The all new mercruiser 502

[mrfixxall]

looks like a upainted hp 500...minus the headers of coarse,also no throttle cable?

http://images.google.com/imgres?imgurl=http://www.fishnet.com.au/content/fishnet/images/gallery/e4b9f80b-adc6-4325-a22c-63054ef9632e_original.jpg&imgrefurl=http://www.fishnet.com.au/default.aspx%3Fid%3D234%26articleId%3D7504&usg=__X_Q7QfNSN8IS8jGJNY2D_pquSPc=&h=955&w=1000&sz=140&hl=en&start=4&um=1&tbnid=Y69jBa-xU0z9VM:&tbnh=142&tbnw=149&prev=/images%3Fq%3Dnew%2B2010%2Bmercruiser%2Bbig%2Bblock %26hl%3Den%26rlz%3D1T4ADFA_enUS348US348%26sa%3DN%2 6um%3D1

[gcarter]

looks like a upainted hp 500...minus the headers of coarse,also no throttle cable?

http://images.google.com/imgres?imgurl=http://www.fishnet.com.au/content/fishnet/images/gallery/e4b9f80b-adc6-4325-a22c-63054ef9632e_original.jpg&imgrefurl=http://www.fishnet.com.au/default.aspx%3Fid%3D234%26articleId%3D7504&usg=__X_Q7QfNSN8IS8jGJNY2D_pquSPc=&h=955&w=1000&sz=140&hl=en&start=4&um=1&tbnid=Y69jBa-xU0z9VM:&tbnh=142&tbnw=149&prev=/images%3Fq%3Dnew%2B2010%2Bmercruiser%2Bbig%2Bblock %26hl%3Den%26rlz%3D1T4ADFA_enUS348US348%26sa%3DN%2 6um%3D1

And it has catalytic converters.

[MOP]

To me it looks like the risers/converter are a multi pass design extending the exhaust tract.

[Dr. David Fleming]

This engine looks like a cross between the 496 and 502. Engine accessories are like the 496, block and internals are 502. The throttle body on the intake is not the 500EFI or 525EFI it looks like the 496 single valve. Actually it is probably closer to the 8.2 Volvo - (European 502 which used the SmartCraft 500EFI intake.)

496 guys should start gathering spare parts.

[HOWARD O]

Whaddya suppose that goes for.....around 15 grand or more? Wonder what it weighs in comparison to a regular 502 of year's past?

[silverghost]

The EPA should finally be happy~ Cat. converters are finally here!
I hear the CO emissions are very low~
Indmar was first to develop inboard cats~
now Merc !
And wait till you see how much these Cat. Converter equiped risers & manifolds cost !
I'd bet the guys at OSCO & Barr are not happy !

[Pismo]

I'd wait a couple years before buying one. There will be bugs to work out. or get the extended warranty. Cast or forged internals?

[CHACHI]

It is a good thing that the marine industry has gone to roller cams.
With the advent of cats on marine motors, the levels of zinc and phosphours will probably cut some more in marine specfic oils and that is not a good thing. I wonder what type of warranty they will be offering on the cats?

Hey, it's just an oil guy thinking out loud.

Ken

[gcarter]

I wonder what type of warranty they will be offering on the cats?

Hey, it's just an oil guy thinking out loud.

Ken

On cars it's 50,000 miles, isn't it?
How do you convert that to hours under severe load?

[mrfixxall]

Depends on the mfr,2yrs-24000 miles to 8yr-80000 miles

[MOP]

Dug up the law it is lengthy to say the least but precise!

http://www.epa.gov/oms/consumer/warr95fs.txt

[Dr. David Fleming]

I don't think anyone but a car manufacturer would produce a cast crank or cast pistons as their only use is in low stress auto engines.

This MerCruiser is likely coming from the Mercury Racing 502 parts manufacture. Old cast 454 was only 310hp the forged crank engines were 375 hp and 502 was 415hp. This new 502 is 380hp probably stock cam and 502HO is 430hp. Article says one is "high octane" I don't believe it I think it is HIGH OUTPUT with a cam as they say both the engines run on 87 octane fuel. The 430hp has got to come with a cam, aluminum heads and the better fuel injection system.

Says aluminum heads with iron block - Cat exhaust can't be aluminum the cat needs heat to work? Guessing here as auto cats really set fire to the lawn and needed heat shields - many!

Closed cooling system for a combination of aluminum and iron parts without galvanic corrosion.

Coolant recovery tank on valve cover and power steering reservoir is 496 style for sure - electronics probably the same late smart craft technology.
Drive oil reservoir is on the exhaust manifold where the old 502 MEFI computor and relays were. Would ignition be single coil or the 525 multi coil? Looks like a coil pack in the back - crank trigger ignition?

Big Chevy rat motor moves into the 21st century!

[blackhawk]

Whaddya suppose that goes for.....around 15 grand or more? Wonder what it weighs in comparison to a regular 502 of year's past?

I'd guess around $20k for a bobtail.

[Ghost]

...Big Chevy rat motor moves into the 21st century!

I think it was BoatUS magazine, but maybe Boating, just had an article on catalytic converters and emissions where they talked about the new big blocks specifically (and where Volvo is going vs Merc), for any who got the mag but missed the piece.

[silverghost]

Indmar a small low production high performance inboard engine builder that mostly builds skiboat engines was the first to successfully develop a marine catalytic converter manifold & riser combo in 2007. I have a big-block Indmar in my skiboat!
Here is an interesting article about Indmar's catalytic converter development.
I hear Mercruiser is paying Indmar a royalty on this new catalytic converter & manifold design!

www.boatingmag.com/article.asp?section_id=5&article_id=858&print_page=y (http://www.boatingmag.com/article.asp?section_id=5&article_id=858&print_page=y)

[Barry Eller]

Is this "New" 502 based on GM's Gen VI block and internals?

[Dr. David Fleming]

This is likely the 502 Gen VI. Even though General Motors gave up on the old Chevy Big Block and redesigned an entirely new V-8 engine which is the 496, the Mercury Racing folks stayed with the Gen VI for all their big motors. The 500EFI is the same block, rods, pistons as the 502MAG MPI and 454MAG MPI. The same with the 525EFI which went to aluminum heads, H beam rods and other improvments like multi coil ignition (if you get an ignition failure it is not the whole system just part of it.) All the bigger Mercury Racing Engine up to the blown 1000hp use Gen VI.

When GM went into financial crisis you know they were not going to keep in production a gas sucking big block like the 496. This was a nice engine update and it seems to in general stock condition to be slightly better than an equivilent 502 which is of course old school 1960's technology.

One thing about old school engines like the small block chevy - designed in the 1950's and the big block chevy designed in the 1960's. Literally millions and millions of these engines were made and used in every kind of vehicle. Hot rod parts are everywhere, there is no limit to the tuning and study of these engines and if you were going to invest in a marginal hot rod market how could you go wrong producing stuff for the Chevy V-8. I think the old big block won out of shear numbers, wide popularity.

For Christ sake if you broke down in the upper Amazon you could probably round up what was needed to fix the damn thing from any junk yard.

Better start saving those spare 496 parts!

[RickSE]

...When GM went into financial crisis you know they were not going to keep in production a gas sucking big block like the 496. This was a nice engine update and it seems to in general stock condition to be slightly better than an equivilent 502 which is of course old school 1960's technology....

GM essentially dumped the 496 when they discontinued it in their passenger truck line up several years ago. For the last few years the only 496 production has been for Marine & Industrial use. I'm surprised Merc. didn't try to keep the 496 going, seemed like a much better engine with reverse cooling and modern electronics; all it needed was aluminum heads to make it a killer package.

[Barry Eller]

Is this "New" 502 based on GM's Gen VI block and internals?

I'll repeat my question...does anyone know, for sure, if the "NEW" MERCURY 8.2L/502 IS BASED ON THE GEN VI BLOCK AND INTERNALS?

[Dr. David Fleming]

Darling, this is a chat site, none of us are engineers at GM or Mercury. The intake manifold has no similarity to the 496 and is a ringer for the 500EFI, 525EFI and Volvo 8.2 intake. The bolt patterns are the same and the general shape of the casting is the same. If Mercury Racing is already using the 502 Gen VI why would someone bother to tool up the 496 when only a handful of used truck engines and small production boat engines would be build. It just doesn't make sense. I think it is Gen VI.

By the way, I talked to Tyler Crockett racing engines and they hadn't even heard about the new 502. When I discribed it to Dave Crockett we were pretty sure it was a Gen VI.

Why is it so important to you anyway? Share the hidden issue with us.

[Pismo]

Darling, this is a chat site, none of us are engineers at GM or Mercury. The intake manifold has no similarity to the 496 and is a ringer for the 500EFI, 525EFI and Volvo 8.2 intake. The bolt patterns are the same and the general shape of the casting is the same. If Mercury Racing is already using the 502 Gen VI why would someone bother to tool up the 496 when only a handful of used truck engines and small production boat engines would be build. It just doesn't make sense. I think it is Gen VI.

By the way, I talked to Tyler Crockett racing engines and they hadn't even heard about the new 502. When I discribed it to Dave Crockett we were pretty sure it was a Gen VI.

Why is it so important to you anyway? Share the hidden issue with us.

It would obviously be nice to know...Is it part of those "millions and millions" or is it something new.

[Dr. David Fleming]

Yah! aint it good!

[harbormaster]

As for what gen this is I have a call in to my GM account rep.

I know we just bought a few GM performance 572 blocks. These new blocks are their own Gen. They are a cross between Gen 4, 5, and 6. They even have a fuel pump boss on them. These are sweet!

As for the guardian system on the new 502, I hope its not the pain in the ass the 496 was....
Go through silt and it coats the water pressure sensor and puts you in guardian mode. OR have you oil foam up on you and it thinks it has no oil pressure and yes....Guardian mode.

[Barry Eller]

As for what gen this is I have a call in to my GM account rep.

I know we just bought a few GM performance 572 blocks. These new blocks are their own Gen. They are a cross between Gen 4, 5, and 6. They even have a fuel pump boss on them. These are sweet!

As for the guardian system on the new 502, I hope its not the pain in the ass the 496 was....
Go through silt and it coats the water pressure sensor and puts you in guardian mode. OR have you oil foam up on you and it thinks it has no oil pressure and yes....Guardian mode.
Thanks Scot, let me know when you find out.

[gcarter]

I'm wondering if this is the basic engine?????


Ram Jet 502 Tech Specs

Block Part Number:
10237292
Block Type:
Cast iron with 4-bolt main caps
Bore x stroke (in):
4.47 x 4.00
Camshaft duration (@.050 in):
224 degree intake / 234 degree exhaust
Camshaft lift (in):
.527 intake / .544 exhaust
Camshaft Part Number:
12366543
Camshaft type:
Hydraulic roller
Compression ratio:
9.6:1
Connecting Rod Part Number:
10198922
Connecting rods Type:
Forged steel, shot peened
Crankshaft Part Number:
10183723
Crankshaft Type:
Forged steel
Cylinder head Part Number:
12363390
Cylinder head Type:
Aluminum oval port; 110cc chambers
Displacement (cu in):
502
Distributor Part Number:
1104060
Distributor Type:
HEI type
Engine Name:
Ram Jet 502:
Engine type:
Chevy big-block V-8
Flexplate Part Number:
10185034
Flexplate Size:
14"
Ignition timing:
8 degree BTDC @ 800 rpm; 36 degree total @
Maximum rpm:
5800
Piston Part Number:
12533507
Pistons Type:
Forged aluminum
Recommended fuel:
92 octane
Rocker arm ratio:
1.7:1
Rocker arms Part Number:
12368082
Rocker arms Type:
Stamped steel
Spark plugs and wires:
Included
Starter Part Number:
9000852
Starter:
Included
Throttle body Part Number
17113524
Throttle body:
Included
Valve size (in):
2.25 intake / 1.88 exhaust; stainless steel
Water Pump Part Number:
14058915
Water pump Type:
Aluminum, short-style







http://www.gmperformanceparts.com/_res/i/parts/collection/06_ENGB_BIGB_RAMJ_01.jpg
http://www.gmperformanceparts.com/EngineShowcase/index.jsp?engId=RamJet502&engine=Ram%20Jet%20502&sku=12499121&engCat=bb

[Dr. David Fleming]

Doesn't look like the Mercruiser 502 manifold that has a removable top. this manifold is a one piece casting with the casting seam around the log. I addition automotive cams really don't work with water flushing exhaust pipes because they suck water back into the engine on cam overlap. Special marine cam is needed or dry exhaust system. 9.7 compression ratio is ok for a few marine areas that sell premium automotive fuel, doubt if MerCruiser would sell compression that high as some areas have no fuel for it. Nice hot rod automotive engine though.

[gcarter]

Doesn't look like the Mercruiser 502 manifold that has a removable top. this manifold is a one piece casting with the casting seam around the log. I addition automotive cams really don't work with water flushing exhaust pipes because they suck water back into the engine on cam overlap. Special marine cam is needed or dry exhaust system. 9.7 compression ratio is ok for a few marine areas that sell premium automotive fuel, doubt if MerCruiser would sell compression that high as some areas have no fuel for it. Nice hot rod automotive engine though.
That's why I suggested it may be the base engine......
Notice that if it is, it has all forged steel internals.

[blackhawk]

As Dr said no way they're gonna re-invent the wheel for a low hp 502. It will be a gen VI engine.

[mrfixxall]

Doesn't look like the Mercruiser 502 manifold that has a removable top. this manifold is a one piece casting with the casting seam around the log. I addition automotive cams really don't work with water flushing exhaust pipes because they suck water back into the engine on cam overlap. Special marine cam is needed or dry exhaust system. 9.7 compression ratio is ok for a few marine areas that sell premium automotive fuel, doubt if MerCruiser would sell compression that high as some areas have no fuel for it. Nice hot rod automotive engine though.

Dr. FYI that cam in that ramjet is whimpy! it will work fine for a marine application,

[Dr. David Fleming]

While we are on the subject.

The great thing about fuel injected log manifolds is they don't have to carry fuel. The big trouble with the ram manifold setup and carburators was the fuel would settle out and form pools and rivers of gasoline running into one cylinder or another. This varried greatly with engine and operating temp, pressure, and tuning. Guys were epoxing popsicle sticks into the log to get the gas to do this or that. Smokey Unick was great at tuning the log setup with carbs - used a plexiglas lid to see inside. Also the length of the ram tubes under the log were tuned to a certain operating range like headers are. Longer tubes for lower speed short tubes for high rpm boost. They used the inertial resonance to sort of supercharge the cylinders - can't do that on your old Buick!

Now the Merc 502 first had the 502MAG MPI log manifold that Mercury developed in 1999 - the staged throttle was swung off to the starboard side. Then along comes Arizona Speed And Marine and they are the ones that developed the 500EFI blue manifold which we are seeing today on the "NEW 502." Tyler Crockett gave me a brief rundown on how this was such a great manifold that Merc Racing had to have it for the 500EFI and then they opened up the throttle larger for the 525 now it appears to have the 496 throttle on it in the "NEW 502."

Maybe this 502 automotive RamJet just sucks in boats - I guess the 454/502MAG MPI did as they quit it. Anybody know the real story on this blue meany 500EFI/524 manifold? Arizona Speed and Marine for Christ sake - there aint no water in Arizona!

[blackhawk]

Maybe this 502 automotive RamJet just sucks in boats - I guess the 454/502MAG MPI did as they quit it.

Huh? Are you saying the 454/502 MPI motors sucked?

[Dr. David Fleming]

I guess if a big block has to suck it would be the 7.4MPI which is the cast piston cast crank, small port head - pick up truck engine that is 310hp. Big block though and big displacement but it is really a car engine. This engine was called by GM the L-28.

454/502MAG MPI Mercruiser - these are great engines, there are three minor variations of the fuel injections system. Plus they have all the big port heads, forged crank and rods and pistons etc. Horsepower was 375/415 hp. This manifold has two throttlevalves that open staged and are mounted sideways on the front of the engine.

7.4/8.2 VOLVO - this is the same as the 454/502 MAG MPI but has the "blue meany" manifold painted black with two throttle valves that open together - apparently the Volvo guys knew a good manifold when they saw it. Horsepower for this European engine was 380/420hp.

500EFI - this is the same engine as 454/502MAG MPI and 7.4/8.2 VOLVO but has a Crane cam, rocker arms, and CMI e-top headers. Supposed to make 475hp. This has the "blue meany" manifold painted blue with two throttle valves that open together.

525 Mercury Racing - This is the 502 with aluminum heads, better Crane cam, and forged internals but also has special H-beam connecting rods and a better CMI long tube headers - makes about 500hp. And of course has the "blue meany" manifold with a large bigger single throttle valve.

"THE NEW 502" - this engine appears to be the old GM/Mercruiser/Mercury Racing 502 with I am guessing, forged crank, pistons, and rods. Guessing from the horsepower the stock cam that the 454/502 MAG MPI engine. The "blue meany" manifold which is not painted and appears to have the large round throttle valve from the 496. - 430hp claimed.

---now the question is who made the "blue meany" manifold. Tyler Crockett says it was made by Arizona Speed And Marine and sold to Mercury because it was better than the manifold of the 454/502MAG MPI.

---does anyone know the story of this "blue meany" manifold?

I don't think any of these engines suck.

[VetteLT193]

I think Merc developed it themselves.

AZ speed might have come up with the mono-blade throttle body, merc might have bought that from them. The whole intake doesn't make a whole lot of sense though. They can make the thing themselves and the design not far off from other projects Merc has had a hand in, like the LT5

[handfulz28]

AS&M DID design the HP EFI/volvo efi manifold...Volvo's parts lists say "Contact Arizona speed & Marine for replacement info". Marine Power also uses/used this intake on their PFI big blocks. AS&M offers their manifold in both rect port and large oval port versions.

GM has their own Ramjet setup.

The original "MPI" setup is a GM truck part...see 454 Vortec.

The MPI/EFI intake was designed by Lingenfelter and was also briefly built/offered in a smaller version for the small blocks.


FWIW, I don't think Merc "designed" the LT5, they built/machined some parts and did the assembly. Merc has a bunch of outboard engineers, but not too many that do hard core BBC stuff. Lots of their pieces are outsourced.

[Dr. David Fleming]

All right! Who the h.... is Lingenfelter? Being a 502MAG MPI fanatic who is in love with the throttle control of the staged throttle - I need the LINGENFELTER story so that I can sufficently BS my way through Donzi life.

[Pismo]

New article in Powerboat. I was very disappointed with the article. It said basically nothing but it is a 502 with heads almost the same as the HP525EFI.

[knots2u]

Indmar owns Barr Marine

[VetteLT193]

AS&M DID design the HP EFI/volvo efi manifold...Volvo's parts lists say "Contact Arizona speed & Marine for replacement info". Marine Power also uses/used this intake on their PFI big blocks. AS&M offers their manifold in both rect port and large oval port versions.

GM has their own Ramjet setup.

The original "MPI" setup is a GM truck part...see 454 Vortec.

The MPI/EFI intake was designed by Lingenfelter and was also briefly built/offered in a smaller version for the small blocks.


FWIW, I don't think Merc "designed" the LT5, they built/machined some parts and did the assembly. Merc has a bunch of outboard engineers, but not too many that do hard core BBC stuff. Lots of their pieces are outsourced.

I didn't say they designed it, Lotus did. But they built them. If they could handle building them, I can't see them buying parts from a speed shop... although stranger things have happened.

this is from the original HP500 EFI marketing stuff, not that it really means a whole lot:


A 502 cubic inch (8.2 L) General Motors cylinder block and rugged GM internal components are the heart and soul of the race-proven HP500 and the all-new HP500EFI. The new HP500EFI features a multi-port fuel injection system which incorporates a high-flow throttle body and tuned intake manifold developed exclusively by Mercury Racing. This, along with an advanced fuel injection system provides instant starting and smooth idling and crisp throttle response. The 500EFI's robust power band spreads torque evenly for improved throttle response across the operating range. In addition to a race-developed multi-port fuel injection system, the new HP500EFI uses an advanced Electronic Control Module that monitors a variety of vital engine conditions, including rpm levels, oil pressure, water temperature and spark timing, keeping the engine in perfect tune. High-quality specialty parts include high performance push rods, rocker arms, valves and lifters. Stainless steel tubular headers enhance engine performance and aesthetic appeal. A one-piece serpentine belt system drives engine accessories including a 60-amp (846 watt) alternator, power steering pump (idler pulley on models without power steering), circulating pump and sea pump. The one-piece belt design is easier to service and provides unsurpassed belt life.


All right! Who the h.... is Lingenfelter? Being a 502MAG MPI fanatic who is in love with the throttle control of the staged throttle - I need the LINGENFELTER story so that I can sufficently BS my way through Donzi life.

Lingenfelter was big into Corvettes. He built the engine for the Callaway Sledgehammer... that was back when he and Callaway were friends / worked together.

Lingenfelter made some of the best engines out there. very reliable, but you paid for it. He died in a racing accident about 5 years ago now. The company he started lives on... I'm not sure if they are so good anymore, they prices and work seem more mainstream.

[handfulz28]

Building isn't the problem, designing is. How many Merc-specific BBC "performance" parts are there on any of these engines? For decades they've outsourced their performance parts: Gil/CMI exhaust, Crane valvetrain, Lingenfelter & AS&M intakes, heck the original 320EFI from '87-88 used a Cosworth designed intake and fuel system. Outsourcing R&D and production to outside vendors, not to mention outright buying of "off the shelf" products, is not as uncommon as you'd think. Consider Rousch, Saleen, Steeda, SLP for the automotive world. Gm outsources A LOT of their performance R&D to shops like Katech.

Like you said, stranger things have happened, but I doubt Merc would go to the effort to design something proprietary (which they usually patent) only to allow a "speed shop" to offer the product to competitors.

I wouldn't doubt this new intake was designed outside of Merc. Wouldn't take much to put together a casting mold that blends a little of everything out there (AS&M/GM Ramjet/Gen VII throttlebody). But it sure does put a limit on the N/A horsepower potential.

[Pismo]

Building isn't the problem, designing is. How many Merc-specific BBC "performance" parts are there on any of these engines? For decades they've outsourced their performance parts: Gil/CMI exhaust, Crane valvetrain, Lingenfelter & AS&M intakes, heck the original 320EFI from '87-88 used a Cosworth designed intake and fuel system. Outsourcing R&D and production to outside vendors, not to mention outright buying of "off the shelf" products, is not as uncommon as you'd think. Consider Rousch, Saleen, Steeda, SLP for the automotive world. Gm outsources A LOT of their performance R&D to shops like Katech.

Like you said, stranger things have happened, but I doubt Merc would go to the effort to design something proprietary (which they usually patent) only to allow a "speed shop" to offer the product to competitors.

I wouldn't doubt this new intake was designed outside of Merc. Wouldn't take much to put together a casting mold that blends a little of everything out there (AS&M/GM Ramjet/Gen VII throttlebody). But it sure does put a limit on the N/A horsepower potential.

Yes, the first aftermarket tweak will be a new intake/throttle body. (and removing the catalyst, replacing with CMIs and gaining 75+hp.)

[BigGrizzly]

First, Arizonaid not design it, nor do the make it. They are an outlet house and do not have a foundry or the like. I do know Merc in Stillwater was working on an intake but I don't know if this is the one. There are many makers that make intakes that bolt on and give good increases over most stock ones, it depends whatyou want to gain. After working in the auto industry for 24 years, I can say the removing the cat on that engine will not get 75 useful ponies. Yes I hear all the stories and tested them to find it is more trouble then it is worth. You don't just remove the cat and go. especially in a wet environment. Especially on a O2 sensor monitored engine.

[Pismo]

First, Arizonaid not design it, nor do the make it. They are an outlet house and do not have a foundry or the like. I do know Merc in Stillwater was working on an intake but I don't know if this is the one. There are many makers that make intakes that bolt on and give good increases over most stock ones, it depends whatyou want to gain. After working in the auto industry for 24 years, I can say the removing the cat on that engine will not get 75 useful ponies. Yes I hear all the stories and tested them to find it is more trouble then it is worth. You don't just remove the cat and go. especially in a wet environment. Especially on a O2 sensor monitored engine.

Well this isn't a car is it.The cat will be highly restrictive and there will be no 02 sensor so I am sure like I said one of the first mods people will try will be to pull the cat/exhaust put on CMI types, a new intake and gain a good amount of hp. If pulling the stock 496 exhaust and replacing it with CMI gained 40-50hp then pulling a cat plus intake will gain more. Will probably need a reflash as well, maybe not. You basically would build a 525 intake and exhaust setup. The heads are close, find out about the cam. Sounds like they largely copied a 525, detuned it and lost significant hp with the cat.

I love that we are arguing about engine mods on one that isn't even released yet....

[LKSD]

Actually there may be an O2, from what I have heard, but I cant guarantee that yet as I dont have the new factory complete info or shop manual on it yet.

I can say tho Giz is not really wrong. He is Right about AZ & on the other topic, I also dont see removing the cats gaining 75hp either. It will gain something, but 75hp seems to be a bit optimistic on that set up.

That also said I do think that there will be people that will want to pop a different exhaust on & remove the cats.. 2 thinkgs there to consider. 1 addign 02 ports to the tails on what ever system you run (not really a big deal if you pony up for the upcharge). AND 2 f'ing with EPA regulations like removing a cat converter may land you in some hot water.. I know in doing so with a street used vehicle it will land you in hot water, but it is too soon to know if the same will or wont apply yet in the marine world.. I am not sure if they will continue to classify it as a being considered an offroad vehicle or not. I know that they are pushing to make mods to newer stuff more of a PITA.. Time will tell as to what really happens..

;) Jamie / Lakeside

.

[BigGrizzly]

Actually there IS an emissions requirement on boats and a fine too. Every new engine thar the outboard manufacturers make has to be certified. Even new lawn mowers have to meet a standard. I have been there and done that. As for the exhaust on the 496- better talk to CarlC. The key word in my statement was Useful$ HP which results in a speed gain. For instance CMI ETops vs tube hedders was 30 HP but not 1 mile per hour gain.

[Dr. David Fleming]

Most automotive electronic fuel injection use upstream and downstream O2 sensors. One is behind the catalytic converter to monitor the exhaust generated by the cat. If I remember right these O2 sensors are a ceramic device that can be shattered by contact with water when they are working. Whatever Merc sets up it will have to deal with a dry O2 sensor enviornment.

Most of the fuel emission regulations are written for manufacturers preventing them from compromising the equipment they produce. Thankfully, except for California, there are no prohabitions on the owner of a vehicle from changing the engine - its still a free country I guess. Some states require an auto to pass an emissions test - this is a fairly complicated process with legal loopholes for vehicles that don't pass - such as spend $100 on repairs and it passes fixed or not. Michigan dropped this ten or so years ago as just unworkable. I don't think there is any testing or examination of vehicles here.

[mrfixxall]

More info! chitty sound track so turn up the volume.....


http://www.youtube.com/watch?v=eM7JFBUs8GA

[BigGrizzly]

They have fixed most of the problem with wet O2 sensors. At least Honda has done this for their ecm controlled 225 and 150 enfines

[gold-n-rod]

If I remember right these O2 sensors are a ceramic device that can be shattered by contact with water when they are working.

Shattered, shattered, shadoobie! :wink:

[Conquistador_del_mar]

Shattered, shattered, shadoobie! :wink:

Another guy who likes Shattered by the Stones? Bill

[Carl C]

[quote=BigGrizzly;547849 As for the exhaust on the 496- better talk to CarlC. The key word in my statement was Useful$ HP which results in a speed gain. For instance CMI ETops vs tube hedders was 30 HP but not 1 mile per hour gain.[/quote]

Thanks Griz, yes the CMIs did nothing for my 496 and I am not alone. Do a search on OSO. As for this motor being a detuned 525...sorry. The 525 is hand built from raw parts. The blocks are CNC machined by Mercury Racing. The innards are stronger and the rods are H beams. It is a hand built blueprinted racing engine using all top shelf parts. The new 8.2 will be built by marinizing short block assemblies straight from GM. It is a production motor. It definately looks like a nice package however but it is not a Merc Racing engine.

I am sooooo glad I lost my 496.

[Dr. David Fleming]

Spent the late afternoon going over the pic of the "New 502" with Dave and Tyler Crockett.

We pulled out a 500 EFI manifold and compared it to the pic the "New 502" is taller because the intake tubes have been lengthed about 1 inch. Tyler and Dave were contemplating doing this on the old blue manifold to get a low RPM tune on the intake. The throttle of the "New 502" is a small diameter 496 unit that will limit the power of this intake well blow its potential of over 500 horsepower.

Crankshaft front pully does not show the wheel for crank triggered ignition - no ignition coils on the valvecovers. A distributor ignition is likely. The front pully setup is stamped steel and is the same pattern as the 525/496 as is the power stearing. Fuel vapor canister is hanging on the side as it did in the old 454/502 - assume the electric fuel pump is not the 500EFI/525 setup.

Horsepower of the "New 502/502HO" - 380hp/430hp is parallel to the 496/496HO - 385hp/425hp. In the 496 this was accomplished by a camshaft change and different tuning of the EFI controller. Tyer suspects the cams used are the 310hp 454 cam in the low performance "New 502" and the 415hp 502MAG MPI cam in the "New 502HO."

Tyler Crockett has several 496 engines he wants to get rid of and enough parts to build another half dozen. He wants to get rid of these so time to stock up on 496.

[BigGrizzly]

I can see why they want to get rid of the 496 engine parts. As for the cam I was told by someone in the know that is was different than the 454 cams both in lift and duration, but who knows, by the time of production, really starts things can and usually do change. As for the intake runners they are longer. this is to move the power up in the rpm range and keep lower and cleaner. It es for mine.