wood45s
Cadet
- Joined
- Apr 26, 2017
- Messages
- 7
[FONT=Arial, sans-serif]Merc/GM 4.3/Alpha I cooling problem, cracked manifolds, impeller, etc.[/FONT]
[FONT=Arial, sans-serif]I purchased a 1995 Starcraft Islander 221recently. Due to improper/incomplete winterizing, exhaust manifolds froze and cracked last winter (2016-17). The engine (vortec 4.3 with 12 bolt intake manifold) seems ok. The engine was rebuilt summer of 2016 with Chev s10 block and rebuilt heads due to busted/frozen block and heads. Also, new pistons, new roller lifters , rebuilt crank, but original cam. They installed used exhaust manifolds. Yes previous owner let it freeze two years in a row. The boat has not been in the water since engine was replaced.[/FONT]
[FONT=Arial, sans-serif]I?ve run it about 3-5 minutes with hoses bypassing exhaust manifolds and see no water leaking or in oil. The block was also pressure tested with about 5-10 psi of air and only leak found was thermostat gasket. I disconnected stern water inlet to engine and piped water over the side, but had thermostat removed and block filled with water. [/FONT]
[FONT=Arial, sans-serif]Very little water was pumped by stern impeller, so I plan to replace impeller with oem Mercury impeller/seal kit. Looks like that kit has most seals, etc required for the lower drive. I?m trying to figure what else I need to replace in the lower right now.[/FONT]
[FONT=Arial, sans-serif]I?ll replace the gear oil with new synthetic. I have some Lucas synthetic now.[/FONT]
[FONT=Arial, sans-serif]Are there any recommendations for manifold/risers brand. I see Mercury oem, Barr, Sierra and others. I am always a fan of made in USA. Sierra has a good looking kit which includes gaskets and fittings.[/FONT]
[FONT=Arial, sans-serif]I plan to replace iron plugs/fittings with brass. Maybe a brass shutoff valve on each side of block for draining.[/FONT]
[FONT=Arial, sans-serif]Previous owner left the starter loose. So that bent the bolts and broke one tooth out of flywheel along with destroying the starter drive. I?ve fixed starter now but hear it going over that missing tooth.[/FONT]
[FONT=Arial, sans-serif]I need to find some way to check engine alignment. I think I saw something about that in the repair manuals.[/FONT]
[FONT=Arial, sans-serif]Dual axle trailer with non functional hydraulic brakes ? I think they?re called break away brakes. I?m looking for options on this; maybe electric is an option. Everything break related has to be replaced anyway. I have a ? ton Suburban for towing.[/FONT]
[FONT=Arial, sans-serif]I know this is boat not a car but I?m wondering why boats pump all that water thru the manifolds. Seems to me all that cool water would cool the engine good just circulating thru the block like a car.[/FONT]
[FONT=Arial, sans-serif]Also, I?m trying to find info on converting to closed cooling system. Seems to me a closed cooling system with antifreeze would be better. But maybe that would be too much trouble and expense. I don?t know yet if this would require different exhaust manifolds. Kinda looks like exhaust manifolds would be same, but plumbing different.[/FONT]
[FONT=Arial, sans-serif]I?m reasonably competent as a backyard mechanic, but have little experience with boats.[/FONT]
[FONT=Arial, sans-serif]I do have Merc manuals 14 for the Alpha and 18 for the engine.[/FONT]
[FONT=Arial, sans-serif]Any suggestions for additional checks/maintenance will be greatly appreciated.[/FONT]
[FONT=Arial, sans-serif]By the way, i?m in Lithia Springs, Ga.[/FONT]
[FONT=Arial, sans-serif]Thx,[/FONT]
[FONT=Arial, sans-serif]wood[/FONT]
[FONT=Arial, sans-serif]I purchased a 1995 Starcraft Islander 221recently. Due to improper/incomplete winterizing, exhaust manifolds froze and cracked last winter (2016-17). The engine (vortec 4.3 with 12 bolt intake manifold) seems ok. The engine was rebuilt summer of 2016 with Chev s10 block and rebuilt heads due to busted/frozen block and heads. Also, new pistons, new roller lifters , rebuilt crank, but original cam. They installed used exhaust manifolds. Yes previous owner let it freeze two years in a row. The boat has not been in the water since engine was replaced.[/FONT]
[FONT=Arial, sans-serif]I?ve run it about 3-5 minutes with hoses bypassing exhaust manifolds and see no water leaking or in oil. The block was also pressure tested with about 5-10 psi of air and only leak found was thermostat gasket. I disconnected stern water inlet to engine and piped water over the side, but had thermostat removed and block filled with water. [/FONT]
[FONT=Arial, sans-serif]Very little water was pumped by stern impeller, so I plan to replace impeller with oem Mercury impeller/seal kit. Looks like that kit has most seals, etc required for the lower drive. I?m trying to figure what else I need to replace in the lower right now.[/FONT]
[FONT=Arial, sans-serif]I?ll replace the gear oil with new synthetic. I have some Lucas synthetic now.[/FONT]
[FONT=Arial, sans-serif]Are there any recommendations for manifold/risers brand. I see Mercury oem, Barr, Sierra and others. I am always a fan of made in USA. Sierra has a good looking kit which includes gaskets and fittings.[/FONT]
[FONT=Arial, sans-serif]I plan to replace iron plugs/fittings with brass. Maybe a brass shutoff valve on each side of block for draining.[/FONT]
[FONT=Arial, sans-serif]Previous owner left the starter loose. So that bent the bolts and broke one tooth out of flywheel along with destroying the starter drive. I?ve fixed starter now but hear it going over that missing tooth.[/FONT]
[FONT=Arial, sans-serif]I need to find some way to check engine alignment. I think I saw something about that in the repair manuals.[/FONT]
[FONT=Arial, sans-serif]Dual axle trailer with non functional hydraulic brakes ? I think they?re called break away brakes. I?m looking for options on this; maybe electric is an option. Everything break related has to be replaced anyway. I have a ? ton Suburban for towing.[/FONT]
[FONT=Arial, sans-serif]I know this is boat not a car but I?m wondering why boats pump all that water thru the manifolds. Seems to me all that cool water would cool the engine good just circulating thru the block like a car.[/FONT]
[FONT=Arial, sans-serif]Also, I?m trying to find info on converting to closed cooling system. Seems to me a closed cooling system with antifreeze would be better. But maybe that would be too much trouble and expense. I don?t know yet if this would require different exhaust manifolds. Kinda looks like exhaust manifolds would be same, but plumbing different.[/FONT]
[FONT=Arial, sans-serif]I?m reasonably competent as a backyard mechanic, but have little experience with boats.[/FONT]
[FONT=Arial, sans-serif]I do have Merc manuals 14 for the Alpha and 18 for the engine.[/FONT]
[FONT=Arial, sans-serif]Any suggestions for additional checks/maintenance will be greatly appreciated.[/FONT]
[FONT=Arial, sans-serif]By the way, i?m in Lithia Springs, Ga.[/FONT]
[FONT=Arial, sans-serif]Thx,[/FONT]
[FONT=Arial, sans-serif]wood[/FONT]