coolhand502

i have had my boat for a year and its fast and no issues, but i think some performance goodies are in order. except for supercharging what are ya'll doin on N/A boats. I would suspect cam and heads, but thats why i'm here to find out

Chris Sunkin

Probably going to need to know what you're looking to upgrade.

If you have Sterling 1200's, you're probably good to go. If you have Merc 330's, you need to start from scratch.

If it's something in between, common upgrades are heads, cams, manifolds/carbs and the typical biggest bang for the buck, exhaust. Each thing you do can cause a ripple effect downstream- big cams need more intake, heads and exhaust. The also strain the bottom end more- sometimes you need stronger components altogether, sometimes just bigger coolers and oiling system mods. That same big cam may necessitate roller rockers & girdles- and probably stronger pushrods. Then you have transmission and outdrive issues- if your Merc 330 is on an Alpha, you have real problems. If the Sterlings are on 6's...

ECeptor

What engine do you have right now and what is your budget?

coolhand502

sorry thats important its 502mag 415hp mpi stock bravo 1 25p prop. the engine is completely stock from flame arrester to exh manifolds. i was thinking exhaust, but wanted to make sure thats a good starting point. also do you have to reflash ecm after exhaust?

ECeptor

Budget?

Exhaust
Cam
Aluminum heads - AFR315's would be nice
Re-program ecm, possibly larger injectors, bigger fuel pump, etc.

coolhand502

i get this right sooner or later bout 6500.00 for now

Chris Sunkin

How many hours on the bottom? If it's in the 300-400 range, adding a bunch of power may drastically shorten it's life.

In that cost range, I'd add a cam, manifold, carb and exhaust. You can probably find a nice set of exhausts on the used market. Cam- probably a Crane 731 or something thereabouts- with Morel hydraulic rollers. A good cleanup on your heads with better valves will give you plenty of flow- aluminum heads will give you a few ponies more but not the best return for your buck.

Save some money for a good engine oil cooler, a drive shower (assuming you have a Bravo) and a new prop to take advantage of your bump in power.

coolhand502

bout 450 hours or so, got a drive shower tell me about oil coolers dont have one of those. i would like to make 80-82 mph by the gps

Chris Sunkin

At 450 hours, I'd want to pull the engine and freshen it up. You're doing a good sized chunk of it anyway- another grand for pistons and a bore is a very worthwhile investment. Have the rods rebuilt with a high-quality rod bolt.

Oil coolers- you'll need a remote adapter to take the oil out of your block and thru the cooler. You might as well add in a remote mount pad for the filter- makes changes so much easier when it's right up top. The oil cooler will go between your water in and the engine and route oil through it. With these mods, you'll need to add an oil temp gauge and a water pressure gauge. No sense smoking your new motor.

Here's all you'll need to know...
http://www.offshoreonly.com/forums/s...3&page=1&pp=20

coolhand502

i have a factory remote oil filter already on the boat. that thread is money, thanks dude. so just build it like you would a street car, heads cam etc. what am i looking for in camshafts?