Motor Upgrade Suggestions
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Motor Upgrade Suggestions
Just found this site a few days ago (great site) looking for some advice... I have a Ford 302 marine motor that's designed for 4k max RPM, and max. torque @ 3kRPM (which is the cruising rpm range). I want to get some more power from the motor (my winter project).
Changing cams does not seem to be an option as the cam that's in there seems best for it's purpose (for raw towing power/torque) - even slightly wildier cams have lower lobe sep. angles which can lead to water being sucked into the motor.
Anyway, I want to get some head work done (stock E5AE castings), but I'm not sure what to do. From past posts, it seems that my stock valve size is appropriate and that port velocity is key to torque. Ultimately, I just want better torque at around 3000 RPM. So should I just get a valve job? porting? Swap to GT 40 heads? How about increasing the rockers to 1.7 ratio?
BTW - I'm running a 600 CFM 4bl carb, performer intake, cam specs are 207/221 @ .050, .445/.453 lift, LSA 117/113, stock bottom-end
Thx. in advance..
Changing cams does not seem to be an option as the cam that's in there seems best for it's purpose (for raw towing power/torque) - even slightly wildier cams have lower lobe sep. angles which can lead to water being sucked into the motor.
Anyway, I want to get some head work done (stock E5AE castings), but I'm not sure what to do. From past posts, it seems that my stock valve size is appropriate and that port velocity is key to torque. Ultimately, I just want better torque at around 3000 RPM. So should I just get a valve job? porting? Swap to GT 40 heads? How about increasing the rockers to 1.7 ratio?
BTW - I'm running a 600 CFM 4bl carb, performer intake, cam specs are 207/221 @ .050, .445/.453 lift, LSA 117/113, stock bottom-end
Thx. in advance..
Senior User
Joined: Oct 2004
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From: Colorado
No such thing as an engine designed for 4k max RPM.
You want more power but want to keep most of the components listed.
Your goodies seem perfect for a street engine, the valve size should be upgraded and performance heads with bigger ports always help at any given RPM. You should focus your efforts on flow, stock heads arent good. Port the snot out them or replace them with somthing better and you will have the engine you want.
You want more power but want to keep most of the components listed.
Your goodies seem perfect for a street engine, the valve size should be upgraded and performance heads with bigger ports always help at any given RPM. You should focus your efforts on flow, stock heads arent good. Port the snot out them or replace them with somthing better and you will have the engine you want.
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Joined: Jun 2003
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Your combo sounds good for a nice torquey steet motor. You may want to port some E7's instead of the E5's that you have. The E7's will flow somewhat better given the same amount of work done on each. In either case limit your porting to blending the bowls, slightly increasing the short side radius, and smoothing and port matching. If you increase the port size, velocity and subsequently torque will be lost. Your dual pattern cam favors the exhaust to compensate for poor flow. Unless you enjoy the work, which some of us actually do, check Ebay for some heads that are already done. I see good deals on freshend heads there all the time. Cheers....
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