Best way to Modify tank for larger pickup?
#1
Best way to Modify tank for larger pickup?
I'm replacing the stock 454 mag with a 530hp 6200rpm 440, and need to know what the best way is to enlarge my fuel pickup? It's an aluminum tank with a screw in 3/8 pickup tube, and I figure I need to step up to at least 1/2" if not 5/8" just for good measure. I can't pull the tank without completely cutting it out and removing the floor. Am I wrong in thinking the only way to do this is to cut a hole in the top of the tank, and bolt down a plate over it with a larger bung welded on? What's the best way of doing this without getting tons of shavings into the tank, or the best way of removing those shavings?
#4
I thought 475-500 was the limit for 3/8? I'm running -8 to everything, and don't want the pickup to be my choke point. The engine has yet to be installed, and I don't have enough room to change anything once it is.
Here are the Engine Specs
440 Cubic Inch BBC 525 hp @ 6000 rpms
Block-
Decked
Align Honed
Bored .060 over
Steam holes drilled
Bore notched
Rotating assembly:
GM Forged Crank, NOS 3.76 Stroke
Eagle H Beam Rods- Resized at Wesco
SRP Forged Domed Pistons
ATI Super Damper
Valve Train:
AFR 265 Oval Port Heads CNC Chambers, inconel Exhaust Valves
Morel Roller Lifters
Scorpion Endurance Marine Rockers
Marine Kinetics Roller Cam
234/240 .63/.61
Fuel System:
Weiand Stealth Intake
Pro Systems HP Holley, 830 CFM
Holley Marine Fuel Pump
Here are the Engine Specs
440 Cubic Inch BBC 525 hp @ 6000 rpms
Block-
Decked
Align Honed
Bored .060 over
Steam holes drilled
Bore notched
Rotating assembly:
GM Forged Crank, NOS 3.76 Stroke
Eagle H Beam Rods- Resized at Wesco
SRP Forged Domed Pistons
ATI Super Damper
Valve Train:
AFR 265 Oval Port Heads CNC Chambers, inconel Exhaust Valves
Morel Roller Lifters
Scorpion Endurance Marine Rockers
Marine Kinetics Roller Cam
234/240 .63/.61
Fuel System:
Weiand Stealth Intake
Pro Systems HP Holley, 830 CFM
Holley Marine Fuel Pump
#5
Offshoreonly Advertiser
Offshoreonly Advertiser
Can you post a photo of the existing pickup and tank bung?
__________________
Marc
www.mercruiserparts.com
www.go-fast.com
www.bammarine.com
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It's not alive -www.BoatStuffExpress.com - temporarily retired
Marc
www.mercruiserparts.com
www.go-fast.com
www.bammarine.com
www.cyborgtransmissions.com
It's not alive -www.BoatStuffExpress.com - temporarily retired
#7
The boat is about an hour away, and I don't know when I'll be able to make it out there, but here is a pic of a very similar pickup tube although on mine the tube isn't welded to the fitting, it looks to be threaded in, and the bung is just welded to the top of the tank.
#10
Platinum Member
Platinum Member
We run the stock 1987 Wellcraft pick-ups with almost 800 HP NA. My guess is they are 3/8" as they are original and the boat had the Merc 370HP new. We also run -6 lines from the tank thru the fuel cut-offs and then to the fuel/water separators. We have -8 SS braided from the F/W separators to the carb...why?...bling. We hold 7lbs of fuel pressure at WOT. Just the facts, not opinion. There are lots of ways to improve preformance in your boat, but larger fuel lines won't add anything but cost. As long as you can hold 6.5 of fuel pressure at the carb fuel rail, you are good to go.