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.
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
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?
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.
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.
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.
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.
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?
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
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.
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