Re: Proud father of twins...165s...pics
ErieRon said:
We all know about the charging system, water seals, and over-heating issues, but really...what else to justify the comments ? I won't mention any names (Jason - "Minor issues? 470's are the basterd abortion child from Mercruiser. The worst engine to ever come out of Stillwater" ),
Naaaa that's cool man.
I'll just break it down by systems for ya.
1. Mechanicals... A block is a block. but the 470 uses an open deck block. There are 3 basic types of blocks. Open deck, semi-closed deck, and closed deck. Out of the 3, open decks are the least expensive to manufacture, and also the least reliable. In any application, open deck blocks are more prone to head gasket issues than their closed deck counterparts.
2. Cylinder head. It's aluminum. Which isn't a problem in itself because of closed cooling. But if the closed cooling system develops a leak, and they all seem to do on 470's. Go to basic chemistry. 2 dissimilar metals plus an electrolyte makes a battery. With a 470 it's 3 metals, Cast iron, aluminum head, and steel head gasket. Add saltwater to it and corrosion sets in VERY QUICKLY.'
3. Aluminum cylinder head.... again. It shouldn't be in a boat. Most every boat engine has overheated at least once in it's life. Aluminum heads do not take well to even slight to moderate overheats and quickly warp. And oh yeah, a severe overheat will warp and ruin the head, but also warp and ruin the "open deck" block.
4. Aluminum head.... again and again. It's not a DIY job. Sure you can swap the head. But there are special tools involved with setting the valve lash. And to set the lash, you replace pushrods. Not a user friendly way of doing it. You can sit for weeks waiting for 1 pushrod to come in to finish what should be a simple job, what is a simple job on every other motor. That is, if you can even get them. Most parts are NLA for 470's.
5. The charging system, we all know about that and how parts to repair are THOUSANDS if they are even available at all. The voltage regulator/rectifier well set you back a cool $700. If you have twin... Double your pleasure double your expense.
Heck, it cost's $500+ just to do an alternator conversion on 1 engine, let alone 2. On top of that... because of the boat design you may not even have the room to do the conversion. Or even worse, You have the room to do it on 1 engine but not the other because the motors are to tight together.
6. The charging system... again, most every boat i've seen with a 470 the engine needs to come out to pull the flywheel. There is just not enough room in the engine bay to use the proper tool to remove and install the flywheel. And if you hack the flywheel off or hammer it on without using the tool... well that's another grand.
7. Cam/water pump oil seals. Same deal as the charging system. To replace a $10 oil seal you need to
A. pull the drive
B. disconnect everything, and pull the engine
C. remove the flywheel and stator
D. remove the front cover
E. remove the water pump
F. remove and re-install the oil seals... and hope the cover doesn't crack in the process. Because they are really really really thin and easy to crack... and they are NLA if you break it
G. Put it all back together, re-install the engine, align it, re-install the drive. Water test it and hope you got all the water out of the oil
F. A $10 part just turned into a thousand dollar job
8. The cooling system. It was under par on the earlier models. On some they used a 3 inch heat exchanger. They are prone to overheating. This was fixed by going to a 4 inch exchanger. If you have a boat with 3 inch exchangers you need to really watch your temps, but really you should swap them out for the 4 inch models. Double your pleasure with twin engine rigs
9. Because mechanic's don't like working on 470's. And if you have to bring a boat into a shop customers will often get charged top dollar for anything other than an oil change. And they will also get charged what's called in the industry as the FU Surcharge
I still feel my initial post on the thread was still the correct advice.
IMO, you should put the least amount of money into them to get them running, then sell it and hope you at least break even.
