Switching from Volvo TBI to Carb on a 1996 5.7 GI

Scott Danforth · Tuesday at 6:04 AM

the other thing for more power if that is your goal. upgrade the heads to vortec. your boat may be a 1996, however the picture in post 16 is of a 1986-1995 intake (non-vortec). most likely your motor has 1991-1995 swirl port heads

if your block is an 880 block, then your motor is a 1995 motor may be a roller motor.

vortec heads are good 40hp over the swirl port heads.

camboat · Tuesday at 9:14 AM

That would be great! Should I put a regulator on it or use it as is?
That will help keep everything looking stock using the low pressure pump and filter setup.
Thanks for the info

Scott Danforth · Tuesday at 9:55 AM

camboat said:
That would be great! Should I put a regulator on it or use it as is?

depends on pressure. if you are over 5-6 PSI, definitely use a regulator.

camboat · Tuesday at 8:31 PM

Just a few more questions.
Here is a pressure regulator with attached gauge to get the fuel pressure dialed in.

Speedway Fuel Pressure Regulator 5-12 psi & Gauge 0-15 psi

I can attach it directly to the Volvo low pressure pump and filter housing to make a clean installation.
Should I use a hard line from the regulator to the carb or will A1 fuel line work? It will be around 10-12" fuel line from the regulator to the carb.
I'm just fine tuning everything before I start ordering all my parts.

Thanks again for the help!
Jack

Scott Danforth · Wednesday at 3:26 AM

I prefer the Holley fuel pressure regulator. The speedway branded parts were iffy

A1 fuel hose is fine

camboat · Wednesday at 12:13 PM

Thanks Scott
I will do the Holley regulator.

camboat · Thursday at 3:53 PM

Since I am going to use the Volvo low pressure fuel pump and Holley fuel regulator, where do I run the fuel over flow line since I will be removing the VST? Does the fuel regulator set to 5 psi eliminate the fuel overflow port?

Thanks

Scott Danforth · Thursday at 3:54 PM

You return it back to the VST tank or back to the tank itself

alldodge · Thursday at 4:10 PM

camboat said:
Since I am going to use the Volvo low pressure fuel pump and Holley fuel regulator, where do I run the fuel over flow line since I will be removing the VST? Does the fuel regulator set to 5 psi eliminate the fuel overflow port?

Thanks

Two things
Your VP low pressure pump may not need a reg, it might but might not, check/test first

The Holley Reg limits the amount of pressure going to the carb, it simply does not allow any fuel above the adjusted pressure to pass, no need to overflow line. Same thing a house water pressure reg uses

Scott Danforth · Thursday at 7:39 PM

Depends on which regulator you buy. Blocking or bypass

camboat · Thursday at 8:16 PM

Which one is better for this application?

camboat · Thursday at 11:13 PM

Would this work for the overfull port on the 1409 carb?

Lou C · Friday at 2:15 AM

That carb had the nipple built in so you can use a standard flame arrestor

Switching from Volvo TBI to Carb on a 1996 5.7 GI

Grumpy Vintage Moderator still playing with boats

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Grumpy Vintage Moderator still playing with boats

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Speedway Fuel Pressure Regulator 5-12 psi & Gauge 0-15 psi​

Grumpy Vintage Moderator still playing with boats

Cadet

Cadet

Grumpy Vintage Moderator still playing with boats

Moderator

Grumpy Vintage Moderator still playing with boats

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Attachments

Supreme Mariner

Speedway Fuel Pressure Regulator 5-12 psi & Gauge 0-15 psi