Re: [electricboats] repurposing torqeedo 2.0 to inboard engine?

John,

I think you are right to view removing the old engines as quite a big job. Don't underestimate that part.  Then getting an electric setup that will deliver enough power to let you get planing speeds for more than a few of minutes (many options but for example 4 AC motors ~80kw and at least 15kwh of battery is the ballpark)  becomes a considerable cost. 

I've helped a few people in my area price out converting similar power boats and each time we've landed at the same $30k-$50k total cost.  If you have a really fantastic boat and the engines are dead, it might make sense.  I ended up with one client in that situation who is diving into it. We have yet to really find out but in theory the electric drives and battery systems should last for decades - longer than you will own the boat, unless you are quite young. 

On May 17, 2021, at 10:01, john via groups.io <oak_box=yahoo.com@groups.io> wrote:



Carsten,

The BIGGEST problem is that they haven't been run or cared for in the past 20 years.  I had a retired buddy that was "car friendly" helping me with them (and paid him a few $$, which worked for both of us).  My objective, beyond just getting them to run - was to get them back into great, reliable shape.

First, rebuilt the carbs, then rebuilt the raw water intake pumps, new hoses, belts, plugs, starters.  New electric fuel pump to replace the mechanical fuel pump.  New water circulation pump, new intake manifold (on port engine - probably on starboard too).  Pulled the heads on the port engine and had them machined, and new valves put in (old valves were all shot, with little or no compression on most of the cylinders). New lifters, new rods.  Port engine is now running - though clattering loudly (not a valve adjustment - maybe a lifter or rod that wasn't adjusted properly?) - so still need to get a mechanic that really knows what he's doing to look at it and finish the job.

Starboard engine will start and run if primed, but also has bad compression on 3 cylinders - so need to pull the heads and have valves done on it.  Old buddy was much less expensive than a "real" mechanic, but has too many other things to do to be available on a reasonable basis.  I've dealt with most of the boat shops at one time or another, and don't trust any of them to do a decent job.   I've got one last guy to try - but he's swamped with work after the freeze we had this past winter took out a bunch of engines....

I would LOVE swapping out all the potential sources of problems of the gas engines for electric motors that just run, don't freeze, and don't have so many holes in the bottom of the boat.   But...   repowering with electric would probably cost (WILD swag) $30-50K to get old motors out, new engines in, and minimal battery capacity.  If I can find a mechanic that can pull and re-install the heads, and tweak things - I should be able to be back in business for around $5K - keep the boat good as original condition (resale value maintained), and be able to scoot down the lake if I need to at some point.

I have toyed with putting motor brackets on the swim platform, and getting a second Torqeedo 4.0.   That would cost another $4-5K for the 2nd motor (I have one), and several thousand for a minimal battery just for proof of concept.  And I'm concerned that two Torqeedo's on the swim platform wouldn't be able to give me enough differential thrust to manage the boat at the dock (at least without adding a bow thruster).

Sigh.

John

On Monday, May 17, 2021, 11:06:37 AM CDT, Carsten via groups.io <carstensemail=yahoo.com@groups.io> wrote:

John, just curious, what's wrong with the Chev's ?

(I know, not related to electric...)

On Monday, 17 May 2021, 21:37:19 GMT+8, john via groups.io <oak_box=yahoo.com@groups.io> wrote:

Carsten,

I think the bad reverse performance is mainly an issue of the outboard having to fight against the hull and keel.  

I previously had a Catalina 27 with a 10hp 4-stroke outboard in a motor well (behind the keel and rudder).  Same thing - did great in forward, but very limited power in reverse.  If I had a strong north wind, I wasn't able to back into it with sufficient control to safely leave the marina.

This may be somewhat also due to the prop being less efficient in reverse (due to cup design).  But I suspect fighting the keel was the bigger issue.

I really wish the economics were better for electric.

I currently have a Chris Craft Commander 410 with two Chevy V8 454 big block engines that are not healthy.  I still believe the engines can be brought back - but finding a good mechanic that will show up and get the job done on my lake is proving extremely frustrating!   I've thought more than a few times about repowering the boat with electric (probably mostly hybrid, running off a generator - to keep the cost of the battery bank within reason).  Butttt....   Getting those two V8 blocks out of the engine room below the main salon will be extremely difficult.  Plus - best possible speed will still be limited to 5-6mph - slower than a trawler, and slower than many sailboats.  I've gotten used to the Dark Side, and prefer a cruising speed of 7-10mph, and really like the option of being able to get up on plane if I need to so that I can get somewhere in a hurry if necessary.

I have taken a LOT of inspiration from this web site:  http://www.deny.org/Escape_the_American_Dream/Work_Blog/Work_Blog.html, as his boat is very close to mine (his is a few years older, and mine has the flybridge - meaning more drag, weight, and windage - but at least in the ball park).  But it also serves as a good reality check.

John

On Monday, May 17, 2021, 01:22:14 AM CDT, Carsten via groups.io <carstensemail=yahoo.com@groups.io> wrote:

Thanks, John

I may reconsider that solution, as you said the reverse was not good. Probably because of the pod ?

When anchoring, I need full reverse power to dig the anchor.

I guess that yellowchair does not need the full reverse power, if he already does well with his present configuration.

Two T4.0's is a bit over my budget, as it is more than I paid for my Maxi 87 1976 boat :-)

I also considered to get rid of my saildrive and make two shaft drives (!!)

By doing so, there is redundancy, and high maneuverability.

Anyone here with two shaft drives on their boat ?

Cheers,

Carsten

On Monday, 17 May 2021, 11:22:18 GMT+8, john via groups.io <oak_box=yahoo.com@groups.io> wrote:

Carsten,

If you're really going to go that route, I'd recommend two Torqeedo T4.0's.

I mounted one as an experiment on an Catalina 30.  One Torqeedo would push the boat at very slow speed. Reverse was abysmal.  I could get by with it as an emergency backup when my Atomic 4 gas engine failed, and neeed to get into my slip once returned to the marina.

However, a single 15-20hp outboard gas engine would be MUCH more cost effective, and get the job done more practically.  I know this is an "electric boat forum", and I own 2 Torqeedos, and have done a fair amount of experimenting with them.  But they're a very expensive solution that is significantly more complicated than a gas outboard.

John

On Sunday, May 16, 2021, 08:19:25 PM CDT, Carsten via groups.io <carstensemail=yahoo.com@groups.io> wrote:

What is your use of the Torqueedo now ?

It seems that you only use it for docking, slow motorsailing etc. as it is a small configuration for your 5T boat.

How about two Torqueedos, one starboard, one port ?

Doubled power, and far better maneuverability when docking.

You just need to buy/find one more T2.0, more batteries, and make the new (retractable) brackets.

No hazzle with mounting an inboard.

Just an idea, as I am considering making two on my mono 4 tonner too.

Carsten

On Monday, 17 May 2021, 03:43:33 GMT+8, yellowchair@gmail.com <yellowchair@gmail.com> wrote:

I have a 28 foot, 5 ton, Tyler Twister (long keel) with a Torqeedo 2.0 mounted on a home made bracket on the (transom hung) rudder. Due to the steeply angled transom, there is no ideal way to mount an outboard, so I am contemplating going back to an inboard engine. What do you guys think of using the Torqeedo 2.0 as an inboard engine? Perhaps a belt drive to the propeller shaft? I'm sure this would void any warranty, but would it work? Would cooling be an issue? Any comments appreciated.