CD 27 Motor Options

[Jon]

What options are available when upgrading the diesel in a CD 27? Are there larger motors that drop in easily? Would the prop pitch & diameter need to change? Would the aperture need to enlarged for a larger prop? How much work would be involved? How much cost?

Jon

[Bill Goldsmith]

Jon,

A prior owner repowered Second Chance, so I can share a little info with you, but I didn't have to do alot of the decision-making myself.

Around about 1991 a prior owner installed a Yanmar 2GM20(F). It's rated 16 hp, 18 hp peak. With a 12 inch two blade prop it provides all the power I need and then some. The engine is not very large, although it did appear to need some widening of the fiberglass flange that supports the steps/engine cover. I would recommend talking to a repower specialist to discuss repitching or replacing the existing prop--it's a function of the displacement, the transmission gear ratio and other factors. It certainly appears that no widening of the aperture would be necessary. I also do not believe a 3-blade is necessary--I get great performance from my 2 blade.

Cost is considerable. You're probably looking at 10 to 12 grand for a brand new engine fully installed. Others with recent repower experience may have more up-to date ideas on cost. You may do alot better with a used, rebuilt engine.

Bill Goldsmith
CD27 #173
Second Chance

What options are available when upgrading the diesel in a CD 27? Are there larger motors that drop in easily? Would the prop pitch & diameter need to change? Would the aperture need to enlarged for a larger prop? How much work would be involved? How much cost?

Jon

goldy@bestweb.net

[Andy Denmark]

Jon, I own a CD-27 with a 13 h.p. Westerbeke and it is all the engine I need. I concur with Bill on the 2-bladed prop -- below 30 feet the 3-blade is a bit smoother but that is all -- speed and thrust are identical if diameter and pitch are correct. We've emperically tested that every way from Sunday. Let's face it, the CD-27 has barely a 20 foot waterline and the speed potential is seriously limited by that. The aperture limits one to a 12 inch prop, so the options are in the gearing and the pitch. You absolutely need enough h.p. to turn the proper pitch -- too aggressive in the pitch or gear ratio and too little horsepower is bad on the engine and probably slow underway There's a happy balance here and sometimes it seems like black magic to find it. IMHO, the magic formula takes readjusting (repitching) for a few haulouts until you get it right. Rarely is it correct out of the box because we all load and trim our boats differently, both of which make a difference.

Hope this helps,

Andy Denmark
CD-27 #270 "Rhiannon"
Lower Broad Creek, Oriental, NC
35*05.7'N, 076*38.7'W



trekker@coastalnet.com

[Jim Stull]

What options are available when upgrading the diesel in a CD 27? Are there larger motors that drop in easily? Would the prop pitch & diameter need to change? Would the aperture need to enlarged for a larger prop? How much work would be involved? How much cost?

Jon

Hi Jon
I am in the process of doing a hull-up rebuild of a 1977 CD27. I did a lot of study and finally settled on the Yanmar 2GM20F as the new engine.
I purchased the engine at the Anapolis Boat show last month. I negotiated the best price I could for the engine and the total ended up a bit less than $6k.
The shop that I bought the engine from told me that they would bill for a weeks work if they were to do a job like this. I have purchased all the manuals and will do the installation myself. I have been taking photos as the work on the boat progresses so if you wish I can share them.
Although the new engine is about 2 in wider than the opening, I find that it is the same width as the old origional Yanmar.
I have the old engine about ready to come out and will see if "twisting" the engine on the hoist enables it to slip thru the opening without cutting the 'glass.
I was interested to read the replys from Bill and Andy on the prop.
I had contacted Michigan Wheel about this and reproduce their reply below.

Dear Mr. Stull:

Thank you for your interest in Michigan Wheel propellers. The following is
the result of the propeller analysis performed based on the data you
submitted. As a result of our analysis, our naval architect suggests you
consider the following:

Diameter and Pitch: 13 L 12
Number of Blades: Three
Material: Bronze
Style: 3-blade Sailer
*Price: App. $ 369.00
*Plus applicable tax and shipping.

COMMENTS:

The recommended clearance between propeller tip and hull bottom is 15% of
the propeller diameter.
Propeller(s) is (are) highly loaded, sizing in this range is experimental
and requires water testing for verification.
We would prefer a larger diameter but it appears that you do not have
adequate space and clearance to install a larger size. (Alternately, a
bronze 14 L 11, 3-blade Sailer may be used. Suggested retail price is
approx. $379.00).

We hope this information is useful to you. For more information on how to
purchase our propellers, please check our web-site for the Michigan Wheel
dealer nearest you.

Again, thank you for your interest in Michigan Wheel. Should you have any
questions or concerns about your sizing, or require any assistance in
locating the suggested propeller(s), please contact our Customer Service
Department at 1-800-369-4335.

Best Regards,

Greg Verseput
Customer Service

To install anything larger than the existing 12" prop will require enlarging the opening on my boat so now I will have to decide what to do!

Jim



jtstull@earthlink.net

[Bill Goldsmith]

It seems my estimate as a bit high on cost. The engine at about 6K plus a week's labor (about $2500 to $3000 maybe at full yard prices?) comes out at about $9K. Not as much damage as I thought.

Bill

What options are available when upgrading the diesel in a CD 27? Are there larger motors that drop in easily? Would the prop pitch & diameter need to change? Would the aperture need to enlarged for a larger prop? How much work would be involved? How much cost?

Jon

Hi Jon
I am in the process of doing a hull-up rebuild of a 1977 CD27. I did a lot of study and finally settled on the Yanmar 2GM20F as the new engine.
I purchased the engine at the Anapolis Boat show last month. I negotiated the best price I could for the engine and the total ended up a bit less than $6k.
The shop that I bought the engine from told me that they would bill for a weeks work if they were to do a job like this. I have purchased all the manuals and will do the installation myself. I have been taking photos as the work on the boat progresses so if you wish I can share them.
Although the new engine is about 2 in wider than the opening, I find that it is the same width as the old origional Yanmar.
I have the old engine about ready to come out and will see if "twisting" the engine on the hoist enables it to slip thru the opening without cutting the 'glass.
I was interested to read the replys from Bill and Andy on the prop.
I had contacted Michigan Wheel about this and reproduce their reply below.

Dear Mr. Stull:

Thank you for your interest in Michigan Wheel propellers. The following is
the result of the propeller analysis performed based on the data you
submitted. As a result of our analysis, our naval architect suggests you
consider the following:

Diameter and Pitch: 13 L 12
Number of Blades: Three
Material: Bronze
Style: 3-blade Sailer
*Price: App. $ 369.00
*Plus applicable tax and shipping.

COMMENTS:

The recommended clearance between propeller tip and hull bottom is 15% of
the propeller diameter.
Propeller(s) is (are) highly loaded, sizing in this range is experimental
and requires water testing for verification.
We would prefer a larger diameter but it appears that you do not have
adequate space and clearance to install a larger size. (Alternately, a
bronze 14 L 11, 3-blade Sailer may be used. Suggested retail price is
approx. $379.00).

We hope this information is useful to you. For more information on how to
purchase our propellers, please check our web-site for the Michigan Wheel
dealer nearest you.

Again, thank you for your interest in Michigan Wheel. Should you have any
questions or concerns about your sizing, or require any assistance in
locating the suggested propeller(s), please contact our Customer Service
Department at 1-800-369-4335.

Best Regards,

Greg Verseput
Customer Service

To install anything larger than the existing 12" prop will require enlarging the opening on my boat so now I will have to decide what to do!

Jim

goldy@bestweb.net

[Mark YAshinsky]

The $6k is just for the engine and the $2-3k just the labor. What about all the other things that seem to come up??? Will it need a new engine panel (and wiring), a new seawater inlet (Goldsmith's Second Chance got one), new exhaust (might want to change out now anyway), Will the prop shaft mate to the other half of the transmission flange (is that even included), etc. Make sure you have a good primary starting circuit (battery to starter). Last winter, ripped out all of the primary circuits (charging, starting, house supply) on Second Chance and went up a gauge in wire size and she starts much better, even in the colder temps.
Width seems to be the problem on getting the 2Gm in. I believe a combination of stripping the engine down (alternator, air cleaner, raw water pump) and some trimming of the fiberglass flange that the companion steps sit on are all that is needed. An earlier thread had someone asking about how much of the flange had to be trimmed. It was earlier this year.

[Loren Lyndaker]

What options are available when upgrading the diesel in a CD 27? Are there larger motors that drop in easily? Would the prop pitch & diameter need to change? Would the aperture need to enlarged for a larger prop? How much work would be involved? How much cost?

Jon

I repowered "Whipporwill" 1980 CD27 Hull #172 with the 2GM20F in 1998. Some trimming required to install plus modifications to the motor bed. I have a 12" diameter x 14 pitch three-blade prop. (not sail prop but full bladed). It performed very well on our 6000 mile one year round trip from Lake Ontario to Maine - Florida Keys and Bahamas and back. We made 5.5 to 6 knots @ 2700 RPM using about .4 gallons per hour. Smaller props will work but are not making use of the engine's power. I believe the 13" diameter may not have enough clearance to run smooth.

Good luck



llyndaker@lacs.moric.org

[Jim Stull]

The new 2GM20F came complete with the instrument panel completly wired ready to plug into the engine.
It also came with the complete cplg, motor mounts, large operators manual and some tools. After the project is complete I will tally up the costs and problems and post them.



jtstull@earthlink.net

[Bob Miller]

Has anyone had any experience with a 1GM10? I currently have a YSB8 and the horsepower of the single cylinder is ok, but wow, a 2 GM? I figured it out once from a formula in SAIL, and a CD 27 needs about 13 hp.

- Bob Miller, CD 27, Good Times



millerfam5050@worldnet.att.net

[Warren Kaplan]

Has anyone had any experience with a 1GM10? I currently have a YSB8 and the horsepower of the single cylinder is ok, but wow, a 2 GM? I figured it out once from a formula in SAIL, and a CD 27 needs about 13 hp.

- Bob Miller, CD 27, Good Times

Bob,
I read an article by a surveyor who said that the "rule of thumb" for engine size was 2hp per 1000 pounds of displacement. Our CD27s displace 7500# so 7.5 X 2 = 15HP. Again, rule of thumb. I believe the 2GM20F rates at 18HP. I think if money was no object, I'd rather go a little higher in HP than lower. Of course, alot depends if you are sailing (motoring) in strong currents of weak ones.

Warren Kaplan



Setsail728@aol.com

[Clay Stalker]

Has anyone had any experience with a 1GM10? I currently have a YSB8 and the horsepower of the single cylinder is ok, but wow, a 2 GM? I figured it out once from a formula in SAIL, and a CD 27 needs about 13 hp.

- Bob Miller, CD 27, Good Times

Hi Bob:

Have a CD27 with a 1982 Yanmar 2GM (13HP) that I think was original but don't know for sure....with a bronze 3-bladed fixed prop, plenty of power in all conditions. The new 2GMs are around 18 or 20 HP I think, and this should be more than enough. I have a friend with a Flicka (6,000 lbs.) with a 1GM and he is underpowered, so I would expect that a CD 27 would be as well. The Yanmar is a great engine, very dependable, quite smooth for a diesel, and easy to work on...expensive, though. You might be able to find a good used, rebuilt one as well. Good luck!

Clay Stalker
CD 27 Salsa #247
Bristol, Rhode Island



cstalker@cheshire.net

[Jim Stull]

We managed to rig the old Yanmar YSB8 up and out yesterday. What a job it was getting it out. Had to cut away several inches of 'glass in the opening to get it thru! IF I could have reached the bolts of the waterlift and other accessories and IF everything hadn't been rusted tight and rounded off. I MIGHT have been able to slip it out of the existing opening. But life is too short!
I will remodel the opening as part of the cabin rebuild.
The new 2GM20F actually looks to be about the same size.
BTW: The 2GM20F is rated @ 18 hp max and 16 hp continuous. Perfect for the CD27.
Jim



jtstull@earthlink.net