500+ hp out of a 496HO
05-30-2004 | 08:00 AM
#11
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Posts: 721
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From: Lake Norman, N.C.
Re: 500+ hp out of a 496HO
There are many ways to get the power you are looking for, but I would not put much money into the 496 since they do not have the best of parts.
I have to agree though, for the extra 15k to 18k for the 525's it would probably not be a bad idea for a procharger with only 3 lbs. of boost
The HO comes standard with the Bravo 1 drive. If you add the XR option you just added another 3k. But this still leaves a lot of room for other improvements and money in the bank
I have to agree though, for the extra 15k to 18k for the 525's it would probably not be a bad idea for a procharger with only 3 lbs. of boost
The HO comes standard with the Bravo 1 drive. If you add the XR option you just added another 3k. But this still leaves a lot of room for other improvements and money in the bank
05-30-2004 | 08:38 PM
#12
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Joined: May 2004
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Re: 500+ hp out of a 496HO
Sermon from the Mount
I remember the pre-publicity press on the 496's a few years back that were to be rated at 500 HP on introduction to the marine market and then the HO comes out at a significantly lower 425 HP. Then there was the story that they (GM) "couldn't get more out of the engines" and the engines have less than efficient cast iron heads but a Vortec design. So, now we see them able to crank out 600+ HP with new aftermarket heads and/or a blower. Confusing? Why would GM put cast iron heads and manifolds on these things anyways when everybody is looking at weight savings and HP?
If I were at the helm of Mercury here is what I would do in the performance dept:
HP small blocks:
350 Magnum at 350 HP
350 "Z06" or a "stroker 383" engine at 425 HP
496 HO at 500 HP
"525" at 600 HP
"525" blown at 750 HP
1050's are fine
Add a 1400 HP
I think there is a need for something in the 600-700HP market/the top end market and give us some high HP small blocks now that the technology is here.
Ah heck, why bother. Too bad Walmart dosen't sell these things!
I remember the pre-publicity press on the 496's a few years back that were to be rated at 500 HP on introduction to the marine market and then the HO comes out at a significantly lower 425 HP. Then there was the story that they (GM) "couldn't get more out of the engines" and the engines have less than efficient cast iron heads but a Vortec design. So, now we see them able to crank out 600+ HP with new aftermarket heads and/or a blower. Confusing? Why would GM put cast iron heads and manifolds on these things anyways when everybody is looking at weight savings and HP?
If I were at the helm of Mercury here is what I would do in the performance dept:
HP small blocks:
350 Magnum at 350 HP
350 "Z06" or a "stroker 383" engine at 425 HP
496 HO at 500 HP
"525" at 600 HP
"525" blown at 750 HP
1050's are fine
Add a 1400 HP
I think there is a need for something in the 600-700HP market/the top end market and give us some high HP small blocks now that the technology is here.
Ah heck, why bother. Too bad Walmart dosen't sell these things!
Last edited by Hydrocruiser; 05-30-2004 at 09:17 PM.
05-31-2004 | 10:17 PM
#13
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From: San Diego, California
Re: 500+ hp out of a 496HO
Wildchild212:
We at Raylar have been on the dyno with two 496 engines for the last month and I can tell you personally that we thrashed our new heads with 62 complete full 5000rpm to 5050rpm loaded pulls. This is about the same as making 62 full rpm blasts in your boat. We tore the motors down after the runs and found no visible wear or damage to our new heads including the valves, springs, retainers, roller rockers etc. The stainless Cometic head gaskets and our ARP head bolts worked perfectly with no signs of gasket leaks.The bottom end of both motors showed no visible or magged damage. The bearings showed only a slight bit of wear and oil pressures were the same as when we started the tests. I can tell you that the 496HO unit with just our heads, roller rockers and our new manifold pulled between 521 to 528 horsepower on at least 6 seperate pulls.
Our new heads are a no brainer, they work awesomly just as we designed them and because they are aluminum, their 10to1 compression ratio uses the same octane fuel as the stock motor iron heads that weigh 110lbs more per engine. We recorded absolutly no knocking or pinging on any of the dyno runs and we were able to reach these levels with no addtional timing advance over the stock settings. We are now testing some of our new camshaft profiles and we expect the 550hp levels an easy outcome!
Ray @raylar
We at Raylar have been on the dyno with two 496 engines for the last month and I can tell you personally that we thrashed our new heads with 62 complete full 5000rpm to 5050rpm loaded pulls. This is about the same as making 62 full rpm blasts in your boat. We tore the motors down after the runs and found no visible wear or damage to our new heads including the valves, springs, retainers, roller rockers etc. The stainless Cometic head gaskets and our ARP head bolts worked perfectly with no signs of gasket leaks.The bottom end of both motors showed no visible or magged damage. The bearings showed only a slight bit of wear and oil pressures were the same as when we started the tests. I can tell you that the 496HO unit with just our heads, roller rockers and our new manifold pulled between 521 to 528 horsepower on at least 6 seperate pulls.
Our new heads are a no brainer, they work awesomly just as we designed them and because they are aluminum, their 10to1 compression ratio uses the same octane fuel as the stock motor iron heads that weigh 110lbs more per engine. We recorded absolutly no knocking or pinging on any of the dyno runs and we were able to reach these levels with no addtional timing advance over the stock settings. We are now testing some of our new camshaft profiles and we expect the 550hp levels an easy outcome!
Ray @raylar
06-06-2004 | 07:00 PM
#15
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Posts: 2,777
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From: San Diego, California
Re: 500+ hp out of a 496HO
26Sonic:
I will try and make this short and simple. 496HO with just our heads and a slight fuel pressure increase made 478HP @4800rpm and 536ft/lbs torque at 3500rpm. We added the roller rockers upped the fuel pressure a little more and made 504HP@4800rpms and 541 ft/lbs torque @3600rpm. We added our new intake manifold and and a 85mm throttle body and made 531HP@4850 and 576 ft/lbs. of torque @3600rpm. We have changed the cam in the motor to a better profile and we think we will see 550HP on Monday 6-7. We have been down on the dyno for over a week because it broke the strain guage and we had to wait for a new one from Superflow. We have already made over 65 hard dyno pulls, some up to 5500rpm and we have had no problems, wear or breakage in any parts on the motors.
Our production heads are cast and in machining as I write this and the first manifolds should be ready in about two weeks.
Thanks,
Ray @ Raylar
I will try and make this short and simple. 496HO with just our heads and a slight fuel pressure increase made 478HP @4800rpm and 536ft/lbs torque at 3500rpm. We added the roller rockers upped the fuel pressure a little more and made 504HP@4800rpms and 541 ft/lbs torque @3600rpm. We added our new intake manifold and and a 85mm throttle body and made 531HP@4850 and 576 ft/lbs. of torque @3600rpm. We have changed the cam in the motor to a better profile and we think we will see 550HP on Monday 6-7. We have been down on the dyno for over a week because it broke the strain guage and we had to wait for a new one from Superflow. We have already made over 65 hard dyno pulls, some up to 5500rpm and we have had no problems, wear or breakage in any parts on the motors.
Our production heads are cast and in machining as I write this and the first manifolds should be ready in about two weeks.
Thanks,
Ray @ Raylar
06-07-2004 | 08:03 AM
#17
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Posts: 1,239
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From: Loto, MO
Re: 500+ hp out of a 496HO
Raylar,
26hp from roller rockers, is this true? I didn't realize roller rockers would get you that much. Your new manifold and bigger throttle body was 27hp.
Thanks for the insight.
Rick
26hp from roller rockers, is this true? I didn't realize roller rockers would get you that much. Your new manifold and bigger throttle body was 27hp.
Thanks for the insight.
Rick
06-09-2004 | 08:14 PM
#18
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Posts: 2,777
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From: San Diego, California
Re: 500+ hp out of a 496HO
RV:
Our roller rockers are a 1.8 ratio instead of stock 1.7. this gives the cam about thirty thousanths more lift and with the reduced friction we showed exactly 26 additional hp on three dyno pulls.
Regards,
Raylar
Our roller rockers are a 1.8 ratio instead of stock 1.7. this gives the cam about thirty thousanths more lift and with the reduced friction we showed exactly 26 additional hp on three dyno pulls.
Regards,
Raylar
06-10-2004 | 06:39 AM
#20
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Joined: May 2004
Posts: 5,762
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Re: 500+ hp out of a 496HO
With a few refinements the 496 could be put out by MM at 500Hp for a reasonable cost too. Then going to an offering in the range of 625-675 HP would be quite popular. Right now you jump from 400 to 500 then up to 1050 and the price going from 425HP to 500 HP is quite high.
