Merc 454
02-16-2011 | 02:06 PM
#11
Thread Starter
Registered
Joined: Aug 2010
Posts: 108
Likes: 0
From: Rescue, VA
You ain't kiddin...
You get to a point with these 330s where you're better off just buying a 370-500hp Merc motor used, and doing a refresh on it before you put it in. You can pick up 50ish Hp and 5ish mph out of putting new heads, intakes, carbs, 1.7 roller rockers, exh., etc. on them, but you still have a tired cast internal motor, and to make any real power you have to change the cams anyhow. If you're pulling the motors and changing the cams, you're better off doing a motor swap.
The single biggest power adder, if you want to keep it cheap, is changing the heads. The peanut port heads are the biggest power drain on that motor. You could upgrade the heads, intake, carb for less than the cost of the Stainless Marine exh. manifolds. If you're not willing to make the commitment to change the motor completely you'll be better off swapping everything but the exh. If you want to later swap the motor the Stainless Marine exh. would likely be the only thing you want to use off of your old motor (aside from accessories). You just have to figure out how far you want to take it.
You get to a point with these 330s where you're better off just buying a 370-500hp Merc motor used, and doing a refresh on it before you put it in. You can pick up 50ish Hp and 5ish mph out of putting new heads, intakes, carbs, 1.7 roller rockers, exh., etc. on them, but you still have a tired cast internal motor, and to make any real power you have to change the cams anyhow. If you're pulling the motors and changing the cams, you're better off doing a motor swap.
The single biggest power adder, if you want to keep it cheap, is changing the heads. The peanut port heads are the biggest power drain on that motor. You could upgrade the heads, intake, carb for less than the cost of the Stainless Marine exh. manifolds. If you're not willing to make the commitment to change the motor completely you'll be better off swapping everything but the exh. If you want to later swap the motor the Stainless Marine exh. would likely be the only thing you want to use off of your old motor (aside from accessories). You just have to figure out how far you want to take it.
02-16-2011 | 05:10 PM
#12
Registered
Joined: Jul 2010
Posts: 449
Likes: 0
From: Deerfield BCH, FL
Im beating my head on the wall now waiting for my 454 to be back from the machine shop, ill let you know what happ with new cam, intake, .040 pistons, and 781 heads, i already had 750 holly ssmarine exhause and edlebok intake...
02-16-2011 | 05:18 PM
#13
Thread Starter
Registered
Joined: Aug 2010
Posts: 108
Likes: 0
From: Rescue, VA
02-16-2011 | 08:21 PM
#14
Registered
Joined: Jul 2009
Posts: 1,569
Likes: 2
From: Grosse Pointe Farms, MI
I wouldn't bother with getting an intake for those peanut port heads if you're going to get a new motor later. If you want it to look pretty for a while by painting the new intake a diff color, or if you just want to pull everything and put it back together new that's one thing. However, if you're looking for a performance gain you probably won't notice much by just putting a new intake on it.
The Stainless Marine Exh. will probably net you 15-20 hp at best (which is 1-2mph), but don't worry about that. It will really help once you put a 502 between your new manifolds.
The Stainless Marine Exh. will probably net you 15-20 hp at best (which is 1-2mph), but don't worry about that. It will really help once you put a 502 between your new manifolds.
02-16-2011 | 09:34 PM
#15
Registered
Joined: Jan 2011
Posts: 60
Likes: 0
Alot of mention of peanut port heads, is this definately what he has? I would suggest pulling a valve cover and getting casting numbers to see which heads you have. If they are large ovals, you would have alot of potential with your motor, and depending on your application, possibly even better off than with rectangle port heads.
02-21-2011 | 08:09 PM
#16
Registered
Joined: Jul 2010
Posts: 449
Likes: 0
From: Deerfield BCH, FL
with 2 weak cylinders i was running 58 with a 21 pitch prop, still waiting on engine back and bob to build the cam every one seems to be in slow motion even considering were in a recession here in s fl
