Formula 271 extension box
Platinum Member
05-01-2004, 06:49 PM
#5
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I assume your talking about an
Imco box.
If your using the exsisting cutout,
you should go with the 3 " raised,
otherwise, you effectively lower the X.
But, you have to raise the motor mounts
Imco box.
If your using the exsisting cutout,
you should go with the 3 " raised,
otherwise, you effectively lower the X.
But, you have to raise the motor mounts
05-03-2004, 04:38 AM
#6
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Location: Toledo, Ohio/Las Vegas, NV
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Originally posted by formulaz583
Now if I could get the thing to stop torking over to the right, so I don't have to drag that tab, I'd be VERY happy.
Now if I could get the thing to stop torking over to the right, so I don't have to drag that tab, I'd be VERY happy.
Last edited by RedDog382; 05-03-2004 at 04:49 AM.
05-03-2004, 09:09 AM
#8
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Originally posted by formulaz583
I knew that post was gonna get read wrong.(because I typed it wrong) They aren't 500 HP's, I meant to say Its a 502 mag that has been rebuilt and dynoed in the 590 HP range with the flame arrestor on it. 612 torque. Now if I could get the thing to stop torking over to the right, so I don't have to drag that tab, I'd be VERY happy.
I knew that post was gonna get read wrong.(because I typed it wrong) They aren't 500 HP's, I meant to say Its a 502 mag that has been rebuilt and dynoed in the 590 HP range with the flame arrestor on it. 612 torque. Now if I could get the thing to stop torking over to the right, so I don't have to drag that tab, I'd be VERY happy.
Are you using the stock efi intake setup or is it carbed? What prop and rpm are you running?
The guy that built my last engine (502 efi) said the stock intake wont make much more than 500 hp, and my extrude honed manifold about 20 more. I was hoping to see 75 with the 600 hp 540 Volvo (Innovation). Does it still lean at speed? My boat kinda levels off up top, still needs the tab at neutral with the port tab up. I just put a set of 23" tabs from Livorsi on it.
The box was just a concideration as I stripped the transom assy off and figured now is the best time if I am going to do it. I really dont think 25-3000.00 is "too much to spend on a 271" if the performance gains were there. All things being equal I will go back with the new hp transom and no box....I'll save the money for a new drive if this one doesnt hold up.
05-03-2004, 09:18 AM
#9
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Originally posted by formulaz583
I knew that post was gonna get read wrong.(because I typed it wrong) They aren't 500 HP's, I meant to say Its a 502 mag that has been rebuilt and dynoed in the 590 HP range with the flame arrestor on it. 612 torque. Now if I could get the thing to stop torking over to the right, so I don't have to drag that tab, I'd be VERY happy.
I knew that post was gonna get read wrong.(because I typed it wrong) They aren't 500 HP's, I meant to say Its a 502 mag that has been rebuilt and dynoed in the 590 HP range with the flame arrestor on it. 612 torque. Now if I could get the thing to stop torking over to the right, so I don't have to drag that tab, I'd be VERY happy.
Are you using the stock efi intake setup or is it carbed? What prop and rpm are you running?
The guy that built my last engine (502 efi) said the stock intake wont make much more than 500 hp, and my extrude honed manifold about 20 more. I was hoping to see 75 with the 600 hp 540 Volvo (Innovation). Does it still lean at speed? My boat kinda levels off up top, still needs the tab at neutral with the port tab up. I just put a set of 23" tabs from Livorsi on it.
The box was just a concideration as I stripped the transom assy off and figured now is the best time if I am going to do it. I really dont think 25-3000.00 is "too much to spend on a 271" if the performance gains were there. All things being equal I will go back with the new hp transom and no box....I'll save the money for a new drive if this one doesnt hold up.
