46 Convertible refit begins

[SKYCHENEY]

Contrary to others on this thread, I would prefer the 6v92s to the 8v71s. For 71 series, I like the 471, 671, and the 12v71. As for 92's, I like the 6v92. Just my experience, having owned most all configurations in trucks, boats, or construction equipment.

 

[Boatsb]

The 6v92 DDEC at 625 hp has issues. I hear rings and the electronics are touchy. Also at that HP they are more or less the same HP as the 8v92 in the 46HP. I dont know from experience how the standard 46 will handle the extra HP and remember the 6v92 is lighter than the 8v92 used in the HP version.

 

[Mick c]

I think the reason that people are questioning your plan to go with 92 series DDs is that theya re very intolerant of overheating- the silicone seals at the end of the liners can leak if they are run too hot, and apparently if the cooling system isn't up to snuff they WILL run hot. And when they leak, it is easy to really damage the engine, and it all happens pretty fast. It seems to me (from half a world away, granted) that you should either keep our 8-71s, or look for modern 4-stroke engines, which would preferably be Cummins M11s. I think the 92 series will cost you a lot, and not get you that much additional performance...Of course, it's easy to give advice, and the free advice here, including mine, will be worth what you pay for it. Maybe the best way to proceed is to clean up the boat and do all the updates and keep thinking about what engines you want to put in. After all, you have a lot of prep work to do before anything goes back in, so maybe you don't have to make a decision right away.

I agree that newer 4 stroke engines would be a lot better option. We felt that the opportunity to purchase the 92 that come with all the accessories may not come up again and they are defiantly the best Budget option. The advantage of these engines is that they are still in a boat and probably won’t be ready to for us until March April next year so we will get an opportunity to sea trial them before they come out. We have paid a deposit and have committed to purchasing the engines so they are locked in. You are right when you say we have a lot of prep to do and realistically we don’t need the engines for 12 to 18 months. Last week Mick and I discussed what you mentioned and agreed that if some 4 stroke engines came along and our budget hasn’t blown out too much then we would be mad to not buy them and then re sell the 92s. Lots can change in a few years so let’s see what happens. Thanks for taking the time to discuss this. M

 

[Mick c]

The 6v92 DDEC at 625 hp has issues. I hear rings and the electronics are touchy. Also at that HP they are more or less the same HP as the 8v92 in the 46HP. I dont know from experience how the standard 46 will handle the extra HP and remember the 6v92 is lighter than the 8v92 used in the HP version.

Hi Scott. Do you know what the differences between the standard model and the Hp. Maybe we should look at upgrading to reflect more the hp spec. If possible? I am familiar with the different keel but I’m of the understanding that the keel walking problem only kicks in around the 30 knot mark? M

 

[Mick c]

Contrary to others on this thread, I would prefer the 6v92s to the 8v71s. For 71 series, I like the 471, 671, and the 12v71. As for 92's, I like the 6v92. Just my experience, having owned most all configurations in trucks, boats, or construction equipment.

I feel that if we get them built correctly we should have many years of good boating. Keeping in mind that the last boat I owned a 40 ft Riviera which we will be getting the same maybe a bit more use we only did about 100 hrs per year. Mainly used as a harbour boat which is basically half an hour to a destination for the day and back again. M

 

[SKYCHENEY]

I feel that if we get them built correctly we should have many years of good boating. Keeping in mind that the last boat I owned a 40 ft Riviera which we will be getting the same maybe a bit more use we only did about 100 hrs per year. Mainly used as a harbour boat which is basically half an hour to a destination for the day and back again. M

The 6v92ta up to 550hp has some decent longevity, even better at 465-485hp which is comparable in output to the 435hp 8v71ti. The 92's are less tolerant of a lack of maintenance, however, since you definitely cannot overheat them and you need to make sure your coolant additives are maintained.

Some of the up sides of the 6v92 over the 8v71 is: 1) Cheaper to overhaul with wet liners and 2 less cylinders. 2) No raw water cooled intercoolers 3) shorter dimension engine so more room in front of them.

All said, not enough reasons to make the change when you could just rebuild the 71's and they'd outlast you but you've already explained your reasons for going this direction. I would opt for modern power if I was going to all of work of an engine swap but I understand the budget constraints.

 

[pdog]

How is the refit coming on this project?