Question about GM 350 engines
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=5604
Printed Date: May-16-2024 at 1:56am
Topic: Question about GM 350 engines
Posted By: nuttyskier2002
Subject: Question about GM 350 engines
Date Posted: January-25-2007 at 9:25pm
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Anyone out there ever tore down a 350 Chevy marine engine, say right around 92 to 95 year model. Specifically I need to know what type pistons are in these. Mine is carbureted and rated at 265 HP. It's a Mercruiser Magnum series engine. I'd like to know if these pistons are dished and if so what shape and cc volume of dish if any. Thanks! Brian ------------- 95 Malibu Echelon w/Mercruiser 350 Magnum Skier Former boats: 88 Ski Centurion Tru Trac II 59 Chris Craft Capri (woody) |
Replies:
Posted By: eric lavine
Date Posted: January-26-2007 at 9:03am
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would a 2004 help? i have a head off, call me, I'll look in my merc catalog, Eric
877-369-6693 ------------- "the things you own will start to own you" |
Posted By: eric lavine
Date Posted: January-26-2007 at 9:13am
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Nutty, they show from 1975 to 1996 using a dish w 4 valve reliefs, I have alot of low low hour sbc late style, stuff laying around,
if I can help you out let me know Eric, got 2 full rooler cams, one from a 305 and one from a 350, one has 12 hours and the other has 30 hours. ------------- "the things you own will start to own you" |
Posted By: backfoot100
Date Posted: January-26-2007 at 10:22pm
| When I replaced the heads on my '86, the pistons were flat tops with four valve reliefs. |
Posted By: nuttyskier2002
Date Posted: January-26-2007 at 10:42pm
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If you know the spec on any of them I may be interested Eric. Otherwise I'm going to go with a Comp Cams P/N 08-416-8. Specs are 212/218 @ .050 and .488/.495 (In/Ex). A cam with similar specs (except .010 more lift on both In/Ex) equiped with the intake I'm getting on an L31 Vortec 350 dyno'd at just under 375 HP @ 5100 RPM and over 425 ft-lbs of torque at 3900. Torque curve was very flat from 2500 to over 4500 RPM. I don't expect to get quite as good of results but anything close will suit me. ------------- 95 Malibu Echelon w/Mercruiser 350 Magnum Skier Former boats: 88 Ski Centurion Tru Trac II 59 Chris Craft Capri (woody) |
Posted By: TRBenj
Date Posted: January-26-2007 at 11:31pm
Must be gross lift, correct? Which rockers does that a$$ume? ------------- |
nuttyskier2002 wrote:Posted By: nuttyskier2002
Date Posted: January-27-2007 at 3:21am
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That is max lift at the valve with 1.5 rockers. These engines ('87 and up) use hydraulic roller lifters which will tolerate higher lifts and a more aggressive cam profile. ------------- 95 Malibu Echelon w/Mercruiser 350 Magnum Skier Former boats: 88 Ski Centurion Tru Trac II 59 Chris Craft Capri (woody) |
Posted By: nuttyskier2002
Date Posted: January-27-2007 at 3:30am
Do you still have the heads off of this one? My engine is a Gen I. Were they still using Gen I engines in 2004? I know that only Gen III engines are available for automotive/truck use now. I thought it was the same for marine. Someone please correct me if I'm wrong. ------------- 95 Malibu Echelon w/Mercruiser 350 Magnum Skier Former boats: 88 Ski Centurion Tru Trac II 59 Chris Craft Capri (woody) |
Posted By: eric lavine
Date Posted: January-27-2007 at 3:14pm
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Yes I still have the head off, it had not quite 30 hours and dropped a seat, it does still have the cam in and I can figure out the part number and try to get the specs, do you have the old cam out? if so if you know the specs on your came i can measure the lobes and compare the 2 numbers thats if you knew yours lets say had .480 lift and a total lobe measurement and subtract from my total lobe measurement. ------------- "the things you own will start to own you" |
Posted By: eric lavine
Date Posted: January-27-2007 at 3:20pm
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Nutty, i can probably get these indmars for $200.00 (Exhaust manifolds) let me know if your interested. he was at $600.00 but then i explained to him when they were new 20 years ago they got big money for them because they were'nt common. ------------- "the things you own will start to own you" |
Posted By: nuttyskier2002
Date Posted: January-27-2007 at 4:12pm
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Eric, let me call you Monday morning about that engine with the head removed. I don't have mine apart yet, just collecting parts at this point. I plan to use the boat as is this spring/summer then do the project next winter. What advantage would it be to switch to Indmar manifolds? ------------- 95 Malibu Echelon w/Mercruiser 350 Magnum Skier Former boats: 88 Ski Centurion Tru Trac II 59 Chris Craft Capri (woody) |
Posted By: eric lavine
Date Posted: January-27-2007 at 6:47pm
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Well......they would be shiny, there is a picture somewhere on the posts and if your worried about weight these would probably knock 60lbs off from stock
Eric ------------- "the things you own will start to own you" |