44 Tolly repower

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cosmo

Senior Member
Joined
May 30, 2013
Messages
110
Location
us
Vessel Name
Shear Bliss
Vessel Make
Tollycraft 44
Our ‘88 44’ Tolly has the DD 8.2s. Contemplating or more out of curiousity wondering about a repower. I am aware of their history and the opinions of them. At this particular point, we are in a better position to repower than if the engines implode years down the line.

Our 8.2s have 250hp and I run them like a trawler. However, if I had a few more ponies……If you could, what would be the optimal repower option? Cummins 370hp? Would Cummins fit height wise? John Deere? Detroit? Has anyone done this recently and what sort of budget were you at? 100k?

First world problems and I like to dream.
 
For sure 100K and maybe more depending on choice. I have never been able to make the math work on a repower. It always pencils out to be cheaper to sell and buy what you want.

Even with a dead engine it usually pencils out to rebuild over repower.

In the commercial world where you operate 1000 hours a year, fuel savings can pay for a repower, but not at 100 hours a year.

Everyone always thinks the expensive part is buying a new engine. They gloss over the fact that new engine mounts must not only be built but designed. Same with the exhaust system and a thousand other little items.
 
Height wise a Cummins 6BTA or QSB will definitely fit. They're not as tall as a Cat 3208 and those were used in Tolly 44s in some years.
 
Thank you both. Tiltrider-agree on cost to rebuild vs replace. What I am worried about is; heaven forbid I blow one of these 8.2s, but I think that ithe engine has to come out to rebuild. Then the adage of ‘do one do both, plays in my head because you’ve already shelled out $$$ for the dismantling of windows, etc to do one engine.

I’m putting cart before the horse. I just am leary of throwing good money after bad. I may just limp these girls along. It’s always in the back of my head that these engines aren’t the most robust even if I operate them in trawler mode.
 
I think some of the issues with the 8.2s had been resolved by 1988, so yours should be some of the better ones. Not a bad idea to have a plan in mind, but if they're doing adequately for your needs, I'd be inclined to run them until there's signs of an issue forming.
 
I would say that any 8.2’s running today are likely to continue running for a long time.
 
I understand your trepidation with those engines based on the 'history', because I refused to buy a boat that had them installed because of the 'reputation'. However, I wonder if that thought was a partial mistake. Agree with tilrider1 that if they are still operational at this point in time then it is likely they will continue to do so provided you keep up on the normal maintenance and don't run them like a rental.
My current Tolly has Mercruiser 454's and I now wish I had stuck to my original plan of only buying a diesel powered boat. Since your Tolly is already a diesel you are mostly there already... tanks, electrical, transmissions and such. Best advice I would provide is asking who is going to do the work?? You or a boat yard/vendor? If you are going to pay to have this done then you would be best served to reach out to those that do this work frequently/daily and avoid a yard that wants to learn how to accomplish this on your dime.
Yes, the 6BTA will fit as many folks have gone that route already. CATs are installed in many as well.... but you might be better off going with the modern power options for serviceability and all that.. not much sense installing a set of engines that have parts that are hard to come by because they are no longer supported by the vendor or the aftermarket.
I to dream of the power conversion as well, but would likely sell this boat and buy another if it really comes to being more than a dream. This assumes that the rest of the boat isn't already perfect in every respect.
 
Our 8.2s have 250hp and I run them like a trawler. However, if I had a few more ponies……If you could, what would be the optimal repower option? Cummins 370hp?
If you run your boat like a trawler, say 7-8 knots, then you're likely not using more than 40-60 hp even in wind/waves. You're planning to run a 370 down at idle speed of 20-30 hp for 8 hours a day. That's realistic for a modern electronically controlled common rail, but for an old fashioned mechanical 6B it may not be ideal, even with a hard run-up at the end of each day.
What's your use pattern? 90% trawler speed with an occasional higher run? Or vice versa?
You may decide to power with a couple of 4B's, maybe even naturals, if you want to turn that tank into a trawler. (BTW, don't forget to increase your rudder area if you do).
 
I’ve a friend with a Tolly 44. The 8.2s were removed and 6BTs dropped in. The fit was good and install done right. The boat was positively transformed from a performance standpoint. He was so thrilled as he could reliably cruise a few thousand nm from WA to AK without the fear of the next gotcha.

The Tolly 44 is a great boat and a pair of 6BT remans would be a real nice addition.
 
I had a 1975 Tolly 37 that was re powered from gas in about 1992 with 8.2’s. Never had any problems with the engines and never saw any reason to replace them. I expect they’ll run fine for many years (sold the boat a couple of years ago).
 
Thank you for the responses. Right now, we are probably 90% trawler speeds with the occasional run up. I also have the minor fear in the back of my head of keeping them low and slow to avoid the problems 8.2’s can have. Ours don’t exhibit any of those symptoms. However, if the opportunity arose to run her up a little more, I may take that opportunity. My wife and I both still work so our time can be limited. Getting to our spot or to our vacation grounds sooner may be nicer? Getting there is our joy also.

I’m not looking for trouble out of these engines….
 
Engine life is always a function of how hard they’re run. Extract 200hp from them for long periods and the probability of failure increases. If you’re running trawler speeds the biggest risk isn’t the engine blowing it’s more that hose or pump will fail. The 8.2 did have specific issues, and like others I avoided boats with them but mainly because it hits the ability to resell the boat. In the end this may be a peace of mind decision more than a real reliability decision. Of course if you replace the engines that’s the time to consider new tanks as well.
 
I have 8.2s and have gone through the same set of thoughts. Seaboard Maine's web site has good information on engine swaps. They also have some specific information on 8.2 to Cummins. The primary physical difference is they are about 3 inches longer if my memory is correct. With a significant horse power increase you are potentially looking at shaft, prop and strut changes as well as needing a larger diameter exhaust system. All is possible but the dollar amount gets really big in a hurry. My current plan revolves around a spare set of 8.2s I was able to pick up. Time will tell for me what ultimately happens. I'm currently showing nortth of 4000 hours on mine and they are doing ok.
 
Not that it is relevant here, but when our stbd engine grenaded last year I opted to repower instead of repairing them for our 34 Tolly sedan. I changed from gas to diesel (Volvo D4). Older engines become a problem at times because new parts are no longer made by the original manufacturer. That was the case with the 7.4L engines. GM stopped producing them. So, another issue you may find along the way is that a professional service group may not install used engines. Kind of like the whole thing about you can't put an old engine in a new car, but you can put a newer engine (with all emissions intact) into an older car. Anyway, good luck however you decide the go. Taking care of the 8.2's shouldn't be too hard so long as you don't overheat them or abuse them is my understanding.
 
Not that it is relevant here, but when our stbd engine grenaded last year I opted to repower instead of repairing them for our 34 Tolly sedan. I changed from gas to diesel (Volvo D4). Older engines become a problem at times because new parts are no longer made by the original manufacturer. That was the case with the 7.4L engines. GM stopped producing them. So, another issue you may find along the way is that a professional service group may not install used engines. Kind of like the whole thing about you can't put an old engine in a new car, but you can put a newer engine (with all emissions intact) into an older car. Anyway, good luck however you decide the go. Taking care of the 8.2's shouldn't be too hard so long as you don't overheat them or abuse them is my understanding.
Just curious, what part on a GM 7.4 did you have trouble sourcing? That engine has massive aftermarket support and GM still sells two different 7.4 (454HO and ZZ454/440) crate engines (though neither are marinized) and thousands of parts in their engine catalog.
 
Just curious, what part on a GM 7.4 did you have trouble sourcing? That engine has massive aftermarket support and GM still sells two different 7.4 (454HO and ZZ454/440) crate engines (though neither are marinized) and thousands of parts in their engine catalog.
I agree, a big block Chevy is a very supportable engine both in terms of basic engine parts and marinization parts. On older generations of the big block it's possible some of the exact parts that were used for marinization, ignition systems, etc. may not be available anymore, but there are plenty of choices out there to substitute with. Pretty much the only thing I can find to complain about with my 40 year old 454s is fuel consumption. Otherwise they're plenty maintainable and reliable.
 
Admittedly it’s been a long time since I owned a pair of 454 marine engines. I had two go to sources back then, Seacamp and Michigan Motors. I see both are still in business and both still support the 454. With MM you can get everything including a ready to go crate motor.
 
Two major issues with a repair today for a catastrophic failure... finding reliable parts and the people with the skills and availability to work on them.

Although I did break both engines down to the shortblock in my slip at the marina it really was in violation of the local policy. Any boat there must be able to vacate under its own power with 72hrs notice. I skated under that while doing my work when I took down the running port engine (turned out to be down 1 cyl).
But at that point it would not be possible for me to remove both engines and another fuel tank while in the slip. Not on a 34' Tolly. They did not design this boat with that in mind. So going on the hard again, was the only option.

Two facilities would do the work but only if doing a repower with new factory available complete engines, nobody sells a new 454 and the 8.1L would require a lot of custom work which would bring the costs way up upon completion (essentially duplicating some of the work the diesel repower involved). Nobody within a normal distance to me would touch these older carbed engines. I mentioned the word 'gas' during the initial call and they would decline to touch them. Deemed too dangerous because of insurance. Outboards only but no inboards is what I kept hearing over and over. Then the discussion was about warranty work. Reman'd engines are too unknown for a business so that was not an option either. Could I have had them install a reman'd pair of shortblocks and then do some other work that I cannot do so easily.. yes, but with a huge caveat.

So, I opted to go diesel which is what I truly wanted when I went shopping. Our plan was to do a repower at some point... it just came a few years too early is all. If I had had a couple of seasons I could have waited and figured out a lot of the unknowns on my own after much research and discussions, I guess I could have eventually got it done, but then I would be facing more yard storage time being added. I worked on the boat quite a bit but was not charged those fees as I have been charged by other yards (a yard that ruined some of those items they touched) that 'other' facility will never see my boat dollars again. Finding good help is real hard these days. North Harbor Diesel did a wonderful job and I have no regrets about what they did. But, I should have bought a diesel boat all along. Now I have brand new engines that I know the entire history about (my history).

I do realize I could have saved thousands of dollars on this entire process, but then the boat would still be in a yard somewhere in who knows what condition. It is hard to work on a boat full time when you have a job that is full time. At this point, the money I spent was worth the boating satisfaction I am now enjoying each weekend. We are going on our first overnight trip out of town this season and I am so looking forward to it.
 
Two major issues with a repair today for a catastrophic failure... finding reliable parts and the people with the skills and availability to work on them.

Although I did break both engines down to the shortblock in my slip at the marina it really was in violation of the local policy. Any boat there must be able to vacate under its own power with 72hrs notice. I skated under that while doing my work when I took down the running port engine (turned out to be down 1 cyl).
But at that point it would not be possible for me to remove both engines and another fuel tank while in the slip. Not on a 34' Tolly. They did not design this boat with that in mind. So going on the hard again, was the only option.

Two facilities would do the work but only if doing a repower with new factory available complete engines, nobody sells a new 454 and the 8.1L would require a lot of custom work which would bring the costs way up upon completion (essentially duplicating some of the work the diesel repower involved). Nobody within a normal distance to me would touch these older carbed engines. I mentioned the word 'gas' during the initial call and they would decline to touch them. Deemed too dangerous because of insurance. Outboards only but no inboards is what I kept hearing over and over. Then the discussion was about warranty work. Reman'd engines are too unknown for a business so that was not an option either. Could I have had them install a reman'd pair of shortblocks and then do some other work that I cannot do so easily.. yes, but with a huge caveat.

So, I opted to go diesel which is what I truly wanted when I went shopping. Our plan was to do a repower at some point... it just came a few years too early is all. If I had had a couple of seasons I could have waited and figured out a lot of the unknowns on my own after much research and discussions, I guess I could have eventually got it done, but then I would be facing more yard storage time being added. I worked on the boat quite a bit but was not charged those fees as I have been charged by other yards (a yard that ruined some of those items they touched) that 'other' facility will never see my boat dollars again. Finding good help is real hard these days. North Harbor Diesel did a wonderful job and I have no regrets about what they did. But, I should have bought a diesel boat all along. Now I have brand new engines that I know the entire history about (my history).

I do realize I could have saved thousands of dollars on this entire process, but then the boat would still be in a yard somewhere in who knows what condition. It is hard to work on a boat full time when you have a job that is full time. At this point, the money I spent was worth the boating satisfaction I am now enjoying each weekend. We are going on our first overnight trip out of town this season and I am so looking forward to it.
Those D4s are a
 

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