'86 Hardtop Perkins to Cummins Swap

[RBRAUN]

I have had an '86 Hardtop for a few years now which came with a 200 hp Perkins. The boat had 1100 hours when it was trailored in '88 and left "unattened" until now. I have recently gotten what I think is a Cummins 220 hp @ 2500 RPM ser 403 6BTA 5.9-M2 engine and have marinized it with parts from the 210. A friend and I have built a stainless exhaust, new engine mounts and I think we are a week from beginning to install the engine.

Some questions for you Diesel Dudes who may have the time and interest????....
1) Does anyone know where I could get a reasonable facsimili of a wiring diagram? This is an old marine patrol boat with all those options which I do NOT intend to make work... I will leave the flashing blue light to K-Mart.
2) Any pictures/suggestions for batteries and the bridge arangements I have seen on some gas engines in these forums?
3) Does anyone know which transmission came with the original 200 Perkins? and does it/should it match to the Cummins 6BTA 5.9?
4) Has anyone added fuel capacity with which they are happy?
5) Any suggestions on mounting a fighting chair? granted this is certainly the chair before the motor syndrome.
6) Any general comments/suggestions etc?

I live on Oahu and plan to use the boat inter-island...20 mile crossings or so to dive, fish and camp.

Many thanks for your time/interest.

mahalo
Bob

[Brian]

I repowered an 86 years ago with a 210 cummins - 2 type 31 batteries fit in front of the engine - on a bridge that spans both stringers. It is a tight fit - but the will fit in there. The fuel capacity should be no problem. We would run out 4 hours, troll all day and back 4 hours and burn less than 70 gallons. You have two 52 gallon tanks installed. That is running at 20 kts and trolling at 5-6 kts. You should be able to obtain the wiring diagram from the Cummins book - it is pretty straight forward. The trans that Shamrock put in with the 210 was a Borg Warner 71 C - with a 1:1 ratio.

[Mistress]

What he said...except it was a 72C 1:1 trans with the 210 Cummins.

I just got a wiring diagram in the mail yesterday from another member. I'll scan it and e-mail it to you if you provide me your e-mail address.

Might be worth perusing/joining www.boatdiesel.com. Are you aftercooled or not?

[RBRAUN]

Many thanks for your comments and suggestions. My email is rbraun@lava.net. I would apprecite your time/effort toward the diagrams you have acquired. This boat/engine will be a kind of cobbled together power train and hopefully the electrical will not become a nightmare...fortunately my buddy who is doing the real work...I am his gopher...is very good at this kind of stuff. Aftercooling is in discussion. I bought a very tired 6B210 to use to marinize the bus engine so I have the trans that is in the boat...I have not looked ...and the 72 C that came with the tired sacrifice engine. I saw your comment last might in another thread about the fly wheel so will do some checking this weekend.

Over here it is unusual to be able to run much faster than 10-12 kts offshore in a 26' boat. We troll at 7.5-10 kts. The north shore of Molokai..about 20 miles long and the south side of Lanai are great diving and trolling...so from my slip it is about a oneway 35-60 mile run depending and then the diving and trolling dink around on a 3-4 day trip means some consideration on fuel but it may be best to carry some "jerry cans" for an additional 20-30 gal on those occasions.

In other threads I have caught the suggestion to join boatdiesel.com and will do so.

After coveting a Shamrock for 15+ years and this one sitting in our pasture for 3 years ...and having never been on one... I am getting excited about making this work. 3 years ago I previously bought a 29' local boat with engine and fishing gear which I thought I would strip and put into the Shamrock but...I just used that boat for 2 years and sold it whole. It was too nice to strip but was too loud to enjoy when off the flybridge.

Can you comment on how I might anticipate noise inside a Hardtop cabin and insight about mitigating noise?

many thanks
bob

[Brian]

Correct - it was a 72C. After using that trans for 2 years - I replaced it with a ZF 220 PL - with a 1:1 ratio and added a trolling valve. The nice thing about that trans was that it had a 5" offset - so it lifted the entire engine out of the bilge by 5". It required me to have new engine mounts fabricated and increase the height of the bait station over the engine by 5" - but it was well worth the effort.

[Shamrock Fisher]

The 72c's must not hold up very good behind a diesel?:confused:

[Mistress]

Why do you say that? It's within the design limits for pleasure ratiing.

That said, I had mine beefed up when it was rebuilt. Figured why have a medium duty engine with a pleasure duty trans. FWIW, the rebuilder said except for both reverse clutches being broken in half, my trans looked immaculate inside. One of these days I might actually install it.

[Mistress]

Turns out my Scanner won't allow me to put multiple pages in one .pdf file (weak version of Acrobat?). The wife can do it at work Monday though.

[RBRAUN]

Many thanks to you all for the help. I have the "new" engine...a 2206BT from a bus that wrecked with 22,000 miles for $1K, and a tired 2106BT from a boat for $1K...they have been merged..run great sound great on the engine stand. I checked/redid wiring new fuses, new batteries, new bat switch cleaned contacts, rebuilt trim tab system.. etc. Fuel tanks come out tomorrow to be outside glassed/inside bead cleaned. Sunday is our target date for completion?

Hopefully there will be no story to tell and things will work ...a derelect boat for 8 years, a $4K fixed up engine and parts...and maybe a sea worthy boat. As Johnny Cash sang..."I got it one piece at a time.."

Mahalo
Bob

[Mistress]

excellent!!!

[Scratcher]

Bob; For noise reduction go to www.soundown.com Its a good site for ideas, they have very good product, be prepared for sticker shock tho, it ain't cheap. That being said, I think planning/designing the sound reduction in while you are redoing the boat is the way to go. Soundown makes custom mufflers too, and engine mounts will make a difference by reducing (or not) the vibration that sets everything aboard to rattling. To me it is a real pleasure to be on a quiet boat and I'm ok with spending the money on something I'm going to enjoy every single trip rather than cosmetics or an electronic gewgaw that is rarely used.

[RBRAUN]

I have heard that experience is what you get when you didn't get what you wanted.... I think I have just gained some experience!

The story continues.... and I know more of what I am about.

1) The installation of the 6BTA 5.9-M2 220 HP @2500 went well. It is much bigger than the Perkins 200 HP...but some thinking solved those size issues. The Engine cover now hinges to port which I tend to like. I cut down the "fish box" aft of the engine to about 1/2 and have mounted a series of filters and have much more room for the fuel/return valves, trim tab motor etc. It starts... sounds....runs... everything great. I have a new 5" stainless exhaust system (larger than the original 4" one) clear to thru the transom.
2) I now know the fresh and raw water cooling system very well now and have learned that the "breather hoses" from the high points in the fresh water side of cooling returning to the reserve tank are essential!!!!
3) The boat is now rewired...everything works..lights, bilge pumps, washdown pump, horn, radios ...all is good on that side of things. Contempory electronics will be added as desired and prove advantageous with use.
3) The next thing I have learned and am learning much more about...thus this email.... is transmissions and gearing.

I believe the new mystery transmission is a Hurth...likely a HSW 800A. I am duducing it is likely near a 2:1 reduction from engine to prop. At about 2500 RPM the boat does 10-12 kts. The boat is near but does not get on plane. I have a 16X17 LH prop

If ya all have time knowledge and interest... I have a couple of questions and would appreciate some guidance. This boat is being put together on a budget by someone who has never done this before and is not generally good at such.

1) I cannot find anywhere on the transmission markings of anykind. How can I find out model and most immediatley important, the gearing?

2) I think I have one or two maybe three options but am seeking advice:

a) Option one is to find out the facts of the transmission and seek knowledgeable advice from a prop shop, preferably one familiar w/ the Shamrock, and see if I can get a prop of appropriate diameter and pitch to give some higher speed to the boat....knowing that w/ a 1 1/4" shaft there are limits to transfering the torque from the engine to the shaft. Does anyone have recommeded contacts for such a resource?

b) Option two is to get another transmission...this being more expensive/time consuming in cost of the transmission and the remounting of a new one.

c) Maybe option 3...Is it at all possible to take the current transmission to a transmission specialist and have the current transmission altered to closer to what I think is the desired 1:1 gearing?

[RBRAUN]

Thanks for the information toward planning for noise reduction. I too very much value an investment in mitigating as much sounds as is reasonable. I was a sailboat owner for 20+ years but now enjoy the efficency of getting to where I want to go in a straight line...quicker. I am more active than passive, diving and flyfishing...rather than tacking and triming sails.

I have the remnants of the original sound proofing whic came w/ the boat in '86 and am surpised how quite it is. After reading on ythe recommended website I am coming to new ideas on how to improve things.

Thanks for your time and recommendation! Mahalo!

[Mistress]

You need a 1:1 or thereabouts transmission. You've got the right or very close to the right prop for 1:1 with that engine. I don't know if they can be modified. I'd prolly get the proper gear and then sell the old gear to recupe some costs.

The 1-1/4 shaft and clearance for the prop prohibit proper propping to accomodate the low geared trans. To establish your gear ratio you need a phototachometer. These can be had for <$50 on Ebay and other sources. tack the crank and tach the output flange/coupler and divide.

FWIW I have velvet drive 72C 1:1 in mine. WOT gives speeds in the mid 20's.

[RBRAUN]

Thanks for the recommendation re: gear ratio. I am afraid you are right re: pull this transmission and get a new one. Mahalo!