1983 Grady 190 with a 470 IO opinions

[Wrestling Coach]

I have a chance at a 1983 Grady with a 470 170hp IO. Boat has been well kept. Any opinions? This would be my first fiberglass boat, first IO boat and of course my first Grady.

Thanks in Advance

 

[bayrat]

Mercruiser stopped making 470 i/o a long time ago so parts could be a problem. They didnt have a great reputation...do yourself a favor and do a search on them before you go further.

 

[Clockwork]

470 is a motor that has a high power to weight ratio but has a bad reputation for head failure among other things. id avoid it for that reason but also i think you should hold out for a grady with a good outboard.

 

[Wrestling Coach]

The most often mentioned problems seem to be the water cooled charging system and the three inch cooling system when the boat is used in warmer water. The external alternator conversion and four inch cooling system seem to correct those issues. Both of which may have already been done on this boat. I haven't looked yet. Will I be able to tell by looking if the three inch manifold has been replaced with a four inch manifold? The problem with the head I have not seen yet. I know it's an aluminum block with an iron head. Better antifreeze these days could help this issue I would think. I have an iron block motor with aluminum heads in a car I have. I will be looking at the boat this weekend. Thanks for your input.

 

[Fishshoreman]

The switch from 3" to 4" is the heat exchanger not the manifold. If it has the conversion for the alternator and the points to electronic ignition the only other major worry with the engine is the aluminum exhaust manifold to the cast iron riser/reservior. This is were the failure takes place and dumps antifreexe into number four and to an extent #3 cylinders. As long as you check the reservior and exhaust manifold connection every two years you will not have a problem. this is a very good engine with an undeserved bad rep. It has the above issues but if you stay on top of them it will run for a very long time. It is also very economical.

I ran one in another boat for 8 years without a problem. Only changed oil, plugs, and the exhaust/ reservior gasket (every two years) and that is it.

Parts are still available. I have a complete spare engine in my shed if you purchase it and need parts. My spare does not have the conversions.

 

[moorehaven]

The 470 is a good economic engine but needs more TLC then other engines. The cooling system is one number on maintenance the reservoir gasket ,antifreeze change.and draining the water pump should be done every two years. If the camshafts seals have not been changed they will have to be addressed. The camshaft journal gets grooved by the cam seals and the coolant ends up in the engine oil . The repair is placing speedi sleeves on the journal . The engine's water pump has a drain on the bottom that needs to be flushed out when you change the antifreeze .The internal alternator should be changed out for an external unit . The engine oil has to be an oil with high levels of ZDDP because of the engine's flat tappets . Make sure that the compression is good and consistent. If you maintain the 470 it will serve you well

 

[Fishshoreman]

Moore, very good point about the cam seals. I forgot about those. You can tell if they are failing by the weep hole in the water pump impeller housing.

The another issue is parts are a bit pricey. The block is manufactured by mercury marine and the head is from a Ford 460 with a hose fitting installed. the parts aren't cheap (relatively speaking) like a small block chevy 350.