500HP's to 575's???
 

I just had my 500HP (carb motors) completely rebuilt and I was wondering what it would cost to make them like the Merc 575. I always liked the look of the 575 motor.

I am guessing it would not take alot to do this??? What would be the approx. cost? Another 75-100 HP per side would be nice!!

Re: 500HP's to 575's???
 

I to have had my '99 HP500's undergo surgery -(complete rebuild) my engine builder did head work & cam change & told me today I should be around 575 hp or better - I guess we will see when they are put on the dyno next week. :eek:

Re: 500HP's to 575's???
 

add whipples for probably less money than mercury parts and get 650-700 horse easy...

Re: 500HP's to 575's???
 

Whipples will cost approx. $8K installed per side with intercoolers. That's not cheap!!
I also don't want that much power, I don't want to have to spend another $15K upgrading the drives for that power.

Re: 500HP's to 575's???
 

Semper Fi, PM Linster. He is currently upgrading 500HP's and is also looking to gain 75-100HP.

Re: 500HP's to 575's???
 

okay thanks :drink:

Re: 500HP's to 575's???
 

the 575's have superchargers too? how much are those gonna cost? or are just talking about gaing 75 HP? big difference....

Re: 500HP's to 575's???
 

You could bolt on some 250 or 256 blowers and single dominator carbs. Run about 4lbs of boost and make 600hp+. Adjust the boost from 3-5# according to the power you want. With all new parts and some Nickerson dialed in carbs it'll still run about 10k.

Re: 500HP's to 575's???
 

Merc's older 575's were 540's with solid tappet cams single plane intakes with 1050 Dominators. The de-tuned version of these was the 540 Bulldog. To get 575 HP out of the HP 500 should be easy and it could still look stock. Have JIMV port the heads and go to a different cam and bump the compression a bit and it should be there. As a matter of fact i think JIMV has a proven package for this motor that will get 600 HP on the dyno. Check his website.

Re: 500HP's to 575's???
 

what cam did he use?to get 600hp and what did he bump the comp to??

Re: 500HP's to 575's???
 

Who is JimV ?

Re: 500HP's to 575's???
 

I do want the xtra 75-100 HP, but I always liked the look of the merc 575's. The blowers look sweet.

Re: 500HP's to 575's???
 

Mercury just discontinued the 575 because their 525 package was very close to the same HP and only used half of the fuel. The new Merc 600 produces more hp than the 575 while also getting better fuel economy. Considering this, are you sure you want to reproduce the 575? I would think aiming for the 525 efi would be a better choice - which I understand can be accomplished at a reasonable cost.

Re: 500HP's to 575's???
 

Are we talking about 575 SCI's or the older HP575's? Either way 75-100 more HP is attainable NA or with a small blower. JIMV is the owner of Valako Race Heads and he frequents this board. Here is his website. http://hometown.aol.com/valakoracehe...raceheads.html
I don't know the particulars about his 650 HP 502, but he is a good guy and knows how to get the most out of heads for marine applications.

Craig

Re: 500HP's to 575's???
 

Get a can of blue paint and go to it. :drink:

Re: 500HP's to 575's???
 

650 HP out of a 502 on pump gas will not happen.

Re: 500HP's to 575's???
 

650 HP out of a 502 on pump gas is possible, but it will require aftermarket heads and good headers. :D

Re: 500HP's to 575's???
 

I would just go with Whipples - make them 600's with low boost.

Re: 500HP's to 575's???
 

The Whipples would be awesome!! But if 600 HP is all he is after it would be cool to do it with stock looking NA motors. It also can help with insurance rates! :drink:

Re: 500HP's to 575's???
 

Insurance...
Factor the cost of insurance into your plans. If you add a blower and fail to inform your agent of this your insurance will be useless. Expect to pay a lot more for insurance with a blower. If you build a 540 and keep the engine appearance stock on the outside you have a pretty high possibility of keeping your insurance the same. Granted your insurance will still be no good but they will likely never know you have made modifications. In the event of a claim they are going to go over the boat with a fine tooth comb. It would be pretty hard for them to tell you built a 540 unless they tear it down. I suspect it would still be easier to get insurance if you tell them you did build a 540 but fudged a little on the rated power and speed.

I am sure some others who have looked into the insurance will have some other thoughts and I would be interested in hearing them as well. With the rate increase of a blower you can pretty well build a 540 with the savings on insurance over the course of a few years.

Re: 500HP's to 575's???
 

600hp should be easy with upgraded heads (Dart, Merlin etc.) and a different cam.

Re: 500HP's to 575's???
 

I think it is possible with a set of Aluminum heads and a solid roller cam.

Re: 500HP's to 575's???
 

Call Innovation Marine in Sarasota Fl. I'm sure they can help you. 941-355-7852

Re: 500HP's to 575's???
 

Maybe I did not say well what I was trying to relay.

I have not found any professional marine engine builder or an marine engine builder with a dyno to say they get 650HP out of a 502 that will be used in a boat reliably.

You can get to that number if you spin a Solid Roller cam up way past 6000 rpm. In reality, It will not have any more torque available past 4600-4800 rpm. It probably would make less torque than a good 600 hp motor to achieve a HP number that would be needed to get that 650 hp number. About 5400rpm it will stop pulling in a boat because the peak torque curve is falling off. I would look at the HP around 5400-5600 to be the top usable HP in a boat. Shooting for 5400-5600 rpm will give the largest torque number and will work much better in a boat. Torque is more important than HP, so my suggestion is to work on the peak torque number, then try to keep it from falling off too fast past 4800 rpm.

Scoogin Dickey has a 509 602HP. Alum Heads 10.2 compression using automobile headers.

Teague offers a 509 620HP Version.

These are my thoughts for what they are worth.