Repowering A 58TC

[Boatsb]

Most 671's have smaller transmissions and of course the mounts will need to be re done. The cost of all that work will not be cheap unless you hire illegals.

I would guess ( I have done repowers before but not 12v71's ) it will cost every bit of 12K just to get the old ones out and the new ones in. Not including cranes, Glass work and such. $3-5K or more

Say the 2 671's cost $10K each. Now the $12K to do the swap. That's more than a rebuild and you no longer have the ability to plane. Even if you get 10 for the RTO engine I don't see the benefit.

[ThirdHatt]

Scott is right Randy, forget about the repower and just fix what is broken. Using different Detroits is exactly the same as using any different engine, everything will be different and the engine beds, hoses, cables, wiring, etc. will need to be set up for the changes ($$$). We can guess all day what a repower might cost but even the best guesses are way more than just to fix what is broken with your engine. Those $20-30k estimates are for FULL rebuilds, whether on yours or swapping for another like engine.

You said the engine ran so the bottom is likely just fine. Find a REAL Detroit mechanic and simply have him swap out just the ONE cylinder kit that is burned and button the darn thing back up. Yes, it really could be as simple (and affordable) as that. It starts to get very expensive when you over-thiink this and that is what may have been (and still?) holding you up.

Using the widely accepted $3k per hole cost estimate for a rebuild, you could easily be done for as little as $5k (allowing for other minor expendatures), as opposed to 4 to 6 times that! Now THAT is an affordable answer to your problem. Heck, you wear that on your wrist! LOL

SO, anybody know a good Detroit mechanic in Tennessee?

[Genesis]

These are naturals guys.

They're not highly-stressed turbo motors.

Pull the head, drop the pan, pull the one cylinder kit, replace it.

Put it back together.

Couple of day's worth of work, done careful and right, maybe three (you gotta re-tune it when you're done.)

You're talking three, four, five times as much money to pull and replace with 6s, assuming you get the 671s for FREE, which you won't. The mounts have to be redone, the wiring is different, and you have to crane and jack all the stuff around. That's going to be a major pain in the ass; I wouldn't even consider it.

You can buy a LOT of fuel for the difference in cost.

Just fix the busted parts and be done with it.

[spartonboat1]

Concur w Eric/Third - don't reinvent the thing. Just do the necessary repairs. These engines were designed with that in mind - you can easily repair one cylinder/associated parts.

Supposedly in WWII there were many cases of DD's (GM Diesel then) running around with missing pistons. I am not by any means suggesting that. But I agree with do the one kit, unless the others have cracked rings or serious compression issues. That is, if you are willing to do it on the cheap.

[SKYCHENEY]

Forget the engines. Its just a riverboat. Mount a couple of outboards to the swim platform and call it good.


But seriously. I agree with the fix what you have principle. That has been what most have stated here ever since you had the problem back in Florida.

[ThirdHatt]

Are the heads still on the engine? I seem to recall something like they were pulled off down in FL and went to a shop and that is when the work stopped due to huge cost estimates for a rebuild.

Did that guy ever bring your heads back to the boat after you declined the full rebuild? Have they been taken care of so that they didn't corrode up on you in the mean time? These things could certainly add to your costs.

[Brian Degulis]

You know what I'd repower it. Sure you could fix one hole probably last forever at hull speed. But with fuel being what it is I think re powering the right way is your best bet even for re sale. But forget the 671s that would be insane. A pair of completly rebuilt 671s will cost the same as a new modern engine so don't invest in the past. If it was my boat I'd put in a pair of cummins QSB 230s size them up with deep enough reductions to turn the props you have on there now. I'd also put them in on floating mounts with Aqua drives smooth and quiet like you can't believe. I'd consider cutting a section out of the hull side below the vent in order to get the stripped down 12 out and the new in. Yup I'd make a modern fuel eficient hull speed boat out of it.

Your first thought was right there you freekin trouble maker stick with it!!!

Brian

[Walter P]

Hey Randy,

You could fabricate some sort of "sea drive" brackets on the stern and run a couple of 4 stroke outboards on it you know. The advantages would be many...such as no more through hulls for raw water intake, no exhaust system to take all that space under the dressers in the staterooms, no more engine alignment issues or leaking stuffing boxes and the list goes on. PLUS you end up with a very large space formally used to house all that iron to do with as you please.

Hummmm, this post started as a joke, but maybe......

Walt

[holtcl]

Randy-

Get in touch with Diesel Don- he can help you 256-259-7728. Highly recommend talking with him before you make any decisions on this. He does the majority of the diesel work in your area. Good luck!

[bobk]

Randy, I'd second Diesel Don, but seems to me you already have talked to him. He aint cheap though, but he does know Detroits.

Bob