454 Magnum Upgrades

[Tommy Gun]

I have an stock Merc 454 magnum EFI 385 HP in my 1995 Cig 20.

It is time to upgrade the motor/headers. Whats out there? Any recommendations? Whipple it?

[Wrinkleface]

Sterling 1500!!!:eek:

[Tommy Gun]

I want to upgrade the motor not replace it...

[Bill N]

Jc Performance got 515hp out of mine with the stock heads & intake. He just used a 525 cam, ported the heads & a good program of the efi.

[Trim'd Up]

I want to upgrade the motor not replace it...

That's a shame. I have a 711 hp 548 that sure would make it fly.:driving:

How much power are you looking to get?

[bajabob 718]

do the heads and cam bigger prop :driving:

[Tommy Gun]

That's a shame. I have a 711 hp 548 that sure would make it fly.:driving:

How much power are you looking to get?

Much as I reasonably can out of this rebuild.

Has Bravo 3.

[mikes280]

bore it 60 put a 4.25 crank in it touch up the heads add a crane 741 and you have a 496 that can make up to 600hp

[JupiterSunsation]

How fast is that boat with the stock motor now?

[Tommy Gun]

How fast is that boat with the stock motor now?

68

[Knot 4 Me]

Are you sticking with the Bravo III after the rebuild or going to a Bravo I? That decision should influence how far you want to go HP-wise with this upgrade.

[Airpacker]

Put a Black Hawk on it and gain mph for cheap :)

[Tommy Gun]

Are you sticking with the Bravo III after the rebuild or going to a Bravo I? That decision should influence how far you want to go HP-wise with this upgrade.

Going to try it with a Bravo 1 lower...we'll see.

[Tommy Gun]

Put a Black Hawk on it and gain mph for cheap :)

Blackhawks have their own set of issues (shifting), but I have considered an Arneson as it would appear that it would produce he desired result and decent dockside manners.

[Airpacker]

Blackhawks have their own set of issues (shifting), but I have considered an Arneson as it would appear that it would produce he desired result and decent dockside manners.

What shifting issues? never had a single shifting issue in 5 summers of running one behind an efi motor.

[baja27]

Tommy Gun , I have a M1 procharger for your motor, keep everything alone and enjoy great cruise speeds without going into boost.

[Bad Idea Baja]

Tommy, I'm really happy with what I did to my 454's. If you want the cam specs & stuff like that, PM me.

[Tommy Gun]

What shifting issues? never had a single shifting issue in 5 summers of running one behind an efi motor.

I have been told they have problems with higher HP and have to be shifted like a crash box????.

[Knot 4 Me]

I think the first question a builder would ask is if you want to keep the EFI system.

[Slandrew]

:iagree:
Jc Performance got 515hp out of mine with the stock heads & intake. He just used a 525 cam, ported the heads & a good program of the efi.

[Airpacker]

I have been told they have problems with higher HP and have to be shifted like a crash box????.

Well, now someone with some serious real world experience running one will tell you different :)

I ran 575 hp spinning 31's thru 1.50 gears and never had any issue. Yes, it does shift a little hard due to big props and solid bite but it always shifted. Not really any harder than a 1.34 Bravo with a big wheel on it.The efi catches the engine load and prevents stalling. I did install a neutral switch over ride so I could start it like a crash box but that was by choice. If we got stuck just floating around for a while at a poker run stop, I would just shut it off in gear and refire in gear, no waiting for the EFI to let the idle come back down.

If I didn't build a 900 for my boat, I would still be running the BH drive.
Great handling, straight tracking, good slip numbers ( under 9% ) and of course, a sweet rooster tail :) The BH was on my boat when my avatar pic was shot.

It outlasted bravo x drives by miles too. 160 trouble free hours compared to 20 to 30 out of bravos. I wouldn't hesitate to run one on a light boat with 600hp.


PS, I picked up 8mph over a B1X.

[Tommy Gun]

Well, now someone with some serious real world experience running one will tell you different :)

I ran 575 hp spinning 31's thru 1.50 gears and never had any issue. Yes, it does shift a little hard due to big props and solid bite but it always shifted. Not really any harder than a 1.34 Bravo with a big wheel on it.The efi catches the engine load and prevents stalling. I did install a neutral switch over ride so I could start it like a crash box but that was by choice. If we got stuck just floating around for a while at a poker run stop, I would just shut it off in gear and refire in gear, no waiting for the EFI to let the idle come back down.

If I didn't build a 900 for my boat, I would still be running the BH drive.
Great handling, straight tracking, good slip numbers ( under 9% ) and of course, a sweet rooster tail :) The BH was on my boat when my avatar pic was shot.

It outlasted bravo x drives by miles too. 160 trouble free hours compared to 20 to 30 out of bravos. I wouldn't hesitate to run one on a light boat with 600hp.


PS, I picked up 8mph over a B1X.

Thx, for the info...the feedback I got was from someone who has tons of experience with them; and runs one.

[Airpacker]

Just my opinion Tom and you know what they say about opinions :)

[Tommy Gun]

Yep, always two sides to the story..thx again for sharing your experience; much better than the "somebody I know". Still think the Arneson would provide the same benefits???