Offshoreonly.com - The Raylar Experience Mercury 496 mods

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The Raylar Experience Mercury 496 mods

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The end of last season I discovered the transom bracket was cracked on my Mercury 496HO powered 2005 Velocity VR1. To replace the bracket I was going to need to remove the engine. Well, once the engine hit the garage floor I started thinking of the most logical things to perform maintenance on while the engine was removed. The motor didn’t have quite 500hrs and rumor has it they are bulletproof stock up to almost 2000hrs. Though it had good compression, I figured at almost 20yrs old, that the best bet would be to at least remove the heads and freshen them up while the motor was out.

I had not worked on this modern of an engine to this extent ever, the last motors I worked on were either piston aircraft which are just about 1920s tractor technology, a Ford 289, and Chevy 350 from my childhood. The most recent motors I had been fully rebuilding consisted mainly of two stroke jet ski motors. But disassembly is always the easy part right? I disassembled the motor enough to remove the heads, and at the time, I didn’t know what the majority of the sensors and wiring and stuff was that I was removing, I just went slow, gentle, and labeled it all very well for reassembly. This project required a quick learning curve.

Now anyone familiar with these engines is aware that the weak spot seems to be the pistons. The upper ring is so close to the valve relief that any excessive heat or pressure over stock seems to persuade the rings to knock off a piece of the piston. Staring at the short block, armed with this knowledge, I easily persuaded myself to continue with the disassembly. After all, If I wanted any extra UMMPF down the road, I would be restricted by the pistons.

Now that the motor was disassembled I began my research on what parts I should put it back together with. As you may already know, a quick search for Merc 496 performance parts turns up just about nothing but Raylar. So the next step is to google “Raylar reviews”, “Raylar experience” and the like. There wasn’t much information I could find other than internet BS and arguments over whether you should rebuild a 496 or replace it and comparisons of the 525 to the 496. So I figured I’d make a post detailing my Raylar experience

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I spent a lot of time on the Raylar website, looked at Larry’s packages, and familiarized myself with his products, tech information, and build kits and give Raylar a call.

The first call was a little rough and honestly I felt a bit turned off by the situation. I had a lot of questions and though Larry spent the time to answer them all he didn’t really seem like he was going to be a boatload of fun or much help or support during the build. I didn’t have a great first impression. Larry directed me to purchase his book, which I did but had not really read, I just flipped through it as I wasn’t really ready to build yet. Once I read the book, I realized that most of the information I was asking him was answered in his book, so If I had taken the time to read it first the conversation would probably have went smoother. So while I’m saving my money (and also now realize that I was part of the problem) I give Larry another call back. The second phone call went much better, at some point Larry says something like “What are you from NY or something?” Ha Ha, I just laughed and replied “New Jersey”. I realized I was probably talking fast and being blunt and it may have put Larry off.

Third phone call, Larry and I are good. I settle on the 625HP kit ....because we all know we are always gunna wish we had more, and this gave me forged internals which allowed for the 800HP Whipple option down the road. Larry was sweet as pie after the $12,000 payment.

Ha ha, I joke but seriously, I did all of the work myself with the exception of the machine work which only consisted of boring and honing the cylinders, and Larry was there for me every step of the way. No phone call went unreturned, and no email went unanswered.

I was probably more work than Larry expected as most people probably have a knowledgeable shop do most of the build. I leaned on Larry a lot even when I could have asked other knowledgeable engine builders ,and that is because when It comes down to this engine, Larry is really the expert. Larry would say things like “that’s up the to the engine builder” and I would say “what would you do?” because I really trusted Larry’s expertise over most anyone else. I have about 50 hours on the motor now and overall I am very pleased with Raylar, the products, the support, and the technical advice, I am happy I got to work with Larry on this build and would recommend Raylar without hesitation.
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A common issue with the marine 8.1, the bouncing around can knock the valley tray off the head and allow it to drop down and rest on the pushrods. Not sure how long mine was like this but the pushrods didn't seem to mind. Larry has the fix in his book. This was about the only issue I could find on this 500hr 496, it was so beautiful inside that I regretted tearing it apart.

There was so much more work then just "rebuilding the motor". Accessories are a complete project on their own! Degrease, strip, bead blast, paint, reassemble!

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For those interested, my build specs researched and decided on myself with my limited experience with this motor were as follows:

Main Bearings: Mahle, coated by Calico: 1 .0024 2 .0027 3 .0027 4 .0029 5 .0030

Crank endplay: .009

Cam bearings coated as well. Rods, started off Calico coated King CR 808 XPN, but had to split shells 1/2 .001 and 1/2 std to get them right so abandoned the rod coating: 1 .0024 2 .0028 3 .0026 4 .0026 5 .0025 6 .0025 7 .0028 8 .0029

Rod side clearance: 1 .019 2 .017 3 .018 4 .018

Ring Gaps: Top .017-.018 2nd .019-.020, Oil .015.

Piston to bore/sidewall: .0042-.0047.

Melling 10778 oil pump but I pulled the stock 70psi spring out and swapped it out for a 60psi. (This gave me at least 10psi per 1000rpm with 25w40 oil)

The rest of the parts were provided by Raylar, Raylar cam, Big Power heads, Autotec pistons made for Raylar, Raylar provided Psi crank and Scat rods, Raylar's new intake, 90mm throttle body, Crower pushrods, Comp rockers, Hastings rings, ARP crank stud kit, Whipple Stage 2 tune.

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