12V71TI service/experience

[Freebird]

There's no inexpensive option here, and bolting turbos on those engines is a VERY bad idea - the compression ratio is different between turbo and NA engines, for one thing!

How much coin are you willing to toss on this? I'd go slow and save the fuel, to be honest - but if you must, then you're talking about a repower one way or the other.

Yeah, I new the compression ratio would have to be lowered, but that could be done fairly inexpensively during a rebuild I would think. Oh well, I'll cross that bridge when I come to it. Just wondered if anyone had done it to know what I would be up against. Thanks for the reply.

[Boss Lady]

changing the compression ratio is the least of your problems, finding all the hardware to bolt on turbos and someone to do it is another issue. If you want to go faster than the installed power will let you, you should be prepared for sticker shock. Your boat will go as fast as you are willing to spend money to get it. If you have 650 HP now and 20 kts speed, and say you want 25 knots, be prepared to move up to 1000 HP and 40% jump in fuel burn to run there. You probably burn 40 gallons an hour at 20 knots, you will burn 70 gallons at 25 knots. $120 an hour versus $210. I would go slower, look for some good replacements at a good price, let them sit in the corner, and run the current engines until they go bang.

P.S. Dont forget about the cost of new larger exhaust, props and shafts.

[Genesis]

Yeah, in the year before I sold Gigabite we got used to a lot of 9-10kt running time.

To be honest, I liked it. Sure, there were times I still kicked it up to 18, but it was much more serene at 10..... and a hell of a lot cheaper!

[Freebird]

"run the current engines until they go bang"

This part of the plan is a given at this point. I'd like more speed, but my billfold needs a healing period having just bought the boat with a lot of work still left to do to get her into shape. I guess I just get jealous when I hear all you guys talking about your big engines. This kinda reminds me of my younger (dumber) days when I wouldn't have a boat that wouldn't run in the 80's or better. Once you got into the upper 90's, every additional 1 mph cost big bucks. "Speed costs money, how fast do you want to go?", remember that quote very well. It just doesn't seem fair that newer 6's and 8's are making as much or more hp as my 12 with half the weight, the other side of the coin. Sure would like to hear from somebody who repowered a 58TC just to compare.

[MikeP]

They may be making more HP for the weight but they are doing it at the cost of longevity. It's not hard at all to make a lot of power; what's hard is to make a lot of power for a long time. Light weight and high power are not the recipe for long life. Obviously, if you have sufficient wallet-weight, none of this really matters. As a former SS/A; SS/F (Mopars of course) drag racer and motorcycle road-racer, we spent tons of money to go that 1MPH faster so I understand your interest.

But I suspect that most of us with these "classic Hatts" are on this site because we DON'T have sufficient wallet weight to, as they say, play with the big boys.

As I've said many times, if I didn't do all the work on my boat, we could never afford to own our 53! Marina mechanic told me yesterday that the work I've done on our boat this year so far would have cost 30k had they done it. None of it was for major component breakdown. The total cost to me in parts was less than 5k. Labor ($120/hr)would have been the rest. I have to say that they seem to do a lot less work in an hour than I do!

[Freebird]

You're right about "wallet weight" being a factor for most of us with classic Hatts. I'm no exception here, but I have to say, I actually enjoy doing my own work, but I know my limitations. If my pockets were deeper, I'd still have a classic versus the new stuff. You can spot a classic Hatt from a mile away, but I have to be close enough to read the nameplate on the new ones to know they are Hatts. Too bad. What's up will all this new euro-crap with all the curves and funky glass patterns? The new Hatts are pretty I guess, but they are sort of like mid-size import autos, they all look the same.

[nor'easter]

As MikeP996 stated, I am here on this forum because I am not interested in a 30+ cruise speed being offered in many/most new convertibles. It just doesn't make sense to me to buy new/newer and know that you are going to burn that kind of fuel, or still go slow and not use the ponies you paid for.

Genesis, I saw your educated and insightful response to another boater looking for a newer 600K CV boat on another forum, and I can relate. I love the classics from Hatt in the 70s and 80s, and hope I can find one that my wife and I can offer a good home to. Many of them came with these plants from DD, and I am not hearing anything that would make me shy away from the 1271s at a reasonable rating (650hp or less in Ns).

[Traveler 45C]

The 12's are 6's bolted together, just like the 16's are 8's.

[doc g]

1271's are thier own block,1292's and 1692's are bolted together 692 and 892's......................Pat

[Traveler 45C]

Hmmm...

I must have read my 8V71 Service and Rebuild Manual wrong. For sure I will go back and look again...