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350hp 350

Old 11-29-2020, 08:55 PM
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Default 350hp 350

I donít know if this is the right place to post or not but here goes.

i have a 2001 Crownline 225br with a 250hp 5.7 vortec engine. 2 barrel carb Alpha 1 1.5 ratio with a 17p merc racing rev4. Boat weighs about 4000 lbs. with straight through hull exhaust. tops out at 45 mph. I want 55-60. I donít want a 383 stroker setup.

Iím thinking about doing a cam swap to a 270/276 marine comp cam, going to a thinner head gasket to raise compression a little, Edelbrock rpm air gap intake and a 650 4 barrel (1409?) carb.

Will this setup push me up to the 350-375 hp range.



Last edited by Dylon333; 11-29-2020 at 09:09 PM.
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Old 11-29-2020, 09:03 PM
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I am not close to an engine guy but just a cam wont get you a 100 hp gain imo for sure !!!
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Old 11-29-2020, 09:08 PM
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Well thatís why Iím here to find is peoples opinions on what I will gain. Or what itíll take to get me to the 350 hp range. Iím pretty sure I can go to a 4 barrel and get to 260, and a very basic cam and get 300. But what do I need to make my 250 5.7 a healthy 350hp?
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Old 11-29-2020, 09:41 PM
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To get a hundred HP gain your gonna need a top end minimum. New heads, intake, roller camshaft, at the minimum. The trick is going to be keeping it making enough torque to get the boat moving and the peak HP within the allowable RPM range of your short block. Call a few companies like E'brock, Trick Flow, etc and see what they have to say.

Last edited by Smitty275; 11-29-2020 at 09:46 PM.
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Old 11-29-2020, 10:05 PM
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From my understanding, it is already a roller cam motor, and I thought the 096 heads were supposed to be good?
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Old 11-30-2020, 01:35 AM
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I doubt a 100hp will gain you 10-15 mph. More like 6-10mph if you are lucky.

Any decent cam will probably require new exhaust with long risers
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Old 11-30-2020, 01:36 AM
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Your engine has Vortec heads, so yeh, youíll be right there for hp.

4bbl carb + intake will put you near /at 300hp.

Those doubting a near 100hp increase maybe didnít notice he has 2bbl 250 hp engine and adding a 4bbl carb and intake too ?

Iím not sure going to the thin head gaskets will be worth it. Personally Iíd stay with normal felproís w/stainless core.

Last edited by SB; 11-30-2020 at 01:41 AM.
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Old 11-30-2020, 07:14 AM
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stock vortec 350 with a good intake and a 4 barrel is around 325 those engines love to rev its very good right out of the box
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Old 11-30-2020, 07:25 AM
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When you say good intake and carb is the edelbrock rpm air gap good? What about the 1409 carb? Well this get me where Iím wanting to be? Paired with that 270 cam? Do you think that 270 cam will give me any chop at idle?
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Old 12-01-2020, 12:22 AM
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RPM air gap, roller rockers, and I used the 218 / 224* @ .050 cam and I think you can get very close to your 350 HP. I added Vortec heads because mine did not have them and gained 8 - 9 mph and ran 60 - 61 mph.
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