351 W rebuild CAM selection |
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Evilsizer
Groupie Joined: August-29-2019 Location: Ohio Status: Offline Points: 62 |
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Posted: September-17-2019 at 6:06pm |
Well since I have torn the motor down due to milky oil I'm going to do a complete rebuild. I would like to know if anyone has tried bumping Performance by changing cam size. I see alot of peaple going to the GT 40 heads also. If anyone has suggestions on a good rebuild and what parts to use it would be great. I do have experience in engines but not marine engines.
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JoeinNY
Grand Poobah Joined: October-19-2005 Location: United States Status: Offline Points: 5693 |
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Well that seems like it was premature as it seems the most likely cause of the oil was the exhaust hoses backing up..
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KENO
Grand Poobah Joined: June-06-2004 Location: United States Status: Offline Points: 10650 |
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You forgot the P after GT40 And.................no no one has ever changed their cam looking for more perfromance. You'll be the first, like Neil Armstrong walking on the moon if you do it You should search the site for whatever questions you have, they've pretty much all been asked and answered The easiest way is to use Google and type in correctcraftfan followed by whatever you're searching for like cam or GT40P or 351 rebuild for example. After reading a bunch of that stuff then ask whatever questions you might have. And like Neil may or may not have said on that infamous day back in the summer of 69....."Good luck to you Mr. Gorsky" |
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MrMcD
Grand Poobah Joined: January-28-2014 Location: Folsom, CA Status: Offline Points: 3592 |
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The Factory Camshaft used in the true Marine engines is no slouch.
They are designed like a nice RV Cam to give you more power from idle to 4400 RPM. I like the factory cam, I used one in a friends 68 Mustang because it had the automatic tranny. He was very happy. It had a snappy idle and pulled well for a 302 in a otherwise stock Mustang. OK it did have an Edelbrock Manifold and 625 CFM carb but for him it worked great zero to just under 5,000 RPM. In a boat changing to more cam will probably have tradeoffs and you might not like them. You must have a strong idle to turn a prop at idle. You need great torque to pull the boat up on plane. Now you need a cam that can give you decent top end power. You need a mix of all three. Not saying you can't make your engine stronger but the factory cams were pretty good. The P Heads are a bolt on improvement. PS: You mentioned you are tearing it down. If you have not pulled the heads off yet drain the block using the drain plugs on the sides of the block. You may need to take the plugs out and poke around in the hole with a nail to clean out rust and get it to drain. Now as you pull the heads you won't have water spilling into the cylinders and you can better see any existing damage. Take a lot of pictures of the heads, head gaskets and block. Get both sides of the head gaskets. We may be able to help you spot problems. |
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Evilsizer
Groupie Joined: August-29-2019 Location: Ohio Status: Offline Points: 62 |
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Ok I see that the block is already .030 over. The cylinder heads are a 1987 E7TE PH. Does anyone know about these heads
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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Don't forget your engine is a RR. Cam selection is limited. |
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MrMcD
Grand Poobah Joined: January-28-2014 Location: Folsom, CA Status: Offline Points: 3592 |
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If you see the block is .030 you know it has had one rebuild. These engines in a Boat are known to run 2,000 + hours if maintained. If the cylinder walls look great you might think about putting new gaskets and heads on and closing it up.
Most get rebuilt because someone made a mistake not because they wear out. |
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KENO
Grand Poobah Joined: June-06-2004 Location: United States Status: Offline Points: 10650 |
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Here's an example of what you'll find with a Google search using correctcraftfan E7TE in the link below
Lots of info link If you Google E7TE PH all by itself you 'll find some other info Are you sure it says PH and not PA ? |
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MourningWood
Gold Member Joined: June-13-2014 Location: NorCal Status: Offline Points: 886 |
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As noted above, the engine should be reverse-rotation, which limits cam choices.
Also, as noted, the original cam responds very, very well to better breathing. I went with Edelbrock Performer heads and intake on otherwise 'stock' PCM 351. Holey Moley, '82 2001 just jumps past 50 mph with incredible pull. |
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1994 Ski Nautique "Riot"
1964 Dunphy X-55 "One 'N Dun" 'I measured twice, cut three times, and it's still too short!" |
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Mille1sj
Senior Member Joined: October-01-2007 Location: United States Status: Offline Points: 276 |
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A new prop can get you a lot more pull as well, if that's what you are looking for.
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Mille1sj
Senior Member Joined: October-01-2007 Location: United States Status: Offline Points: 276 |
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I recently finished a complete rebuild of a 302 and sunk a lot of money into it, but my plan is to get another 40 years out of this boat. If you want better performance and plan to hold onto the boat, I say upgrade the cam, intake and heads. I went with the GT40P heads. |
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