F-36 Gas to Diesel

prowlersfish · Post by **prowlersfish** » Sat Nov 10, 2007 4:25 pm

Sounds like your moving right along .

Danny Bailey · Post by **Danny Bailey** » Sat Dec 08, 2007 5:09 am

Monday will be three weeks that the fuel tank parts have been over in the welding shop....wish I had gone with plastic tanks. In the meantime, I have finished scaping and painting the bottom, waxed the hull, pulled the trim tab actuators off for replacement, and installed new larger seacocks and scoops. The new beds are 2.5 treated (old arsenic treatment) close grained pine epoxy glued to the stringers, bolted with 1/2 x 12" lag bolts and glassed on the sides with stitchmat and polyester resin. The aft vibe mounts will sit directly on the stringers. I epoxied 1/2 plywood on the sides of the stringer to get the width of the vibe mount. http://i235.photobucket.com/albums/ee26 ... 0_0523.jpg http://i235.photobucket.com/albums/ee26 ... 0_0522.jpg http://i235.photobucket.com/albums/ee26 ... 0_0518.jpg I have done some close measuring and am fairly certain that I can get the tanks past the engines, so next week the engines are going in. I still don't know how much I'm going to have to cut off of the shafts...so I can be doing that while waiting for the tanks. My plan is to slide the engines as far aft as the bottom of the transmissions will allow to get as much clearance on top as possible. Without sliding them aft, the top of the engine would not go under the floor.

guzzoa · Post by **guzzoa** » Fri Dec 28, 2007 2:18 am

Hi Danny,

I am in the same work, I am repowering a 36 Convetible (1974) from 440s to cummins 6bta 330. I am also in the mess of replacing the tanks.
Just few questions...

Will you need to change from 1.3/8" shaft to 1.1/2"?
Will the floor need to be raised or the 6BTAs fits in that space?

The transmission I am buying is a ZF220A (1.5:1) with 22x22 4 blades props

Best Regards from Venezuela

Antonio

rossjo · Post by **rossjo** » Fri Dec 28, 2007 10:21 am

1-3/8" shaft with 330 HP is very marginal.

I don't think 22" dia blades will fit with the stock struts.

Danny Bailey · Post by **Danny Bailey** » Sat Dec 29, 2007 5:18 am

Antonio,
I picked up my tanks from the welding shop yesterday. The initial estimate for building them was 3-5 days & $800 - $1,200 labor. I supplied the 1/4" 5052 aluminum ($1,200) already cut up and fitted. Actual time was 40 days and labor was $1,660 and now I have to worry about them corroding for the rest of my life. If I had it to do over I would buy plastic tanks and put them somewhere. I am leaving the 1 3/8 shaft. I'll be turning a 20 x 21 three blade initially and expect to re-pitch it to a 20 x 23? next haul out depending on performance. If it fails I'll go bigger. My son runs a 1 1/4" shaft in his 28 Bertram with 4BT's turning 18 x 24's and they have not failed in 5 years. Good choice on the ZF 220A 1.5:1. That's the same trannies I'm using. I've owned one before and it will do the job...just keep the couplings aligned. As far as fitting under the floor.... I have the starboard engine down and aft within .005 of lining up with the shaft, and a string pulled across the lower edge of the floor will barely clear the highest points on the engine. My engines have jacket water aftercoolers on top so they may be higher than yours. I may raise the floor 3/4 - 1 inch just to have room for soundproofing. I'll try to post some more pic's next week. Good luck with your project...it's a bear!
Danny

prowlersfish · Post by **prowlersfish** » Sat Dec 29, 2007 7:08 am

Antonio
The engines should fit under the floor they will be real close buit ok .
I am running 22X22 three blade wheels a liltle closer to the bottom then spec but work ok . A 20" would prop would clear better. if you have 22X22 four blades you will need to remove some pitch. you need to prop these engines to turn a honest 2900-2950 rpm ( 100-150 rpm over rated rpm ) by proping this way you reduce eng load and the engine will burm cleaner and last longer. I have 1 1/2 shafts and am using the stock struts. I think you could get by with 1 3/8 shafts . proping them to turn above rated rpm will reduce the load on the shafts also .

rossjo · Post by **rossjo** » Sat Dec 29, 2007 9:43 am

The 6BTAs fit right under my floor on my F32 - the floor joist had to be notched to clear intercooler however, and only 1" sound proofing, but they fit with the stock shaft location.

Good luck - you'll love the boat even more with the diesels!

guzzoa · Post by **guzzoa** » Sat Dec 29, 2007 10:34 pm

Guys thank you to all for the information.

Is very hard to get usefull information about repowering a Trojan over the net. Trojan is not very common here in Venezuela so I have no examples to follow here.

Danny, stop worry about your alluminium fuel tanks

, I have alluminium fuel tanks in a 29ft boat I also own, they receive a large ammount of salt water spray, the sheet is mutch lighter than yours and they stand very good! so no problem there just make a good conection to the boat ground and to the zincs.

I agree with rossjo, the 1.3/8 shaft is very marginal, specially in 316L o 304, I am purchasing 1.1/2 in aquamet 19.

Paul, I will check with my prop shop in Miami about that. Very usefull hint, thanks!

More questions!

How mutch you raised the engine mounts?
Where can I get the stock struts? mine are damaged and corroded.
What about the exhaust? will need risers? original exhaust mufflers and hose diameters will work?

again... Best regards from Venezuela and happy new year!

rossjo · Post by **rossjo** » Sun Dec 30, 2007 12:16 pm

I'm not sure what material Troan used on its shafts, but 1-3/8 is marginal for 330HP. I would refer to your local boat yard (have any?) on the struts ... and 4" dia exhaust would be best (wasn't the stock exhaust 3"? it is on my other boat with a 454).

Good luck!

prowlersfish · Post by **prowlersfish** » Sun Dec 30, 2007 1:42 pm

I think 4" exust would be a liltle small I am running 5" at the outlet ( 6" before the muffler ) I may change it all to 6" . I was told by former trojan dealer that trojans came with aqumet 22 shafts may or may not be corect. I belive you can get the struts here (trojanboats.net) or marine tech , if not mabe you can get the part number. they where made by buck aquin ( wrong spelling ) I will check on the specc of 1 3/8 shafts .

Apple · Post by **Apple** » Sun Dec 30, 2007 4:02 pm

Gentlemen...
Per Cummins engine installation guide.
6" exhaust for 330's.
Minimum Racor 900 or equivilant fuel filters.
1/2" Fuel feed and return lines.
2" water intake hose for cooling.
This one is off the top of my head...1100 cranking amps minimum
per engine. I'm using (2) 925 group 31s per engine.

1 1/2" AquaMet 19 for the shafts.

The dealer gave me an installaton guide, installation drawings and a "cheat sheet"( Cummins minimum requirements for warranty).
They are all in storage, when I get them back, I can share more info.

Guzzoa... Buck Algonquin makes struts...problem is, unless you are a dealer, you can't order direct.

RWS · Post by **RWS** » Tue Jan 01, 2008 8:08 am

With my Yanmar 315 LP installation, similar to Apple, I ended up with the same sizes & specs as he did.

We also chose to enlarge the side exhaust ports on our International, and to include a new anti-siphon loop with new outlets as an insurance policy against the possibility of snorting sea water water back into the engines.

The other exception is the shaft size.

The International Express Cruiser used 1.25" shafts, and due to thier legnth, there are TWO per side. This does not apply to the mid cabin express which had the engines further aft, utilizing one strut per side.

Although we could have bored the existing 1.25" struts to accept new Aquamet 22 - 1.5" shafts, it was economicaly more prudent to move up to a shaft diameter of 1.75", use the les expensive Aquamet 19 and replace the four struts with two newly fabricated ones. This also increased our "safety factor" for the shafts, as we were close to the grey area with the 1.5" Aquamet 22's. The only draw back is the weight of the spare shaft that I ordered for long trips away from the home base.

BIG DITTO on Apple's Raycor 900's. A different dealer offered to do my refit job with a set of 500's, however with the fuel return volume on these engines, they would have proved to be inadequate. I ran away from that unknowledgable dealer in a hurry.

By the way Apple, I'd love to compare actual prop size, RPM's and performance data.

RWS

Danny Bailey · Post by **Danny Bailey** » Fri Jan 04, 2008 8:09 pm

I now have them where they're gonna stay and have bolted the mounts. I ran out of room to service the stuffing box before the transmission casing came too close to the bottom. If the stuffing box had been 4" further aft, I could have lowered them another 3/4". http://i235.photobucket.com/albums/ee26 ... 0_0586.jpg http://i235.photobucket.com/albums/ee26 ... 0_0575.jpg http://i235.photobucket.com/albums/ee26 ... 0_0585.jpg I picked up my materials this afternoon for painting the fuel tanks. I'm going with Interlux 353 Primewash and Interprotect 2000E epoxy. Antonio, I'll get you some measurements on the mounts next trip to the boat.

prowlersfish · Post by **prowlersfish** » Fri Jan 04, 2008 9:24 pm

Looking good Danny. I have diffrent mounting brackits for the mounts
the stringers did not have to be rased in fact they where cut done slightly.

Danny Bailey · Post by **Danny Bailey** » Sat Jan 05, 2008 4:43 am

Thanks Paul. Do you have any digital pic's of your installation?

Trojan Boat Forum

F-36 Gas to Diesel

22" dia blades

6BTAs in F32

Repower

good luck