Originally Posted by MILD THUNDER (Post 4525468)

I'm not so sure I'd be condeming your current engines to the graveyard already. They've served you well for the past 15 years, and 300ish hours, is certainly not a level of making them ready for the trash bin. AND, they have not even been torn down to evaluate exactly what the issue is, and already you're builder has you buying new power?

At 300 hours, for all you know, they might need a fresh hone job, some rings, bearings, etc. If they were truly "NEW" mercury 454 420hp engines, they should have been standard 4.250 bore size. There should be room for an overbore, even IF, a cylinder was hurt. Or, be sleeved.

Those 454 / 420 engines, had decent parts in them. Certainly capable of supporting the power you are at. A fresh rebuild on the shortblock, some new EQ iron heads, and a blower upgrade, and I don't see any reason, you can't make 600, 650, 700+HP, without getting into them being radical time bombs.

Even IF, the block was trashed, you can find those blocks for a song these days, few hundred bucks. I just saw a guy out your way the other day selling a STD bore 4 bolt main 454 block, for around 500 bucks.

Before I'd hit the big red panic button, I'd want to see exactly what the problem is , and what it will take to fix it. There's nothing exotic in those engines, that should be costing a million bucks to refresh/rebuild them.

Originally Posted by mike tkach (Post 4525494)

i don,t understand how a builder can say the engine is beyond rebuilding without taking it apart and inspecting the internals unless salt water has eaten block&heads up.jmo.

Originally Posted by MILD THUNDER (Post 4525468)

I'm not so sure I'd be condeming your current engines to the graveyard already. They've served you well for the past 15 years, and 300ish hours, is certainly not a level of making them ready for the trash bin. AND, they have not even been torn down to evaluate exactly what the issue is, and already you're builder has you buying new power?

At 300 hours, for all you know, they might need a fresh hone job, some rings, bearings, etc. If they were truly "NEW" mercury 454 420hp engines, they should have been standard 4.250 bore size. There should be room for an overbore, even IF, a cylinder was hurt. Or, be sleeved.

Those 454 / 420 engines, had decent parts in them. Certainly capable of supporting the power you are at. A fresh rebuild on the shortblock, some new EQ iron heads, and a blower upgrade, and I don't see any reason, you can't make 600, 650, 700+HP, without getting into them being radical time bombs.

Even IF, the block was trashed, you can find those blocks for a song these days, few hundred bucks. I just saw a guy out your way the other day selling a STD bore 4 bolt main 454 block, for around 500 bucks.

Before I'd hit the big red panic button, I'd want to see exactly what the problem is , and what it will take to fix it. There's nothing exotic in those engines, that should be costing a million bucks to refresh/rebuild them.

Originally Posted by blown (Post 4525503)

Hello Mild. When we discussed the cost of rebuilding them with new blocks (he was adamant about that) and replacing any worn out parts and all the accessories so they would essentially be new motors, he was ball parking at least 10k per side and said at his own price to do it he'd rather see me go the 540 reman route or find low hour drop in 496HO's. Of course he hadn't pulled the motors so couldn't be 100% sure yet whats inside and the exact cost, but I trust Dave as we've had a long and good relationship with him. Maybe much of this comes down to the fact that he's probably not the cheapest option in town for motor work. Whose high quality and fair price for engine building in the Chesapeake area?

In any case today I now have an option on some low hour Merc blue motors. Gonna go see them next week and very likely to pull the trigger on them and just get it done.

The motors i have now, any idea of a realistic asking price to offload em? Stbd motor runs but only holds 35# in cylinder #8, the rest vary between 100-130. Didn't do compression tests on port motor, but its running fine.

Originally Posted by blown (Post 4525503)

The motors i have now, any idea of a realistic asking price to offload em? Stbd motor runs but only holds 35# in cylinder #8, the rest vary between 100-130. Didn't do compression tests on port motor, but its running fine.