What's diffrence between HP500, 502, 509 and 540?
 

Hi boat guys,
in Europe it's hard to find somebody who knows about US-engines... :(

I have a 454 L and want to update to about 600HP (probably by changing the engine). I already have an XR drive, trim tabs, full hydraulic steering, procharger system but try to find out about the right engine and best price to all this...

Thanks in advance for your answers...

Re: What's diffrence between HP500, 502, 509 and 540?
 

Have one built in the US and have it shipped over complete. :cool:

Re: What's diffrence between HP500, 502, 509 and 540?
 

The HP engines are built by Mercury Racing.

The other numbers you posted are cubic inch ratings.
The HP500 is 502 cubic inches.
A 509 is an overbored 502.
A 540 is a stroked 502.
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Re: What's diffrence between HP500, 502, 509 and 540?
 

Thanks Mudball,

so, to go near to 600hp it would be best choice to get a 540 as a good base and maybe procharge it? :rolleyes:

Re: What's diffrence between HP500, 502, 509 and 540?
 

You can easily get 600hp out of a 540 without supercharging it. Depending on which prochager you have and how much boost you run, you could get 700hp+ by installing it on a 502. You should be able to get 600-650hp by installing it on a 454.

Re: What's diffrence between HP500, 502, 509 and 540?
 

the differance is cubic inch and cubic dallors!!!!

Re: What's diffrence between HP500, 502, 509 and 540?
 

I purchased a 540 now and hope to see a good 85 mph after installing it together with my CMI elbow tops and captains choice. what prop would you require with XR drive, full hydr. steering and trim tabs?

Re: What's diffrence between HP500, 502, 509 and 540?
 

That's a hard question to answer!
What is the boat?
What is the drive ratio?
What prop were you originally running and at what RPM?
What does the new motor's HP compared to your original one?

By the way, congratulations on your 540!! Those sure make a HUGE amount of torque!!
Kent

Re: What's diffrence between HP500, 502, 509 and 540?
 

Fun--more Fun-- Holycxxp Fun!!!!!!!!

Re: What's diffrence between HP500, 502, 509 and 540?
 

Hi Mud,
Boat is a Baja 235 FORCE (see old little picture at left), gear ratio is 1.5, original prop is 3-blade 23 mirage and did around 55 mph on 4750 rpm with the origninal 454 L Gen VI (330 hp) with Holley throttle body injection. This Injection will be switched to the 540 too.

Re: What's diffrence between HP500, 502, 509 and 540?
 

85mph seems pretty optimistic with an older v-hul like that.But keep us informed as to how it turns out. I know a guy with an old Wellcraft nova and he put 800hp in the engine room and it never got over 70mph the hull just didnt get out of the water. GOOD LUCK.

Re: What's diffrence between HP500, 502, 509 and 540?
 

You might want to check into using your old injection with the guru's. Those computers can be a nightmare with any other motor than what it came on.

If it were my boat, I would be using a good intake and Holley carb.

Anyway, doing a slip calculation, you were at about 20% slip!!! That's a LOT!! But you mention a Mirage and not a plus. The plus may be a much better prop for your boat.

Given the same situation, you are going from 330 to hopefully 600 hp, if the 540 ends up built right, so that is a lot!

If the 540 ends up needing to turn 5200 or so, maybe a 27 Mirage Plus would be a good place to start. That's probably where I would start. If the 27 hits the rev limiter, then the 29 would be next. Of course, maybe your boat might like a Bravo prop. If you can try one, just use 1" bigger than when using the Mirage Plus. Bravo's only come in even sizes, but are actually 1" less than marked.

My best guess is that you might be in the mid to upper 70's with the new power, once it's all dialed in. Maybe better! You never know!

I would recommend calling Throttle Up propellors for better info!
I'm no guru, just been through the repower myself a couple of times!

Also remember that many small boats (yours and mine) run out of hull at about 75. They get really funny. You will need external hydraulic steering at those speeds, and probably some large tabs to calm it down.
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Here's a recent example. My old power (22ZX Donzi) was a 7.4 MPI. I hit a best of 63 (on gps), usually around 61-62. I put an HP500 in mine a while back and now I have hit a best of a little over 78 (on GPS), with 76-77 every day. The difference in speed is mind boggling!! Just a measly 15mph, but it's HUGE!! I went from a 24p Bravo to a 28p Bravo with this. I have not started playing with props, yet.

Here's why:
I installed full hydraulic steering and it is still a handful over 75. The tail end starts to move around, and it's generally scrary! I'm still working on the handling!

Best of luck with your new power! It should be really FUN!!
Please be careful!
Kent

Re: What's diffrence between HP500, 502, 509 and 540?
 

Hi all,

thanks for answering so fast. :-) It's always very interesting to hear about your experience with almost simular sice boats. I guess we wont procharge it first but sure build full hydraulic and long trim tabs in it. I sure will have to change the 4 injectors from the original throttle body (Holley) to 85 pph to get enough fuel. Sounds like fun already... ;-)