Re: 55 Convertible Repower underway
Quote:
Originally Posted by
saltshaker
I think you made a good choice. The c18 is based on the 3406, probably one of the best engines Cat ever built. The C18's have been doing well and are reported to be 10K hour engines. When I was looking at a boat with them I did some research and couldn't find a Cat dealer that ever needed to do a bottom end overhaul on them. I believe there is a 55C for sale in Tx that has them in it. Might be worth talking to the owner for some first hand info. You may want to look into renamed C18's or 3412's. Should save a lot of cash and the engines are like new. I would think the 3412 would be very close in size to your 12v71's. What size shafts do you have? Don't go too shallow on the reduction gear or you will pay for it in performance. Good luck and keep us posted.
I ordered the C18s bobtail yesterday (still considering which gears to buy). I did look at remanned, and they were a good bit cheaper, but no warranty. Thanks for the heads up on the TX boat. I had seen that and talked with the yard that did the repower. They were very helpful. They chose to use the old ZF gears which were 1.5:1. They claimed the boat ran 30 kts. We are refabricating the engine beds to allow the engines to sit horizontal with down angle transmissions. We assumed we would stay with the same 1.5:1 ratio that the 12V71s had? Do you think that's too shallow?
Re: 55 Convertible Repower underway
Quote:
Originally Posted by
sobetz
I ordered the C18s bobtail yesterday (still considering which gears to buy). I did look at remanned, and they were a good bit cheaper, but no warranty. Thanks for the heads up on the TX boat. I had seen that and talked with the yard that did the repower. They were very helpful. They chose to use the old ZF gears which were 1.5:1. They claimed the boat ran 30 kts. We are refabricating the engine beds to allow the engines to sit horizontal with down angle transmissions. We assumed we would stay with the same 1.5:1 ratio that the 12V71s had? Do you think that's too shallow?
I would think 2:1 would be better but not sure if your shaft sieve will be sufficient. A 1.75:1 may be a good compromise. I had new Twin Disc down angle gears in my 46C. They were great for the 11 years I had them. Why did you order the engines bobtailed? Will they still let you package them with the gears once you make a decision? The price with gears is typically much better than buying them separately. Who is doing the re-power and who is the Cat dealer?
Re: 55 Convertible Repower underway
Quote:
Originally Posted by
saltshaker
I would think 2:1 would be better but not sure if your shaft sieve will be sufficient. A 1.75:1 may be a good compromise. I had new Twin Disc down angle gears in my 46C. They were great for the 11 years I had them. Why did you order the engines bobtailed? Will they still let you package them with the gears once you make a decision? The price with gears is typically much better than buying them separately. Who is doing the re-power and who is the Cat dealer?
Shafts are 2.5" AQ22. Just barely an adequate safety margin for 1150HP according to the shaft company, but the cutlass bearings and shaft tubes are too tight to upsize, so I am going to risk it. Im looking at the Twin Disc quick shift with express mode with integrated bow thruster. Tolchester is doing the repower (they repowered my last boat and did a great job). They are a sub dealer for Alban CAT, but they are a full dealer for ZF and Twin Disc so I wouldn't get a better tranny deal from Alban.
Re: 55 Convertible Repower underway
Thanks for the pics so far. Curious about seeing your quote for the mezzanine/tackle center project. Does Tolchester do all the glass work and new fabrication there as well?
Re: 55 Convertible Repower underway
Tolchester Marine will do a good job; they are not cheap, though. But they have a lot of repower experience, and with high-end repowers like this one thin on the ground, they should treat you very well indeed. VERY well indeed.
Wouldn't he have to increase the gauge on the DC wiring if he goes from 32vdc to 24vdc? Just curious. 24 would be better, no more multiple DC systems, all your electronics ought to run fine on anything from 12=36 vdc.
Re: 55 Convertible Repower underway
Jim,
I think we should take a ride up there and take a look when the owner permits us...
Re: 55 Convertible Repower underway
Quote:
Originally Posted by
whaler23
Thanks for the pics so far. Curious about seeing your quote for the mezzanine/tackle center project. Does Tolchester do all the glass work and new fabrication there as well?
I'm getting the mezzanine quote from Annapolis Harbor Boatyard. I've been pleased with John Norton. He's done nice work for me.
Re: 55 Convertible Repower underway
Quote:
Originally Posted by
jim rosenthal
Tolchester Marine will do a good job; they are not cheap, though. But they have a lot of repower experience, and with high-end repowers like this one thin on the ground, they should treat you very well indeed. VERY well indeed.
Wouldn't he have to increase the gauge on the DC wiring if he goes from 32vdc to 24vdc? Just curious. 24 would be better, no more multiple DC systems, all your electronics ought to run fine on anything from 12=36 vdc.
I do need some expertise on the elecrical side. Tolchester is supposedly bringing someone in to take a look at that.
Re: 55 Convertible Repower underway
Quote:
Originally Posted by
whaler23
Jim,
I think we should take a ride up there and take a look when the owner permits us...
You guys are welcome anytime. I'm down there a lot and the engines won't arrive until January. Let me know when you want to come. I would greatly appreciate your insights.
Re: 55 Convertible Repower underway
That is a lot of HP for 2.5" shafts. You might want to look into using Auqamet 22HS. It's stronger than the 22 and may get you where you need to be. You may also be able to use a thin wall cutlas bearing and increase shaft size to 2.75"