Repower 1985 36C.

[Chrisibyl]

Has anyone done a repower from gas to diesel on this vintage 36C?

Thinking about 450 hp electronic Cat or 480 hp electronic Cummins. Too big?

Any advice or experiences are appreciated.

[DeeRow]

Here is an article about a 32 Hatteras repower (http://boatdiesel.com/Articles/APage.cfm?P=20030903_Introduction.cfm). and this is an article about a36 Hatteras repower (http://boatdiesel.com/Articles/APage.cfm?P=20030202_Introduction.cfm&Y=2003)

[36Hatt]

I have a 1984 36C that was repowered with Cummins 330bs. I know of another that was repowered with 370bs. The B series leaves ample room for maintenance and a bit of clearance at the top. Those engines provide a cruise speed aroud 20-22 knots. The Cummins C series (450 etc) would be very tight particularly in height. A better possibility in my view would be the new QSM 5.9 witht 380 hp. and a lot of torque. I would be interested in hearing where you end up.

Richard Smith

[A Daily]

I have a 1988 36 with Cat 3116 @ 350 HP. There's plenty of room around the engines. I cruise at 18K a little higher than the largest factory installed diesel option. More HP would be helpful, the newer engines have more HP using roughly the same footprint. The exhaust was a pretty big part of the project. The last few 36's had side exhaust. Squeezing mufflers, risers, ect along with the new engines took some planning. I bought the boat right after the re-power was done, but can appreciate how much work was involved to make everything fit.
The original shafts were 1 3/4 , 1.92-1 twin disk gears were the transmission choice. The original 24/26 three blades worked fine with a little tuning, although I am thinking about trying some 4 blades that I have in the basement. Top speed is 25Knots, fuel burn seems to be 24GPH, and with the extra weight and push the boat really rides well, and will take seas most other small boats won't. This hull design needs a lot of power to make it go, but it outperforms just about anything in it's class in sloppy conditions. This is probably one if not the last 36 built, it has cored hull sides like the 38 so it's probably a little lighter than your's. I would go for the biggest engines that will fit, you'll need them with this model. I have a few digital pictures of the engine room if you're interested. Good Luck with your project. Tony Daily adaily3224@aol.com

[36Hatt]

My 36C also has cored sides so Hatteras must have started this series that way.

Richard

[jim rosenthal]

Chris, I think the 450 or 480 hp engines are a good choice. The C series Cummins will fit in the old-style 36 boat which is a far smaller boat than what you have, so they ought to fit in the bigger 36 boat you own. That hull is not as fast as the earlier boat, but what small fraction you lose in top speed you make up for in interior room and comfort.
With the larger engines you wil not only have better speed and power, you will have longer engine life as the B series or 3116 would have to work harder to move the boat, decreasing their life. It's pretty clear at this point that most modern marine diesels are wound up rather tight from the factory and if run at their rated loads will have a shorter life than you would want.
Another engine you should look at besides the C series Cummins is the Lugger at that rating, I think it is the L6108A2 or the L6125, I can't recall which. They are excellent marine diesels as well, and legendary for their reliability and life. The same company make Northern Lights gensets.

[Chrisibyl]

Thanks for the replys.

Does anyone know the performance data for this hull with the factory 3208TA Cats or the 6-71 TI Detroits?

I am also curious about the factory gears and propellors that were installed with the diesel engines.

Thank you.

[tomfishn]

The original specs for diesel came with 2 Detroit 390 hp. The transmissions were 1.51 to 1 The shaft size 1 3/4 and the prop size was 24X26.5 3 blade and I donot know the speed. I expect the speed was cruse 18 to 19 knots and the top end was 24 knots and now for the story. When I purchased the Hatteras the engins had been updated to 671TI 485 hp. and was still acheiving the same speed. what a education 7 diesel mechanics and 20 prop changes we found the problem. First this is a heavy boat and very sea worthy. Got caught off Bald Head Island , North Carolina 70 mph winds 14 foot seas and she handled great. The crew said the Hatteras could take more than the could. Engins We went into the engines and found that number two cylinder and nunber 5 cylinder were bad and still crusing 18 to 19 knots. So a rebuild was in store. After looking around for 6 months decieded where to go. Had both engines rebuilt out of the boat. The only way to go. Cruse now 22 to 23 Knots and top out at 29 knots smoke is gone and all you have to do is scrape you nail across the starter button. due to the weight the higher hp engins are the way to go. i have not been off shore so I donot know what the fuel consumption is due to the weather but hope to go shortly. the pops have to be changed a little because I am off about 40 rpm at full load so I am thinking lighten the cup. Do not go with 4 blades because you do not receive the performance. If you go with a lighter horse power consider 2.0 to 1 Transmission. Hope this has bee a help.

[Chrisibyl]

Thanks Tom. Your information is a big help.

I wonder if anyone would have the performance curve data (hp & torque) on the 6-71@485. I would like to compare that information with the perfromance curve data on the C7 Cat@455 and the QSC8.3 Cummins@484.

[tomfishn]

Please send me an address or fax number and I will send you what information I have. Tom 910-343-1234 fax 910-343-9262 or EMail tomc@tidewaterac.com Thank you, Tom

[gpaskalakis]

I was wondering about the results of your repower. How do you like it?

I am going to repower my 1987 36 this winter and was wondering what engine/trans/props you went with? I was considering the Cummins 370B or 450C, any advice?

George

[Chrisibyl]

George; We are repowering this winter. We're going with Cat C9, 503 bhp, ZF285A, 1.96:1 ratio, 2" AQ22 shaft. Prop calcs indicate 26x35 4b med cup or 25x36 4b med cup. Post your phone or email if you would like to discuss further.

[gpaskalakis]

My e-mail is gpaskalakis@hotmail.com.

[hmacdonald]

Here's a thought for your consideration. Last boat was '84 36C with 450 6-71s. Bruce Angel, now the engineering guy at Hatteras advised changing gear from 1.5 to 2.0, 2" shafts and 28x33 5 blades. This raised cruise from 23 to 26k, but I had to take 2" of pitch out. The best benefit tho was the change in running angle. Where the boat formerly required a lot of tab, after the changes it hardly needed any for optimum speed/fuel consumption. I am assuming that the added blade area of the 5's produced more of an upward vector of force through the shaft angle. Whatever the reason, it sure brought the bow down. You might want to consider the 5's

[Chrisibyl]

Thank you for your post. I'd heard about Bruce Angel and a 36C. I've actually tried to contact him to get the details of what he did with this 36C. He hasn't returned my emails or phone calls. I'm sure he's busy building/selling big new Hatts and dosen't really have time to help with 19 year old 36 footers and I understand that. As you can see we will have plenty of HP, the right gear and shaft. I'd like it though if you could confirm the prop dia. With our current 26" props we have 2.875" of clearance between prop tip and hull. A 28" wheel would cut the clearance down to 1.875" which is less than the 10% recommended. I wonder if he changed shaft angle to make more room for the larger wheel. Michigan Wheel also suggested a 26x34 M-500 (5 blade) when they calculated the 26x35 Dyna Quad. By the way, do you still own the boat? Regards, John Siegfried

[hmacdonald]

Yeah, the props were (are) 28" diam. They are Rollas, but that should'nt matter. We used the original 13/4" struts, and cut down 2" cutlass bearings to fit. Therefore shaft angle was not changed. Bottom clearance did not seem to be a problem-- no vibration or anything. The 5 blade props are also inherently MUCH smoother than the 3's. I sold the boat to a friend a couple of years ago when we had the opportunity to move into a '91 50C - but that's a different story-and project. The 36 is still local and is getting a lot of use with its new family. IMHO you're right on the money with the 500hp Cats. That Jim Wynn hull with the prop pockets really likes a lot of push. In regards to difficulty in reaching Bruce, he did the engineering for me during a period when he wasn't at Hatteras. Now that he's back, he is in perpetual motion and is very hard to get up with. If you should need any more info on what we did you can email me at hmacdonald@cox.net Harry MacDonald