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Topic: So, yeah, I really needed this... (Read 2821 times) previous topic - next topic

So, yeah, I really needed this...

..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":
2015 Mustang GT Premium - 5.0, 6-speed, Guard Green - too much awesome for one car

1988 5.0 Thunderbird :birdsmily: SOLD SEPT 11 2010: TC front clip/hood ♣ Body & paint completed Oct 2007 ♣ 3.55 TC rear end and front brakes ♣ TC interior ♣ CHE rear control arms (adjustable lowers) ♣ 2001 Bullitt springs ♣ Energy suspension poly busings ♣ Kenne Brown subframe connectors ♣ CWE engine mounts ♣ Thundercat sequential turn signals ♣ Explorer overhead console (temp/compass display) ♣ 2.25" off-road dual exhaust ♣ T-5 transmission swap completed Jan 2009 ♣

So, yeah, I really needed this...

Reply #1 –
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.
trick flow street heat intake , 24lbs injetors, ported GT-40's (Chip) long tube headers. and a Performance Automatic C4, with a hurst shifter!

So, yeah, I really needed this...

Reply #2 –
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.

So, yeah, I really needed this...

Reply #3 –
Don't marine engines rotate in the opposite direction of a car engine? I swear I heard that they did.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

So, yeah, I really needed this...

Reply #4 –
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.

So, yeah, I really needed this...

Reply #5 –
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.
One 88

So, yeah, I really needed this...

Reply #6 –
Quote from: CougarSE;173660
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.


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

So, yeah, I really needed this...

Reply #7 –
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.
2015 Mustang GT Premium - 5.0, 6-speed, Guard Green - too much awesome for one car

1988 5.0 Thunderbird :birdsmily: SOLD SEPT 11 2010: TC front clip/hood ♣ Body & paint completed Oct 2007 ♣ 3.55 TC rear end and front brakes ♣ TC interior ♣ CHE rear control arms (adjustable lowers) ♣ 2001 Bullitt springs ♣ Energy suspension poly busings ♣ Kenne Brown subframe connectors ♣ CWE engine mounts ♣ Thundercat sequential turn signals ♣ Explorer overhead console (temp/compass display) ♣ 2.25" off-road dual exhaust ♣ T-5 transmission swap completed Jan 2009 ♣

So, yeah, I really needed this...

Reply #8 –
http://www.epi-eng.com/ET-RevRot.htm

Quote

Reversing the direction in which the crankshaft of a given engine rotates is not particularly difficult. But reversing the engine can add considerable extra expense because of the nonstandard pieces needed, including:

(a) a special crankshaft with the rod-journal oiling passages drilled to the opposite side of the rod throws in order to support the reversed bearing load phasing,
(b) a special camshaft because reversing the crankshaft reverses the firing order (no, you can’t just use a gear-drive to run the cam in its normal direction, and running it backwards opens the intake during the exhaust cycle and the exhaust during the intake cycle),
(c) special accessory drive provisions,
(d) reverse rotation crankshaft seals,
(e) specially-engineered oil pan (especially critical in dry sump systems);
(f) reverse-rotation starter and alternator,
and a host of other details depending on the ignition and oiling systems used.

So, yeah, I really needed this...

Reply #9 –
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.

So, yeah, I really needed this...

Reply #10 –
don't marine engines use different distributors and other miscellaneous electronics?
91 ranger 2.3 turbo - nowhere near stock
87 thunderbird turbocoupe
06 pontiac g6 gt
:birdsmily:

So, yeah, I really needed this...

Reply #11 –
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...
2015 Mustang GT Premium - 5.0, 6-speed, Guard Green - too much awesome for one car

1988 5.0 Thunderbird :birdsmily: SOLD SEPT 11 2010: TC front clip/hood ♣ Body & paint completed Oct 2007 ♣ 3.55 TC rear end and front brakes ♣ TC interior ♣ CHE rear control arms (adjustable lowers) ♣ 2001 Bullitt springs ♣ Energy suspension poly busings ♣ Kenne Brown subframe connectors ♣ CWE engine mounts ♣ Thundercat sequential turn signals ♣ Explorer overhead console (temp/compass display) ♣ 2.25" off-road dual exhaust ♣ T-5 transmission swap completed Jan 2009 ♣

So, yeah, I really needed this...

Reply #12 –
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.
trick flow street heat intake , 24lbs injetors, ported GT-40's (Chip) long tube headers. and a Performance Automatic C4, with a hurst shifter!

So, yeah, I really needed this...

Reply #13 –
put a 350 in it

dont worry about the stern drive
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1957 chevy LSX Turbo project (race car)
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