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Camshaft selection

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andyg

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"Hello everyone. I am new to w

"Hello everyone. I am new to working on ford engines specifically but I know my way through the insides of engines. I have a 1977 Searay 24 foot with twin ford 302's on it. Currently under full throttle the engines max out at 4000 rpm's. I am looking to get more power to spin them up to around 4500 and possibly put slightly bigger/ more pitch propellers on it. It has Alpha I drives which max out at 300hp i believe. I have some parts picked out to re-do the top end of the engine but I am not sure on camshaft selection. I am worrying about having the top end power while maintaining idle ability. (Yes I know that it is difficult to have best of both worlds in this way). The engines are 225hp stock and i would guess that I should get them to 275hp each with a better flowing intake, mild port/ polish the ports, and the camshaft. Is this camshaft a good choice?

Also are my heads any good in the first place? The only numbers I can find on them are 14 on the lower left of the head and a 351 inside under the valve cover.
Thanks and any help is appreciated.

http://store.summitracing.com/partdetail.asp?part=SUM%2DK3600&autoview=sku"
 
So you are saying that going w

So you are saying that going with a bigger cam will cause water to back into the cylinders because of the duration? If thats the case I will have to live with it. Hopefully changing intakes and a mild port cleanup will help my higher rpm's? What is your opinion on this? Also thanks for the quick reply.
 
"For us normal boaters ,Yes.To

"For us normal boaters ,Yes.Too much overlap will suck water into the motor,the reason the Big Boy`s aren`t affected is because they use a "dry exaust manifold" such as "Gill Headers".the exaust water goes a lot further before it gets dumped into the exaust system unlike the risers we use."
 
Andy...

What pitch of prop

Andy...

What pitch of prop do you currently have on those motors right now? Too much pitch will cause top end RPM to be lower than desirable. More Hp will try and spin those props faster and get up to operating RPM. You may not have to play with the props after you beef up those Fords.

Wrench
 
"For each number drop in pitch

"For each number drop in pitch your engine will increase 200 RPMs. Use this attached spreadsheet to get the right prop.

<center><table border=1><tr><td>http://www.marineengine.com/discus/icons/mime_msexcel.gif""" align=left alt=""application/vnd.ms-excel"">prop finder
[url=""][b]Copy of Boat_Speed_Finder-79780.xls[/b][/url] (22.5 k)</td></tr></table></center>"
 
"In a 24 footer, I would pull

"In a 24 footer, I would pull the 302's and build a pair of 351's.
Here is the pitch.
The 351 will out torque the 302.
Instead of trying to build killer 302's (hp wise)
build easy going 351's.
I picked up a pair of 351's off EBay for $250 each, including fresh water cooling on both."
 
Thanks for the help on this be

Thanks for the help on this before i did anything that might have bad results. I have thought about building 351's but comparing the amount of work involved I figure I should look into a newer boat. I see many boats with twin 454's that would be great fun for decent prices.
 
Andy:

Are you losing more h

Andy:

Are you losing more hair? Your brain just gained more growth room in the crainium because some hair roots fell out. Good choice! Just teasing you so don't have a BM over it; I am as bald as a cue ball w/a few dust bunnies on the side--darn barber still charges me full price and I use a washcloth for a comb.
 
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