterize the area where the sensors are in operation, then don't tune in those areas (most likely idle and around idle). The rest would be open to modification via units like our CMD Marine.

So who is going to be the first to install a wideband on a 8.2 to characterize the a/f curve? :drink:

They are in fact 4 narrow bands.

They share many parts, but they are different. The new 430hp motor has a much smaller camshaft and the entire valve train itself is closer to the old 502 Magnum MPI engine. So, like the older 502 Mag motors, there is plenty of power left over. Its a standard 502 MPI so older headers, superchargers, cams, etc. work.

They would work in this app but because the motor has very little power enrichment, its more important to have a calibration that will work properly. Doesn't take long to hurt these motors as lean as they are run now (14:1).

From all the motors we've tested, the black Merc Marine motors have all been within 2% of there propshaft HP rating at the flywheel. If you use the SAE standard, they are almost below the power during sweep pools but very close to there rating. During steady state, power levels increase in most of these motors because the clearances decrease and the motor reaches higher efficiency, but its not the 30hp they say the outdrive takes. the 8.2 is rated 5hp more than the 496 mag HO, and 15 more the 502 Magnum MPI, not 30-40 more....

The PCM is not really a problem at this point. Our SC system will be out around June/July as well as many other upgrades.

Dustin

I see your point. And from my earlier post, i must have calculated with my head under my arm. I did not notice that untill now.:lolhit:
I just lifted these specs for the 8,2HO from Mercury Marines website. As you can see, they say the hp is measured at the prop.

HP/Kw @ Prop 430/321
Max RPM (WOT) 4600 - 5000
Displacement 502 CID (8.2L)
Engine Type V8
Bore & Stroke 4.47 x 4.00 in / 113.5 x 101.6 mm
Compression Ratio 8.75:1
Fuel Requirement 87 Octane (R+M)/2
Engine Control System PCM 555 with SmartCraft CAN Capability
Fuel Delivery System Gen III Cool Fuel
Fuel Injection System Sequential Multi-Point Electronic Fuel Injection
Induction System High-inertia induction system
Ignition System Distributorless Ignition w/Knock Control and Platinum Spark Plugs
Charging System 65 Amp/917 Watt Alternator
Water Drain System Single Point Air-Actuated
Exhaust System Tuned Runner Exhaust Manifolds with 316 Stainless Steel Tubular Dry Joint Elbows
Cooling System Closed Cooling, Long Life 5-Year Anti-Freeze, Brass Sea Water Pump
Accessory Drive System Serpentine Belt, Stainless Steel Spring Automatic Tensioner
Recommended Engine Oil Mercury MerCruiser Full-Synthetic Engine Oil, 20W-40, NMMC FC-W rated
Engine Guardian System Low Oil Pressure, High Coolant Temperature, High Exhaust Manifold, Temperature, Low Drive Lube, Low Sea Water Pressure, Low Voltage, Over-rev control, Knock Control
Bravo One X Ratios 1.36, 1.50, 1.65 (high altitude)
Bravo Two X Ratios 1.81, 2.00, 2.20 (high altitude)
Bravo Three X Ratios 1.81, 2.00, 2.20, 2.43 (high altitude)
Bravo One XR Ratios 1.26, 1.35, 1.50
Bravo Three XR Ratios 1.65, 2.00
Weight lbs/kg (engine only) 1080/490
Digital Throttle & Shift Optional
Warranty 2-year limited (non-SeaCore models)*
4-year limted (SeaCore models)*
*Warranty applies to Installation Quality certified boat builders
Corrosion Warranty 3-year limited (non-SeaCore models)
4-year limited (SeaCore models)

This is why I suspected that the 425 was prop too. In the manuals and old brochures I have, they also state 415 prop hp. for the 502MPI. I don't doubt yours, or Raylars measurement for a second, that is why I am getting confused. Why would merc post it as prop hp if it is crank hp. When you get to dyno a 8,2HO I would be very interested to hear what the results are. The only engine I know of, where Mercury is clearly stating crank hp. is the 1200SCI. My personal belif at this point, is that everything is crank hp, both black and blue motors.

Sorry for the long rant.

It's really a marketing game more than anything else. The standard Merc engines can vary 25-30 HP. That's why you see some boats faster than others with equal power. I've dyno'd 496 HO's from 387 all the way to 430 at the prop. Regular mags 350 to 373 at the prop. The blue motors are much more consistent and ususally make more than advertised. I've also dyno'd a Volvo 8.1 (420HP) that made 385 at the prop. Of course this is with my dyno using sae standard correction factor and an electronic weather station doing the automatic calculations.

Bob Lloyd
Full Throttle Marine

Bob

Thanks for info. I sort of had the same thought. Do you only dyno these engines at the prop, or do you have any examples for flywheel hp?

What this boils down to is, that you can buy a black merc that either makes the clamed hp on the flywheel or prop, depending on how lucky you are. That's comforting:eek:

When you are saying that the blue motors make a little more than rated power, I quess you are talking flywheel hp? I recall reading that the 525EFI makes around 530-540 crank hp.

I've got both dyno's, and my SuperFlow is far more accurate/consistent then my propshaft, so basically I only use our Superflow for almost everything. Every Volvo, Mercury and PCM motor I've seen, keeping in mind they are basically the same, make very close to the stated HP, but all are at the flywheel. Merc has stated propshaft for as long as I can remember, but I've just never come across that.

The 525's make between 540-550hp with standard correction or 515-525hp SAE correction. OEM's must use SAE corrections, and if your in warmer climates such as ours, then you get better standard corrections as it calculates to 60deg F. SAE is a later standard and what most OEM's use.