i own a 1980 cd36 which recently blew the main seal on the transmission side of the engine block on the original perkins 4108 and have decided to repower it and am considering replacing it with a yanmar 4jh5e with km35p transmission. does anyone have any experience with a repowering? any tips, pointers etc would be most helpful. my boat is currently on the hard in georgetown, exumas, bahamas.
thanks
kurt samuelson
repowering a cd 36
Moderator: Jim Walsh
Re: repowering a cd 36
I see no one answered you, I dont check this area of the board often (I wish everything was still in one place like it used to be).
Did you start your repower yet?
I repowered my CD36 a few years ago down in Martinique, with a Volvo D2-40, I considered the 39hp Yanmar as well (probably the one you are considering, I dont recall the model name). I can offer a few thoughts:
I chose the Volvo over the Yanmar mainly because the Volvo is a 4 cylinder and the Yanmar a 3, thus the Volvo in theory is going to cause less vibration. I have never been on a CD36 with a Yanmar so I cannot say its a fact. Price wise at the time the engines were within $50 in price and after looking at parts price lists long term maintence was not going to be different (unlike old Volvos which are notorious for parts prices). The Volvo also came stock with a 110amp alternator and used a 1" serpentine belt, if I recall on the Yanmar the big alternator was an upgrade and even then used twin 1/2" v belts rather then serpentine. The Volvo is actually a Perkins-Sabre block and it is marinized by Volvo. Not saying one is better then the other, just telling you what I saw. 1800 hours on the engine now and not a single issue.
I do think a 40hp is a bit more power then a CD36 needs, but both Yanmar and Volvo do not offer a 35 and I think a 30 is not really enough. Other marine engine companies do offer 35s, but since I spend a lot of time outside the US I wanted a truely global engine as far as getting parts and Volvo and Yanmar are the only two that fit that description (in small engines that is). If you dont plan to go much farther then the Bahamas, you might consider other options such as Beta, Universal, etc.. and step down a tad in HP.
Replace the water heater while you repower. Its much easier to do at the time and if your heater is origonal its likely near the end of its life if it isnt already.
Even if your engine bed looks okay from the outside and you think you can reuse it with the new engine, cut the glass off and romove it and give it a real inspection. The CD36 engine beds are notorious for rusting badly and with the old engine out its time to give it a serious look and replace if nessisary.
Modern engines are much smaller then the old 4-108, take full advantage of that. I installed mine lower in the engine room, as low as it could go really. This now allows me to be able to lay on top of the engine and reach the transmission and everything else behind the engine. No more going thruogh the cockpit locker to access anything behind the engine. Consider this when you do the install, it makes life MUCH easier. Setting it lower did require changing the angle of the stern tube though. I removed the old bronze one and replaced it with a fibreglass one. The diameter of the hole with the old tube removed is large enough that the new tube has tons of wiggle room to go at any angle the engine might need. Fill with epoxy and glass new tube in, its worth the extra effort. No matter what you do I wouldnt use the old stern tube, the design sucked in that the hose that connected the stuffing box was clamped onto it in an area that was entirely inaccessably without removing the stern tube.
A PSS shaft seal is terrific and it fits much better with newer engines in the very limited space back there.
Oh, and probably not an issue for most, but make sure the bolts holding the tranny are tightened enough! I never thought to check them (engine was delivered with the transmission already bolted on) and apparently they were loose, about a month after putting in the new engine, the transmission literally fell off because the bolts vibrated out! That was an interesting experience to say the least with no damage fortunately, in fact because the space behind the tranny is so short even when it fell off it stayed engaged to the engine and still worked!
Good luck with the repower, its expensive, but I am very happy with my result.
Did you start your repower yet?
I repowered my CD36 a few years ago down in Martinique, with a Volvo D2-40, I considered the 39hp Yanmar as well (probably the one you are considering, I dont recall the model name). I can offer a few thoughts:
I chose the Volvo over the Yanmar mainly because the Volvo is a 4 cylinder and the Yanmar a 3, thus the Volvo in theory is going to cause less vibration. I have never been on a CD36 with a Yanmar so I cannot say its a fact. Price wise at the time the engines were within $50 in price and after looking at parts price lists long term maintence was not going to be different (unlike old Volvos which are notorious for parts prices). The Volvo also came stock with a 110amp alternator and used a 1" serpentine belt, if I recall on the Yanmar the big alternator was an upgrade and even then used twin 1/2" v belts rather then serpentine. The Volvo is actually a Perkins-Sabre block and it is marinized by Volvo. Not saying one is better then the other, just telling you what I saw. 1800 hours on the engine now and not a single issue.
I do think a 40hp is a bit more power then a CD36 needs, but both Yanmar and Volvo do not offer a 35 and I think a 30 is not really enough. Other marine engine companies do offer 35s, but since I spend a lot of time outside the US I wanted a truely global engine as far as getting parts and Volvo and Yanmar are the only two that fit that description (in small engines that is). If you dont plan to go much farther then the Bahamas, you might consider other options such as Beta, Universal, etc.. and step down a tad in HP.
Replace the water heater while you repower. Its much easier to do at the time and if your heater is origonal its likely near the end of its life if it isnt already.
Even if your engine bed looks okay from the outside and you think you can reuse it with the new engine, cut the glass off and romove it and give it a real inspection. The CD36 engine beds are notorious for rusting badly and with the old engine out its time to give it a serious look and replace if nessisary.
Modern engines are much smaller then the old 4-108, take full advantage of that. I installed mine lower in the engine room, as low as it could go really. This now allows me to be able to lay on top of the engine and reach the transmission and everything else behind the engine. No more going thruogh the cockpit locker to access anything behind the engine. Consider this when you do the install, it makes life MUCH easier. Setting it lower did require changing the angle of the stern tube though. I removed the old bronze one and replaced it with a fibreglass one. The diameter of the hole with the old tube removed is large enough that the new tube has tons of wiggle room to go at any angle the engine might need. Fill with epoxy and glass new tube in, its worth the extra effort. No matter what you do I wouldnt use the old stern tube, the design sucked in that the hose that connected the stuffing box was clamped onto it in an area that was entirely inaccessably without removing the stern tube.
A PSS shaft seal is terrific and it fits much better with newer engines in the very limited space back there.
Oh, and probably not an issue for most, but make sure the bolts holding the tranny are tightened enough! I never thought to check them (engine was delivered with the transmission already bolted on) and apparently they were loose, about a month after putting in the new engine, the transmission literally fell off because the bolts vibrated out! That was an interesting experience to say the least with no damage fortunately, in fact because the space behind the tranny is so short even when it fell off it stayed engaged to the engine and still worked!
Good luck with the repower, its expensive, but I am very happy with my result.
Russell
s/v (yet to be named) Tayana 42CC
s/v Lady Pauline Cape Dory 36 #117 (for sale)
s/v (yet to be named) Tayana 42CC
s/v Lady Pauline Cape Dory 36 #117 (for sale)
-
Bob Brown
- Posts: 60
- Joined: Jun 3rd, '09, 19:22
- Location: CD36 Barbara Lee 1981 Hull 41 Haverstraw, NY
Re: repowering a cd 36
I have a Yanmar 38 3 cyl. installed in my CD36. The engine was installed by the PO and had installation issues with the metal bed which caused problems. The rear mount were canted inwards which caused the motor mounts to break 4 times in 600 hours. Last year the soft metal bed was replaced with white oak stringer, the hull was built up and the stringers were glassed to the hull. The engine was moved forward about 3 inches which should help with the boats balance, I can't say I noticed the difference. The engine has a shake at low RPM which I think (hope) is a dirty injector, she runs smooth above 1500 rmps. The injectors are out being serviced now. The vibration from hours of running with broken mounts ruined the shaft, cutless bearing and PSS. The new shaft was reduced to 7/8" and the PSS has a direct water feed off the manifold now. The narrow shaft leaves a little more wiggle room, our boats have really short shafts that don't leave much room for error. I agree with the other comment that you should definitely check the metal bed when the motor is out. I didn't do any of this work but the yard said it was a nasty project with lots of fiberglass grinding. One guy grinding and one holding the shop vac. Logic would say that a 4 cylinder would run smoother than a 3 cyl.. Hope this help.
Re: repowering a cd 36
I selected the 4 cylinder yanmar 50 hp with matching km35p transmission as it was an almost identical match to the old perkins 4108. engine arrived in georgetown bahams about a week and a half ago. Dont see any major corosion issues on the existing bed but am concerned about fabrication of the stern mounts as the rear part of the perkins (as well as the yanmar) needed to be suspended from above due to upward sweep of stern. also will install dripless shaft seal. plan on placing the engine this friday wiith factory rep from nassua ariving next tuesday for final allignment.
was your stern portion of engine also suspended from abovef?
thanks for your input
kurt
equus
hull #37
was your stern portion of engine also suspended from abovef?
thanks for your input
kurt
equus
hull #37
Re: repowering a cd 36
Yes, the stern portion of my new engine had to be suspended, its kind of weird, but not hard to get a fabrication shop to build something that does the job.
Russell
s/v (yet to be named) Tayana 42CC
s/v Lady Pauline Cape Dory 36 #117 (for sale)
s/v (yet to be named) Tayana 42CC
s/v Lady Pauline Cape Dory 36 #117 (for sale)