Howdy y'all - I was basically given a Chevy 6 cylinder the other day, and I was able to track down the numbers only as they applied to marine applications. I'm wondering if this is essentialy ONLY good for a boat, or if it can be converted to my car (50 Chevy)? Is this even possible or is it more trouble than it's worth? Thanks for your time.
In my remember's ,the main thing is the cooling system and how the water is prewarmed by the exhaust manifold. But then again that was always on V-8 stuff so maybe the 6 wouldn't have it.
I always thought this was the case on boats with dual engines? One side turns normally, and the other is set up for reverse rotation to balance out the two ***emblies?
Marine engines usually have br*** fittings and freeze plugs instead of steel to minimize corrosion. Some had extra oil capacity and maybe a windage tray. All electronics were flame proof, alternator, starter and distributor. This was usualy accomplished by making the distributor air tight and the others had spark arresting screens. Camshaft was a grind for cruise at about 3000 rpm in most. Marine cams aren't designed for on/off throttle of street driving. I've never seen a marine only casting number. I have converted a couple of 350s for street use. Even a reverse rotation motor can be done. It's usually a matter of camshaft and water pump swap.
Gentleman - thank you. I guess the big question now is how much trouble it would be worth to get it to work for a car. I've heard good things about a 250, maybe with a full teardown and rebuild with the right parts it would work for my application?
If it has been run with salt water cooling the water jackets may be eroded past the point of saving. If it had a sealed system that's better.
I have one, it is going in a 48 fleetline aerosedan. A good friend has one in his 50-51 4 door. They are very good engines, good cam, good distributor curve, (he has a pertronix in his). Has the nice cast aluminum rocker arm cover too. I would agree to beware of a salt water motor. But-they are 165 horses and I think they are standard rotation. For the 50 chevy swap, my buddy mounted a 3/8-1/2 inch steel plate to the block and then drilled his motomount holes toward the front a couple of inches to clear the steering box. he mounted the p***enger side in the stock location. Fab'ed up the mounts, (I will use some from Speedway), and was good to go. Had to remove part of k member to use a later model 3-speed. I am going with a 2004r, and he is going to change to that too. His car runs 80++ all day out in the long roads in west Texas. Everything but the water temp hooked right up too. This is a good swap. Good luck.
I think the cam needs to be changed even if it's a conventional rotation motor - marine engines idle way down low to allow them to dock without crash'n into the dock if I remember right - been a while.
A couple more things. Usually they have a more durable set of gaskets, primarily oil pan and head gaskets (sometimes are stainless). Though not apparent, water pump most likely has br*** bushing and impeller to resist corrosion. GM-based V8's (are most similar to truck or industrial application motors) with hypereutectic aluminum pistons & low rpm cams. Carbs are special J-throat / coast guard approved. Be careful of two things. 1. Cracked block -- from failure to winterize correctly, sometimes because block drains get clogged with corrosion slag and don't drain --- (a leading reason as to why lots of them become "available" --- not saying that's your situation, though). 2. Corosion. If salt water was circulated through the block and its more than a few years old, then beware. Pull head and inspect for blocked p***ageways. Pull freeze plugs and shine a light in and see if you can chip large chunks of slag away. Block gets too thin too fast, salt + heat = tremendous rate of corrosion. Three weeks ago my boy and I tried to repatriate a pair of 350 chevys (a right and left rotator) for another use. They were used in salt. Chipped multiple pounds of metal out of the jacket through the freeze-out plugs on one of them, using screwdriver and shopvac --- complete fricking waste of time. BTW, a few notes regarding reverse rotators --- depends on manufacturer and year. In general, the reverse motor uses a reverse grind cam, then drives it with a pair of gears, not a timing chain, so it can run the cam + distributor + oil pump in normal direction but the crank backwards. Pistons may show the alignment marks facing rear instead of forward. Starter runs reverse, since flywheel runs reverse. Crankshaft seals, if molded one-piece, might have the little wiping marks in a reverse pattern --- if you use the wrong seal, it can pump oil out at the seal instead of retain it. Hope some of this helps. Good luck! CT
I'm running a Mercruiser 230 in my 64 nova for the past 8 years. not had any problems with it. I just stripped of the marine stuff and switched over off my old block. i was told the marine motors has 10 more hp than the auto versions of the same blocks. Istill have the mercruiser badge on the block , it's a good conversation piece, and split exhaust is a must always. Go for it.
a boat motor of any kind has to stand up to severe use and are stronger than p***. this is a good motor.
Thanks for tips dudes - as soon as I can get a closer look at it (it's currently pinned into place by a bunch of **** in my friends garage that should have been tossed or sold in a yard sale years ago) I'll try pulling the freeze plugs and seeing if it's even worth the time and h***le. Turns out it came as an extra motor when he purchased his lobster boat (obviously salt water, but I don't know if THAT motor was ever exposed to the corrosive stuff). Once I find out more I'll call on some of you guys and your wealth of knowledge to see just what I got my hands on. Thanks again, and you can't beat FREE.
May be easier to pull the water pump and look into it that way. Am told that salt-used marine blocks are not worth trouble to rebuild. If its a freshie, though, totally different story. Also ok if it ran with a closed cooling system set-up instead of drawing sea water. At least you weren't out $300, which is what my kid gave for that pair of boat anchors. Well, we had time together I guess.
My 454 was/is originally a 330 horse Crusader marine engine. One of a pair....Casting number came up as a truck block.Works great so far!
The marine cam is not that bad: rated at 192 degress @.050 lift and 288 degress at .006..... .402 lift on intake and exhaust on 111 with 65 degree overlap.
Mine is cracked-welded up on the outside, coated with por 15 on the inside. Gonna put some super-duper Caterpillar stuff on welds, then see if it works. These engines are supposed to have better timing gears too.
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