Re-powering

[Fuzzy]

To DGill:  I see that you are repowering your '87 for more power.  Can you tell us all here what you
will be repowering with?  I would be interested in your project and I wouldn't be surprised that
others on here would also be interested.
Larry

[dgill]

Hi Larry,

My 1987 C34 had an M25XP.  Good engine.  Has nearly 3000 hrs on it.  Good compression.  I am re-powering because I want a bit more power.  I am retiring this coming June and am expecting to be using my boat more.  So even though I might have gone several thousand more hours on the M25XP my experience with it on my boat is that it is under-powered.  I think back then the 23hp was a price point decision for Catalina.  Anyway, to answer your question, I am having a BETA 28 installed.  This engine, with the Atomic 4 mounts (which lower it a bit) will fit nicely in the engine room.  The BETA also is Kubota based so there are the advantages associated with that, as you all know.  Additionally, this engine is pretty user friendly and has the nice feature of a built in oil change pump.  This engine will be upgraded with a serpentine belt/pully system.  I also will have the upgraded cockpit panel which has more gauges.  There are other things that I just can't remember at the moment.  I hope that this helps.  D. Gill

[Stu Jackson]

Hi Larry,

My 1987 C34 had an M25XP.  Good engine.  

I think back then the 23hp was a price point decision for Catalina.

DGill, I think it was less a price point than the fact that the M35 was not being produced by Universal until 1987!    The M25XP started in September of 1986, which would be hard to fit into earlier boats.  You ust have gotten one of the first ones, based on your year and hull #.

See the History of Universal Engines, here:  http://shop.torresen.com/marine_diesel_direct/Universal/index.php?p=include&contentsection=universal&contentname=modelhistory&finalcrumb=Universal+Diesel+Engine+Model+History

Good luck with your repower.  It would be great if you could document it.  Perhaps a Tech Note article could be prepared, we'd be glad to help with that.

[dgill]

Hey Stu,

Thanks for the info. and the chart/history.  I am edified. 

DGill

[Les Luzar]

Stu,
For the record, my boat was built in November of 1986 (87 model), hull number 355 and I too have a M25XP.

[Stu Jackson]

Lez, somewhere there are two C34 skippers: one with the last M25 and one with the first M25XP.  Somewhere around a late '86 or early '87 boat.  Right?  Thing is, we don't know if they are C34IA members or even read this board.  Might be hoot to find out, huh?

[Ralph Masters]

Ciao Bella is hull CTYP0367L687 with the M25XP

Ralph

[Les Luzar]

Ralph,
Based on your hull identification number your boat was built in December 86. And, as Stu said, I agree that it would be fun to find out which hull number got the first M25XP and the last M25....

[Ralph Masters]

There is another C34 two slips up from me, I'll check his HIN and engine this week end if he's at the marina, and Brad Young is coming into our marina when he gets his boat back in service.  We'll have 4 C34's at Pier 32 Marina here in beautiful San Diego.

Ralph

[Ron Hill]

Guys : It will be interesting to see how a Beta 28 fits, as D. Gill is having it done by someone else. 
No complaint on my part, just wish I had the means (and less personal curiousness - on doing it myself).

I'm sure it will fit in that "hole", just interested in the mods that are necessary.  My thought

[Fuzzy]

dgill:
Thanks for getting back to us on the project you're about to take on.  When does the actual work start?
Please keep us informed and if you can keep a photo log.  It appears that a bunch of us are really interested
in your upgrade.
Again, Thanks -  Larry

[Stephen Butler]

Have been thinking about this interesting project and am a bit confused (more than normal).  Replacing an older engine to gain reliability is certainly understandable, but if the Beta 28 (a 25hp unit) is being installed for more power, I do not understand how the very slight hp increase is going to make any difference in the hull's performance. Would a few hp along with a different prop make a telling difference?  Our 1990 with almost 2000 hours seems to push the hull within a narrow speed band. I am not a naval power expert, so no doubt am missing something critical. Having asked all this, the Beta 28 looks like a fine replacement and I am anxious to follow this installation.

[stevewitt1]

Stephen
Very interesting observations.(must come with the first name) One of my former boats was an Allmand 31. That boat originally had a 16hp and was repowered with the M4-30 25hp. You certainly seem more knowledgeable on this subject than me but here's my observations and questions:
If you up the HP on any given displacement hull wouldn't any speed (calm conditions or motoring into weather) be the same for any given diameter and pitch prop at a given rpm regardless of hp?? A higher HP motor may allow going to a larger prop thereby providing greater thrust. At that point speed would be influenced by hull design, condition, wind and wave conditions.
BUT, if a 23hp and a 25hp are both capable of turning the same 15x10 prop at the same revs wouldn't the speed difference be virtually zero?  The 25hp may do it with greater ease but wouldn't any true advantage only be the result of say; at a given condition the 23hp would only develop 3100rpm and the 25ph maybe 3300rpm.  These are assuming identical transmission reduction ratios and props?

Just wondering
Stephen     visit us at www.ocontoyachtclub.com and www.warbirdsix.com

[Stephen Butler]

Stephen, you voiced my thoughts exactly.  And if you add in the admiralty law for displace hulls, which our C34s are, then one would expect a larger bow wave, but not much speed increase for the higher hp engine, even if the prop was changed.  Again, maybe I am missing something.  I can see a higher hp for driving accessories, but for hull performance? 

[Ted Pounds]

Yes, hull speed is the limit for displacement hulls.  And for a C34 23hp is more than adequate for calm conditions.  However a really stiff headwind (and the resultant sea state) might require a lot more...