What engines fit in my 79 Cat 30

[ZTS213]

Please Help! I bought a 1979 catalina 30 project without the motor.
I have a yanmar 2qm 20hp that won't fit and an atomic 4 that won't fit. I'm guessing the boat came with the universal 5411 because of the wide stringers the atomic 4 doesn't even touch, and from what I got from the original owner it had a ysm12 he pulled out. It's not the size of the motors I have that prevent them from fitting it's the fact that I can't get the Trannys to line up with the prop shaft. The prop shaft is a few inches lower than the Trannys. The output shaft is almost level with the engine mounts on my 2qm and atomic 4, is the tranny output shaft lower than the mounts on the universal 5411 or ysm12? What can I put in it that will line up?? Any info will help. Thanks Zachary.

 

[The Garbone]

An Atomic 4 will fit fine , if the boat was previously a diesel the bunks may need adjustment and brackets need to be made to fit the wider space. I built a plywood template to aid in setting up the engine bunks and mounts, dropping my A4 in next friday.

Check our the Moyer Marine forum, I am not the first person to put an Abomb in a diesel C30.

 

[Stu Jackson]

Check our the Moyer Marine forum, I am not the first person to put an Abomb in a diesel C30.

Yes, the factory was the first.

 

[Guts1236]

I put a beta 25 in my Catalina 30. You just do you have to make them fit. By the way I am extremely happy with the beta engine.

 

[ZTS213]

An Atomic 4 will fit fine , if the boat was previously a diesel the bunks may need adjustment and brackets need to be made to fit the wider space. I built a plywood template to aid in setting up the engine bunks and mounts, dropping my A4 in next friday.

Check our the Moyer Marine forum, I am not the first person to put an Abomb in a diesel C30.

Did you have trouble likeing up the prop shaft? What kind of angle was your motor sitting at?

 

[Anonymous 121765]

ZT,

I changed my 5411 to a 3M20A several years back. I had to design motor mount transition brackets. If wanting to use the engines you have, you will need a bracket that lowers the tranny to align with the shaft. Remember if you do lower, because of a shallow space under the engine, you may not have oil pan room.

Here are a couple of my bracket sketches, engine compartment & my engine dimensions that may give you some ideas on how to tackle this job pal.

CR

 

[The Garbone]

Did you have trouble likeing up the prop shaft? What kind of angle was your motor sitting at?

I bought a new shaft coupler and cut the old off with a sawzall. Old coupler was pretty soft and I stopped just a hair short of the shaft. Using the level app on my iPhone the shaft sits at 2 degrees and I made sure the jig was centered on the shaft and also had a 2 degree rise.


Dropping the motor in Friday the 10th. Did a complete teardown and resleeved. But did a lt of measuring and cutting with the jig. Should go.

 

[The Garbone]

Here is a post with the best photo I could find of the engine beds.

What is in a Name | Every good thing.... https://svknotaclew.wordpress.com/2014/05/13/what-is-in-a-name/

Note it was from last May.

My first A4 I got running but while testing in the garage had a corrosion induced failure of the #3 cylinder wall. Turning it into a 3 cylinder water pump. I bought a second A4 for $150 and have completely redone it since you never really know what is going on inside a used marine engine.

 

[woodster]

ZT,

I changed my 5411 to a 3M20A several years back. I had to design motor mount transition brackets. If wanting to use the engines you have, you will need a bracket that lowers the tranny to align with the shaft. Remember if you do lower, because of a shallow space under the engine, you may not have oil pan room.

Here are a couple of my bracket sketches, engine compartment & my engine dimensions that may give you some ideas on how to tackle this job pal.

CR

i like your sketch work there Ron you must be a draftsman of some sort

 

[jrowan]

Nice drawings Ron, you're always the consummate pro.

As far as the A 4 engine, it has to fit. The Atomic 4 was what the C-30 was designed
around. As Ron illustrates, you may have to alter the mounting position with new, custom
mounting plates but the A 4 will fit. Ask Moyer Marine if the oil pan has to modified or had an altered version to fit the C 30.

 

[FastOlson]

The diesel option for that year was probably the Yanmar YSM12, a horizontal single cylinder engine that made for an easy installation on any make of boat where height was limited -- this solved a problem with a lot of boat models designed for the low-profile A4 gas engine.
This model is nowadays out of production, but they are very reliable and you might find one rebuilt.

Loren

 

[Anonymous 121765]

Woods,

Ya caught me pal. I started as a draftsman right out of high school. If you remember the movie Grey Lady Down, I did some piping design on the double hulled ship that raised Charlton Heston's Nuclear sub off the bottom. The Navy has two of them, an ASR21 & ASR22. I still do side projects from home as a consultant using various CAD programs.

JR, thanks for the kind words pal.

CR

 

[ZTS213]

Thank y'all for all the info. And yes captnron great drafting. If I deside to go with the A4 I will make your designed mounts a see if they'll work but I have mixed feelings on using the gasser or saleing the two engines I have and just getting a ysm to make it easier since the tranny output shafts are the lowest point on the engine unlike the a4 and 2qm. Also I was contemplating converting her to electric drive. Any opinions on that?

 

[ZTS213]

2qm blue print.

 

[ZTS213]

Electric drive setup. This is the smaller setup. If I go with it I'll go with one a little beefier.

 

[Anonymous 121765]

Z,

When I repowered, the 25XP was abit too long & I would have to extend the forward engine/setee hatch area to accommodate it. If I remember, I found the Perkins & Yanmar to have a too-high profile or too deep a pan.

I settled on the 3M20A. It wasn't a hard install sans the brackets. I run thru alot of currents & seas & my normal cruising speed is about 5.5 KTS (w/a 3 blade prop). I can push it when needed to 6.5knots but, if replacing an engine, the HP & RPM'S may change the prop pitch for maximum performance. Not to worry, as I have a simple test to see if you need to change your pitch.

Oh, what joy (or stupidity) to be a boat owner huh?

CR

 

[woodster]

Woods,

Ya caught me pal. I started as a draftsman right out of high school. If you remember the movie Grey Lady Down, I did some piping design on the double hulled ship that raised Charlton Heston's Nuclear sub off the bottom. The Navy has two of them, an ASR21 & ASR22. I still do side projects from home as a consultant using various CAD programs.

JR, thanks for the kind words pal.

CR

lol i thought so ...i took drafting and mechanical drawing for 5 years in high school and technical school thought i wanted to be a draftsman and found out i like reading them better than writing/drawing them lol somewhere around here i still have some of my drawings from high school you know the ones on the yellow paper that was such a baer to keep clean while working on the drawing ...i may have a set of my tools somewhere in my lifes treasures ...i think i will look and see if i do ....lost my bamboo slide rule....man i wish i had that thing back