Repower dilema

Field Tester

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So I found out yesterday that I need to repower my 31' JC. I have been cursed with the dreaded 3116 block failure! Unfortunately, I don't have an extra $20K + to do this right now. So here are my options... 1. bring the boat home and let it sit next to the house for a few years and hope I can save up enough $$ to repower, or 2. try to sell the boat as is for close to nothing in a horrible economy. Either way I'm without a boat for a while!:mad:

I'm hoping for some advise from some of the experts here. If there was some way I could swing a repower, what are some resources I could look into for pricing on a reman?
 

Field Tester

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Yes, I can do 95% myself. So far, a friend who is a marine diesel mechanic advised I going with another CAT. A 3126 as it would be the easiest to swap. It would drop right in. Also, he said I could trade in my old one to bring the cost down a little. If I go to a cummins, I cant do a trade in. Also the motors mounts would be a little different on the cummins. The upside was that he said I could probably go to a 315 cummins and have the same speed because its much lighter than the CAT.
 

Tuna Pursuit

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I'm just a cummins fan. The B & C's are so simple and dependable. I'm on my second boat with B's in it and my next boat will have a C. Good luck which ever way you go.
 

WoundUpMarine

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reelsportfishing

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Field tester, My buddy is going to repower his 32' Topaz in the winter. He has 2 3208's 320 hp. One has a new block and both have new fuel injector pumps. You could probably buy one of these for 7 or 8 grand. Not sure if your tranny would match up. You could hear these engines run before you bought one. Cheap way out with a good engine. Boats in Pt. Judith. Alot of the JC,s had this engine. Good luck!
 

captainlarry84

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options $$$$$$$$$$$$$$$

Your options are all expensive. I would price out the trade in on the 3116 for a 3126 as the foot print is the same. However my fish choice would be the Cummins 370 HP reman with a 2:0 gear your boar would beat to a better drum.

A third and most likely the cheapest would be a 315 HP Yanmar @ 3800 PRMs an a 2.5 gear. You would save over 1000 pounds and it will fit with room to spare. Your boat would run like a rabbit and church bell quiet. Al Grovers has repowered about 6 JCs so I am sure you could get a very accurate quote on the cost.

Also Grovers will do refinances on Yanmar repowers. Plus you may get a buy out on the CAT with the 1:5 gear or sell it Pvt.
 

Field Tester

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Hey Capt. Larry!

I should have known to go to you first. I think I'll go see them over there. I have decided that I am just going to put the boat on land and save every penny I can to repower. If it takes a couple of years, then so be it. In the mean time, I will go through the boat from top to bottom and make everything perfect. One thing I don't like that I plan on changing is that I currently have a motor box. I would like to tear up the deck in the pilot house and raise it so I have a flush deck. I have to take some measurements, but I think I will still have enough headroom as the current motor doesn't stick up very far above the deck. IThe breather from the airsep sticks up the most. I also definitely want to go to a 2.0 gear. ( I have a 1.5:1 now) The gearI have is a twin disc 507A I think:confused:, or 508 maybe?. It only has 1100 hrs on it, so I would like to see if I could find someone to change the ratio in it. Twin Disc told me it can't be done and quoted me $10K for a new gear, but others have told me it can be done. I don't see why not?

Right now I'm leaning towards the 3126 as it's the simplest to swap and I'd get the trade on my 3116. I think it would be the least expensive for me. If I can get the gear changed, I think I'd be good to go with a nice set up that will hopefully last me a long time.
 

tunaorlater

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Keep an eye on boatdiesel.com they come up for sale quite often.
 

captainlarry84

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ZF gears

You most likely have either the 506 or 507 TD. Most likely the 506, both great gears and worth a few dollars. Your best bet is to sell the unit as is. The new ZF 220 or ZF 280 gear is what you should be looking to use. They are much cheaper and lighter, plus for a 31 JC that is all you need. In addition because they are so much smaller your new power will fit lower in the hull, which will make getting rid of the motor box easier. On single screw NE boats it is the gear size that gives you the most trouble in getting the motor low in the keel.
 

Field Tester

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So I've been exploring my options and am still open to all ideas on what's best for my repower. The boat is being hauled this week, the motor will come out the following week, then I will be bring the boat home after that. I have been pricing a 385hp cat 3126, and a cummins 6bta 370hp. Looking for pros and cons of both. I will post my rebuild in the projects section once I get going.
 

BillD

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So I've been exploring my options and am still open to all ideas on what's best for my repower. The boat is being hauled this week, the motor will come out the following week, then I will be bring the boat home after that. I have been pricing a 385hp cat 3126, and a cummins 6bta 370hp. Looking for pros and cons of both. I will post my rebuild in the projects section once I get going.

I'm partial to the 6BTa 370S, on my 2nd pr.
Prop them to 3100-3150, no cons.
 

tunaorlater

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I would personally want the cummins over the cat but the cat will be a piece of cake to swap out and in the long run probably a cheaper repower so if it were my boat I would put in another cat.
 

Field Tester

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I would personally want the cummins over the cat but the cat will be a piece of cake to swap out and in the long run probably a cheaper repower so if it were my boat I would put in another cat.

That's what I'm leaning towards for all of your reasons. The price between the two motors is almost the same from what I've gotten so far with the exception that if I go with the cat I'll get $5500 for a trade in on my old motor. If I go cummins, I have to try to sell mine on my own. My problem with staying with the cat is that currently I have a motor box which I would like to eliminate by raising the deck in the pilot house. With my current cat, if I did so I would only have about 6'2" of headroom. Ok for me, as I am under 6', but maybe not desirable for others. That cat is a big motor! A yanmar would give me a ton of room, but Im just not convinced on those motors yet.
 

jojobee

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We have some 380hp 6LY3 engines we are looking to blow out at around the 6LP 315 price. PM me and we can talk. Or call
908-337-4789
joe
 

captainlarry84

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Power

The 380 Yanmar would be ideal power for a 31 JC. Question; For ease of install can you use the 220A gear or must you use the 280A, which makes the fit a little harder.
 

jojobee

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The 220A is rated for that engine but it does have a 10 degree down angle where the 280 is 8 degrees
 
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