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Why is the Gen 7 496 such a bad platform to build

Old 09-19-2015, 08:52 PM
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Default Why is the Gen 7 496 such a bad platform to build

So the 496, seems like aside from Raylar nobody likes modding these motors. Why? Is it just because of the cast pistons that come in the motors? I see some things about these motors that GM did that has advantages, the symetrical ports, the 18 head bolts opposed to the standard 16, the already swapped firing order, closed cooling. If you go into it knowing you are going to beef up the rotating assembly, is this really that bad a platform to start with?

So through Raylar you can buy a 511 CID kit for 9 grand that includes:

BigPower Aluminum Cylinder Heads
BP-206 Max Effort High-Lift Camshaft
CoolGap EFI Intake Manifold
Billet Throttle Body
1.7 Ratio SS Roller Rockers & AFN nuts
ARP Re-torqueable High Strength Head Bolt Kit
Cometic MLS Head Gasket Set
4.5inch Stroke Forged Crankshaft
Forged H-beam Connecting Rods
Forged Flycut Pistons
Rings & Wristpins
High Strength Main / Rods / Cam Bearing Kit

For that you get 625 horsepower. Is that really that much more than building an equivalent earlier gen motor?

These motors seem like such a redheaded step child, I would like to know why they are so frowned on. In my situation, since converting the instrumentation to smartcraft, I have pretty much the option of building what I have, or swapping to something like 525's, but I don't think I could touch a used pair of 525's under 30 grand, and then still they would most likely need the top ends done. I would love some input from guys familiar with building these, and if you are happy with the decision.
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Old 09-19-2015, 09:27 PM
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Yes, I think the controversial engine builder(s) should be considered as part of the equation too. If you give the package to a dipschjit engine builder, you will get screwed. Less people know & understand the 496 than the Gen 4 and Gen 5. The long and everlasting debate is that you can get far more horsepower out of just selling the 496 and buying a 525 or just building a 500HP for more power. I broke this down on a spreadsheet 50 times and its dead even. I finally gave up and just wanted to be different. I am sure there are naysayers but I am still happy with mine. I mean c'mon, its still cubic inches and cam right? What is the differnce if you built a FORD or MOPAR? More expense? Yes, but the 496 can be done very close to a 525 rebuild cost.

I did the 600HP package from Raylar and had the machine work done locally, a bunch of 75 year old "old timers" (my dad and a bunch of wacky 1960 drag racer buddies) built them, Dustin Whipple reflashed my computers and I am at 200 trouble free hours. They dyno'ed at 640 HP each. "Ray" was still around when I built them. I called and asked for the 600HP kits. Then, when I got the parts, I called and said "give me the main, ring gap and tolerances you prefer for a bullet proof build" he gave it to me over the phone. I gave this to the machine shop and my old man and never looked back. That was 4 years ago now. 95% of the reliability comes down to the build and the ECU program. IMHO

Heck, I would love to do the 8.1 block with a 4.5 bore from DART, the Raylar stroker crank and the NEW Raylar heads... It would be a real thumper.

The downside. I think the block might be a little brittle. Why? I have heard about the motor mounts ripping right off the block/casting failing. But I dont have an Apache running in 8 footers so I dont really care.

The Raylar parts are engineerd for what they are. A 625 HP kit, if you compare the crank to LUNATI you arent going to see it or compaing the Raylar intake to a Wilson intake you are going to fall short of expectations. But, the parts deliver for the intended HP range.

The good side is that I took the heads to 2 differnt shops to have them ported and both shops said you could gain performance but they were more likely to ruin them than make them better (true story). Now, Raylar also has ultra high flow heads too.

I am happy. I have always asked the same question as you. Mine turned out pretty well. When you finally break it down it will be so close it doesnt matter. Just pick the one you want.

Last edited by Keith Atlanta; 09-19-2015 at 09:29 PM.
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Old 09-19-2015, 11:38 PM
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Mine turned out well also. They do have a lot of potential. The biggest downfall of the 496 is/was the intake. The right cam for the restrictive intake and a whole Lotta welding and fabbing on the plenum will yield a whole lot of torque. 650hp is obtainable.
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Old 09-20-2015, 07:05 AM
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So where is Ray now. What caused them to split?
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Old 09-20-2015, 07:31 AM
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I am also planning to build the 496 in the future. Leaving it stock internal for reliability until rebuild needed. I believe the hate comes from the stock piston horror stories and the fact in stock form they are "fugly motors". Merc really could have cleaned the wiring up with a little attention to detail. Instead they covered the mess with the plastic engine cover. I like the fact that when the Raylar kit is installed the engine drops back in without much re rigging needed. I also like the fact its something different from the norm.
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Old 09-20-2015, 07:55 AM
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Vortec Bandit has done as much R&D as Raylar themselves. He has been super successful with this platform.
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Old 09-20-2015, 08:08 AM
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Why is there just a $300 price difference between these two ?
Is the crank only $300 ? I must be missing something.

600HO / 496cid Stage 2 - $8699
Our stage 2 marine performance package bumps the 496 / 8.1L to 607 horsepower & 638 ft-lbs of torque.
BigPower Aluminum Cylinder Heads
BP-206 Max Effort High-Lift Camshaft
CoolGap EFI Intake Manifold
Billet Throttle Body
1.7 Ratio SS Roller Rockers & AFN nuts
BigPower Forged Flycut Pistons, Rings & Wristpins
BigPower Forged H-Beam Connecting Rods
ARP Re-torqueable High Strength Head Bolt Kit
Cometic MLS Head Gasket Set
vs

Raylar 511cid Stroker Marine - $8999
Our popular 600HO kit, stroked to 511cid thanks to a 4.5 inch stroke crankshaft. Our 511 marine performance package makes 625 horsepower & 660 ft-lbs of torque.
BigPower Aluminum Cylinder Heads
BP-206 Max Effort High-Lift Camshaft
CoolGap EFI Intake Manifold
Billet Throttle Body
1.7 Ratio SS Roller Rockers & AFN nuts
ARP Re-torqueable High Strength Head Bolt Kit
Cometic MLS Head Gasket Set
4.5inch Stroke Forged Crankshaft
Forged H-beam Connecting Rods
Forged Flycut Pistons
Rings & Wristpins
High Strength Main / Rods / Cam Bearing Kit

Last edited by SB; 09-20-2015 at 08:10 AM.
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Old 09-20-2015, 08:24 AM
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Originally Posted by SB
Why is there just a $300 price difference between these two ?
Is the crank only $300 ? I must be missing something.



vs
If correct, that's an easy decision. More is better right?
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Old 09-20-2015, 08:58 AM
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I have built a 496 8,1 using a Whipple 3.3 kit... It made 900 lbs ft torque and just shy of 900 hp. Replaced the heads with Dart cast iron, cleaned the chambers up, and very little bowl work. Replaced the crank with a 4340 Scat stock stroke forged in the USA , and machined on Scats priority equipment made for the custom cranks this crank was right at $2600. used 6.700 rods and ordered custom pistons from CP, this was a + .005 oversize piston. .990 pin. Used ARP main studs and head studs. MArine Kinetics did the cam. lifters have to be a shrouded type with a .700 wheel or you will dump oil at the wheel slot in lifter , due to the lifter oil galley location.... I used ARP rocker arm studs and locks with Scorpion Endurance rocker arms, this all cleared the valve covers, not using any Loctite on nuts. I used .120" wall pushrods.Timing chain set came from Crane, the most important thing to check is the cam sensor distance .040- .060... do not damage reluctor wheels on crankshaft.. If they are you can order from GM, heat them in the oven and slide them on...
The oil pump is a regular BBC, use a Melling 10770 or 10778. Put a new crank sensor in, no air gap just install set on wheel and tighten bolt.
I tried buying Aluminum heads from Larry@ Raylar, he gave me the runaround, thinking I was friends with his old partner Ray, because of the information I knew on who designed the heads, who cast them and who machined them... There's no doubt in my mind, I would have made more power with the aluminum heads.....Larry, later admitted; to his thoughts on my knowledge after it was too late for me to cancel the Dart heads. There was some secrecy on his part on certain questions I ask relating to pistons and even the oil pump. Being in business, myself I would have answered those questions if ask too me..... I was told some not the truth statements referring to reluctor wheels and locking mechanisms on the rocker arms. I wanted to buy; bare heads with a CNC program porting, no valves or components..Larry, tried to tell me it wouldn't work without his set-up WRONG !!!!!!
Dustin, did all the calibration for this package... we started with a stock crank and decided; the next season we would use the custom so to up boost to 8 psi and not worry about breaking the crank snout off. Scat typically, makes this crank for a 4.500 and 4.750 stroke. I had to machine about .300" off the counter weights to remove the excess weight or the counter-weights would have looked like Swiss Cheese !!!!
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Old 09-20-2015, 10:11 AM
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Make sure you stick to the factory head bolt torque sequence . Our local marina contacted me searching for 496 cores a couple weeks ago. They had a pair of Volvo Penta 8.1's with bad risers ( not the same as Merc stainless Risers) and had to do the heads. On reassembly , old school tech used regular BBC specs and started pulling threads out of the blocks immediately. He thought they were rotted , so he tried other motor and killed that one . Lightweight blocks ?
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