500 hp to 540
 

looking for someone who has been through this. I want to go to 540's from my current hp 500 efi's. Can't decide whether to sell my hp 500's (170 hrs, efi) complete and start from scratch or sell the cranks, heads, maybe pistons and efi setup and use the 500 block and cmi exhaust, bolt ons etc. from the 500 and buy 540 crank rods pistons and new heads (afr). I am planning on not using the efi as my goal is 650 plus hp. Anyone done the math?

is supercharging your current motors not an option?..I dont have a lot of experince with the 500EFI's but i would think at
170ish hours you would be fine..

I made my 500EFI's 540's. If you want to ditch the EFI setup then just start from scratch.
I kept the EFI setups (with port work and monoblade TB) but I replaced the crank, rods, pistons, cam, heads, TB.....I should have just bought another block and kept the 500 long blocks intact.

But I did pull 630hp/700tq fully dressed on Precision Marine's dyno.

if you are going that route, sell your engines complete, way more $$ buy a pair of complete marine carb 540's you will far ahead $$ wise

I'm curious why to sell and buy 540's? Is it really beneficial? My bumped up 500's are only a few seasons old but if I decide to keep my current ride I am considering stroking the existing blocks. From a price point my builder can do it reasonably without the hassle of buying and selling. And I know how they were put together with what parts. Vallako did my induction and I out flow the Darts and am set up for bigger cubes. How much $ would be saved buying vs. Building???

On a 500HP carb engine, I would turn it into a 540ci.
On a 500EFI, I would sell them and start from scratch. There is just too much that needs to replaced or modified on the EFI to get the hp above 600-625.

Fixx
 

Iwould keep what you have and install a set of prochargers..Ibet you will pick at leaste 10-15 mph..

Cool

The money that it takes to get the 500 EFI intakes to be able to supply enough air for a 540 set up can get pretty expensive. There are easier ways to do it.

Check WTB Threads
 

There are a few buyers looking for complete HP 500 pairs. This may help decide which way to go, based on what u can get out of your motors.

its not a wise decision to make a 50efi into a 540 especially if your motors are low hours fresh and can be sold for considerable amounts. one would think that the trade off would cost them a reasonable amount, but done correctly with top of the line parts in the 540's you could end up breaking even. i would expect close to 700HP all day.

depends on what you want and are willing to spend. couple diff things come to mind depending on where you wnat to be power wise. i you want to be in the 600-650 range that is pretty easy with heads, cam, throttle body, injectors and programming. Also some 500 efis had the good rods and some didnt, later ones did.

Now, i just found out that the throttle body from a 525 is bigger than the one from arizona speed. check with Ron potter as he has some 500's that are 775 from a 540 block.

The thing to reember is HP costs money, how much can you afford.

btw my 500's are 625 and 670 tq with afr heads 509 CI and all the work i mentioned above.

+1 with Griff

I spoke with my engine guy and after going throught the numbers we agree I can sell the 500's and for the price of the new block would probably end up money ahead verses upgrading the stock hp 500. The one twist he threw in was his cost of block, crank, pistons, rods and all that he will need is the same for 572's as it is for 540's. He suggested the tall blocks for a mildly built easy 650-675 hp. Near as I can tell the worst part would be moving the exhaust up .5" on transom (tall block) however if I sell 500's with headers I can have tails built .5" lower to exit existing holes with new headers.
Any experiences with 572's? I am thinking have him put together 572 short blocks then Bob (Marine kinetics) cam and a couple sets of AFR's.

Ok, here is the million dollar question....I know the engines are only worth what someone is willing to pay but what can I expect to get for 2 complete 2004 hp 500 efi with 170 hours, with and without headers?

Define "170 hours". Since new (2004) or rebuilt?
The amount sold for will also depend upon the quality of the rebuild. Machine work, parts and who performed it.

170 original hours. The person I bought it from ran it on a fairly small lake so it didn't see much wot time.

I would sell the lower end complete, regardless. The price you'll get for the used crank, rods, heads and pistons won't be all that much (and you don't have to disassemble it).

You can sell your motor, less injection even, for a decent amount. IMO it will be much more than what you could have sold your crank, rods pistons and heads for, less what you pay for your new rotating assembly and block.

Remember, right now your motor has the Merc built label on it, along with work that went into its assembly, not to mention piece of mind for the buyer that's its been removed properly and still in balance. Once you take it apart, all of that goes away.

I would guess $4,500 each. I could be off, but that's a good starting point for arguments sake!

:coolcowboy:

I would be interested in the 500 s .

I just sold a 496 mag(375 HP) with 400 hours for $4500 complete. It had all the accessories on it. An HP500 at 170 original hours should go for $7000 IMO. It will be much less costly if you save all your accessories for the new engines.

PS....I went to a 540 and my engine guy is working on a couple of HP500's right now that he is turning into 540 and 509. He'll definitely give you some pointers if you need anything....always willing to help. motorsbyshooter.com

Sorry, exhaust went with it and it was $6100 total for 496mag with silent choice exhaust system.

they should be worth 10-14k easy each.

After talking with a few people that have sold them the concensus is around 12 - 14k per enging complete is a good price. I would entertain selling minus exhaust. I also have captains call (silent choice) that will be sold sperately.

Remember these blue motors were a $17,000 UPGRADE on the option list!

You can build some really nice carb motors, using better blocks and parts with the money you get for your merc motors. I wouldnt take the mercs apart. People pay for the turn key idea.

Why stop at 540CI? When starting from scratch, 598CI tall decks really wont cost any more. You can build some 750HP 598's easily!

you need to check on the exhaust ...those might not work on a standard BBC setup ......m

The CMI's are the replacement for the older gil exhaust and will fit on 502's and standard BBC

"Why stop at 540CI? When starting from scratch, 598CI tall decks really wont cost any more. You can build some 750HP 598's easily!"
As I posted earlier I am thinking of 572's but the tall deck may cause clearance issues with hatch lift and if I didn't buy custom tips I would need to move holes in transom.