GM 6.2 Marine engine going in my Luhrs 28 boat

[Rlobe14]

Very nice job!!! I know that you are/or have swapped back to gas due to lack of power/speed you wanted. I was planning on swapping my 350's, Bravo Drives on my 97 silverton 31 foot express. planing hull, and it is 9000 lbs. I am hoping to get 30 MPH out of it. With your experience with the performance of these 6.2's, do you think twins will do the job? Thanks, any advice would be much appreiciated!! I already have the gassers out, just would like to hear from somebody that has done it.

[wideboyi]

HI i have two chevy 6.5 desiels in my boat supercharged that make 300hp each but manifolds are gone on one engine what make are your headers please

[mongo731]

What kinda horsepower you looking at here, about 150? Torque about 350? I thought about doing the same thing in lieu of my 440 Chrysler, but I'd like some speed too.

[2772980]

thanks for the info. I order the manifolds, and need to see if it will be wider than 4.3 engine. Do you know the model of the starter?.

[Flounder3906]

@2772980 My starter is a 28MT, which I bought cheap (around $95) over the Internet. Probably made in China. It's important to have the little rear brace attached also. Otherwise these starters can snap the bolts attaching it to the block, and even crack the engine block. It takes a lot of torque to crank a diesel over.  Use #2 AWG battery cables also..........not #4 like a gasser would.

[2772980]

I have 2 engines 4.3 that i want to replace with 6.5 diesel non turbo. I have the engines, and will appreciate any info. Will they fit Alpha One Drive ? Need to change the gears? Were i find the marine starter for ? Anyone alse sells manifolds and risers beside Osco, very limited on space.Did you install the damper on the flywheel that come with 6.5 engine?Does it have to be set back(spaced) from the housing? I can use all the help I get..

[Flounder3906]

@2772980 You can find more details about my build on the iboats.com Forum. Search for "Luhrs 28 diesel repower". The bellhousing bolt pattern on the 6.2/6.5 is identical to a GM gasser 305/350, so any drive that will attach to a 350 will attach to the 6.2/6.5. One small modification has to be made for the nose of the starter on the diesel, as it's a little bigger. By the way I'm not using a marine starter. It's not required by USCG for a diesel engine.

[Flounder3906]

@Flounder3906 I'm not aware of anyone besides OSCO making the manifolds. Possibly Barr but I'm not sure about that. I used a standard GM manual trans flywheel. Damper is standard for a 350 gasser marine engine. Nothing special has to be done for spacing. It's the same as the gasser 350.

[lms3333]

@Flounder3906 Osco and Peninsular are the only two I ever found. Osco's are cheaper...

[lms3333]

Osco and Penisular are the only two casting manufacturers I know of, but the Oscos

you used are the more economical by about $70 each. I never found one from Barr.

Nice project--clean work!

[kimmer6]

Hey, manifolds appear bass ackwards. Is that being used on a Vee drive? Nice setup. I am putting a 6.5 turbo diesel in my 21 foot whale back to replace the gutless 47hp Perkins inboard. I mated the GM engine to a Mercruiser Bravo One outdrive. I insulated the stock manifolds with ceramic wool wrapped in glass cloth, aluminum tape, and hard cased in a layer of epoxy. It should work after the smoke burns off! The rain quit so I am starting to work on the boat again. Can't wait to try it!

[Flounder3906]

@kimmer6 Yes my boat is a V-drive, so the flywheel faces the bow. Thanks for the comment and I wish you good luck with your conversion.

[Flounder3906]

The manifolds and risers are made by OSCO. (about $1300 but worth it) I also added a Sherwood G7B raw water pump (made my own bracket), driven by a V-belt. I changed the alternator to a marine unit that's non-sparking, and installed a marine drive damper on the flywheel. (standard 13.25" dia. damper for a Chevy/Mercruiser marine engine) That's about it. Oh and I'm using a Racor fuel filter, which you can see near the top of the engine temporarily tie-wrapped in place.

[TheGoogs91]

also what did you do for exhaust manifolds? did you build them or buy them? thank you

[TheGoogs91]

How did you convert it to marine duty?

[GTIVR62801]

Can't wait to come back to NJ and get a ride in the boat!

[archbuilder71]

cool! I remeber starting up my outboard on a cold winter day doing much the same thing! Can't wait to see it pushing your boat next season!