Head advice on BBC
#21
#23
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Originally Posted by amer3
cp has them for 1500. just need springs 880 6155 rec Edelbrock i have flow chart on them. had my flow when i got them.i can email it to you.
http://www.cpperformance.com/detail.aspx?ID=4094
http://www.cpperformance.com/detail.aspx?ID=4094
#24
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I have used the edelbrocks on 454's and 509's with good results. On the 454 I had changed from rectangle port closed chambers 105cc to the edelbrocks at 110 cc's so I lowered the cr and still picked up about 200rpm's but I had to increase the timing to 40 with the flattops to get the power due to the change to aluminum heads and 8.9 cr.
#25
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Originally Posted by Pat McPherson
Probably 20-30HP. Not really worth the time and $$.
If you cut the heads to install hardened seats for larger valves, the bowls will likely need to be ported again.
Hey Jeff,
How did you get to 8.5:1 with flat tops? Did you deck the block and mill the heads?
Also are you sure your intake won't seal against rectangular port heads? Some oval port intakes do...
If you cut the heads to install hardened seats for larger valves, the bowls will likely need to be ported again.
Hey Jeff,
How did you get to 8.5:1 with flat tops? Did you deck the block and mill the heads?
Also are you sure your intake won't seal against rectangular port heads? Some oval port intakes do...
I called Holley and the ports could not be ported on my oval port EFI intake to match the Rec ports.
Thanks,
Jeff
#26
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if you weld them up you can probably port them to match. back in the day when the were racing 900cc z1 kawasakis they welded up the intake port to go from a stock 28mm carb to 44mm carbs, there was no material left from the original port after all was said and done cuz the new ports were huge. id lay a gasket from a rect port on the intake and see how much you would have to build it up with alum welding before port matching it! if there a will there's a way. merc doesn't look at it that way, nescessity is the mother of invention
#27
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Thanks for all the great input.
It sounds as though the edelbrock marine ovals are the best bet. If I add them to my setup how much HP, RPMs, and Speed do you guys think this would add to boat?
I have a Bravo 1, 1.5 drive, 25 pitch Lab finished Mirage running 4600 RPM 66 MPH GPS.
Thanks,
Jeff
It sounds as though the edelbrock marine ovals are the best bet. If I add them to my setup how much HP, RPMs, and Speed do you guys think this would add to boat?
I have a Bravo 1, 1.5 drive, 25 pitch Lab finished Mirage running 4600 RPM 66 MPH GPS.
Thanks,
Jeff
#28
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Originally Posted by jeffswav
Thanks for all the great input.
It sounds as though the edelbrock marine ovals are the best bet. If I add them to my setup how much HP, RPMs, and Speed do you guys think this would add to boat?
I have a Bravo 1, 1.5 drive, 25 pitch Lab finished Mirage running 4600 RPM 66 MPH GPS.
Thanks,
Jeff
It sounds as though the edelbrock marine ovals are the best bet. If I add them to my setup how much HP, RPMs, and Speed do you guys think this would add to boat?
I have a Bravo 1, 1.5 drive, 25 pitch Lab finished Mirage running 4600 RPM 66 MPH GPS.
Thanks,
Jeff
I would guess 3 to 5mph increase...
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#29
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Does anyone have the flow numbers for the Edelbrock Marine heads?
Where is the substantiating information that warrants this recommendation?
Anodizing, Inconel and price sure makes them sound attractive but what are you getting beyond that?
Where is the substantiating information that warrants this recommendation?
Anodizing, Inconel and price sure makes them sound attractive but what are you getting beyond that?
#30
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Originally Posted by RLW
Does anyone have the flow numbers for the Edelbrock Marine heads?
Where is the substantiating information that warrants this recommendation?
Anodizing, Inconel and price sure makes them sound attractive but what are you getting beyond that?
Where is the substantiating information that warrants this recommendation?
Anodizing, Inconel and price sure makes them sound attractive but what are you getting beyond that?
I would say that they have to be a hell of a lot better than peanut port heads...
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