Highly suggest glassing in new beams for your engine mounts. Those beams tied into the transom act just as a car/truck frame. Once you apply the torque of a strong engine, there's a chance it could separate those old beams from the floor. You would be stuck right back to pulling the engine and outdrive again to replacing the beams and glassing them in. Can't wait to see the end result of your project. FREAKING AWESOME!!!!!
Same idea to also consider the mentality of risk it vs know for sure. Glassing in has the ease of mind that you know that it will be as good as can be reasonably done. Likely with better than factory materials.
Heck yeah, another RUclipsr once took their diesels out of their yacht for gas LS and it was stupid. Going from gas to diesel makes all the sense in the world. Fantastic
@@summertop511Well they DID get it re-floated. I stopped following it when the insurance issue came up plus the entire thing was just too reckless for me.
Aaron and Em, several commenters have talked about potential issues presented by the high torque of the diesel engine (beefing up stringers and engine mounts etc,) but an additional significant area of concern when putting a diesel in front of and alpha or bravo drive is the drive capacity to handle high power and more specifically, HIGH TORQUE. The bravo is a very beefy drive but only designed to handle so much torque. Subjecting the drive to drop throttle starts that load the drive above its torque limit can be problematic for reasons I probably dont have to explain to you. Make sure you check your specs for compatibility in this regard if you havent already. Mercruiser does make a special X and XR series bravo for diesel and high output gas engines. To my knowledge, mercury does not recommend the bravo for any diesel applications. Bravo X will handle gas engines up to 600hp and diesels up to 370HP. Not sure about the XR. Do some research. This is a challenging project. Im impressed with your skill and courage to take it on.
Volvo Penta makes excellent stern drives for diesels, if the bravos don’t work. Like others have stated adjust everything for the diesels torque from drive shafts drives and stringers. God bless on this project. Will be an adventure….
The nice thing about diesel in a boat is they like running at full power for hours on end. Gears can always be fixed, or you swap props. Keep the blowers, fumes are bad either way. Fitting cooled exhaust manifolds could be a tough one. Though there are a few guys up here in WI that make them all of the time.
Thanks for being down to earth and honest about yourselves and projects . i really like how you are teaching the Kid , i love seeing the young people getting involved in the mechanics . you have a great channel don't change
You should replace the engine mounts in the boat that way you ken last longer then the boat. Plus you could give the engine bay a good scrub and repaint. Will look minted if all spotless.
The rot in the stringer ends will continue to rot. The rot is a fungus,, .. It must be removed to last any length of time. It might be handy to remove the top off the stringer Past the motor mounts and use pressure treated wood to replace it... Simple is usually the best. Then lay matting with directional over it to cover the stringer. Also making a knee brace from the stringers to the transom while you are at it is a good idea too. (20 + years of boat racing, building and fixing here)
@@86foureyefreak22 Sorry.. Here in CA we have a copper sulfate pressure treating that is not oil base... Mixing polyester resin and acetone 50/50 and soaking in a first coat works... You can also use heart redwood but more layers of glass are needed. You might try oak with you painting on water base coper sulfate preservative can work too. Even eucalyptus is outstanding also. Most of all just replace the top portion of the stringer with new lumber and glass over it..
when ford started putting diesels in their trucks, they quickly learned that the cross members that were riveted could not handle the torque of the motor so they had a beef up fix for the first few model years, If I were you, I would heed the suggestions of people with knowledge here and beef up to the max those stringers and buy the proper outdrive.
NOT a boat builder, but enjoy the stuff the Ship Happens couple are doing to their boats. They're rebuilding a wooden WWII Harbor Defense Motor Launch, and are replacing portions of stringers, frames and deck beams with scarf joints. They epoxy and bolt them into place. I'd think if it works for a 70-foot twin Cat ML, it'll work for your boat. I'd think some Coosa Board 'wedges between the back of the engine stringer and transom would be plenty strong when epoxied into place. You could drive a couple of long SS lag bolts from the back of the boat through the transom and stringer to hold things together even better, then 'glass over that. They also have a twin Cat speed boat they're doing work on. No hull work, but good info there, too. Their two engines are in an engine compartment not much bigger than the engine compartment on your boat, and turbo heat is no big deal there.
I will give ya a tip since your going this far when the engine is done add an adapter to the drain for the oil pan add a tube to bring it out beside the engine add a shutoff valve then add a longer tube that is threaded to that to add a cap just in case the valve opens for some reason, but the main reason is you remove the cap add a hose the you can crack open the shutoff valve then you can suck out the oil from the bottom and make it faster and easy to do oil changes !!
On some boats they pull the drain hose for the oil pan out the drain plug in the bottom. Great idea as I was thinking the same idea. I can’t wait to see how this works out. I’m a dirtymax fan and love mine. Awesome videos!
I would build a cradle between the stringers out of aluminum stock to help handle that torque. Most ski / wakeboard boats have this setup. Wood stringers are always an issue, but you may not have the ability to replace enough of the stringer system with a composite setup. Brace what is there.
Hey guys I just bought my first Bayliner 2858 Ciera Command Bridge and my first thought was to diesel swap it. My quest for “how possible is this” lead me to your channel and I am very excited to follow along your journey.
Hmmm... never thought about sleeping on the boat with that big gas tank... of course I was a kid, totally uneducated. My Father was totally conscious of ventilation when refueling... still, there's always a risk. Saw the aftermath of a boat that exploded in a covered dock, nothing left... transom blown across the narrow channel.
Fantastic! Me personally? Thinking CAT C7, mid 2000s vintage, pre DEF. But great choice. Again, lower RPM, More Torque, may need to look gears and prop. Have Fun!
Your alignment issues will come when you go to put the outdrive back on. There is a tool(easily made) that will align the gimbel bearing with the hub. Otherwise the drive shaft will not go in no matter how much you struggle. I don't believe I still have the one we made--but if we made it, anything is possible
There is a product called skunk stabilizer that will make those stringers very beefy when using the boat in the winter months at altitude. It will require holes but the again you are looking for strength rather than beauty.
I like this! Considering all the problems with gasoline on boats (storage, fire risk, etc), I don't understand why diesel isn't the standard in all marine applications.
Hey folks, been watching your channel for a while and enjoy your content. I have replaced my transom and stringers before as a rule of thumb you can do a scarf joint on the stringers, the way it works is 10 x the height of your stringers and considering your tight space it’s probably better to replace them. Here in Australia we use F17 hardwood and marine ply heavily soaked in west systems epoxy, your coosa board maybe much more durable can’t say I have never used it. Also all penetrations for bolts etc we always drill oversized and fill them with epoxy then re drill. Bolts are then installed with polyurethane marine sealant. Looks like you have it all under control and really enjoy your videos Shaun in Australia.
Great content. I once presented a technical paper on reverse engineering. One thing we found helpful on complex fit-up situations was to take digital photo from above [the plan view] and then write the dimensions measured on the photo. Save many trips to re-measure and rework later.
If you’re going to remove the pistons, check out speed of air pistons online. Make great pistons for diesels. Engine will run quieter and more efficiently. Seriously, check them out, you won’t regret it.
Cove and glass the engine beds onto the transom with three or four layers of 600 gram double bias cloth or similar with west system or similar epoxy resin. Go from narrow to wide strips in increasing widths. best to do it after transom repair is glassed.
Sounds like a great swap. Exhaust manifolds could be the major issue. If somebody else has done one, all the better. Freeboard is important(distance from waterline to exhaust highest point after turbo). Look forward to the build.
Check out the torque specs between both motors that will give you an indication if you need to replace the stringers. It will also depend on which prop you are using. The pitch will cause different stress levels. You need to research the correct pitch for the RPM you will have to maximize your planning speed and cruising speed. You could use a variable pitch prop but that is expensive but can be an option. By the way, a variable pitch prop makes docking and maneuvering so much easier. Hope this helps. Also make sure both motors are rotating in the same direction.
FSG aka Aaron + Emily, very smart move from a safety and efficiency perspective! Changing diameter and blade pitch on the prop can adjust RPM differences re knots per hour, planning etc. You two are the A-team!
Oh I’m so happy to actually see someone do a Duramax swap in something instead of swapping a Cummins!!! Everyone is always doing a Cummins swap instead of the Duramax swaps and I say it’s because everyone likes the simplicity of what all you actually need to run a Cummins!!! I see square body trucks out there with Cummins in them along with plenty of other vehicles out there but very rarely do I ever get to see a Duramax swap in any thing!!! I’ve always told myself that if I ever go putting a diesel engine in one of my square body trucks or even any one of my 1967-1972 Chevy trucks it would definitely be a Duramax swap for sure and definitely Not a Cummins swap!!! My Duramax I have now is a 2007 classic body style and I have had it since 2010 and it also has definitely helped me recover on my last truck that I had and ended up literally paying for it twice in full and that definitely put me in the hole badly but after selling that truck and getting my Duramax I have definitely been recuperating the money that I have lost on my last truck because I have had to do absolutely nothing to my duramax at all other than regular maintenance things on it!!! I’m definitely really hoping that I can learn from you on how you end up doing everything for the swap and maybe that will help me get a better idea on what I might need or what I might have to look for in putting a Duramax in one of my square body trucks that I have definitely been wanting to do for quite some time now!!! Awesome video for sure and I am definitely looking forward to many more videos on this build for sure!!!!
I think you are on the right path. More torque, better fuel efficiency and better longevity for what you want. Plus you can get about the same RPM as the big block because they originally used the 396 for the first generation of junk diesel engines. I'm glad that GM keeps the same Bell housing and still a similar side mount for easy swaps. But the most important thing is seeing Aaron back to working on a diesel again 😊. I can't wait to see you guys have fun again in the water.
Interesting swap . . . the Duramax for the 7.4 BB. Make sure you get the proper exhaust (aka Wet Exhaust). Not sure if the turbo/supercharger needs cooling (?) Have you thought about the fuel tank? ( I believe diesels have a return line and usually there is a spare fitting on the fuel tank). Also you may want to inspect and pressure test the fuel tank. (usually 3 psi is all you want/need to test ). As for a partial replacement on the stringers . . . yes . . . , as long as you can identify where you get into good wood. Then fiberglass a few extra layers of 1708 cloth in the area where old/new meet. Most of the strength is in the fiberglass, since it is the outer layer. The wood acts like a core, as long as you have about 1/8" thick (or more) fiberglass over the wood. The iboats website has a forum with a restoration section for lots of examples from folks who have repaired/restored their boats. I've done a partial repair on the stringers of my Formula 242. It is all do-able stuff.
Don't forget to get a diesel generator and pull out the gas generator so you don't have to have two different fuels if the boat already has a stand along generator.
@@robertnelson3745 I couldn't recall. Might be worth adding one if there is room. Or even a propane powered one, which would add a second fuel but much less smell when anchored in spot. My backup generator for my house will run on both propane and gas. Though those "solar" generators are always sponsoring youtube channels ... might be a good time for a add spot for one of those large battery banks and solar panels :)
I’d recommend replacing those stringers completely with the amount of torque your Duramax will produce I think that would be a wise move. I’d install some stainless steel T plates to the end of the new stringers where they connect to the new transom and then fibreglass them all in using F type fire proof resin. I would add smaller port to starboard stringers to strengthen the hull but allow gaps for water to drain to the bilge and be collected by the bilge pump. I’d definitely use a solid synthetic or plastic wood for the stringers for a permanent solution.
I keep thinking of things . . . You may want/need to check the camshaft spec's on the Duramax engine vs. what a marine diesel version would have. The 7.4L BB that you took out of the boat has a very mild cam, with hardly any valve overlap. That is to avoid 'exhaust reversion' in a 'wet exhaust' engine. If the cam is too aggressive (higher valve overlap) you may pull water back into the cylinders at idle speeds (hydrolock).
For the stringers and tying it all back into the Coosa, well worth watching Andy at Boatwork Today's series on the rebuilding the transom of his Bertram. Great series of videos and will answer all the questions you have. He'll be sure to help you too. Good to hear that the exhaust turbo manifold cooling and water injection is being dealt with, that did worry me somewhat but I should have realised that you'd both have it all in hand. Cheers from the UK
What a great project. The 1990 big block Baja I bought was built with a higher X factor. This placed the out drive farther out of the water for less drag and made it faster than a stock boat. It was good for another 5-4 mph. I have a feeling you are looking for reliability rather than speed as your boat is meant for cruising and is quite heavy.
This is mind blowing guys. If anybody can do it, it's you two. I can't wait to see this boat run. Watching it all come together is going to be exciting.
Another thing to consider is the difference in torque of the engine swap. Assuming the Duramax has more torque, it may want a 'beefier' engine mounting, rather than the lag bolts into 25 year old wood. Also your outdrive gear ratio may not be optimized for the Duramax . . . you can change the Bravo 3 prop set to a higher (or lower) pitch as a way to get the best performance. No need to mess with the gears in the Bravo 3.
I am very interested to see how you rework the exhaust manifolds. The Mercruiser manifolds expel the cooling water overboard through the transom plate. I can't wait to see how you work that out!!
Sandwich existing stringers with 3/4 marine grade plywood or two bye. Fiberglass the ends to the transom. 3/4 pvc pipe for drainage under stringers. From one side to the other. So it can drain to the middle outbound drain hole if needed. This swap is brilliant. Thanks for sharing. 👍🏻👍🏻👍🏻
Hey yall, make sure you replace that rubber donut at the fly wheel. It will blow out if its not good and you'll end up with a pain in the butt to change it. Been there done that.
Was literally typing question about keeping exhaust cool without water jacketed manifolds as you answered at the end! Youve already thought of everything! ha great project good luck and cant wait to follow more!
Did the rest of the job ever get done? How did the transom turn out? Did the swap of the engine work out with the drive assembly? Did the boat get back into water?
Brilliant swap idea Aaron with the important parts bolting right up with just a flywheel change. I will say I respect your knowledge, small block ford guy here, I see a mess of valves n computer controlled things that would be a no go for me. Riveted on your builds and thanks for being real.
I would not trust those old rotted wood trusses to hold the Tork of a diesel plus a turbo. Box it out with steal or aluminum. Tye it into any thing solid. The motor and drive want to go forward. You just patched the transom. The out drive pushes on that . The last thing you want is that engine and drive coming up through the floor coming at you.
Suggestion; IMO, (I'm not an expert) laminate Coosa boards to make beams the size of the stringers to replace the rotted stringer wood. Sister them into the existing solid stringer, with a staggered end into the wood, using Total Boat epoxy to adhere everything. Epoxy the other end to the transom. This should establish a solid joint between the stringers and transom.
This is an awesome conversion. There's already been a ton of helpful comments from knowledgeable marine folks. You're going to be getting much more to help you guys through this conversion. This just shows the great following you two get!
The stringer needs to be replaced. Thr transom and striker take all of the pressure together. If you have a space or gap or soft spot it will bow the transom and cause the lower unit to not seal properly. The stringers are pressured to the transom and the fiberglassed as if you are making one piece. And also sealing one piece. DO NOT USE PRESSURE TREATED WOOD!!!!! GOOD grade wood or the new synthetic pieces you are using will glass in good. Fiberglass does not stick to treated wood.
I love this project. In my imagined project I swapped Mercury Marine LS with Mercury Marine TDI (4.2 biturbo - Audi analogue). I think it would also work. It's also fun to watch how different youtubers doing they project Chris from B is for build swapped twin Cummins diesels for two custom built LS engines. You are going opposite. Anyway, love you guys, I will watch impatiently! ;-)
The boat project is getting even more exciting! Worse case if it won’t turn the rpm’s to get on plane, you should be able to get a different prop since the diesel has more torque than the big block.
Aaron hit up the local EAA chapter, there is usually one or two that have built a fiberglass airplane, they would be a great resource for any re engineering you need to do with the composites.
EVERYBODY throws shade on the LB7, and although most of that is because of the injectors, it's not a fav. The LB7 in our '02 Sierra has been rock-solid, however. 90% of the time, the truck has been towing our race car and has been great for that. If the 3208 in our Wanderlodge ever dies I'd strongly-consider a Duramax replacement for it.
Get up with pure desiel and they can probably help you out. I go with them when changing from 6.0 to the Cummings motor. They have the plate to transfer the bolt pattern for the trans
great idea, you do need to remember to finish the transom. you should glass in the perimeter, that would tie in the transom to the rest of the boats hull.
This is going to be awesome. I plan on doing the exact same thing (x2) I have a 2000 Cruisers Yacht 3375 that needs a complete restoration. Twin 454s that I want to swap out with Duramax. Definitely going to watch this build.
recall people on the coast used to stick 80's GM non turbo engines in as they sipped fuel and with no elevation changes to deal with, you dont need a turbo
May be able to solve the lower RPM issue by using a higher pitch prop. May have to go custom but, hey, if it works! GOOD LUCK and keep us tuned in to the progress!
We have a cabin cruiser like yours, it had 7.4 Mercruiser and about 7 years ago we re powered with a 4 cylinder Yanmar diesel, it wasn't cheap but we haven't had a single problem since, lots of power. We use our boat all the time and love it. No more dead on the water problems like we had many times with the 7.4 engine. Good fuel saving too.
Now this going to a great conversion look forward to this one! Hope you use raycor fuel fuel filter set up to motor with cat conversion fuel filter to engine srew on 25:22
I had a feeling a diesel was going in the boat, I love it, please do yourself a favor and install new motor mount bushings on the back of the bell housing while it’s out, it will make aligning the engine so much easier, love the video 👍😁❤️
I don't know much about boats, but that looks like a great swap , Aaron sure is a knowledgeable mechanic, great job you two hard working young people . PS Emily is such a great speaker making everything you do so easy to understand, and so beautiful . Lots of love from pa ❤❤❤
You might need a new (or different) propeller to bring it out of the water up on plane. If I can find the chart, I'll send it to you. Looking forward to the Duramax rebuild or go through or whatever you call it.
I enjoy watching the two of you work together. So much fun and knowledge being passed around. No matter what you are working on at the time it is always fun watching you. I have one of your Garfield shirts and live in Jacksonville, Texas and was wondering if I came to you could I get your autographs?
GM Had Duramax diesel Van and the turbo is located more towards the back of the engine and lower if you run into clearance issues. I was a service director at a Chevy dealer and we worked on all the vans for the local Air Force and they used those on the flight deck for transporting pilots out to and from the plane.
Highly suggest glassing in new beams for your engine mounts. Those beams tied into the transom act just as a car/truck frame. Once you apply the torque of a strong engine, there's a chance it could separate those old beams from the floor. You would be stuck right back to pulling the engine and outdrive again to replacing the beams and glassing them in. Can't wait to see the end result of your project. FREAKING AWESOME!!!!!
Good point!
Same idea to also consider the mentality of risk it vs know for sure. Glassing in has the ease of mind that you know that it will be as good as can be reasonably done. Likely with better than factory materials.
It's gonna be a shit load torqueier than the petrol. Cannot agree more
Called stringers.
Thank you so much!!!!
Heck yeah, another RUclipsr once took their diesels out of their yacht for gas LS and it was stupid. Going from gas to diesel makes all the sense in the world. Fantastic
Italian yacht to be correct lol. Then it mysteriously sank. Hmmmmm
@@summertop511Well they DID get it re-floated. I stopped following it when the insurance issue came up plus the entire thing was just too reckless for me.
and then it sank due to stupidity and he complained insurance wouldn't cover his obvious insurance scam
As I said in another post, F is for Fail, replacing diesel with gas in an Italian scow.
For your cooling needs, implement closed loop cooling. Run antifreeze in it vs water. Or dex-cool.
Have the crank machined for keyway instead of pin that shears on harmonic balancer
Aaron and Em, several commenters have talked about potential issues presented by the high torque of the diesel engine (beefing up stringers and engine mounts etc,) but an additional significant area of concern when putting a diesel in front of and alpha or bravo drive is the drive capacity to handle high power and more specifically, HIGH TORQUE. The bravo is a very beefy drive but only designed to handle so much torque. Subjecting the drive to drop throttle starts that load the drive above its torque limit can be problematic for reasons I probably dont have to explain to you. Make sure you check your specs for compatibility in this regard if you havent already. Mercruiser does make a special X and XR series bravo for diesel and high output gas engines. To my knowledge, mercury does not recommend the bravo for any diesel applications. Bravo X will handle gas engines up to 600hp and diesels up to 370HP. Not sure about the XR. Do some research. This is a challenging project. Im impressed with your skill and courage to take it on.
Volvo Penta makes excellent stern drives for diesels, if the bravos don’t work. Like others have stated adjust everything for the diesels torque from drive shafts drives and stringers. God bless on this project. Will be an adventure….
The outdrive alignment tool will be a necessity for aligning the engine coupling to the outdrive. It will make life so much easier.
He mentioned that
@@MrSuzukiyamaha you don’t miss a trick!
The nice thing about diesel in a boat is they like running at full power for hours on end.
Gears can always be fixed, or you swap props.
Keep the blowers, fumes are bad either way.
Fitting cooled exhaust manifolds could be a tough one.
Though there are a few guys up here in WI that make them all of the time.
Wrapped PPE headers would make more sense
BOOOST~! Cool. There are great diesel combinations in our modern world.
Of course we already know where that boat's former big block Chevy is going. Into that sweet '57 Chevy!!!
You should look into putting a keyway in the crank Dave's auto center talks about it alot
Exactly…he highly recommends machining for a key way
It is great that the bell housing bolts up perfectly. And the fly wheel is made exactly for this application. 😁 That simplified this swap a ton! 😊
I am so happy seeing you work so in sync. Your demeanor is great.
Been running a diesel inboard on our boat for over 20 years, love the turbo whistle at full noise
Yeah and its not a bomb waiting for a spark!
Thanks for being down to earth and honest about yourselves and projects . i really like how you are teaching the Kid , i love seeing the young people getting involved in the mechanics . you have a great channel don't change
You should replace the engine mounts in the boat that way you ken last longer then the boat. Plus you could give the engine bay a good scrub and repaint. Will look minted if all spotless.
The rot in the stringer ends will continue to rot. The rot is a fungus,, .. It must be removed to last any length of time. It might be handy to remove the top off the stringer Past the motor mounts and use pressure treated wood to replace it... Simple is usually the best. Then lay matting with directional over it to cover the stringer. Also making a knee brace from the stringers to the transom while you are at it is a good idea too. (20 + years of boat racing, building and fixing here)
Never use pressure treated lumber, can’t glass it.
@@86foureyefreak22 Sorry.. Here in CA we have a copper sulfate pressure treating that is not oil base... Mixing polyester resin and acetone 50/50 and soaking in a first coat works... You can also use heart redwood but more layers of glass are needed. You might try oak with you painting on water base coper sulfate preservative can work too. Even eucalyptus is outstanding also. Most of all just replace the top portion of the stringer with new lumber and glass over it..
If you could find some teak, that would be my choice
@@MrDmorgan52 That would be an excellent choice
The RPM will be the only problem. I would be looking or studying what type of gear add on to multiply the RPM. Good Luck!
Very cool, I have been thinking of doing the same in my 1980 Searay. Interested to see what you do for exhaust and engine control.
when ford started putting diesels in their trucks, they quickly learned that the cross members that were riveted could not handle the torque of the motor so they had a beef up fix for the first few model years, If I were you, I would heed the suggestions of people with knowledge here and beef up to the max those stringers and buy the proper outdrive.
NOT a boat builder, but enjoy the stuff the Ship Happens couple are doing to their boats. They're rebuilding a wooden WWII Harbor Defense Motor Launch, and are replacing portions of stringers, frames and deck beams with scarf joints. They epoxy and bolt them into place. I'd think if it works for a 70-foot twin Cat ML, it'll work for your boat. I'd think some Coosa Board 'wedges between the back of the engine stringer and transom would be plenty strong when epoxied into place. You could drive a couple of long SS lag bolts from the back of the boat through the transom and stringer to hold things together even better, then 'glass over that.
They also have a twin Cat speed boat they're doing work on. No hull work, but good info there, too. Their two engines are in an engine compartment not much bigger than the engine compartment on your boat, and turbo heat is no big deal there.
And they do all woodwork using West System epoxy, which I mentioned in my other comment!
I will give ya a tip since your going this far when the engine is done add an adapter to the drain for the oil pan add a tube to bring it out beside the engine add a shutoff valve then add a longer tube that is threaded to that to add a cap just in case the valve opens for some reason, but the main reason is you remove the cap add a hose the you can crack open the shutoff valve then you can suck out the oil from the bottom and make it faster and easy to do oil changes !!
On some boats they pull the drain hose for the oil pan out the drain plug in the bottom. Great idea as I was thinking the same idea. I can’t wait to see how this works out. I’m a dirtymax fan and love mine. Awesome videos!
I would build a cradle between the stringers out of aluminum stock to help handle that torque. Most ski / wakeboard boats have this setup. Wood stringers are always an issue, but you may not have the ability to replace enough of the stringer system with a composite setup. Brace what is there.
The bravo has different gear ratios for diesels. Gale banks use to make this. They can help on how.
Install the new style diesel pistons they have dimples in the face and run quieter
Hey guys I just bought my first Bayliner 2858 Ciera Command Bridge and my first thought was to diesel swap it. My quest for “how possible is this” lead me to your channel and I am very excited to follow along your journey.
Hmmm... never thought about sleeping on the boat with that big gas tank... of course I was a kid, totally uneducated. My Father was totally conscious of ventilation when refueling... still, there's always a risk. Saw the aftermath of a boat that exploded in a covered dock, nothing left... transom blown across the narrow channel.
Fantastic!
Me personally? Thinking CAT C7, mid 2000s vintage, pre DEF.
But great choice.
Again, lower RPM, More Torque, may need to look gears and prop.
Have Fun!
Your alignment issues will come when you go to put the outdrive back on. There is a tool(easily made) that will align the gimbel bearing with the hub. Otherwise the drive shaft will not go in no matter how much you struggle. I don't believe I still have the one we made--but if we made it, anything is possible
We bought one, luckily we are doing at a friends shop who is very experienced.
@@flyingsparksgarage glad you have access to experienced help. Also glad you are addressing the heat issue with the headers. Have fun and enjoy
There is a product called skunk stabilizer that will make those stringers very beefy when using the boat in the winter months at altitude. It will require holes but the again you are looking for strength rather than beauty.
Make sure the motor will turn the out drive the correct direction. I’ve heard some boat motors run opposite of car or truck motors.
I like this! Considering all the problems with gasoline on boats (storage, fire risk, etc), I don't understand why diesel isn't the standard in all marine applications.
Because they are more expensive
You're going to be amazed at how far the wood is going to be rotted underneath the fiberglass. But I'm sure you'll get it handled just fine.
Hey folks, been watching your channel for a while and enjoy your content. I have replaced my transom and stringers before as a rule of thumb you can do a scarf joint on the stringers, the way it works is 10 x the height of your stringers and considering your tight space it’s probably better to replace them. Here in Australia we use F17 hardwood and marine ply heavily soaked in west systems epoxy, your coosa board maybe much more durable can’t say I have never used it. Also all penetrations for bolts etc we always drill oversized and fill them with epoxy then re drill. Bolts are then installed with polyurethane marine sealant. Looks like you have it all under control and really enjoy your videos Shaun in Australia.
Great content. I once presented a technical paper on reverse engineering. One thing we found helpful on complex fit-up situations was to take digital photo from above [the plan view] and then write the dimensions measured on the photo. Save many trips to re-measure and rework later.
If you’re going to remove the pistons, check out speed of air pistons online. Make great pistons for diesels. Engine will run quieter and more efficiently. Seriously, check them out, you won’t regret it.
Cove and glass the engine beds onto the transom with three or four layers of 600 gram double bias cloth or similar with west system or similar epoxy resin. Go from narrow to wide strips in increasing widths. best to do it after transom repair is glassed.
Sounds like a great swap. Exhaust manifolds could be the major issue. If somebody else has done one, all the better. Freeboard is important(distance from waterline to exhaust highest point after turbo). Look forward to the build.
Glad to see a youtuber swapping gas for diesel and not diesel to gas in a boat!
F is for fail, you mean?😂
@@Torch4ya 🤣
Check out the torque specs between both motors that will give you an indication if you need to replace the stringers. It will also depend on which prop you are using. The pitch will cause different stress levels. You need to research the correct pitch for the RPM you will have to maximize your planning speed and cruising speed. You could use a variable pitch prop but that is expensive but can be an option. By the way, a variable pitch prop makes docking and maneuvering so much easier. Hope this helps. Also make sure both motors are rotating in the same direction.
CAD...cardboard aided design...I love it!
FSG aka Aaron + Emily, very smart move from a safety and efficiency perspective! Changing diameter and blade pitch on the prop can adjust RPM differences re knots per hour, planning etc. You two are the A-team!
Consider closed cooling. Considering the state of everything (in pieces) this would be a great time to make that decision.
I am thrilled that you all are swappong in a Duramax motor. It better suits the size of boat that yiu have.
Oh I’m so happy to actually see someone do a Duramax swap in something instead of swapping a Cummins!!! Everyone is always doing a Cummins swap instead of the Duramax swaps and I say it’s because everyone likes the simplicity of what all you actually need to run a Cummins!!! I see square body trucks out there with Cummins in them along with plenty of other vehicles out there but very rarely do I ever get to see a Duramax swap in any thing!!! I’ve always told myself that if I ever go putting a diesel engine in one of my square body trucks or even any one of my 1967-1972 Chevy trucks it would definitely be a Duramax swap for sure and definitely Not a Cummins swap!!! My Duramax I have now is a 2007 classic body style and I have had it since 2010 and it also has definitely helped me recover on my last truck that I had and ended up literally paying for it twice in full and that definitely put me in the hole badly but after selling that truck and getting my Duramax I have definitely been recuperating the money that I have lost on my last truck because I have had to do absolutely nothing to my duramax at all other than regular maintenance things on it!!! I’m definitely really hoping that I can learn from you on how you end up doing everything for the swap and maybe that will help me get a better idea on what I might need or what I might have to look for in putting a Duramax in one of my square body trucks that I have definitely been wanting to do for quite some time now!!! Awesome video for sure and I am definitely looking forward to many more videos on this build for sure!!!!
I think you are on the right path. More torque, better fuel efficiency and better longevity for what you want. Plus you can get about the same RPM as the big block because they originally used the 396 for the first generation of junk diesel engines. I'm glad that GM keeps the same Bell housing and still a similar side mount for easy swaps. But the most important thing is seeing Aaron back to working on a diesel again 😊. I can't wait to see you guys have fun again in the water.
Key the crankshaft get rid of the weak dowel pins that hold the timing and crank pulley
Interesting swap . . . the Duramax for the 7.4 BB. Make sure you get the proper exhaust (aka Wet Exhaust). Not sure if the turbo/supercharger needs cooling (?) Have you thought about the fuel tank? ( I believe diesels have a return line and usually there is a spare fitting on the fuel tank). Also you may want to inspect and pressure test the fuel tank. (usually 3 psi is all you want/need to test ). As for a partial replacement on the stringers . . . yes . . . , as long as you can identify where you get into good wood. Then fiberglass a few extra layers of 1708 cloth in the area where old/new meet. Most of the strength is in the fiberglass, since it is the outer layer. The wood acts like a core, as long as you have about 1/8" thick (or more) fiberglass over the wood. The iboats website has a forum with a restoration section for lots of examples from folks who have repaired/restored their boats. I've done a partial repair on the stringers of my Formula 242. It is all do-able stuff.
You guys are on a roll with your projects lately, keep up the good work!
Cool new project. Looking forward to your first boat outing with the Duramax. You 2 have so much fun.
Don't forget to get a diesel generator and pull out the gas generator so you don't have to have two different fuels if the boat already has a stand along generator.
Dont think it has a generator.
@@robertnelson3745 I couldn't recall. Might be worth adding one if there is room. Or even a propane powered one, which would add a second fuel but much less smell when anchored in spot. My backup generator for my house will run on both propane and gas. Though those "solar" generators are always sponsoring youtube channels ... might be a good time for a add spot for one of those large battery banks and solar panels :)
They have an Onan portable generator they take and run on the stern.
And diesel heater like Webasto!
I’d recommend replacing those stringers completely with the amount of torque your Duramax will produce I think that would be a wise move. I’d install some stainless steel T plates to the end of the new stringers where they connect to the new transom and then fibreglass them all in using F type fire proof resin.
I would add smaller port to starboard stringers to strengthen the hull but allow gaps for water to drain to the bilge and be collected by the bilge pump.
I’d definitely use a solid synthetic or plastic wood for the stringers for a permanent solution.
I keep thinking of things . . . You may want/need to check the camshaft spec's on the Duramax engine vs. what a marine diesel version would have. The 7.4L BB that you took out of the boat has a very mild cam, with hardly any valve overlap. That is to avoid 'exhaust reversion' in a 'wet exhaust' engine. If the cam is too aggressive (higher valve overlap) you may pull water back into the cylinders at idle speeds (hydrolock).
For the stringers and tying it all back into the Coosa, well worth watching Andy at Boatwork Today's series on the rebuilding the transom of his Bertram. Great series of videos and will answer all the questions you have. He'll be sure to help you too.
Good to hear that the exhaust turbo manifold cooling and water injection is being dealt with, that did worry me somewhat but I should have realised that you'd both have it all in hand. Cheers from the UK
I thoroughly agree watching Andy at Boatworks Today is a great idea.
What a great project. The 1990 big block Baja I bought was built with a higher X factor. This placed the out drive farther out of the water for less drag and made it faster than a stock boat. It was good for another 5-4 mph. I have a feeling you are looking for reliability rather than speed as your boat is meant for cruising and is quite heavy.
This is mind blowing guys. If anybody can do it, it's you two. I can't wait to see this boat run. Watching it all come together is going to be exciting.
Another thing to consider is the difference in torque of the engine swap. Assuming the Duramax has more torque, it may want a 'beefier' engine mounting, rather than the lag bolts into 25 year old wood. Also your outdrive gear ratio may not be optimized for the Duramax . . . you can change the Bravo 3 prop set to a higher (or lower) pitch as a way to get the best performance. No need to mess with the gears in the Bravo 3.
Just here for the water cooled manifolds and turbos
PPE makes jacketed up pipes and a turbo stand. We are not sure about the manifold yet.
Love watching you guys work on and explain what you’re doing to your equipment. Keep up the great work.
I am very interested to see how you rework the exhaust manifolds. The Mercruiser manifolds expel the cooling water overboard through the transom plate. I can't wait to see how you work that out!!
This boat is gonna be better then new when y'all are done with it! Can't wait to see and hear it run.
Sandwich existing stringers with 3/4 marine grade plywood or two bye. Fiberglass the ends to the transom. 3/4 pvc pipe for drainage under stringers. From one side to the other. So it can drain to the middle outbound drain hole if needed.
This swap is brilliant. Thanks for sharing. 👍🏻👍🏻👍🏻
Hey yall, make sure you replace that rubber donut at the fly wheel. It will blow out if its not good and you'll end up with a pain in the butt to change it. Been there done that.
I think ADDvanced made a youtube video about stringers, cousa etc. on their project boat. He is pretty good at doing DIY boat stuff.
Was literally typing question about keeping exhaust cool without water jacketed manifolds as you answered at the end! Youve already thought of everything! ha great project good luck and cant wait to follow more!
I love it what a great idea I think just change the prop to get it to come to plain!
Did the rest of the job ever get done? How did the transom turn out? Did the swap of the engine work out with the drive assembly? Did the boat get back into water?
Brilliant swap idea Aaron with the important parts bolting right up with just a flywheel change. I will say I respect your knowledge, small block ford guy here, I see a mess of valves n computer controlled things that would be a no go for me. Riveted on your builds and thanks for being real.
I would not trust those old rotted wood trusses to hold the Tork of a diesel plus a turbo. Box it out with steal or aluminum. Tye it into any thing solid.
The motor and drive want to go forward. You just patched the transom. The out drive pushes on that .
The last thing you want is that engine and drive coming up through the floor coming at you.
Suggestion; IMO, (I'm not an expert) laminate Coosa boards to make beams the size of the stringers to replace the rotted stringer wood. Sister them into the existing solid stringer, with a staggered end into the wood, using Total Boat epoxy to adhere everything. Epoxy the other end to the transom. This should establish a solid joint between the stringers and transom.
Your skills are amazing. All the best with your project.
❤ that is such a smart idea switching to diesel. I am so excited for y’all. Can’t wait to see the final product.😊
And of course you can always change the prop😊
This is an awesome conversion. There's already been a ton of helpful comments from knowledgeable marine folks. You're going to be getting much more to help you guys through this conversion. This just shows the great following you two get!
The stringer needs to be replaced. Thr transom and striker take all of the pressure together. If you have a space or gap or soft spot it will bow the transom and cause the lower unit to not seal properly. The stringers are pressured to the transom and the fiberglassed as if you are making one piece. And also sealing one piece. DO NOT USE PRESSURE TREATED WOOD!!!!! GOOD grade wood or the new synthetic pieces you are using will glass in good. Fiberglass does not stick to treated wood.
I love this project. In my imagined project I swapped Mercury Marine LS with Mercury Marine TDI (4.2 biturbo - Audi analogue). I think it would also work.
It's also fun to watch how different youtubers doing they project Chris from B is for build swapped twin Cummins diesels for two custom built LS engines. You are going opposite. Anyway, love you guys, I will watch impatiently! ;-)
Nice motor. You might want to change the coupler. Depends on how old it is. You will need an alignment tool to align the outdrive.
totally makes sense to sway in a diesel. can't wait to see it run
Hay gang. Hope all is well... Might you have any idea when more boat videos are coming. I'm interested in the motor change. Thanks 😀
The boat project is getting even more exciting!
Worse case if it won’t turn the rpm’s to get on plane, you should be able to get a different prop since the diesel has more torque than the big block.
I love how you guys share each step of your thought process. Hopefully increased torque won’t be an issue. Love your channel!!!
I love to watch you to take on a project and work out the detail as the project advances!
Aaron hit up the local EAA chapter, there is usually one or two that have built a fiberglass airplane, they would be a great resource for any re engineering you need to do with the composites.
Sweet video! I hope it all works out for you! We will see you at the finish line. Love you guys!
EVERYBODY throws shade on the LB7, and although most of that is because of the injectors, it's not a fav. The LB7 in our '02 Sierra has been rock-solid, however. 90% of the time, the truck has been towing our race car and has been great for that. If the 3208 in our Wanderlodge ever dies I'd strongly-consider a Duramax replacement for it.
The engine block mounts on the duramax should be the same as bb/sb mounts I didn’t have to use any plates on the swap I did. BBC to duramax swap
This is great info
This is gonna be awesome. I never expected this. Can’t wait for this. Good luck and stay safe.
Get up with pure desiel and they can probably help you out. I go with them when changing from 6.0 to the Cummings motor. They have the plate to transfer the bolt pattern for the trans
Cummins, NOT Cummings!
great idea, you do need to remember to finish the transom. you should glass in the perimeter, that would tie in the transom to the rest of the boats hull.
Great series you two. I love watching boat modifications and coming up with new ideas. Keep up the good work!
This is going to be awesome. I plan on doing the exact same thing (x2) I have a 2000 Cruisers Yacht 3375 that needs a complete restoration. Twin 454s that I want to swap out with Duramax. Definitely going to watch this build.
recall people on the coast used to stick 80's GM non turbo engines in as they sipped fuel and with no elevation changes to deal with, you dont need a turbo
May be able to solve the lower RPM issue by using a higher pitch prop. May have to go custom but, hey, if it works! GOOD LUCK and keep us tuned in to the progress!
We have a cabin cruiser like yours, it had 7.4 Mercruiser and about 7 years ago we re powered with a 4 cylinder Yanmar diesel, it wasn't cheap but we haven't had a single problem since, lots of power. We use our boat all the time and love it. No more dead on the water problems like we had many times with the 7.4 engine. Good fuel saving too.
Better reinforce the transom to handle the torque of the duramax, especially if you tune it for off-road use!
Now this going to a great conversion look forward to this one! Hope you use raycor fuel fuel filter set up to motor with cat conversion fuel filter to engine srew on 25:22
Awesome video thanks for sharing 👍 😀 sending love ❤and prayers 🙏 from IRELAND 🇮🇪
I had a feeling a diesel was going in the boat, I love it, please do yourself a favor and install new motor mount bushings on the back of the bell housing while it’s out, it will make aligning the engine so much easier, love the video 👍😁❤️
it is so good to see a wife working with her husband on this project good luck guys
Or,,, husband working with wife, lol
I don't know much about boats, but that looks like a great swap , Aaron sure is a knowledgeable mechanic, great job you two hard working young people . PS Emily is such a great speaker making everything you do so easy to understand, and so beautiful . Lots of love from pa ❤❤❤
You might need a new (or different) propeller to bring it out of the water up on plane. If I can find the chart, I'll send it to you. Looking forward to the Duramax rebuild or go through or whatever you call it.
I enjoy watching the two of you work together. So much fun and knowledge being passed around. No matter what you are working on at the time it is always fun watching you. I have one of your Garfield shirts and live in Jacksonville, Texas and was wondering if I came to you could I get your autographs?
GM Had Duramax diesel Van and the turbo is located more towards the back of the engine and lower if you run into clearance issues. I was a service director at a Chevy dealer and we worked on all the vans for the local Air Force and they used those on the flight deck for transporting pilots out to and from the plane.