Comp Cam
 

Has anybody used this comp cam in there baot? Part number 11-232-3. It is a cb xm 262h-12. has 262 and 268 at .006 and 218 and 224 at .05 with .505 and .515 lift. I would like to know what kinda results was seen with this cam. It is for a 330 hp 454 mercruiser. I plan on just sticking it in with no major mods. Is in a 230 Conquest Powerquest(power play).

thanks
dan

My cousin has that same hydraulic flat tappet cam on 110* lobes in his upgraded 330hp engines. With some old GM oval port (semi open chambered) heads that he had pocket ported, larger valves, bore notch job, Holley 830 carb, dual plane intakes they made 461hp @5100rpm and 510ft.lbs of torque on the dyno. It's a pretty good cam for a 454! Like Budah said---you should have your heads at least pocket ported. I'm not sure how far in RPMs you can go with cast pistons, but because of the cast pistons he was a little nervous and wanted to make peak power at right around a lower 5000-5200rpm.

I'm doning a valve job to it with just cleaning up the exhaust port (polishing). Everything else is stock. Hoping for about 360 hp out of it and to get 57 mph. I might be asking for to much. Right I got the cam installed. It looks like its 4 degree's retarded. I don't like this, but is this good for top end? I'm going to Re degree it today. My timing chain has 2 degrees advance key on it, may use it

anybody with input before i button this thing up?

thanks

Dan

I went with the 262. I'm putting it back in boat right now. It's set in, just have to hook it up. Wish i would have found this forum sooner. I will probably coming out this winter anyways with my luck. Hope it has some power now, Comprission check out now. I had 2 intake and 4 exshuast valves leaking. thing would only do 48 mph and had to work to get there. From what i heard a 350 ci will do that in this boat. It's is suppose to do 57 mph. After three props, I started looking in the engine. It run nice, but didn't performe. If this thing runs 57 I'm happy.

thanks
dan

I took it out today and all i got out of it was 48 or so and about 4000 rpms. full load and fuel. It is supposed to do 57 mph. It runs just like it did with stock cam and the 4 bad exhaust 2 bad intake hammered out seats and one cracked head. What's going on. I have 1.32 ratio 19 pitch vengeance and 19 pitch mirage plus. 100 to 150 rpms more out of vengeance. not speed difference to speck of. this is not even a 5000 pound boat, can't see pitching it down. What's wrong?????

thanks

dan

danielthelen,

Well, I think I can tell you at least one problem that you are having is this:-----Any time you are expecting to increase HP and performance out of a stock Merc 330hp engine withOUT doing some bowl/porting you are not going to get the increases out of it that you're expecting and you will be disappointed and it sounds like you have just arrived there. Years ago we also tried doing that to a pair of stock Merc 330hp engines by just installing a larger cam and we were very disappointed too---the boat actually went slower. The 330 comes with oval port heads and in their stock, factory condition they are only designed for so much lift and duration that the camshaft will allow through them. Budah tried to tell you in his first post that; "the heads need a port job" and then with another post he asked if you did the heads. I backed it up with what we did to my cousin's oval port heads on his 330's. Again, when it comes to getting more performance out of a 330---the HEADS are what you need to start with FIRST.

I remember another friend of mine bought a brand new 27' Excaliber in 1985. He had a stock 330hp Merc in it. For parts and labor he spent about $2000 on a Holley carb, three angle valve job, installed larger valve springs, machine hardend 10* lock and retainers, new cam and lifters, and new double roller timing chain. He did NOT have the heads bowl/pocket ported---BIG mistake! After all that, his boat lost RPM (can't remember how much) and went 2mph SLOWER---he was NOT happy!!!

What year is your boat? You either have the "peanut port" heads or the perhaps the "049" castings which are better, but either will work fine with porting. You can add larger valves too which will give you another 10-15hp or so, but the port work is where you need to begin----this is what will allow the new larger cam to do its job. The bennefit is that both ported heads with larger cam will enhance each other. Once you have done that, add a good set of free breathing exhausts like Stainless Marine or a GIL and it will really start waking that engine up! :)

The camshaft should have worked great. Check the engines compression, it should be around 155. If not, something is wrong with your combo. The timing should be 34 degrees total @ 3500 rpm.

I am guessing that the camshaft is not set with the intake valve centerline at 108 - 110 degrees ATDC. I prefer 110 degrees for a marine engine. If your compression is really high, 180 or higher, the camshaft timing is wrong (easy to do with an aftermarket multi-keyed lower timing chain sprocket set).

One last thing, the gear ratio in the drive should be 1.50:1. The boat won't pull a 1.36:1 gear, no matter what prop you have on there. Don't ask me why because I don't know, but very few combinations will pull that gear for some reason! You need a 1.50:1 gear ratio with a 21 pitch prop to solve your speed problems.

Sincerely
Dennis Moore

Thanks for the input guys, giving me better idea what's going on. first off. not trying to get allot of power out of it, trying to get a least 330 hp. I don't See how that's happing here. I have talk to a few people over the years and they all said 57 or so with 454, I'm getting 48, big difference, My cam timing was at 112, The cloyes time set with three keys, 0 was 112, + 2 was 114, and - 2 was, 116. I messed around for over two hours on this thing i messed it up, double triple check, had enough of taking the bottom gear off so i put i, at 112. Not Impressed with $90 timing chain. So should I take this back apart and put an off set key in it to get it right?
It was a very hot and humid day yesterday when i took it out and i was loaded. I may try again to day and do some more timing, base time is a 12 right now, but still hot and humid.



thanks
dan

Here's what I done, I have gotten some new used heads off an Chevy truck engine with the same casting number's, (old heads cracked) They had harden seats in them, I used the valve train of the original heads, ground valves and seats and lapped them in and blued for proper seal. I Polished the exhaust ports getting rid of all sharp corners, and guide bosses....etc. Installed comp. 262 286 comp cam. New chain. degree in at 112( not happy about) and have 155 psi compression.

I need to do some more timing checks,

This boat is suppose to do 45 mph with 350 Chevy and 57 mph with 454. I'm getting 48 mph If this is true, that means i'm lacking 60 hp or so. Maybe i have be lied to in the passed of speeds, Maybe i'm chasing a ghost here. But i heard it this from about 6 to 7 different people over the years. The guy i bought the boat from told me it did 57 mph. Even with gps i don't see it. The motor either isn't putting the power out, or something dragging it down. This thing gets out of the hole great, Can't believe how good it takes off, It hits 3500-3700 rpms or so and just about acts like back pressure, It's slow going to 4000. I have captains call, I does make small difference in power. I don't think it wish going to a 17 pitch prop. I'm at 19 right now and the guy I bought if from had a 22 on it. (Dog when i got and and top speed was worse)

Thanks guys, I thank you for any info, I'm trying to give all information and facts i know to figure this thing out.

Dan

I have a friend that had a 330 with a 1.33 alpha drive in a 24' Formula SS. He ran a 17 pitch Mirage +. That boat ran 52mph @ 4500rpm.
Try the smaller prop, you need to see 4600rpm.

That makes sence to me Patrick. If that's all the boat will do, that's what it does. I should repitch it again. I talked to the guy I bought the boat from on the phone, he still says it does 57 at 4300 or so with 22 pitch protester that it come with. I do have the alpha drive, 6 years ago i was looking at buy one of these boats the has the same set up, that guy said 57 mph too. (I bought a 211 Four Winns Liberator instead with 350 mag. Wich out performed this boat.) I looked all spring for this model Power Play (Power Quest) Talked to two other owner's that had this Boat. 56-57 mph. But they were all trying to Sell There Boat!! The guy a bought My 19 Pitch Mirage from sold them boats new, he said it should do high 50's. I feel cheeted with only 48 or even 50, my Liberator with 350 would do 50 mph anyday of week. I bought this boat for an upgrade, not a down grade!

thanks for the input

Dan

Dan, before jumping off the deep end on your engine I'd look seriously at your drive/prop combination. Like Dennis said a 1.32:1 gear ratio is all wrong for that boat. You need a 1.5:1 gear ratio. I would at the very least try another prop. Maybe something like a Ballistic. Alpha's don't usually require the larger diameter of the Mirage props. You probably are 60 HP down, but mostly due to the RPM your're turning. In fact, the cam change would have raised your RPM range a couple of hundred so you really hurt yourself with the engine mods. Drop down in pitch and do some testing. Maybe try to borrow a 1.5:1 drive from someone.

Bob

Dan,

Dennis Moore, bobl and some others bring up a very good point when it comes to having the correct gear set-up in your outdrive-----and though I am NOT an expert, please understand that the engine mods I have described in the previous posts of this thread are mods I have had lots of trial and error experience with since 1982 and seeing others do similar upgrades over the years when it comes to the 330hp engine. Therefore, my suggestions are made to you assuming that you already have the correct gearing in your drive, etc. which sounds like you may not at this time, and I would start there before doing any further engine mods as the others have suggested. It sounds as if your really aren't looking for much more power anyway. The Alfa drive is a bit of a different animal too----one that I know very LITTLE about. I hope all goes well for you. :)

Right now i'm trying to get a 1.50 ratio drive. Like to get a back up anyways. I just talke to a guy from Il. He has a 1987 Power Play 230 conquest just like mine. 454 alhpa 1.32 ratio. running a 19 picth Marige. He gets 57 mph out of his in some chop trimed up. he said it takes some chop to do it, but it will do it. His is all stock. Can't help but think there something wrong with my set up. Chould the thunder volt ingition causing a problem? Any Idea's before i get my new drive?


thanks
dan

Maybe I missed it, but what is the carb and what type of tuning tests have you done other than compresion?


BT :cool:

I've noticed one thing you keep saying.

"this boat will go 45mph with a 350 and is supposed to go 57mph with a 454"

If the 350 is the 260hp version and you have a 454/ 330hp then thats only a 70hp difference. You will never see a 12 mph gain to 57mph with only 70 more HP. It should be more like a 4 mph gain. Especially when you factor in the added weight of the 454.

good point griff! I figured the 70 hp would make more difference. I have only heard one testimony on a 350 in one of these boats. I have heard 6 or 7 on the 454. I also have to take that into account too. I'm feel like i'm not hearing the whole story. Need to go out on one of these boats with same set up to see for myself.

Blue Thunder. Stock Rochester carb. I only did cleaning with a carb kit. No changes to carb as far as jet or rods settings.

I do have mufflers in exhaust tips. The guy i talk to last night didn't have any. Wide open tips 4". I wonder if this could have a factor? they do lock restrictive and are pretty quite when its running. also has Corsair Capitan's call. I think there Cosair tip too.

Certain types of mufflers can be VERY restrictive! My cousin had some of what resembled ice auger / drill bit looking mufflers which are inserted in the rubber hose tailpipes he had and they just killed performance! Since he had his 330hp engines upgraded, he has removed his stock Merc cast iron exhaust manifolds and rubber hose tail pipes and has replaced them with GIL exhaust manifolds and one piece dry tail pipes---now we're talkin'!!! :)

Couple thoughts on your carb. Make sure the air valve on the secondaries is opening properly, make sure throttle cable is opening throttle plates fully, make sure your rebuild kit did not have a .124 needle and seat (my last ones did), should be .135 and do a plug reading after a WOT blast to ensure tan plugs (proper a/f mix). That qjet carb will work well on your engine if all is right.

BT :cool:

I cut out my exhaust mufflers in my tips. Not a fun job and hated to cut a good set of tips up, but it was worth it. I got a good 50 mph out of it and it would rev up to 4500 rpms with trimd up (wouldn't do before) Power don't fall of a 3500 like it did. It was 98 degrees today too, so that's going to hog power and the scummy river water probably don't help. There was an extra set of baffles in the tips that i didn't see.

I also got a new drive ordered with 1.5 ration. I may get this thing to move yet.

thanks
Dan