Are marine engines REALLY that bad?

Posted By: Greg55_99

Are marine engines REALLY that bad? - 05/08/14 07:35 PM

Recently, I've been in the hunt for a bare 440 block and put out an ad on Craigslist. One of the local responses I got was from a Marine Engine shop that has a lot of Chrysler parts in the pig pile. They'll let a used 440 Chrysler Marine short block go for $130. Knowing what I know about salt water cooling, are these blocks really that bad as the basis of a rebuild? The price is more than right.

Greg

Posted By: Cab_Burge

Re: Are marine engines REALLY that bad? - 05/08/14 08:21 PM

I woud look at each block as some, if not many, of the larger inboard mariine engines had a on board captive cooling system, not using the outside water to cool the motors

I had a employee from New Hampshire that had a small inboard outdrive 4 cylinder motor (under 20 ft)that he brought with him from back east when he and his wife move to SO CA, it had a captive cooling system onboard it

I ended up buying a IMP Aztec V I/O that had been in the Pacific Ocean from new that the exhaust and engine block where ate up beyond repair from the non captive cooling system it had been built with. Salt water does seem to corrode more than most fresh water does

Posted By: b54406barrel

Re: Are marine engines REALLY that bad? - 05/08/14 08:29 PM

And make sure it's not a reverse rotation.

Posted By: dogdays

Re: Are marine engines REALLY that bad? - 05/08/14 08:31 PM

Bare block, rotation doesn't matter.

Saltwater corrosion does, though.

R.

Posted By: Greg55_99

Re: Are marine engines REALLY that bad? - 05/08/14 08:36 PM

I fell into the reverse rotation trap 30 years ago when I bought a motorhome 413 for a build. Silly me. But I think it was the CAM, not the crank that rotated backwards. Question, is the knurl on the reverse rotation crank backwards from the standard car crank?

Greg

Posted By: dogdays

Re: Are marine engines REALLY that bad? - 05/08/14 08:44 PM

Yup, the industrial engine with the two gear cam drive will need a reverse rotation camshaft.
Yup, the knurl on the reverse rotation crank is backwards for clockwise Normal rotation. But, as was recently pointed out, using a lip type seal puts the seal away from the knurl. So it shouldn't matter.

It'd be nice to sonic test the bores before money changed hands, that'd give an indication of the block's usefulness.
Looking at the condition of the cooling holes in the block could help too.
R.

Posted By: vdriver

Re: Are marine engines REALLY that bad? - 05/08/14 09:19 PM

Having owned LOTS of boats over the years, I would stay away from any salt water cooled block. I've had 2 that rusted from the jackets into a cylinder - the first was an OMC Buick V6; the other a 413 Chrysler Marine. To be fair, the 413 was .060 over, the Buick was std. Both had open cooling systems and were run extensively in salt water.

Posted By: Greg55_99

Re: Are marine engines REALLY that bad? - 11/14/14 07:21 PM

Bringing this topic back from the dead. I'll be looking at a "rebuilt" Marine 440 engine complete boat transmission tommorow that's sitting on a palet. Owner can't tell me if it's forward or reverse rotation. No stickers. He says the engine spent it's life on Lake Winnepasaki in NH (fresh water). So what can I look at to tell if it forward or reverse rotation? Also, is popping out a soft plug for inspection a good way to check for corrosion?

Any help?

Greg

Posted By: JohnRR

Re: Are marine engines REALLY that bad? - 11/14/14 07:45 PM

yes pop a soft plug , but you will more than likely see corrosion, is the motor RAW water or closed loop cooled ?

You aren't thinking of trying to run the engine as it sits are you ? Boat engines are not like car engines.

Posted By: Greg55_99

Re: Are marine engines REALLY that bad? - 11/14/14 08:10 PM

I believe it's fresh water cooled. It's on a pallet and has supposedly been rebult along with the boat transmission. I don't need the transmission and he'll let the motor go for $500. Of course that could be false economy. I have a set of 69 440 heads and other parts from a car so I'm mainly interested in getting a good short block. Reverse rotation is no good to me.

Greg

Posted By: 80fbody

Re: Are marine engines REALLY that bad? - 11/14/14 08:31 PM

I have some marine parts left from a BB purchase last year. Pretty much same deal as yours. Not sure there's any easy way to tell it's reverse on a pallet. That said the only things that really affect the shortblock are the cam, cam intermediate gear, distributor and crank knurling.

So if you plan on tossing in a new cam, gear and distributor that pretty much just leaves the crank knurling. If you did end up with a reverse knurled crank you can just pop it and have the knurl polished off. That will give you a chance to go thru the rings & bearings making sure the previous owner did things right.

Posted By: JohnRR

Re: Are marine engines REALLY that bad? - 11/14/14 10:04 PM

Quote:

I believe it's fresh water cooled. It's on a pallet and has supposedly been rebult along with the boat transmission. I don't need the transmission and he'll let the motor go for $500. Of course that could be false economy. I have a set of 69 440 heads and other parts from a car so I'm mainly interested in getting a good short block. Reverse rotation is no good to me.

Greg

Rebuilt for $500 ??? Treat that as a CORE, do NOT assume just because it's got a shiny paint job that it has been REBUILT ?? Also what pistons are in it ? It could be low compression ???

Posted By: vdriver

Re: Are marine engines REALLY that bad? - 11/14/14 10:29 PM

Quote:

Quote:

I believe it's fresh water cooled. It's on a pallet and has supposedly been rebult along with the boat transmission. I don't need the transmission and he'll let the motor go for $500. Of course that could be false economy. I have a set of 69 440 heads and other parts from a car so I'm mainly interested in getting a good short block. Reverse rotation is no good to me.

Greg

Rebuilt for $500 ??? Treat that as a CORE, do NOT assume just because it's got a shiny paint job that it has been REBUILT ?? Also what pistons are in it ? It could be low compression ???

About 30 years ago I bought a beat up old flatbottom/v-drive that I got just for all the parts I needed for a boat I was building - exhaust manifolds, steering gear, v-drive unit,
etc..it also had the "rebuilt" 413 referenced in my reply above. I never trust anybody's "rebuild" anyways, so I tore it down for a look-see. I found 2 finger-tight headbolts, and the 8-bolt flywheel was held on with 5 bolts and nuts, one of which was one size smaller then the rest and flopping around in it's hole. It was at .030" over, so I had it punched to .060", and it cracked a wall within a month.

No more backyard rebuilds or saltwater blocks for me.

Posted By: B5 Bee

Re: Are marine engines REALLY that bad? - 11/15/14 01:08 AM

How to spot right hand, or reverse, rotation.

Pull dist, look at the dist drive and cam gears, they will be cut backward compared to a left hand, or standard/automotive, rotation. This is so with the backwards spinning cam, the oil pump will turn in the proper direction. There may also be a thrust "spacer" to keep the dist drive gear from walking away from the oil pump, LH rotation pushes the drive gear down, RH pushes the gear up.