..as if I don't have enough projects on the go. My uncle (the one that gave me the speed boat) calls me up. He's stuck in the middle of Halifax Harbour, his boat having just died. I obviously couldn't offer much help (what with living 60 miles from the harbour) so he had to call the coast guard to tow him as, and then he brought the boat here.
Turns out he overheated the engine and ignored the red light on the dash. He kept going until the engine stopped. The engine, by the way, is a small block Chevy (I'm thinking 305). I pulled the plugs and ran a compression check. All cylinders are between 40-60 PSI except one, which is at 120. My father seems to think the timing chain slipped because it happened to his '78 Ramcharger 20+ years ago. That might explain low compression across the board, but it wouldn't explain the high compression in one cylinder. I'm leaning more toward the rings having gotten hot enough that they'd lost their tension - either that or the oil on the cylinder walls baked off and the rings gouged 'em all to hell. I'll try putting some oil in the cylinders later on once the rain stops, to see if that brings it up any (which would verify rings). Regardless, it looks as though the engine's gotta come out (you should see where the is hidden).
So, anyway, yeah. I've got yet another project. Anyone know anything about GM marine engines? Are they the same as car engines, or at least close enough that I could get an old truck or Caprice for the engine and swap it in? I do know that marine engines are hella expensive...
So this is what I've got to look at in my driveway now. The neighbours must think I'm crazy. I might just hang a sign on it saying "No, it isn't mine":
yeah man GM motors are the same. it's propbly got special type headers/manifolds though for the water. and such. but nothing you cant just swap over to a new engine. so yeah you can pick any car/truck engine for it. it's more likly a 350 verry common engine for a boat. my bro did a rebuild on one a few years ago.
It may have a different crank. I know the industrial 305/350 from combines had a differnt crank since it sits in the tractor backward.
Don't marine engines rotate in the opposite direction of a car engine? I swear I heard that they did.
Yes, most of them do. Plus they have slightly differnt cams that make more HP and TQ at lower RPMs and differnt water pumps also.
I wouldn't think they would have a camshaft optimized for low rpm. Most boats cruise at 3000+ rpm. The engines are designed for mid to high rpm cruising.
Carmen, externally they would be the same, I've never heard of the car transplanted engine rotating in reverse. The one thing you do have to worry about though.. Is it a fresh water engine or a salt water engine? The salt water engines require special gaskets so as not to deteriorate. Most boats do not have a closed cooling system, they suck water out of the lake/sea they are in and run it through the engine.
It all depends on the boat. The boat he has doesn't look like a speed boat to me. That is why I made the comment that is it more than likely cammed for lower RPM.
They list a lot of options for the chevy marine engines.
http://www.theautochannel.com/autoparts/marine-enginespartschevy/index.html
It is a salt water engine. I wouldn't even mind getting a car engine and resealing it (new head/intake gaskets) if it'd save some $$.
As for reverse rotation: I would think that would be a simple matter of swapping the cam from the boat engine into the car engine and swapping plug wires around.
Not all marine engines are reverse rotation. A friend of mine has a 31-footer with two 350's. One is standard rotation, the other is reverse. He ran into a huge problem when his yacht club had a poker rally and both of his engines died. Some genius aboard the boat decided to swap the starters between the two engines because neither would turn over. He swapped the starters and still nothing. Then somebody found a blown fuse. They replaced the fuse and cranked the engines....
...with the wrong starters on them. This caused both engines to rotate in the opposite directions they were designed to. That caused the exhaust manifolds to become intakes and the intakes to become exhaust - not normally a serious problem as it will simply result in the engine not starting. When the exhaust outlets are under water it's a different story entirely. Within a split second both engines were hyrolocked with salt water. He had the boat towed as and left it for a few days before coming into my work and asking me what I thought. I told him to remove all spark plugs, swap the starters proper, and crank the salt water out, add some oil to the spark plug holes, crank it some more, and to change the oil, then run the engine until hot, then change the oil again. He did all of that and managed to save the engines, though one is burning a bit of oil now. That could have been a very, very expensive mistake.
http://www.epi-eng.com/ET-RevRot.htm
my first thought if that thing showed up in my yard would be,,,,,,,
humm,, wonder if my Pig Pole on the tractor could be used as a cherry picker. Id assume the motor is midship or just slighly aft but most all exterior and decking would have to come off. Need help?
seriously, have you decided what your gonna use to pull it?
a good couple trees side by side with a beam and chain hoist?
man,, just looking at the whole situation makes me feel depressed. Id hate to have to pull that thing.
don't marine engines use different distributors and other miscellaneous electronics?
Yes, it's got a weird distributor on it - points type, with some sort of provision to allow the stern drive to shift properly. The very first thought I had was "Gotta drop an HEI in there" but apparently it can't be done. Actually I had wanted to go with a TPI 305 (they're a dime a dozen) and pick up some reliability and fuel economy (I'd be worried that a TPI 350 would overpower and break the stern drive). I am gonna look further into exactly what makes that distributor special, 'cuz if I can adapt an HEI I'm going to.
It is, BTW, a 305. I found a decal on the stern drive that says "5.0 liter". I think it is a standard rotation engine (with only one engine there would be no reason to add the extra cost of reverse rotation), but I'll be able to tell for sure by cranking it. When running the compression check it did not even occur to me to watch which direction everything was turning.
If I do replace it with a car engine I will be swapping the electronics, manifolds (yes, they're wet), and accessory drives - I'd basically only be using the basic long block.
Scott: Getting the engine out is something I haven't figured out yet. Obviously my cherry picker won't do it. I have a chain hoist in the ceiling of the garage, but the boat won't fit inside. I may have to make up a tripod and mount the chain hoist on it, or I may tow the boat to a friend's house and have him pull it out with his front-end-loader. The engine is aft, in its own little room. Top and sides are easy to get at, but front, back and bottom look like they're almost impossible. Changing a cam would definitely require pulling the engine.
*edit* so the rain stopped for a moment. I went out and checked the rotation and took a pic. The belt is turning in the direction shown by the arrow. Been a long time since I've worked on a SBC, but I'm pretty sure I remember them turning in that direction...
Note the amount of space between the water pump pulley and the bulkhead...
carm i think the 350 would be of a beter bennifit for you as it can produce more power over a 305 stock for stock. i'll have to talk to my brother and see what his buddies in the boat club do. if they can run the type of dizzy you want or the efi. but most of the guys run 4 barrel. quadra jets. or modified hollyes. with the spouts that poor the fuel down the bowls. my brother also has a camshaft out of the chevy motor he built a few years back i'll ask him for the grind number and what company it's from so you can get an idea of what should and shouldnt be needed.
put a 350 in it
dont worry about the stern drive
skip the 350 and go 454 :hick:
305 heads plus 350 block equals 350HO
check it out.
i put myself in your shoes and i think i found my solution to the cherry picker if i lived there.
I would get up in the attic of that shop there in the background and s up a hardwood 4''x8''x16' beam up near the gable of the rafters.
Id mount it so that 10' ws inside and 6' stuck out. It would make a great tool for future engine pulls and you would have vertually no limit on how tall things are anymore. Youd just want to oil base paint it so it lasts a long time and having hardwood is a must.
Only you know how the upper rafter part of that shop is but your an engineer type,, you can figure out lumber bracing and all the dynamics of making a decent lift point using that bulding.
The bonus is that this puts the boat near all our tools. I know you gotta have some sort of beam lying around or at a local sawmill.
i put a circle on your pic where im talking about. The engine really aint all that much weight , the trick is bracing and using your already vertically and inclined rafters and the horizontal 2x strap which are already opposing eachother where they meet at the top. Thats called a triangle,, and they are strong.
so what if you got something sticking out of the shop from now on,, put a canadian flag up on it. im sure no ones gonna bump their head on it either. All i can say is you better get on her before it gets too cold.
heres how id do the beam,, sorry for the sloppy drawing.
i didnt include any gables inbetween the first and last one cause they can be transitioned from the upward force to the downward force as illustrated. The blue and red shows new lumber.
he could but then the special manifolds wont work for the big block and those things arent cheep. also it may not fit . thats why small block chevys get used cheep and replaced ez. bc im sure if he checked the oil in that thing it's blacker than black thats a problem with boats it's tough to change the oil in them.
are you sure its a points distributor? That engine is a centerbolt bolt valve cover engine so 87 and newer. And none of the centerbolt engines used the big HEI, they had a small cap HEI with a remote mounted coil. But its a boat. More than likely that is a roller engine..
The boat is newer than I thought it was (apparently it's early 90's, I was thinking early 80's) but it's definitely a points-style distributor. You can see the old-style "canister" coil atop the engine, next to the port-side manifold. The guy at the marine shop told my uncle he couldn't put an HEI in because it would screw up the shift solenoids. Personally, I don't believe that. I don't know anything at all about stern drives and very little about marine engines (but I do know car engines, which a 305 first and foremost is, and an engine's an engine as far as basic operation goes anyway) but I do know electronics, and I'd bet that if the shift solenoids are relying on any signal from the points at all it'd be a simple tach signal. I fully intend on looking into it, because I'd much rather have an electronic distributor in there (and it isn't even my frickin' boat!)
Scott: That beam/arm coming out of the garage is a fine idea, but it'd be a bigger project than actually swapping the boat engine, and another project is exactly what I don't need :hick: I've decided a pair of tripods (one on each side of the boat) and a beam between them with a chain lift hanging from it should suffice...
Cougarcoupe88: Good point with the manifolds AND with the "not fitting" - look at that space between the water pump pulley and the bulkhead, there ain't no way a big block is gonna fit in that hole. Can't make a hole in the bulkhead because it's actually one of the gas tank walls.
About 10 yrs ago, I put an engine into a friends boat after his son changed the oil and forgot to tighten the drain plug.......scratch 1 GM 305. I went to a place that built marine engines and I picked up a 350 instead of a replacement 305, the friend wanted bigger engine and the extra cost was minimal. We were told that pretty much the only differences between a car engine and a marine engine was the cam design and the marine engines had brass expansion plugs, and that reverse rotation wasn't usually used on single engine setups. Mainly with twin engines to counter a torque issue. Just my .02
the cams used in mairine engines are just pure tourque. as you run the engine in rpm ranges no trans to shift to the next gear like in a car.
we contimplated putting that "marine" cam into the "rebuilt"(new crank) 305 in my pickup when i owned it. to just have it be an monster for tourqe but we also said a 327 instead of 305 but this never happened in the long run as it was just gonna be a BEATER.
Probably a little too late here, but I have taken apart a few Mercuriser and Volvo Penta Stearn drives.
Both use "marinized" GM engines. Marinized meaning that they are equipped to handle prolonged high rpms better than a typical GM truck engine. For example my boats 4.3L Merc runs 4500 at cruizing speed and the 4.3L in my blazer red lines at 4000. I believe (not 100% sure) the the crank, cam and bearings are different than a typical GM engine. Only dual engine boats have the port engine running backwards, to even out the torsional forces of the prop rotating.
I once overheated my marine 4.3 to the point of cracking both heads, and did not damage the pistons. We just slapped new heads on and were back on the water the next weekend. So I would suggest that you tear this engine apart, and if need be send her to the machine shop go .030 over and rebuild. Unless installing a 5.7L is appealing (it would be to me).
Another word of caution: once you replace the engine don't forget the new impeller. It would be a shame to cook another motor for a little rubber part that is $11 at Canadian Tire :) And for the future, Mercruiser recommends the impeller be replaced every 500hrs, it is the most common inboard failure point, and likely the root cause of your overheating problem.
That's the sickening part... there's a brand new impeller sitting in the sink in the cabin. He knew (was told by marine shop) that the old one was weak and just didn't get around to installing it :hick: