Mercruiser 6.2L Info

Tom2395	Anyone have any opinions on the Mercruser 6.2L MPI Horizion. I'm repowering a Luhrs 290 from Marine Power 5.7L's	2002-11-26
vinney	Befor you pull the old engines out. I would add 600 pounds to the boat and check the static line. I had a customer that we had to go the other way pull the big blocks out and install small blocks because we couldnt get the static line correct because of the deck in the boat. If you figure the weight vs. power the small block mpi engine packs quite a puch for the weight. If you go up to high in horse power you may have to change gears and props. If I had my wish I would make the power with small blocks. If you had the room. You could install 350 mpi and if that wasnt enough you could add procharges that would get the job done. The procharger has a new ecm and keeps an eye on fuel pressure so you don't hurt the engines. static line is the key to a repower if is wrong you will be buying another set of engines.	2002-11-26
coupedeville	I think that you'll find that the 6.2 Mercruiser is a small block. I just checked the spec's, and near as I can tell, it's a 5.7 with a half inch longer stroke. Mercruiser lists it under the small block, and lists it at the same weight as the 5.7 MPI Horizon.	2002-11-26
dick	The 6.2 is a small block , just stroked out,so I'm sure you won't have a weight issue.If any thing they might be lighter them your old engines, with the use of composites for some of the engine pieces.	2002-11-26
Walt T	6.2 puts out more torque, but really, the 5.7 can be modified to do the same at less cost. Of course the EFI is always nice.	2002-11-26
Tom2395	Vinney, thanks for the reply. not sure what you mean be checking the static line??? i'm replacing small blocks with a small blocks right??? also going to fuel injection and getting more torque. i'm putting in new trannys and new props. switching to Mercruiser from marine power due to better warranty. marine power excludes water intrusion from day one. btw - the old engines are totally shot 5.7L's. water intrusion due to failed manifold gaskets. started as a loss of RPM which I thought was bad fuel. After swapping out the gas I had a compression check and found 3 dead cyl on the port and 1 on the stb. after the heads were pulled found a valve head snapped off and the cyl's all rusted, amazingly the motor was still running.	2002-11-27
djohns19	Tom, The 6.2's are also "small blocks". I do not know the specific spec's. yet the weight difference should be very small. Your proposed engine supplier should be able to supply that info.-no sweat.	2002-11-27
vinney	I came off a boat today and had big blocks on the brain. How old our your old engines. I think if you do some investagation. Your engine may of failed from something else. Alot of engine fail from water get in them. But its not mean bad manifolds or risers they just get blamed for it. Water will be drawn into the engine at idle if the height of the riser to the water line of the boat is not at a correct height. static line. More engine fail from this that bad manifolds and risers. I call it the silent kill of marine water cooled engines. The new engines require more static line than the older style engines. Preroller cam. If the person doesn't understand static line find someone that does. 6.2 I was thinking big blocks I have been working with this guy all day on his big block boat.sorry. The term we use today is water reversion that when water is pulled into the engine at idle because of the positive pull on the exhaust. The air space riser to water line is the static line the number we use today is 13.5 inches the olds it was 8.5 inches. If there is water in that air space it will be pulled into the engine at idle and take the exhaust valves out or if it goes to long you will be buying engines.	2002-11-27
Capt Ken	Vinney, e mail me, [edited]	2002-11-27
Tom2395	Vinney, thanks! I understand now - hieght of the riser to the water line must = 13.5". i'll check the measurements.	2002-11-27
vinney	Tom If there is one thing I can do for you is bring static line to your attention its very important. If you keep an eye on your static line wether this boat or your next it will save you an engine. Its the dirty little secret that no one talks about. Engine manufactures or boat builders. you can call the engine manufacture and ask them and they will deny it all day long. If you get a guy off the record he will spill the beans. I deal with water reversion every day. There are alot of engine failures because of this that customer eat. I think its wrong. I usally the last guy to see the boat and the damage has been done and then I give them the bad news.	2002-11-27
flashback	Don,t mind vinny, he.s hung up on static lines, every time someone has some water in an engine he.s hollering static line . it can and does happen but it isn't the only thing.........	2002-11-27
vinney	Flashback I see one thing you don't work in this business If you can't add anything get a life. If you are in the business you need to go back to school your way behind the curve. If you want to trade W2 you can e mail me. Oh you I'm self employed are you. No one tells me what to do. If knowledge is related to how much you make I no one thing you knowledge is alot less. I don't see you all much to the sits. Go reads your books and sit down.	2002-11-28
vinney	I have never seen any of your posts that help people. Are you one of these guys who talk with no knowledge. I have one question why. You don't work on an outboard without checking compression. Its the samething for a four-stroke with a water problem. You check static line first so you don't chase your tail. You don't work on this stuff or you would now. I see this a major problem. you dont. That means you don't have your head over engines. I do. Befor you open your mouth think. You need to school up on you knowledge If you can't find the stuff on water reversition I will help you. I own my own business and I'm not buying engines because I don't know what I'm doing.	2002-11-28
flashback	Darn vinny, take it easy man! your kind of touchy today... all I,m saying is tom,s post has nothing to do with water injestion yet you bring up the subject.. and why would you suggest adding 600 lbs to his boat for an engine change when the engine he is upgrading to in no heavier than the existing ones. the last 6 posts I've seen you involved in, you suggest static line failure as if there were millions of boats running around with major design flaws..... I,m sure there are some out there but in most cases reputable manufactures do not design boats that suck up water where its not wanted........ and your right about my posts. If I can,t help, I keep my mouth shut.....Happy thanksgiving......	2002-11-28
Tom2395	Guys, i know water was my problem. i'm just trying to make sure I figure out what the cause is before throwing more cash into it. my new mechanic (he seems very good) tells me it was a failed manifild gasket. I need to go over the whole thing with him as he doesn't know the whole history. this is the second re-power for the boat (the 1st was before I purchased). what can be done if it is a static line problem? the new engines are 35lbs heavier by spec. I know the old engines have a sleeve or extension between the manifolds and riser. I also see on the option list 3" or 6" risers. would using the 6" help? i do most of the basic maintenance but acknowledge I am a novice when it comes to the engine stuff and leave it to the pro's. however I like to be an informed novice so i'm doing my homework here. thanks for all the input.	2002-11-29
Jbeaux2000	Tom...I took this quote exactly from an older posting from vinny... It tells you how you or your shop can test to see how much height you need and therefore if the 6"riser would help. AS you know, the cause can be from many things....but from what I can tell...the first thing should be to test the static line to make sure it is not contributing...then repair(replace in your case)the motor. here it is: Static line The way to determine true static line is to get a 1 inch clear hose about 12 feet long. Put one end over the boat and in the water. then take the other end put some water in it. Take the end that is not in the water make a loop in it with water in the loop. Lower the loop below the engine and keep the end above the engine. So you have a loop with water in it and the end above the engine the level in the hose is the true water line. You make a mark on the engine usally on the exhaust manifold then measure up to the top of the riser this distance is the static line. Static line for a Flat tappet cam shafts was 8 and 3/4 inches. The new roller cam requires 13 and 3/4 inches of static line so that the engine will not ingest water in thru the exhaust at idle. You can take and engine and run it out of a boat with out water to it and put your hand over the exhaust at the riser and feel the positive pull on the exhaust at idle. If there is water present within that 13 and 3/4 it will be pulled into the engine thru the exhaust side. We have made an example to show customers an engine with clear exhaust hose and put water in the hose and you can watch the water being pulled into the engine. If you are milking up the valve covers the water is being pulled in thru the exhaust up the exhaust valve and in to the valve cover. static line if the boats seen the cylinder heads of prematurely check static line. I hate to steal, but I found this to be helpful in your case. Quick way to test/find out if something could have led to the problems that had nothing to do with the original motors. It would give me peace of mind concerning my new motors at the very least. I hope you and/or your mechanic can figure it out. I would agree with V, rule out static line first, then replace motors. I am a novice, but it seems logical. Good Luck	2002-11-29
flashback	Tom, Your last post sheds new light on the subject, if the original engines in the boat had riser extenions, then by all means you need to use them. as Vinny has said, that height is what keeps the water out.. good luck......	2002-11-30
hondon	Jeez guys, we sure got off the subject.That 6.2 is simply a small block bored. This is the first real engine by Mercruiser that we have seen in a long time.Wheight differances should be minimal.	2002-12-07
bond-o	The 6.2l.... a 377cid is stroked, Not bored....4.01" bore X 3.75 stroke...	2002-12-07
Walt T	I would like to interject if I may, the reason there is pull in the exhaust at idle. That is caused by 'cam overlap'. Cam overlap is the period of time the intake and exhaust valves are open at the same time. This creates a scavenging effect in the cylinder to help rid it of outgoing exhaust gases. This is why you cannot put wild automotive cams in marine engines. That 'whump whumpity whump' idle you hear on wild cammed engines WILL suck water in your engine at idle. The reason roller cam engines need more static line is because they have a longer overlap period. You can see this at this link: http://www.boatdoctor.com/walt/camshaft.swf On a boat that has been built with the static line at exactly the minimum distance from the risers, the risk of ingestion becomes greater with every item you store on the boat, especially in the back. I should note that static line should be checked with the total weight that is usually in the boat. If the owner goes boating with his brother 'Bubba' who weighs 400 lbs, it won't do you any good to check static line with just yourself in the boat. It's not that the manufacturers build defective boats, it's just that weight adds up, and in some boats will put a boat in danger of ingestion. Water weight in the hull, transom, floor and stringers will also add up. Static line is easily overlooked since a lot of boat repair joints only work on boats on trailers and are loathe to put a boat in the water for a test run because of the time it takes. The problem is, the static line doesn't get checked until the customer has bought a 2nd or third set of engines.	2002-12-07
magster65	I saw a boat suffer damage from being launched. I guess repeated use at the same (steep) ramp caused the aft to dig in a little deep and it was gulping water... two 5.7's. ouch! That info. about the long duration cam shaft is true as well, the same fella overcammed a few engines before he got the 'through transom' type of exhaust. He's blown up a couple too. All in all I think he's replaced 8 engines. Must be nice to have money to burn. It's a 26 Chris 'offshore' style 5.7 / bravo's. 70 mph	2002-12-07
geriksen	Hey Vinney, you might call it "static water line" so the non-professionals can figure it out without having to go through the whole "you don't know anything" bit every time. If you haven't read the service bulletin "static line" could mean just about anything. just a suggestion	2002-12-09
wrkalot	Starting a new thread with my problem.	2002-12-13

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