Gen VI 454 swap

« **on:** February 28, 2017, 12:44:28 AM »

Hoping I can find some advice search didn't really field anything.

I have a 21' Spectra Mini-day with a stock 454 that was pulled from a much smaller boat.

A local guy is selling a complete Gen VI (wiring, comp, everything).

What kind of needs will I run into for this swap? Is Efi doable? Will my water logs bolt up? Basically except for maybe a cam swap, I'd probably run the motor dead stock.

Boat has a Berk JC with I believe an A impeller and a Place Diverter.

« **Reply #1 on:** February 28, 2017, 05:53:50 AM »

The efi will have to be heavily modified and won't really ever perform to what a carburetor can do unless you are one seriously talented tuner. You will need to dumb down the computer, make it open loop, make numerous electrical changes and more.

You would be better off if you really want to go this way to find a Mercruiser MPI set up to swap. It's going to be marine spec, USCG legal and run like it's scared.

The budget route would be to go standard carburetor and electronic ignition with an electric fuel pump.

JMO...

GT

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« **Reply #2 on:** February 28, 2017, 12:49:00 PM »

Just thinking out loud:

What is the Gen VI out of?
What do you gain from the swap?
What are the specs of your current engine?
What are the specs of the Gen VI?
Head casting numbers would help the decision process.

You might be down-grading to a newer, but lower output engine. Your original intake (depending on port shapes), exhaust, and distributor are compatible if you wanted to go that route.

« **Reply #3 on:** February 28, 2017, 09:16:27 PM »

Thanks for the quick response gents.

I have no specs on my 454 I bought out a customers boat from Jet Boat Performance in Atascadero. After my original 454 Hipo marine seized. If remember right the boat at JBP was like a 17'
Flaty.
It runs but no where near how my old motor did.
Efi would be nice we boat at very extreme elevation changes 1 weekend we might be at 200ft the next 5000. But it isn't a must.

Really I don't know what I would gain. The motor is out of a truck, and the local guy wants $500 for everything.

« **Reply #4 on:** February 28, 2017, 09:29:15 PM »

Quote from: Jcruiser on February 28, 2017, 09:16:27 PM

Thanks for the quick response gents.

I have no specs on my 454 I bought out a customers boat from Jet Boat Performance in Atascadero. After my original 454 Hipo marine seized. If remember right the boat at JBP was like a 17'
Flaty.
It runs but no where near how my old motor did.
Efi would be nice we boat at very extreme elevation changes 1 weekend we might be at 200ft the next 5000. But it isn't a must.

Really I don't know what I would gain. The motor is out of a truck, and the local guy wants $500 for everything.

It's extremely difficult to get an O2 sensor to work with EFI on a boat.

I cheated on a major way when we took the boat to Tahoe.

I had two carburetors and a distributor timing plate. The elevation carburetor, that also worked at Almanor was jetted for elevation, the other for sea level and we would put three degrees of timing in it.

That EFI won't perform like you think it will.

JMO

Sent from my SM-G900V using SoCal Jet Boats mobile app

« **Reply #5 on:** February 28, 2017, 09:29:16 PM »

Quote from: Jcruiser on February 28, 2017, 09:16:27 PM

Thanks for the quick response gents.

I have no specs on my 454 I bought out a customers boat from Jet Boat Performance in Atascadero. After my original 454 Hipo marine seized. If remember right the boat at JBP was like a 17'
Flaty.
It runs but no where near how my old motor did.
Efi would be nice we boat at very extreme elevation changes 1 weekend we might be at 200ft the next 5000. But it isn't a must.

Really I don't know what I would gain. The motor is out of a truck, and the local guy wants $500 for everything.

It's extremely difficult to get an O2 sensor to work with EFI on a boat.

I cheated on a major way when we took the boat to Tahoe.

I had two carburetors and a distributor timing plate. The elevation carburetor, that also worked at Almanor was jetted for elevation, the other for sea level and we would put three degrees of timing in it.

That EFI won't perform like you think it will.

JMO

Sent from my SM-G900V using SoCal Jet Boats mobile app

« **Reply #6 on:** February 28, 2017, 09:34:11 PM »

http://www.speedwaymotors.com/Moroso-26100-Distributor-Timing-Indicator,586.html

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Jcruiser

Gen VI 454 swap

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