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525 EFI Head Flow Numbers

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Old 11-20-2011 | 01:09 PM
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Default 525 EFI Head Flow Numbers

Anyone have flow numbers or a link? I know they are Edelbrock heads but I believe they are made to Merc's specs? Plenty of numbers on Edelbrocks's site but big differences between the heads. Not sure what compares to the 525 heads.
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Old 11-20-2011 | 08:46 PM
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The best answer I got from merc tech support was they were
118-120cc on the combustion chamber, he would not give me
the exact number or any other specs. Also valve stem dia. is 3/8.
I think the edelbrock marine heads are pretty close to the 525 head.
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Old 11-20-2011 | 09:11 PM
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Are you sure there are big differences from the Edelbrock heads ??

I thought they were very close. I have Edelbrock rect ports on my engines and thank god I had them flowed before I put them on. Had to do lots of porting on the exhaust side to get proper intake to exhaust flow ratio. I bought them for 3 reasons. 1. Wanted aluminum heads but on a budget. 2. did not want to deal with the angle changes of the other aftermarket heads. 3. They are exact replacements for stock steel heads as far as mounting points, bolt holes and sizes etc.

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Old 11-21-2011 | 10:57 AM
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Originally Posted by rw40426
I think the edelbrock marine heads are pretty close to the 525 head.
That's what I was thinking. Using those numbers on Desktop Dyno 2000 I get 570hp @ 6000 rpm so probably close. If I lower the exhaust side number about 10% I get 550hp @ 5500 which is damn close.
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Old 11-21-2011 | 10:59 AM
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Originally Posted by Smitty
Are you sure there are big differences from the Edelbrock heads ??

I thought they were very close. I have Edelbrock rect ports on my engines and thank god I had them flowed before I put them on. Had to do lots of porting on the exhaust side to get proper intake to exhaust flow ratio. I bought them for 3 reasons. 1. Wanted aluminum heads but on a budget. 2. did not want to deal with the angle changes of the other aftermarket heads. 3. They are exact replacements for stock steel heads as far as mounting points, bolt holes and sizes etc.

Smitty
I just glanced but the difference between the Performer and Victor(I believe) was quite a bit. I think the Victors are much larger heads though, so as rw stated they are probably close to the Edelbrock Performer Marine Heads.
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Old 11-21-2011 | 12:39 PM
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Go with AFR's you will NOT be sorry!!!!
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Old 11-21-2011 | 01:30 PM
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Originally Posted by offshore420
Go with AFR's you will NOT be sorry!!!!
Not going with new heads. I was using a desktop dyno program and wanted to see how accurate it was.

I'm getting my heads ported and I'm hoping they flow similar to the 525 heads.
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Old 11-21-2011 | 01:39 PM
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Originally Posted by onesickpantera
Not going with new heads. I was using a desktop dyno program and wanted to see how accurate it was.

I'm getting my heads ported and I'm hoping they flow similar to the 525 heads.
JV is the best! Should see some good #'s
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Old 11-21-2011 | 02:23 PM
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Originally Posted by onesickpantera
Not going with new heads. I was using a desktop dyno program and wanted to see how accurate it was.

I'm getting my heads ported and I'm hoping they flow similar to the 525 heads.
OK, I see.

I can tell you this, from my experience with Desk top dyno, plugging in all the numbers and running a hundred diff. combos, then picking the combo and putting it to the test on a real dyno, it was a total waist of time. DD number's weren't even in the same ball park as the actual dyno runs.
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Old 11-21-2011 | 03:17 PM
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Originally Posted by POWERPLAY J
JV is the best! Should see some good #'s
Yeah he has a great reputation and seems to be a good guy. I'm not looking for much but I figured I might as well get them ported while the heads are off.

Last edited by onesickpantera; 11-21-2011 at 03:38 PM.
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