Which GM block is 1988 5.7 Cobra (Four Winns 200)

Afternoon Gents and others...<br /><br />Can anyone tell me if the engine in a 1988 Four Winns 200 5.7 Cobra has a one piece rear main seal or not. Also if the cam is a roller or flat tappet.<br /><br />I believe this boat, even though it last came from north Texas has seen a lot of salt, plus, though it runs good, it has "way" too much blow by for me...So I'm considering an engine change. I can get GM crate engines in the money and don't want to get into any flywheel problems.......Or any other problems if anyone has any tips. (Assuming that using the marine carb, alternator and starter..is a given)<br /><br />I believe that the truck engines have a similar cam if my information is close to right.<br /><br /> Also what should be done in regard to the outdrive as far as checking for salt damage...I have zero experience with anything but fresh water boats.<br /><br /><br />Thanks..Stan

Re: Which GM block is 1988 5.7 Cobra (Four Winns 200)

Hey Stan,<br />I can't help you with the OMC,+ Saltwater part of the equation..........<br />But,<br />You're right about the GM crate engines......<br />A Long Block for a 1988 Truck is about the Best drop-in motor you'll find.......<br />Pop in a set of Brass Core Plugs,+ All the accessories from your OMC....<br /><br />You'll be Boating in Style in No Time........

Re: Which GM block is 1988 5.7 Cobra (Four Winns 200)

Evidently they think that in '88 it could have been either. The flywheel bolt pattern is different.

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Ayuh, Only 2 ways I know of to be Sure about the crank seal.......<br /><br />1 is to Look.......... <br /><br />The other is to check the Block #s.........<br />There's the Casting #, Just behind the Port Head, on the Top-side of the bellhousing flange..........<br />There's a Stamping # on the front edge of the Deck, right at the Front of the Starboard-side Head.........<br />And,<br />There Should be a Tag rivited to the Block somewhere around the Starter, with the OMC #s..........<br /><br />I'm pretty sure your motor is a Flat Tappet motor........<br />Your choice of Cam will be a Personal Thing......<br />The 1 in the Truck motor will be about Perfect, for a Boat.......<br />But, Hey, as long as you don't get Tooo Crazy,<br />Why Not......... It's Only Money.........

Re: Which GM block is 1988 5.7 Cobra (Four Winns 200)

Stan,<br />If you're using your back Button,<br />You've got to Refresh to see your post......

Re: Which GM block is 1988 5.7 Cobra (Four Winns 200)

10-4 and hello again Bondo...<br /><br />My parts department wants to know if the engine being replaced is a 2 piece rear main, or a one piece. Evidently they think that in '88 it could have been either. The flywheel bolt pattern is different. <br /><br />I was just curious about the type of cam for my own edification..it's possible that I might use a different cam, haven't decided yet. I might sacrifice a little low end for a little more performance..raise the max rpm threshhold a tad . Maybe not too. I had a Baja with a good set of heads and a 260 Comp Cam ( maybe 268..I can't remember for sure) that was a good combination years back.<br /><br />Thanks ...Stan

Re: Which GM block is 1988 5.7 Cobra (Four Winns 200)

10-4 and hello again Bondo...<br /><br />My parts department wants to know if the engine being replaced is a 2 piece rear main, or a one piece. Evidently they think that in '88 it could have been either. The flywheel bolt pattern is different. <br /><br />I was just curious about the type of cam for my own edification..it's possible that I might use a different cam, haven't decided yet. I might sacrifice a little low end for a little more performance..raise the max rpm threshhold a tad . Maybe not too. I had a Baja with a good set of heads and a 260 Comp Cam ( maybe 268..I can't remember for sure) that was a good combination years back.<br /><br />Thanks ...Stan

Re: Which GM block is 1988 5.7 Cobra (Four Winns 200)

10-4 and hello again Bondo...<br /><br />My parts department wants to know if the engine being replaced is a 2 piece rear main, or a one piece. Evidently they think that in '88 it could have been either. The flywheel bolt pattern is different. <br /><br />I was just curious about the type of cam for my own edification..it's possible that I might use a different cam, haven't decided yet. I might sacrifice a little low end for a little more performance..raise the max rpm threshhold a tad . Maybe not too. I had a Baja with a good set of heads and a 260 Comp Cam ( maybe 268..I can't remember for sure) that was a good combination years back.<br /><br />Thanks ...Stan

Re: Which GM block is 1988 5.7 Cobra (Four Winns 200)

10-4 and hello again Bondo...<br /><br />My parts department wants to know if the engine being replaced is a 2 piece rear main, or a one piece. Evidently they think that in '88 it could have been either. The flywheel bolt pattern is different. <br /><br />I was just curious about the type of cam for my own edification..it's possible that I might use a different cam, haven't decided yet. I might sacrifice a little low end for a little more performance..raise the max rpm threshhold a tad . Maybe not too. I had a Baja with a good set of heads and a 260 Comp Cam ( maybe 268..I can't remember for sure) that was a good combination years back.<br /><br />Thanks ...Stan

Re: Which GM block is 1988 5.7 Cobra (Four Winns 200)

OK Stan, according to my 88 OMC Shop manual, both the small block V-8 and V6 used the one piece rear main and flat tappets. But as Bondo says, good idea to check the serial # to make sure you really have an 88 engine in the 88 boat, sometimes you could have and engine/drive from the year before....<br />BTW, the engine # s OMC used for the V-6/V-8s (GM) were on a sticker on the thermo housing..if you take that # to an Evinrude/Johnson dealer, they should be able to look up the year of the motor for you.

Re: Which GM block is 1988 5.7 Cobra (Four Winns 200)

Thank you gentlemen..<br /><br />I will check the block numbers...I have taken the boat to it's winter home. I have an old service station building we will keep it in about 90 miles away close to the lake we frequent.<br /><br />I also think that it is a one piece rear main with flat tappets. Just wanted to have other opinions, so I could get a little insight on engine cost. The variance is considerable from the 1 piece to the 2 piece main.<br /><br />I have a good older 400 small block that I could stroke (or not) but the flywheel would be different.<br /><br />I also have a perfect old flywheel(heavy,thick)and coupler for the 2 piece rear main engines out of a 1979 260 Mercruiser.<br /><br />Does anyone know if that would work with the 5.7 '88 Cobra drive?? I think the drives are similar...u-joints and gimble bearings are the same I think (maybe the flywheels?). I would probably build the older 400 block if I didn't have to buy another flywheel, etc.<br /><br />Thanks to all ...Stan

Re: Which GM block is 1988 5.7 Cobra (Four Winns 200)

stan dose your curent 1988 motor have center bolt valve covers or the old style 4 bolt on out side of the valve covers