Comp Cam question
 

I was thinking about the comp cams xtreme energy 270/276 or 276/282 hydraulic roller cam. Has anyone used either one of these? If so what are the docking manners like. Staying with the stock bore 350cu engine. Going mostly dry with the exhaust. Water will enter at the tips.

I'm not familiar with the two you have listed...I have twin 355's in my 255 Formula and I'm running a Comp XM264/270 Hydraulic Roller. These engines idle at 700 and drop to 650 in gear. The "dock manners" are great. great!! You have to open the hatch to hear any "Cam" sound at all...thru hub stock exhaust. Here's the link to mine http://www.compcams.com/Company/CC/c...?csid=168&sb=2.

I'm still tuning mine in but these are sweet cams. I'm running their whole kit...had to work the spring pockets a little to take the big springs and I have Comps "Scorpion" Needle Bearing Rockers....very smooth...very quiet...and great power to 5500 plus. I'm running Bravo I's with 1.5 gears and Mirage 23" props. My boat is a close match to yours and performs very well.

I recommend the Comp XM Roller Series.

I had a 383 with trick flow heads and a Performer RPM intake and the XM276HR, I made 437hp@5400RPM and 479 lbs/ft @ 4100. It had a noticeable idle over stock, but still went into gear fine. You will be just fine keeping it dry to the tips. My water entered right after the short EMI riser and went into a S-pipe and had no problems, but I had a few more cubes. I have since gone to a bigger cam and have this one wrapped in newspaper waiting for another motor. Let me know if you want to save over paying full price. $150 shipped sounds fair to me. PM me if you are interested.

I should also note that it is a step nose for an 87 and later OEM block.

Nice, thanks for the feedback. andy

What heads are you going to run and what other modifications are you going to do?

Oh I now see you have twins. Well you could at least save on half your cams.

I am running the comp 262 Xtreme Marine flat cam on my Vortec 355. wish I would have went bigger.

Vortec heads modified for the larger lift and port the exhaust side mainly with full roller rocker setup.

Not running a Comp cams but a Crower hyd roller with 221/230 @.050 thru GLM manifolds, stock elbow/risers and thru hull. Bark at light off is impressive, but is tamed a bit once it stabilizes (EFI motor). Noticeable idle, no reversion noted, docking is fine. I run about 700 rpm idle once warmed up. Cam has a 114 LSA.

That spec is almost the same. What did you do with the ecm? Did you try it without making fuel changes? Oh yeah, what year is yours? Mine are 1998 or 1999 engines. Still need to confirm that.

Cam is 00483LM Crower 221/230 @.050 and .525"/.545" on 1.5 rocker, 114 LSA. Kept the ECM (MEFI 1). Motor was a 95 Mag EFI/MP motor with non-vortec heads. Kept non-vortec style to utilize the existing EFI system.

Major changes from the stock Merc 350 Mag EFI/MP configuration were: Dart heads, bigger exhaust valve size, bigger cam, tiny bit more compression (.1 pt), stroker crank. Motor started and ran on a test stand with the major mods on the stock tune. Actually ran very well. I set base timing then installed bigger injectors (stock were 24 lb, new injectors were 42 lb) and it ran with the stock tune as well but was pig rich as expected when you nearly double the injector size. I then trimmed out the fuel and it runs great. Real happy with how it performs. Made minor changes to timing table.

Very interesting. What did you use to get into the computer? I was thinking on investing in the MEFIBurn system but really would like to see it in action in person first. Not sure if anyone around Wisconsin has the system for me to witness yet. My application / project shouldn't require much either. Probably can stay with the same injectors too.

Thanks again for the feedback might pick your brain again over winter. Andy

I used MEFI Burn. I'd be happy to share my experiences with you. PM me for more info.