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View Full Version : 93 350mag vs std 350



77charger
11-17-2002, 09:36 PM
What is the hp of both motors and what are the internal differnces.Does the mag have forged crank and pistons,4 bolt block,etc.

XTRM22
11-26-2002, 05:54 AM
If memory serves, the std 350 was 230 at the crank with a 2 barrel carb, 260 with 4barrel and manifold, the 350 mag was 275 at the crank with 4 bolt main, roller cam, decent intake manifold and a weber 650 4 barrel, and it had all the good internal parts. I then added carb spacer, better ignition, and imco headers to mine. Then sold the boat bought one with a big block and never looked back! 350 mag is a great motor in a small boat.
Chuck

jjy73
11-26-2002, 09:13 AM
I am looking at a 22' checkmate with an 88 350 mag. and an alpha one. How much power can an alpha take before it blows out? I would like to hit about 70mph with this boat. how much HP would I need?

77charger
11-26-2002, 06:56 PM
Thanks for the info there.Right now i am pushing 57-59 on gps with a 21 eliminator.But the boat comes on plane fast and seems to have good throttle response.
jjY i think the max hp for the aplha to be safe is 300 hp others have gotton away with more but you have to be cautious with the throttle i have heard.To get to 70 you will def need more power than your drive can handle safely.

boatnam2
11-27-2002, 05:43 AM
77 charger i had a 93 ultra with the 350 mag alpha combo.i ran the shit out of that boat and never even changed a spark plug.i bet i was putting 15 to 20 hours on it a week,sometimes more.i would run it morning to midnite at the river non stop.i dont remember how many hours it had on it but it was a lot, 6 years worth. i seen the boat this last year at parker and its still running good.the best prop i found was a 21" 5 blade.the 3 blade sucked and a 4 blade was ok.very good motor pulled my fat ass out on a single no problem.

CV-23
12-06-2002, 07:20 PM
77charger....merCruiser never used a 4 bolt main on any 350 they sold. The 350mag used a taller manifold and they jetted the QJet richer. The 350mag was first offered in '88/'89. All 350's use roller cams from '87 on. I run a 350/260hp Alpha 1 in my '88 Glastron/Carlson CV-23. Its a great engine and very dependable with the original QJet still feeding it. I've run 56mph on GPS with this setup. A guy I know is running a dual turbocharger on his 350 and recorded 70mph/GPS with his CV-23. He also toasted a piston last Summer. Must have been a tad on the lean side....Mike.

HP350SC
12-11-2002, 07:05 PM
CV-23 is right.350 mag. is 2 bolt,cast pistons and crank.I was sure pissed when I found out what was in my boat.I bought it new in '92,paid an extra $2000 over the base 350.Thats a lot of money for a roller cam,tall intake and weber(Carter)(Edelbrock)carb! Right now it has Crower cam and roller rockers,thru-hull exhaust,B&M 144 at 6-7lbs. boost,full MSD ignition,Dart iron eagle 72cc chamber heads w/2.05 intakes and 215cc runners,and Holley carb.It's in a 20'Blue Water open bow v-hull with a bravo drive.Spins a 25 pitch high-5 w/1.50 ratio 5000rpm.Speedo says 72mph.

JAM
12-23-2002, 04:41 AM
I too have a '95 350 Mag (carb) with an Alpha. Does anybody have a good guess what the HP rating might be now that it has an IMCO manifold/exhaust kit?

Ian
12-23-2002, 02:34 PM
Hey Jam did you put the exhaust on, or did you have it installed. My merc has 265hp, i'm not sure if that makes it a mag or standard. With two adult males and about thirty gallons of gas I can do 60 mph with a 23 pitch 3 blade at 4800 rpm's, still comes out of the hole well too. The boat is a 21ft bahner (eliminator mold) with an alpha 1

JAM
12-24-2002, 04:43 AM
My boat is a '95 Hallett 210 (21') which I just bought in September. My best guess is that I'm the third owner and the IMCO exhaust was already installed when I purchased the boat. I'm just trying to learn the ins and outs of the boat, including an estimated HP. I think the 350 MAG w/ carb is rated at 275 HP, I just don't know how much HP the IMCO kit adds. I guess I should call IMCO and ask...
FYI - On my last trip to Havasu, I was able to get 60 mph (indicated, not GPS) with two adults, about 75 gal in the belly tank, and my 4-blade (unk specs) prop installed. I'm anxious to try my 3-blade to see if I can squeeze a few more mph on the top end.