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Originally Posted by ICDEDPPL
(Post 4370749)
That was fast!:eekdrop::eek:
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Originally Posted by donzi matt
(Post 4370710)
Larry has been great to deal with, and I am impressed with what I have bought. There is nothing magical here just the same recipe that makes power on every other big block. I will say the heads look very, very nice. The cam would appear to be ground by cam motion, and I like what I saw there. It's hard to tell how much was done to the intake, but what I can see looks to be done nicely. An Accufab 90mm throttle body is about the only obvious thing that lets you know the motor isn't stock, you can hardly see the heads under everything.
I only had one hitch in this whole project, and that is the front crossover pipe. With the thinner head gaskets the bolt holes just won't quite line up. I ended up opening the bolt holes up to 1/2 inch to get things copacetic. Other than that everything fit perfect, lined up right, and went together properly. I am waiting on my Rinda to get here to properly dial in the bypass hole in the throttle body and set the TPS properly. It certainly sounds healthier than a stock 496 HO, I am very much looking forward to the next phase when I can really put some cam to it and a nice exhaust on it. I set the fuel pressure, hit the starter, and it fired up nearly instantly. The only gaskets I replaced were the exhaust gaskets and the intake gaskets, and I could have probably reused them if I wanted to, but they seemed iffy so I replaced them. The only thing I need to find now is a flame arrester to fit this throttle body, the stock one is way too small. https://youtu.be/WWG8BEXrgIY Congrats, it sounds much healthier than the stock HO cam. Wait till you mod the risers. It will even get better. Too bad winter is fast approaching. Any plans on a late fall test run? |
Originally Posted by Ryan00TJ
(Post 4370927)
You do not mess around Matt! I don't blame you, I'm the same way when building my previous engines.
Congrats, it sounds much healthier than the stock HO cam. Wait till you mod the risers. It will even get better. Too bad winter is fast approaching. Any plans on a late fall test run? MAybe tomorrow when I stop for coffee I'll stop at his shop and chearlead for a few. LOL. |
Originally Posted by thirdchildhood
(Post 4370529)
It differs from the 454/502 engine and everyone told me that it would become a "white elephant". Sure enough, it was discontinued and Mercury is back to the 502 crate engine.
white el·e·phant noun a possession that is useless or troublesome, especially one that is expensive to maintain or difficult to dispose of. I think I finally found the name for my boat. :coolcowboy: |
It's just what I was told when I ran it by a lot of people. It wasn't cheap driving to South Tennessee to pick up the 525 for $20,000 and then I had to have the exhaust tips relocated. I just really wanted the 525 but Donzi did not offer it in a 22 Classic except for a couple of one offs.
White Elephant: " A rare whitish or light-gray form of the Asian elephant, often considered sacred in parts of South and Southeast Asia". ;) |
Originally Posted by motor
(Post 4370322)
Can you give me a link to one of the 200.00 dollar 8.1 blocks .I need one and I haven't seen a price anywhere close to that .Not kidding .I will pay you a finders fee for a good one..Don't need a non useable one
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Originally Posted by donzi matt
(Post 4370710)
I set the fuel pressure, hit the starter, and it fired up nearly instantly.
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Originally Posted by Naughty Kitty
(Post 4371028)
What did you have to do to set the fuel pressure, on the stock cool fuel system the pressure is vacuum regulated and can't change the pressure (except to maybe pull off the vacuum line)?
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Originally Posted by Naughty Kitty
(Post 4371025)
I got two long blocks sitting in crates...might be willing to part with one, however not for $200.00 when the core charge was $500.00 :confused:
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Originally Posted by donzi matt
(Post 4370710)
I never thought you were beating up on me, I dig your Donzi, and have watched a couple of videos of that 525 barking on youtube. Truth is, if I had only one motor I probably would have bought a 525, but I have twins, and I just couldn't swing the coin to buy two used 525's and refresh them.
Larry has been great to deal with, and I am impressed with what I have bought. There is nothing magical here just the same recipe that makes power on every other big block. I will say the heads look very, very nice. The cam would appear to be ground by cam motion, and I like what I saw there. It's hard to tell how much was done to the intake, but what I can see looks to be done nicely. An Accufab 90mm throttle body is about the only obvious thing that lets you know the motor isn't stock, you can hardly see the heads under everything. I only had one hitch in this whole project, and that is the front crossover pipe. With the thinner head gaskets the bolt holes just won't quite line up. I ended up opening the bolt holes up to 1/2 inch to get things copacetic. Other than that everything fit perfect, lined up right, and went together properly. I am waiting on my Rinda to get here to properly dial in the bypass hole in the throttle body and set the TPS properly. It certainly sounds healthier than a stock 496 HO, I am very much looking forward to the next phase when I can really put some cam to it and a nice exhaust on it. I set the fuel pressure, hit the starter, and it fired up nearly instantly. The only gaskets I replaced were the exhaust gaskets and the intake gaskets, and I could have probably reused them if I wanted to, but they seemed iffy so I replaced them. The only thing I need to find now is a flame arrester to fit this throttle body, the stock one is way too small. https://youtu.be/WWG8BEXrgIY Now I am depending on other people, and that is disappointing. Keep up the good work! |
Originally Posted by donzi matt
(Post 4371050)
What kind of shape is the long block in? I would like to find another spare.
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Who is the guy that was at he Buffalo Poker Run this year with a 26 ft Sonic - Merc 496 with a Whipple set up and completely different fuel system installed with an Aeromotive 1000 fuel pump and PCM recal by Whipple ? His set up looked to be very well put together by whomever. I do no not know who built it either.
I looked at it but do not know what internals were changed out from the engine side of things. He really liked the package and it was reliable for him. I would have to say whoever did the set up in his boat really did a nice job. Forget what hp and torque numbers were. Maybe he can give out all the details. Seen the boat running as well looked to be strong on the power side. |
The whipple setup is a really nice kit and comes with a high flow fuel system included (Aeromotive marine pump, regulator, fuel cooler and high flow fuel filter) along with new fuel line kit and high flow (63 lb/hr) fuel injectors). I may someday down the road go with this kit after I do the bottom end as well. Should put me around 800 horsepower. I may never get there with this boat but you never know.
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I spent a little bit of time today dialing in the idle a bit now that I have my Rinda scanner (thanks BUP). Set the TPS via the idle stop screw to .71 volts on the Accufab (as low as it would go and the throttle blade was hooking the bore a bit) , started the motor and still had an IAC duty cycle of 100%. Took the throttle body off and drilled the hole from 1/4" to 9/32", reinstalled and found IAC down to 65-70%. Took the throttle body off again and increased the hole to 5/16" and reinstalled. Now I have IAC counts at about 20-30%. I didn't like the feel of the throttle plate fully closed so I brought the stop screw up so TPS is about .76 volts. The throttle plate off idle feel is much improved, IAC is down to 10-20% which eliminates almost all of the IAC hiss, and with the IAC hole in the throttle body closed with my finger the idle is right at 600 rpm. I'm going to leave it right there and see how it does once it is back in the boat but I am happy with it.
I also modded my factory flame arrestor so it would fit over the throttle body. I sort of hate it. It fits, but I don't like how it looks, kinda hack to me. Nobody other than myself will ever see it but it really irritates me, maybe I will be able to find some sort of better solution over the winter. At this point this motor is done, ready to go back in the boat and get going on the next motor. It will probably be 2-3 weeks before I see parts for that motor. |
Matt your welcome and I am so glad that you got it in your hands. 100 % IAC duty cycle at idle is one sure way of going thru IAC's in short order. Stock Merc 496 usually run at 25 to 35 % duty cycle and still hiss like cat. Just saying.
Good luck with your build. |
Matt want to ask what is your idle speed without your finger closing the IAC hole ? THX
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Right around 650. I am assuming with IAC count varying that is very close to where the ECM is targeting idle. One thing I find interesting is that the gear position indicator is always saying the engine is in gear, even if I jumper the connector. I believe the out of gear idle RPM is supposed to be 600 while in gear is supposed to be 650.
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Sounds like you have a shift in gear switch gear problem - either its connection or the switch itself. This can put the engine in guardian mode at some point. Its location of the switch is on the shift bracket.
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The bracket and switch are still in the boat, I just jumpered the plug on the engine harness. I was assuming it is a simple open or closed switch. It has never been an issue in the past so I doubt it is an issue now. I will compare it to the other motor when I have that running on the floor.
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So I have shipping notifications for my second kit on the way. I should have all my parts Friday of this week for the next motor. I have been doing some thinking and it seems kind of silly to enhance the intake, cam, and heads, but leave the stock exhaust so I decided to order Dana Powerflow exhaust for both motors. I went with the larger 3.5" risers and the extended length since I don't have silent choice to worry about. Another option Bob thought I would need is shaving a bit from the mounting surface of both inboard manifolds. It isn't much he is taking off, but he recommended it to make fitment in the boat a little easier. I also went with the hard anodizing and powdercoated the manifolds gloss black. He had all the parts in stock so hopefully the machining and powdercoating won't take too long and they will ship soon. I am pretty excited about this, I think it is going to round the package out pretty well.
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You gonna dyno one of them Matt?
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I don't think so, at least not in this form. Bobl from Full Throttle Marine did some pretty extensive testing and with a very similar setup to mine and a whipple tune in the ECM it made 553 horsepower through the full wet exhaust. I think I will wait and see what the boat runs and if it delivers what I think it should I won't worry about it. If it is a slug I will dyno them after pulling them back out next fall. I would like to dyno them after the stroker kits and larger cam to see what it makes on the ported intake. There is no real data out there on that and I would like to know what kind of power it makes.
I forgot to mention I also got O2 bungs in all 4 risers, now I need to start looking into a 2 channel data logging wideband setup for each motor. I am huge fan of the NGK AFX setup, primarily because it uses the nearly bulletproof NTK sensor instead of the chitty Bosch sensor, but it doesn't datalog or do 2 channels, so time to do some research on a good setup. I don't really want to add anymore gauges to my dash so I might mount the controllers in the bilge and be done with it. |
Innovate make a nice dual channel unit, but you my not like it due to the fact they use the Bosch LSU 4.9 sensors
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This post seemed to have all the knowledge 496 HO people involved. I hope my inquiry is relevant. If not I will repost separately.
I had been running a 2004 Mercruiser 496HO Gen 7 engine with Innovation Marine HP3 Gen II engine setup plus Raylar 517ci stroker crank and Mahle 4032 alloy forged pistons (030 over bore) with Rayar Cool Cap intake manifold, HP3 heads with 2,25 intake/1.82 exhaust valves and Jim Valako porting which dyno'd at ~625cshp on 87 octane since 2008. Refresh required in 2014. During refresh also increased TB from RV Morris bored / Jim Valako ported 77m to 92mm TB and increased cam lift from HP3 Gen II .596/.596 to .666 intake/.629 exhaust maintaining HP3 Gen II cam duration and LSA. to obtain 74.8% total exhaust/intake flow ratio versus 83.1% from previous setup. The engine recently detonated with the new engine configuration destroying two of the forged 4032 alloy Mahle pistons during AFR data logging sessions with 91 octane. Cause is believed to be fuel pressure regulator going lean off set point. Question. What is the leanest naturally aspirated engine AFR that is safe from detonation damage from idle to 2200 rpm? Plane out is ~2200 RPM. Significant MAP/engine load increase begins at ~4000 rpm. Knowledgeable responses only please. |
What RPM were you at when the motor burned down? What was the AFR at that point? Do you have timing numbers for the point where you lost the motor and was there any adjustment to your timing table since the changes were made to the motor? In my experience increasing stroke on an engine generally requires less ignition timing, but you changed a lot of items at once so you can't necessarily go on a generality like that. It sucks you burned down a fresh motor like that but it opens the door for quite a bit of learning about tuning a setup like yours. One last question, are you still on the 555 ECM or have you converted to a MEFI setup?
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The motor would still run but knew something was wrong. Leak down test confirmed it and pulled heads to find the broken pistons. Still running the 555 ECM. Maybe you misunderstood. The motor was bored,stroked, Raylar intake, HP3 Gen II cam, heads, back in 2008 and ran great for 350 hours. All I did this time was refresh, bigger throttle body and valve lift. Dustin retarded the timing a lot in the midrange rpm's this time versus previous build. When motor quit I lost all Diacom and Innovate data logger recordings of the run. But did watch the AFR during that run and the AFR was in the high 12's low 13's for cylinder #8 where the previous engine ran best. The fuel pressure was confirmed set at 48 psi at start but was 47.4 psi after run. However I suspect the initial damage likely occurred during the non instrumented run from the launch ramp to the boat slip the day before. After that run the fuel pressure was found to be at 42 psi instead of the 48 psi set point. Attached is AFR, MAP and timing data for current and preceding engine config.
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I did misunderstand, I apologize. I thought you added the stroker crank this year. That's what I get for posting before my coffee.
To make sure I am understanding you correctly, were you just running from idle to 2200 from the ramp to your slip when the fuel pressure was low? If so I have a hard time believing at that low of a load that you would have melted a piston. |
2 Attachment(s)
Originally Posted by donzi matt
(Post 4374183)
I did misunderstand, I apologize. I thought you added the stroker crank this year. That's what I get for posting before my coffee.
To make sure I am understanding you correctly, were you just running from idle to 2200 from the ramp to your slip when the fuel pressure was low? If so I have a hard time believing at that low of a load that you would have melted a piston. |
Originally Posted by Rage
(Post 4374234)
No, sorry for the poor writing skills. The fuel pressure was low (42 psi) during the run between the ramp and the slip but I did do a brief burst of higher rpm's during that run. Most of that runs rpm before and after the burst was ~2500 - 3500 rpm I guess. Also the pistons did not melt. A chunk broke off of two pistons at the same location, the intake valve relief. Pictures attached. The Idle to 2200 rpm inquiry has to do with the fact that is the only rpm range where the new engine shows leaner AFR than the previous engine when fuel pressure is at the set point that as arrived at from the fuel pressure vs AFR tests on the new engine. This is planning for the future when engine is repaired and I am wondering/asking if that could cause a detonation problem that could damage the engine then when it comes time to make more AFR runs to provide data for Dustin to recal the fuel tables.
As for your leaner condition at idle to 2200, personally I don't think you have much to worry about as far as damaging the motor, but I could see it having a lean sag around 1600 where it looks like AFR bumps up to mid 14's. Probably wouldn't hurt anything to have Dustin clean that up in the calibration a bit. Is this normally what you see for an AFR line on this motor? Looks like it is all over the place, but I am not sure if you are measuring each cylinder individually or what. I am used to a much flatter AFR curve but I am also not used to measuring individual cylinders, just complete banks. |
Rage, can you put just 8/28 and 9/2 runs together ?
On the 9/2 run, it looks like 1600rpm and especially 2400rpm (high AFR spikes) could be detonation causing those 'high spike' AFR readings. The 8/28 run appears possibily same thing, but I can't quite make them out. Too fuzzy on my computer screen. Thanks. |
BTW: Can we get a mod to break up this thread ? I would like to see DonziMatt's 8.1 builds and Rage's 8.1 issues discussed entirely but seperately. It would do bhetter justiuce for both. IMHO of course.
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I am not very knowledgeable on EFI mapping, but I personally think, these lean air fuel ratio numbers being talked about, are playing with fire while under load.
Back in the days of carbureted vehicles, spark knock, at low rpm, high load situations, was a real problem. My general opinion, is that while 2200RPM is a slow engine speed, it is not impervious to being rattled to death there, even getting on plane. Some boats can really load the engine down trying to get on plane. With a carb, its very possible that while planing, the loss of engine vacuum, will make the carb go into power enrichment. When adding power, without adding displacement, or forced induction, you are simply raising cylinder pressure to make that power increase. Looks like you added cam lift, without adding duration. Generally, this will help build more power, esp at lower rpms. Basically, what I'm saying, is, when the HP per ci goes up, the tune becomes more and more critical. What works at .85hp per ci, may not work at 1.3hp per ci. I used to believe in textbook AFR numbers I read online. I also used to believe, lean makes big HP numbers, and rich kills power. While quite different than what we are discussing here engine wise, I have witnessed 900-1000hp roots blown carb'd engines, make peak power on the dyno, with an AFR of 11.5. Leaner than that, it lost power. My personal engines, run low 11's currently at WOT. I have had it in the low 12's briefly at wot, and the engines layed down, top speed suffered. I then decided, I'm gonna just start giving the engine what it wants in the fuel, and timing department, and kind of ignore, what the internet says. |
just a couple questions about those piston pics. I am no expert engine builder but looking at the pics it seems the top ring groove is pretty high up and there is not much material left in the valve notch. were the pistons cut for more valve clearance? the shape looks a little odd but it could be the picture. when the engine was refreshed is it possible the ring end gap is tighter than before and the ring butted and pushed on the top of the piston where it is the thinnest? just a couple thoughts and hopefully I can learn something.
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[QUOTE=SB;4374301]BTW: Can we get a mod to break up this thread ? I would like to see DonziMatt's 8.1 builds and Rage's 8.1 issues discussed entirely but seperately. It would do bhetter justiuce for both. IMHO of course.[/QUOTE
Done. New thread: Detonation Issues - "Why is the Gen 7 496 such a bad platform to build" |
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Second motor is together and running. It went together just as well as the first and lit right off. Cam is off a off a bit which I am attributing to slack in the chain, but just about the same amount as the other motor, so they should be matched just fine.
[ATTACH=CONFIG]547693[/ATTACH] The only setback I had was when I opened the wrapper on the throttle body it had been damaged in shipping. I am sure I could have sent it back, but instead I though I would try out my metal working skills as it seemed like a waste to junk something that was more or less perfectly fine, I think it came out pretty good, kind of impressed with what I could do with a vice and a couple of sockets for shaping. [ATTACH=CONFIG]547694[/ATTACH][ATTACH=CONFIG]547695[/ATTACH][ATTACH=CONFIG]547696[/ATTACH][ATTACH=CONFIG]547697[/ATTACH] And of course, the obligatory first start video. https://www.youtube.com/watch?v=D9_JbwAh5wE&feature=youtu.be I can't wait to get the Dana exhaust and hear what they sound like then. I am going to have a hard time waiting for spring. |
Lookin good Matt! Remember reading that the dbl roller 496 chainsaw were on the looser side when new. Should not be a problem. The tb looks nice, you did well blending it back in. I would not have returned it either. Make sure you post pics and videos when the new exhaust is on.
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If you have the early aluminum exhaust manifolds they flow very well. The ports are huge and they are light.
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I have the cast iron manifolds. Looking at the Dana design I can't see how the stock exhaust could flow nearly as much.
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Originally Posted by donzi matt
(Post 4376272)
I have the cast iron manifolds. Looking at the Dana design I can't see how the stock exhaust could flow nearly as much.
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I wish I could have afforded CMI's, but I just couldn't swallow 10 grand plus for headers. I think the Dana's will support everything I am going to do with these motors, shave a bit more weight and be an improvement in flow over what I have now. Those CMI's sure do look horny though.
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