'77 Luhrs 28 ft. diesel repower SPLASHED!

[Oldrod 47]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

Looking forward to next phase. Gets the wheels turning, could get me in trouble!

 

[Luhrs28]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

Hi Guys:

Jay: I've decided to keep the name, just 'cause I like it. My cousin pointed out that the Big Ten is actually 12 teams now but they still call it the Big Ten.

By the way I've been watching some of your old Mercruiser 5.7 videos, to see what all I need to do the conversion. I have to keep remembering because my boat is a V-drive the engine sits bass-ackwards.

Wayne: I boat mostly Raritan Bay between NJ and Staten Island. I also went up to NY harbor twice this summer, and out into the Atlantic just a little (maybe 1 mile). Next year I plan to be more adventurous and head offshore further for fishing.

Arch, Springer: Thanks for checking in on my project. I'll try to keep posting anything interesting as I tackle it.

Bert

 

[Billin21]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

Awesome thread!. I must say that I am little disappointed in the possibility that after all the hours and fabrication, you may get rid of the Diesel. Either way, Very very cool!

 

[ezmobee]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

You're all going to think I'm nuts but I'm going to repower it with a gasser Chevy 350 over the winter.

This is unacceptable.

This would be like Oops deciding to shorten his boat again.

 

[sasto]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

This would be like Oops deciding to shorten his boat again.

Don't count it out!

Good Luck, Bert. I will be watching too!

 

[Luhrs28]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

Believe me I've done dumber things than installing a diesel engine and then taking it out after 6 months. Way dumber.

Anyway I was thinking GM's love for parts commonality is going to help me yet again. The bellhousing adapter on my diesel engine is actually for a Chevy 350. Same for the motor mounts. I'll just transfer them over to the gasser. So a lot of the work I did to put the 6.2 in wasn't wasted.

Oh, I did one other dumb thing. Just before I decided to go gasser I filled the boat's tanks with diesel fuel. Now I get to siphon it all out again. Duh!

 

[springer59]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

Bert, you wern't supposed to tell anybody you filled it with fuel! COME ON MANNNN !Still chokeing on that one.Wife asked if you & I could be related.(I was adopted & my Mom is from up 'round Va.) LOL> That sounds real familar to some of the deals I have done,... Recently!! Good luck,keep stroking,& I'm still thinking about that swap on my Luhrs too.

 

[MADONN]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

My after all that work i cant belive your taking the diesel out. I have a 27ft. silverton with a 350 chevy vortec in it she performs great but a gas guzzler big time!!! I am rebuilding a 6.2 to put in it as we speak. I was wondering what size heat exchanger you installed in it. Also is there any overheating issues.

 

[Luhrs28]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

Madonn: I had a custom heat exchanger built for it, but it's not all that big. I think it's 5" dia. X 20" long. I never had an overheating problem but when I first started running the boat the engine temp was around 210F so I drilled 6 little holes in my thermostat. (that's an old Mercedes diesel trick) After that it ran 170-180F all summer. I have a 1 1/4" thru-hull with a pickup scoop on the bottom of the hull and a Sherwood G7B raw water pump and it worked great.

I will say the 6.2 gets awesome fuel economy. I could cruise around all day at hull speed on $40 worth of fuel. It's a great choice for minimum fuel burn.

 

[sdowney717]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

I noticed in your medium speed video the boat was going on the slow side.
But why do you want more HP, does the boat feel sluggish with the 6.2 diesel?

I had two of the GM 350 diesels in cars and they were quite underpowered.

my dad had the 6.2 turbo diesel in a Chevy duelly truck and it had trouble maintaining speed up the hills.

The whole point of which engine to use is based on what you want to get from the boat.

Maybe you should consider selling what you got and getting a twin engine boat.
what would the boat you have now get on the market?

 

[Luhrs28]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

sdowney: Well I really like the boat plus I'm sure I wouldn't be able to get much $$$ for her, so I want to repower again. The boat originally had a Chrysler 360 V8 which made 250HP, so I think the closest Chevy/Mercruiser equivalent is the 5.7. Even if I only gain 4 knots and less noise it's well worth doing. (in fairness to the 6.2 I should've had mufflers instead of the straight exhaust. I plan to put mufflers on the gasser 5.7)

If I screw this up then next winter I'll drop in a 454. I'll just keep repowering until I get it right or my bank account is drained, whichever comes first.

 

[desertcpl]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

I read all of your thread and you did a great job and I really like Luhrs
but this is my take on this
1. I thought all along that the 6.2 was going to be way under powered for a boat this size
2. I would go first to a bigger diesel, you mentioned about your great fuel consumption as apposed to your neighbors gas boat, way big difference
3. you have always got to consider resale value on a boat, diesel will bring in more value
4. if you do decide to go back to gas skip the 350 it still will not do what you want, it will work its butt off and the fuel consumption will not be that much diffence than the 454. with a boat this size

 

[Jhudds]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

Luhrs,

Instead of swapping out right off the bat, why not try a different prop and install mufflers on the diesel engine?

The prop change may make a slight difference in speed, and the mufflers would definitely help with noise.

I think the better gas mileage outweighs the additional speed you would get with a large gasser. Whats you top end speed now with the 6.2?

 

[dakotamusic12]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

I can add that my Luhrs 280 with a LM318 is topping at 17mph. Bottom is fresh and clean so I am curious to see Luhrs' top speed too. Judging by the video that diesel is beating the same as my 318 and probably 1/4 the fuel.

 

[F14CRAZY]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

Can you mod the 6.2L a bit to gain a decent amount of hp/torque? I was thinking of a cam (though a diesel truck cam is pretty torquey already) and dialing up the injector pump delivery (though that might just make it smoke like a freight train).

Is is acceptable to add a turbo to the 6.2L? Does the 6.5L share parts interchangeability? Not sure how much more those make but if you could swap just the short block itself and bolt up everything else that would be fairly cheap/easy since you've already invested in manifolds, controls, etc

 

[QC]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

You don't chase diesel power with cam mods . . . you're on track though regarding fuel as without more air (naturally aspirated) she will smoke bad.

BTW, turbos are natural mufflers Luhrs

 

[Luhrs28]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

Guys, I hear you and nobody is a bigger diesel freak than me, but the fact is a GM turbo 6.5 is about the only more powerful oil-burner that will fit in my engine compartment. I just realized one day that I could probably buy 2 or 3 gasser 350's for the cost to install the turbo 6.5.

Dakota: I would be ecstatic to see 17 MPH. I don't have a GPS but based on time/distance I think my 6.2 diesel only made 10-11 MPH.

Anyway I'm still mulling over my options. On Saturday I'm going to consult the gurus at my boatyard. If they happen to have a good low-hours 454 sitting there I might pounce on it.

 

[MADONN]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

Lurhs 28, I sent you a private message a while back check it out let me know what you think.

 

[QC]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

I just realized one day that I could probably buy 2 or 3 gasser 350's for the cost to install the turbo 6.5.

This has been my position on diesel for pleasurecraft forever. And I have sold and serviced diesel engines for my entire 30+ year career. Plus the difference can buy a bunch of fuel in between.

 

[jfalco]

Re: '77 Luhrs 28 ft. diesel repower SPLASHED!

dont take that diesel out, believe me a few mph just isnt worth it, going fast in a boat is not relaxing at all, i have had boats that went 60mph and now i have a 23ft boat that has never been over 17knots and i enjoy this boat the most, your going to kick your self right in the azz, just fab some muffs on it and enjoy that boat, you did a beautiful job on it and i been following your thread from day one and i was really impressed, you have something different, 28ft boats are a dime a dozen but try and find one with a diesel in it for a reasonable price and good luck, i watched your you tube vids and that boat moves along just fine, if you really want to go faster buy a cheep speed boat and drive it for a little while and i guarantee you will change your mind,