500+ hp out of a 496HO
 

What needs to be done to get 500 to 550 hp out of a 496HO? A blower is out of the question. This would be a project for a friend of mine. I am assuming that it would not take to much to accomplish this hp.
Mark

Re: 500+ hp out of a 496HO
 

Talk with Arizona Speed and Marine. They have a complete intake system that is suposed to produce 600hp.

Re: 500+ hp out of a 496HO
 

I believe Raylar is who you want to talk to.It will take heads etc. but Ray says he can do it.Check old posts for their web siteor Powerboat mag.BOB

Re: 500+ hp out of a 496HO
 

Here is a place to check. http://www.raylarengine.com/

Here is a link to another thread that talks about their products. http://www.offshoreonly.com/forums/s...ad.php?t=72206

Re: 500+ hp out of a 496HO
 

Thank you for the info. simple head change is awesome. Has anyone tried the heads yet?

Re: 500+ hp out of a 496HO
 

whipple also has some things you can do also...

Don

Re: 500+ hp out of a 496HO
 

By the time you tear down the engine for the head, cam, and piston and manifold change you will be into it for the same as a whipple blower. Why say no to the blower so quickly?

Re: 500+ hp out of a 496HO
 

Cobra. not sure yet about putting blowers on the 496 yet. High compression, blowers have not been on these motors long enough for me to feel real good about putting one on. The gentleman that it is for would like to stay right around 500 to 550 horse.
Mark

Re: 500+ hp out of a 496HO
 

I am surprised that the 496 Magnum and HO come with cast iron heads. All that extra weight. Raylar http://www.raylarengine.com/ has the solutions from a package deal standpoint for this engine. Alum heads, forged pistons, manifold, cam. It's nice to have the option of going this route or going supercharged. The heads raise the compression from 9:1 to 10:1 by the way which may make the engine need higher octane fuel and less adapt possibly to adding a supercharger later. Although 425 HP is pretty decent in the HO already i think there is more to be had!

http://www.procharger.com/2003newsle...e.systems.html

"Powerboat magazine recently tested the 496 Mag HO, 5 psi Procharger system. In before-and-after testing in a 28’ Eliminator Eagle V-bottom, the radar gun showed a 14 mph gain from the installation of the ProCharger system, running pump gas".

496 Magnums with a Procharger:
3.5 psi boost gives 550 HP
5.0 psi boost gives 590 HP

496 H.O.'s with a Procharger:
3.5 psi boost 580 HP
5.0 psi boost 625 HP

The HO is about $ 3500.00 more than the 496 Magnum. Money better spent put towards a blower and/or heads? You can see in the attachment below that the Procharger is a clean looking system and is intercooled. Considering the 525 EFI @ 500HP is roughly $ 18,000.00 more than a 496 HO it sure is a temptation to get an HO or Magnum and supercharge it. The 525 EFI of course having forged parts is a good candidate for adding a supercharger to as well I would imagine and the Whipple can bring it up to around 800-900HP.

My guess is that if you go 3 psi and get 500 HP you ought be ok in a 496 Magnum and put the approximately "$ 15,000" difference in the bank.


http://www.azspeed-marine.com/whipple.html
Whipple's are $ 6,600.00 ea if you prefer that brand. They say 5-6 psi boost offers "nearly" a 50% HP boost.

I never added a supercharger myself but would love some personal experience stories on the feasibility and durability of "adding" a supercharger to an engine that is already at 9:1 compression and does not have forged parts. I see a lot of "factory" supercharger applications using engines with lower compression ratios down to 7.5:1. Is engine life affected?

http://www.hotboat.com/test_data/index.cfm
A cool site with lots of engine/boat combo tests. Fun to compare claimed speeds and actuals.

Re: 500+ hp out of a 496HO
 

Ive been contemplating this for 2 years now ....I'm done 3.5 lbs Prochargers are going on my 353 fas-tech 496 ho...spoke to a couple guys running the 5 lb kits for 2 seasons now no problems reported and these guys run them hard.

Looked at Whipple's but you can only run them in 7-10 min spurts wide open (I like to hammer down at times longer than that in Poker runs)

Really interested in the aluminum heads from Raylar but I don't believe they will be ready for this season and I would like to hear some results and feed back before I invest that way( especially without a intake to help the heads out..Arizona speed intake 4k plus 2.4k for heads more than the Prochargers)
3.5 kits run about 4300.00 per engine and 580 hp is not bad for that kind of money still ahead from the cost of the blue motors.. even if you drop a motor 9k to replace (not what you want to do but considering the blue motor price not bad)you are still ahead...5 lb kit is only about another 800.00 per engine..
3.5 kit no ECM changes needed either..
On Formulas you need to notch the port side outer stringer Formula engineers said it would still warranty the boat no major problem seen,


You can think this one out forever , I'm done let you know mid June how she runs...

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

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!

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

Re: 500+ hp out of a 496HO
 

raylar could you give us a break down for the 496ho on each upgrade you made and it's hp gain ? such as just heads first then a cam upgrade etc.

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

Re: 500+ hp out of a 496HO
 

Amazing Raylar can do what GM and Merc couldn't or wouldn't. Same with putting a blower on with 3 psi to get to 500 HP. Nice to have options.

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

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

Re: 500+ hp out of a 496HO
 

WOW that is amazing gains!. Looks like the 496 has more potential than anyone thought.

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.

Re: 500+ hp out of a 496HO
 

I think one of the few instances you will see a gain of 26 hp from the addition of 1.8 roller rockers, indicative that the cam in the 496 Mag with Raylar heads on it does not have nearly enough lift. The smaller cam is one of the differences between the Mag and Mag HO motors. To just bolt 1.8 roller rockers on any old motor I doubt you will see these kind of results unless. For what Raylar is trying to accomplish hp wise using the addition of bolt ons, without opening up the motor, makes their package simplistic, which most anyone buying their package could accomplish.

Re: 500+ hp out of a 496HO
 

Well it sounds like a cam change will help. That is if there is enough clearance with the piston. However, I remember Raylar indicating the stock setup wouldn't take too much more lift.

Raylar, any results from you cam testing this week?

Rick

Re: 500+ hp out of a 496HO
 

Why is this? If it is intercooled (using seawater) and boost is not excessive, why only 7-10 minutes?

John

Re: 500+ hp out of a 496HO
 

So the intercooler is using the antifreeze from the heat exchanger (the closed system side), rather than taking seawater directly into the intercooler?

Design wise that doesn't make a ton of sense because all the cooling of the inlet charge is dependent upon the primary heat exchanger from closed loop system on the engine. Makes no sense at all when you have an immedaitely available unlimited supply of cold water available. Makes a kit simpler since the plumbing is standardized..

Can you just plumb it straight off the sea strainer instead?

Or am I missing something?

Thanks,
John

Re: 500+ hp out of a 496HO
 

Thinking further, is it just the heat creep issue for cooling the engine itself that the primary exchanger cannot keep the engine cool. This is an issue for intercooled or non-intercooled forced induction applications.

Is this what you are talking about with regard to the heat exchanger not being large enough?

John

Re: 500+ hp out of a 496HO
 

I would like to know what the 496 Mag HO made on the dyno before any changes were made. Doesn't Merc rate it at 420 at the propshaft?

Re: 500+ hp out of a 496HO
 

Them are some great numbers Raylar. I will relay the info. Thank you for the info. If I remember I think I sent for a catalog. Is there any way to double check to make sure

Mark Clement

Re: 500+ hp out of a 496HO
 

Hey Guys:
Just to let you know the facts. The stock HO cam is a .501 lift and is 222 duration intake, 230 duration exhaust @.050 with a 114.5 lobe centers. This is a realitivly small lift and duration cam for a 496 big block. The problem is that the factory pistons have a small intake valve relief and at this duration they can only take about a .535 lift and at a bigger duration lets say 236 etc they can take only about .510 lift. Our current testing on the dyno shows that our new .538 lift special duration cam can make about 525hp with our heads and manifold and short tube marine headers. To go higher than this in horsepower will mean either new pistons or flycutting the existing pistons which we have done. Currently with a bigger cam test we have seen some slight lean WOT pulls with the Mercury stock program ECM, so we are still testing to see if we will have to look at ECM reprograming to get to a reliable safe 525hp to550HP level. It is our feeling that the Merc closed cooling system on this engine can easily keep a 550hp 496 engine in a good cooling range, above this horsepower only time and in boat testing will show what the system can do, I do believe some minor raw water pump changes will give a higher system capacity. The stock pump is a low pressure unit, 3 to 5 psi, most of which run about 2.5 to 3.0 psi,which has caused some problems even in stock 496's. We believe a pump with a 5.0 to 10.0 psi pump could greatly increase the systems cooling capacity at high horsepower levels.
Hope my updates and blabbering will answer some of your questions and concerns. We are not going to let any boaters use our products and damage their motors, bad for business!
Ray @ Raylar

Re: 500+ hp out of a 496HO
 

Raylar, do you have the baseline 496 Mag HO dyno #'s

Re: 500+ hp out of a 496HO
 

BGIII:
Yes, we ran the base 496HO engine on three power pulls which put out between 420 to 433 HP @4900 rpms and the torque was between 526 ft. lbs @ 2500 rpms and 561ft. lbs at 4400rpm. The motor hit the rev limit at about 5050rpms.

Re: 500+ hp out of a 496HO
 

Thanks Ray, I appreciate the information.

Re: 500+ hp out of a 496HO
 

I just sold a '90 Eliminator with a HP468 engine. 502 cu. carb model Mercury Racing engine. Previous owner installed roller rockers, and a Dart intake. Running the stock 468 exhaust headers they (Mercury Racing Engineers) estimated the HP to be over 500.

Running a three blade Bravo One prop, 1.50 ration Bravo One outdrive the boat would go 72mph (gps) on pump gas. Two thirty gallon tanks and at wide open throttle 6200rpm, I have run the boat on the Ohio river for over a half hour steady. The previous owner said the Racing Engine was designed to run wide open throttle as long as you could feed it gas. And I believe him after torturing this boat for five years with never even a hickup out of it. The leak down numbers over five years only moved a point or two even after loosing the water pump and boiling the coolant.

So, my point is if you want reliability over and above everything else, put your money into the Racing version engine now, and then in the future hop it up (blower or supercharger. )

I am looking for a replacement boat and I won't buy one with out the engine having "forged" parts. I have an Audi TT Roadster 1.8 litter 4 cyl with a turbo that produces 225 HP. With a different turbo and exhaust people are producing 338 HP. The TT 225 Quatro has forged parts while the regular TT has cast parts.

Go with the strong internals and you won't regret it.

Cheers.

Re: 500+ hp out of a 496HO
 

My 496 has 830 horsepower... Whats the problem ?

Re: 500+ hp out of a 496HO
 

Betitbig:

Who redid your engine block and heads on your 496 for 830HP with a Whipple? Is your Whipple the new 3.3 or the 2.3 unit? Who dyno'ed the motor at 830HP? Curious what you spent for the whole package? What drive have you hooked up to a 830HP 496? Did'nt your first 496 with a Whipple kind of unrap itself? Thanks for the answers?

Ray @ Raylar

Re: 500+ hp out of a 496HO
 

Wildchild, I had a 496 Mag 375hp and installed a Procharger 3.5 lbs boost system. Takes about two easy days and 2 six packs.This was on a 2003 Advantage old school bottom 22 foot bow rider. Speeds increased from 62 mph to 76 mph with a Bravo 1 4 Blade 28. All I did was run 93 octane pump gas.

I would not spend the extra $3000 tp $4000 on an HO. For the same money you can get the Procharger. Dollar for dollar the 375 with Prochagger is by far the best way to go to get power form the 496. I put over 60 hours on the motor with nothing but 25 hour oil changes. I sold the rig to get a Laveycraft cat but the Advantage is still going strong. Good Luck.

Re: 500+ hp out of a 496HO
 

830 HP even to an XR is a drive buster for sure, not a matter of if, but when :drink:

Re: 500+ hp out of a 496HO
 

Ray,

See Betitbig's thread on the 496 CMI Headers - he describes the build and builder of two Whippled 496's.

Re: 500+ hp out of a 496HO
 

I guess i'll just keep my fingers crossed... Easy on and easy off.

Re: 500+ hp out of a 496HO
 

Ray,

This engine was a combined effort by Dustin at Whipple and Larry Peto in Tucson, AZ.

This engine has the 3.3 Whipple. Larry did all of the head work and internals, while Dustin spent hours dialing in the
computer.

Larry dynoed the motor running 8lbs of boost at 830hp and with 6lbs of boost at 753hp.

Money spent? Once your so far in does it matter? Let alone the time involved by Dustin and Larry. I probably around $25k into just the motor, let alone other upgrades to try and handle the power.

My first motor that yes did grenade (stock internals) is now redone also and has the 2.3 Whipple on it. It ran 640hp on the dyno with 6 1/2lbs of boost.

Re: 500+ hp out of a 496HO
 

We've got a 3.3L 496HO in Larry's oven as well :evilb: :evilb:

He does some very nice stuff for sure.
Not counting the Whipple cost we are at less than $10k for ported heads, upgraded valves (inconel exh) and springs all forged internals (Raylar crank), Eagle H beams, JE forged pistons, Sendure oversized heat exchanger, roller rockers under stock valve covers....assembled and dyno'd with a 1 year warranty (at 750hp).
BTW, those dyno numbers are with the stock exhaust :D

Not bad :cool: