I'm considering DIY overhauling both 8v71Ti's in our 58' YF!!

So I'm faced with several decisions on which direction to go with overhauling in frame or engine swap for our 1972 58' Yachtfisherman.
Yes, I am well aware of the size and scope of the project. No I will not hire a "professional" to do the job as I have no need since I can do most of the work myself while having access to many friends in the overhaul industry for technical guidance .

My main discussion questions are mainly to those that have done "in frame" overhauls and to those that have done engine out swaps. This experience is very valuable to me. Any thoughts, tips and ideas would be greatly appreciated!

Not to be overlooked, I have contemplated the idea of perhaps going to a newer engine (cummins/CAT) but obviously the costs are vastly different and perhaps prohibitive.

So let's here the pros and cons, the experiences and the do's and don'ts.

Mario

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Originally Posted by MarioG

So I'm faced with several decisions on which direction to go with overhauling in frame or engine swap for our 1972 58' Yachtfisherman.
Yes, I am well aware of the size and scope of the project. No I will not hire a "professional" to do the job as I have no need since I can do most of the work myself while having access to many friends in the overhaul industry for technical guidance .

My main discussion questions are mainly to those that have done "in frame" overhauls and to those that have done engine out swaps. This experience is very valuable to me. Any thoughts, tips and ideas would be greatly appreciated!

Not to be overlooked, I have contemplated the idea of perhaps going to a newer engine (cummins/CAT) but obviously the costs are vastly different and perhaps prohibitive.

So let's here the pros and cons, the experiences and the do's and don'ts.

Mario

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From a cost perspective, plan on about 13-14k per engine. About 5k for new turbos and blowers. 3k to get the heads reworked. 4k for the basic overhaul kit (pistons, rings, bearings, liners), 1k for injectors, 1k for gaskets and consumables. I've built many engines, so in many respects, it wasn't my 1st rodeo... fitting the liners is a tough job, and the sheer weight of the components makes it hard. The ER on my 63 is huge, so I was able to pull the upper oil pan (130lbs), without lifting the engine. If you can't do that, I'd advise against it. Access to the underside of my engine was easy. Without that access, farm it out.

It seems to me that the biggest problem is that you all live on your boat. Living on your boat whilst you are overhauling the engines sounds like a very unpleasant situation to me. Do they need it that badly?I would think that your most efficient and cost effective way to do this is to contract for two rebuilt 8-71 long blocks, and swap them into your boat. Send your engines back as cores.

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Originally Posted by jim rosenthal

It seems to me that the biggest problem is that you all live on your boat. Living on your boat whilst you are overhauling the engines sounds like a very unpleasant situation to me. Do they need it that badly?I would think that your most efficient and cost effective way to do this is to contract for two rebuilt 8-71 long blocks, and swap them into your boat. Send your engines back as cores.

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Yeah, no way we'll stay on the boat. Probably stay at our house or somewhere.

The long block idea sounds interesting.

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Originally Posted by dottieshusband

From a cost perspective, plan on about 13-14k per engine. About 5k for new turbos and blowers. 3k to get the heads reworked. 4k for the basic overhaul kit (pistons, rings, bearings, liners), 1k for injectors, 1k for gaskets and consumables. I've built many engines, so in many respects, it wasn't my 1st rodeo... fitting the liners is a tough job, and the sheer weight of the components makes it hard. The ER on my 63 is huge, so I was able to pull the upper oil pan (130lbs), without lifting the engine. If you can't do that, I'd advise against it. Access to the underside of my engine was easy. Without that access, farm it out.

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Yeah, by the looks of it, there is poor access under the engine . Engine will have to be lifted somehow.

Mario, I’m finishing up this exact project now on my port engine. You can’t pull the oil pan without lifting the engine, which means unhooking it from the transmission, or lifting both somehow. At 3200 or 3500 pounds that task alone is tough. I didn’t want to do all of the piston and internal work myself so bought a long block from MTU. Yep, they have a long block program where they will give you about 2k back for your block. Once this was factored in the long block cost me 16k. Now yes the turbos and blower, intercooler and anything else you want to change will be on top of that, but I figured if I got it from MTU I stood a better chance of getting it done right than farming out to someone I didn’t know. Also, up here in NE there are simply not a whole lot of shops that will do this. You can find their long block program if you google it. Take LOTS of pics with the camera because it greatly improves your confidence when putting the accessories back on to the new engine. The little things take an inordinate amount of time to figure out if you don’t take pics....... and from several angles helps too.

Why bother doing all that work if its not your regular job. I'd suggest working some extra time and having it done..

1) if you get hurt and cant work your screwed.
2) I'd not buy a boat with a DIY overhaul as a reliable rebuild.
3) I can make asmuch or something more money doing things I do well for work than it cost to hire a good mechanic to do what he does best.

And most importantly that's a lot of work. A repower is probably easier than an inframe.

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Originally Posted by johnjen50

Mario, I’m finishing up this exact project now on my port engine. You can’t pull the oil pan without lifting the engine, which means unhooking it from the transmission, or lifting both somehow. At 3200 or 3500 pounds that task alone is tough. I didn’t want to do all of the piston and internal work myself so bought a long block from MTU. Yep, they have a long block program where they will give you about 2k back for your block. Once this was factored in the long block cost me 16k. Now yes the turbos and blower, intercooler and anything else you want to change will be on top of that, but I figured if I got it from MTU I stood a better chance of getting it done right than farming out to someone I didn’t know. Also, up here in NE there are simply not a whole lot of shops that will do this. You can find their long block program if you google it. Take LOTS of pics with the camera because it greatly improves your confidence when putting the accessories back on to the new engine. The little things take an inordinate amount of time to figure out if you don’t take pics....... and from several angles helps too.

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A quick search found me this:

https://www.mtu-online.com/mtu-north...e/long-blocks/

Unless you REALLY enjoy this kind of work and you are good at it.. I'd hire it done.

You might also be able to hire a good DD mechanic who would agree to have you be the second pair of hands, but he would be in charge. I've done that a few times and it's worked out well. I'm the helper- I learn a lot, and save a few dollars in the bargain.

MTU guaranteed long blocks are a good idea. You still have to have rebuilt turbos, blowers, heat exchangers, etc.

I don't envy you. Are your present engines THAT tired? Really?

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Originally Posted by jim rosenthal

Unless you REALLY enjoy this kind of work and you are good at it.. I'd hire it done.

You might also be able to hire a good DD mechanic who would agree to have you be the second pair of hands, but he would be in charge. I've done that a few times and it's worked out well. I'm the helper- I learn a lot, and save a few dollars in the bargain.

MTU guaranteed long blocks are a good idea. You still have to have rebuilt turbos, blowers, heat exchangers, etc.

I don't envy you. Are your present engines THAT tired? Really?

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If I did go with MTU long blocks I would think most of the technical overhauling is done leaving only the accessories to install (turbos, blowers ect)

I'm not worried about the work involved. I can handle big projects myself no problem. I do have lots of friends though.

Yes, the current engines are very tired now. All the symptoms of low compression are there.

I’m not trying to talk you out of doing the work yourself I can only this information from growing up in boatyard hell and my observations from watching the diy process. If you are going to do it make sure to clean up as you go. The heads are heavy, have very sharp edges and things get slick with oil and diesel in a hurry. I had a customer drop a 6-71 head on his hand and it mangled it. There’s also times that I saw owners pull an engine apart 3 times and it still would spin a cam bearing after about 3 minutes of run time. The only way my Dad would do it for a customer was pull the engine, send it to a dealer and let them rebuild it and test run it. If you do decide to press on you are going to need a set of a-frames with a stout cross bar and a pair of quality come-alongs. We used a length of 2” shaft material. You also need to shore up the floor. You can cut 2x4’s and brace from the stringers. Once you have the engine lifted it’s not much more work to set the engine on a cradle and roll it out the door on pipe rollers. We had our old hoist set up with a pair of I-beams where the straps go and a long I-beam with a counterweight to reach in and lift the engine out. It was an Algonquin that was on rails that was electric so it was very controllable and quiet so you could hear the spotter. Check around and see if something’s available to get the engines out. That’s a lot of heavy iron.

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Originally Posted by MarioG

A quick search found me this:

https://www.mtu-online.com/mtu-north...e/long-blocks/

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I really enjoy learning from these threads. I used to dream of QSM’s or Cats if we win the lottery, but see that this MTU option probably makes vastly more sense. One question, why the “long block” distinction? I read the MTU web site description, and did some searches which lead me to a great David Pascoe article on Detroit’s vs all the 4-strokes, but didn’t find anything else specific about “long block”. I assume the MTU has to fit in the same 8V71 engine space and mounts?

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Originally Posted by Boatsb

Why bother doing all that work if its not your regular job. I'd suggest working some extra time and having it done..

1) if you get hurt and cant work your screwed.
2) I'd not buy a boat with a DIY overhaul as a reliable rebuild.
3) I can make asmuch or something more money doing things I do well for work than it cost to hire a good mechanic to do what he does best.

And most importantly that's a lot of work. A repower is probably easier than an inframe.

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What Scott said. I'm a firm believer that everyone should do what they do best. Fly some extra trips and hire a mechanic to do the boat work.

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Originally Posted by MarioG

If I did go with MTU long blocks I would think most of the technical overhauling is done leaving only the accessories to install (turbos, blowers ect)

I'm not worried about the work involved. I can handle big projects myself no problem. I do have lots of friends though.

Yes, the current engines are very tired now. All the symptoms of low compression are there.

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Looks like they re called MTU long blocks because Detroit belongs to MTU but they have to be identical to the older Detroits. It is a better option than rebuilding as you know they will be done right. Plus in our boats there is really no access underneath so they d have to be raised or taken out anyway. florida Detroit Allison, up on the river, is probably the local dealer for these long blocks.

Personally i dont think you want to rebuild your engines yourself. Just one mistake is all it takes to be back to square one. This is why i repowered but the long blocks are a good alternative

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Originally Posted by nautibake

I really enjoy learning from these threads. I used to dream of QSM’s or Cats if we win the lottery, but see that this MTU option probably makes vastly more sense. One question, why the “long block” distinction? I read the MTU web site description, and did some searches which lead me to a great David Pascoe article on Detroit’s vs all the 4-strokes, but didn’t find anything else specific about “long block”. I assume the MTU has to fit in the same 8V71 engine space and mounts?

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A long block is the block assembly (short block) plus the cylinder heads. Same engine just comes with the liners and crank installed and the heads with valve job already torqued to the block.

I have assisted in some engine swaps where we used a sky track lift to remove the engines. We secured an I beam of the proper length to one of the forks. Then the I beam is sent through the salon door or wherever the access point is and attached to the engine. Old engine out and new one back in place in one sitting. No need for jacks, shoring up, etc. Just make sure everything is loose and ready to come out before you call the rental company if you are doing a one day rental.

Do any of the newer engines use sleeves like the older DDs did?

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Originally Posted by Pascal

Looks like they re called MTU long blocks because Detroit belongs to MTU but they have to be identical to the older Detroits. It is a better option than rebuilding as you know they will be done right. Plus in our boats there is really no access underneath so they d have to be raised or taken out anyway. florida Detroit Allison, up on the river, is probably the local dealer for these long blocks.

Personally i dont think you want to rebuild your engines yourself. Just one mistake is all it takes to be back to square one. This is why i repowered but the long blocks are a good alternative

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Clearly, as of now, an MTU long block makes obvious sense.

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Originally Posted by MarioG

Yes, the current engines are very tired now. All the symptoms of low compression are there.

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You mean you checked the valve adjustments and then did a dry compression check followed by a wet one in any suspect cylinders and ALL of it is bad on the lower end?

You may find you're lucky and just have to R&R head(s).... or rebuild one or two jugs and get a whole bunch more hours out of them.

There's a lot you can do before you condemn the whole motor.

I have very hard cold starts, smoke like a volcano when cold. Bluish smoke, the smell of unburned fuel in the exhaust is nauseating. High oil consumption.

Try this company’s products first. In particular their Oil Flush and also FTC fuel additive.

www.costeffective.com.au

They have an American distributor. I’ve always used these two products on my four DDs over the past 16 years.

Plenty of other testimonials on the website. There is actually a testimonial from a DD boat owner with engine symptoms similar to yours.

Definitely not snake oil. For a couple of hundred dollars you may save thousands.

For a frame of reference, my neighbor is needing the top ends of his 1271ti’s done. After paying $20k to the Detroit dealer here for new injectors, the dealer bid $57k for the job. I’m not able to say what else that might include. They did include a 4 hour charge in the estimate to determine what parts would be required which didn’t sit well. Dealer claims both in-frame builds could be completed in four days. They must have a 24 hour machine shop to make that claim.

Mario, if you pull them out this is what you ll be looking at...

These guys were pretty good ... Luis can work out of various yards. He s great with shafts alignments thru hulls etc

https://youtu.be/nvjsv4KzCb8

First thing I would do is pull the air box covers and check the ring tension. I would bet that most of these MY engines are not worn out or tired but have stuck or broken rings from sitting and lack of use. I rebuilt both my 12’s myself after 10,000 hours of hard canyon and charter use and found the main bearings and crank journals measured almost to new specs. People on this fourm go way overboard and do knee jerk stuff when it’s unneeded. Unless the engines were overheated or run out of oil I wouldn’t even mess with long blocks.
Fix what’s wrong and run it!

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Originally Posted by rsmith

First thing I would do is pull the air box covers and check the ring tension. I would bet that most of these MY engines are not worn out or tired but have stuck or broken rings from sitting and lack of use. I rebuilt both my 12’s myself after 10,000 hours of hard canyon and charter use and found the main bearings and crank journals measured almost to new specs. People on this fourm go way overboard and do knee jerk stuff when it’s unneeded. Unless the engines were overheated or run out of oil I wouldn’t even mess with long blocks.
Fix what’s wrong and run it!

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+1 for what he said. My main and rod bearings were as new. Cross hatching still visable on the liners, but the valves were a different story. You can get a remanufactured head or get yours reworked with new valves for 4k or so, another 1.5k for remanufactured injectors, labor, poor man's rebuild.

Mario, I apologize if someone's already said this, but perhaps you should get an engine survey first, and find out what they need? Perhaps they only need cylinder kits and heads Maybe the main bearings and bottom ends are okay?

Ditto all of the above. You owe it to yourself to go through the diagnostics before you pull the pin.

It would sure stink to pull the kits and find out the problem was something less.

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Originally Posted by rsmith

First thing I would do is pull the air box covers and check the ring tension. I would bet that most of these MY engines are not worn out or tired but have stuck or broken rings from sitting and lack of use. I rebuilt both my 12’s myself after 10,000 hours of hard canyon and charter use and found the main bearings and crank journals measured almost to new specs. People on this fourm go way overboard and do knee jerk stuff when it’s unneeded. Unless the engines were overheated or run out of oil I wouldn’t even mess with long blocks.
Fix what’s wrong and run it!

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When I bought my first DD boat, a 73 46 Bertram MY in 2002 with 8-71TI's I knew nothing about them. Asked around and I had many point me in the direction of some old time DD pro's still in the field.

One thing I got over and over was how stout these are and how well they will still perform even if hurting. Take Rsmiths advice and look further into them before assuming they are done.

I have nearly new 8-92's now and even then still nervous about how long will they last. Bet I am pushing up Daisey's long before they give up the ghost as long as no overheats occur.

Nothing to lose by checking.

I agree, it is a good idea to look deeper. It would be a nice to find a simpler problem that would be easier to fix. But all of this discussion is also very good to formulate a plan of action as well as options.

Mario, these guys are probably right. In my case the intercooler sprung a leak, sprayed the inside of the engine with salt water, and seized over the winter layup. I have a ton of pics that I will try and upload soon. Everything from what it looked like when I took off the blower and air box covers, to the fork lift with VERY LONG forks that plucked it off the back deck after we rolled the engine through the salon out to the back deck. I pulled just the engine, and stripped it of exhaust and blower turbos etc.....the heavy stuff so I didn’t need to support the floor from the underneath. It’s a big job, but I had “loose” quotes of $15-$25 for a rebuild in frame. I decided I would spend the money on the essentially new block and heads and go forward with a new engine that I would maintain from day one. Mario if you pm me I can email you a bulk load. I took pics of everything as I took it off the old engine so I would remember orientation when reassembling. In 5 or 6 years I can retire, and figured I wanted fresh power so I could be confident taking the boat south to the keys and Bahamas. These engines really are well designed and with a little time and study you could probably fix most problems yourself. No sensors or electronics to worry about. And I think if you could run them fairly regularly they probably would run forever. So if I were you and it wasn’t seized I would check the air box covers and rings first. But, depending on cost, the long block is exactly the same block on the same footprint with essentially new cranks and vitals. They actually need your engine serial number to make sure they set up exactly the same engine on the new block.

Hi Mario,
I did an in frame on my Chris Craft with 8v71ti's back in 1999. The most important thing to consider is access to the connecting rods under the engine. Also, it is VERY important to have a Detroit Diesel Engine Book to give you all the torque settings. The book will also give you detailed instructions and what parts to take off and in what order for an in frame. On my engine, the oil pan could not be removed. I just removed it and left in under the engine. Back then, I had the physical ability to work in contorted positions and the strenght to torque down those large bolts. I couldn't do it today. I bought only factory Detroit Diesel parts and didn't have any problems. I had a Detroit Dealer build the pistons with rings and install them in the liners and ordered Relaibuilt heads. All I did was take off the old parts and installed the new ones. I remember I had trouble removing one of the liners. It was cracked in half around intake ports. I rented a tool that looked like a dent puller and got it out. Once it was all together, I had the same Detroit Mechanic install the injectors and fire it up. I think I have about 800 plus hours on it now and it still has 55 PSI Oil pressure and starts on a half rotation with NO SMOKE bone cold.
Best of luck to you,
John

I have a 1978 53MY with 8v71Ti's and completed an in-frame last year with the help of an experienced DD mechanic. Or should I say, I helped mechanic which I was completely fine with. I need the experience. All in I was around $15k, but I was able to get the kit and some other parts at cost (blowers and turbos were fine). We lifted the engine using aluminum I-beams spanning the width of the salon and two chain falls. We lifted once we removed everything we could in order to reduce weight.
The trick was access under the block once lifted. Fortunately the mechanic had a small framed son that was limber enough to slide under the block to perform some work.(don't worry we had the engine sitting on secured to blocks!)
Overall it was a great experience, however I hope I never have to do it again. Good luck!
Jeff

That seems like a fabulous p4ice for two motors.

A great place for DD parts is Interstate McBee, highly recommended by many DD mechs. I had both my V12's done with their parts and the mechanic really was impressed with the apparent quality.

When it comes to the Marine industry it blows my mind the rates that vendors charge to a customer. Which of course so to diesel truck shops. these older diesel engines are a breeze to rebuild, get a service manual, youtube and determination and you will be fine. I have been quoted engine swap and rebuild numbers before and the vendor doesn't know we have a fleet of trucks and equipment which we do all our own work. Yes tearing down a motor in a shop is way better and cleaner, but I have done it in the middle of a job site. These older engines don't have ecm and sensors that cause troubles. So you would be capable of attempting the rebuild yourself. I would recommend getting parts from non marine dealers, prices would be way better. That what we have done. Many special tools can be made or found on ebay. The newer engines are the same , we just swapped an engine out of a 2009 Mack, the labor was about 3-4 days lots of specific part swapping, but it took 2 days of computer work to get all of sensors to be happy. We have a laptop and software that ran us about 8k. Something to also consider if your wanting to swap are the reman cummins options. Again gather your info then shop around away from the water. Do the math and shop around when you are doing this project. Marine vendors sometimes put the screws to an owner because they have money. That concept frustrates me because it eats up you boat budget and takes away from other projects.

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Originally Posted by Texastailboard

When it comes to the Marine industry it blows my mind the rates that vendors charge to a customer. Which of course so to diesel truck shops. these older diesel engines are a breeze to rebuild, get a service manual, youtube and determination and you will be fine. I have been quoted engine swap and rebuild numbers before and the vendor doesn't know we have a fleet of trucks and equipment which we do all our own work. Yes tearing down a motor in a shop is way better and cleaner, but I have done it in the middle of a job site. These older engines don't have ecm and sensors that cause troubles. So you would be capable of attempting the rebuild yourself. I would recommend getting parts from non marine dealers, prices would be way better. That what we have done. Many special tools can be made or found on ebay. The newer engines are the same , we just swapped an engine out of a 2009 Mack, the labor was about 3-4 days lots of specific part swapping, but it took 2 days of computer work to get all of sensors to be happy. We have a laptop and software that ran us about 8k. Something to also consider if your wanting to swap are the reman cummins options. Again gather your info then shop around away from the water. Do the math and shop around when you are doing this project. Marine vendors sometimes put the screws to an owner because they have money. That concept frustrates me because it eats up you boat budget and takes away from other projects.

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So your saying you dont charge for time on the software when you use that $8k computer?

Not that some vendors cant be trusted but keep in mind the $2,000,000.00 minimum liability insurance, the comp and healthcare costs, rents and vehicle costs for working on boats. If you work on trucks ask your carrier how much adding marine insurance will add.

Its mind blowing. When you need to pay those costs you cant do work for $50 an hour.

The engines themselves may be similar- often are- but the work environment is different. Taking an engine out of a truck, with unlimited room around you, is not the same as having to crane it out of the engine room of a boat, and trolley it out through the aft doors, or lift it through a hole in the roof. Overhauling the engine itself seems to be the least of the work- getting it out and then back in is quite a bit more demanding.

There’s a lot of truth to that. It took about about 3/4 day to get the engine out of my yachtfish, and we had a pretty good plan and all the right equipment there. It’s one of those things where you gotta be careful, cause if you drop that sucker.............

[QUOTE=Canuck Dennis;344591]A great place for DD parts is Interstate McBee, highly recommended by many DD mechs. I had both my V12's done with their parts and the mechanic really was impressed with the apparent quality.[/QUOTEThanks for this info, there are many disadvantages to living in California and now this one, fortunately other outfits aren’t showing the same policy.. http://interstate-mcbee.com/calirestrictions.aspx does anyone know what’s up with this? Regards, Craig

[QUOTE=Top Hatt Craig;344790]

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Originally Posted by Canuck Dennis

A great place for DD parts is Interstate McBee, highly recommended by many DD mechs. I had both my V12's done with their parts and the mechanic really was impressed with the apparent quality.[/QUOTEThanks for this info, there are many disadvantages to living in California and now this one, fortunately other outfits aren’t showing the same policy.. http://interstate-mcbee.com/calirestrictions.aspx does anyone know what’s up with this? Regards, Craig

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Really? You have to ask?

Doing business in California sucks. If it's legal to sell it's a delivery issue. If it works it's a environmentally sensitive issue.