Last Minute Jitters Before Buying New Engines & Gears

jziegler · Post by **jziegler** » Aug 27th, '09, 20:23

Hi All, I would really appreciate some advise before a big investment.

I have been studying this website for the last 2 years and bought a 1962 31 Express last summer 08. About to buy engines and want to make sure this is what I need. I know many don't like the lower HP Cummins but I am fine with that. Not in a big hury. I will be removing original gasers, shafts, props, etc. Is there any last minute things I need to make sure that I am getting or not getting. Here is what is what's on my quote from Cummins:

Factory Cummins Remans
DR6008RX 6B220 (6BT 220 HP) with ZF63a trans. 1.5 to 1 ratio, 7-degree downangle
All engines above have a 2 year 2000 hour warranty

All engines above include the following options:
Instrument panel
30 FT ext. harness
Exhaust elbow wet, 90-degree. Not a riser
Isolator mounts
Dry air cleaner
Gear cooler. Oil pump out hose,
Gear cooler hoses.
FOB Your door- south Florida
Sea trial and inspection

Also, I have up to 3 years before doing the sea trial and starting the warranty. This gives me time to do the engine swap and other work on the boat.

Are there any big additional things/options I will need.

Thanks in advance for all your help. Joe Z

In Memory Walter K · Post by **In Memory Walter K** » Aug 27th, '09, 21:18

Are these set up to be fresh water cooled? I assume so but just make sure.

scot · Post by **scot** » Aug 27th, '09, 21:51

I'm not a ZF guru, but the ZF220A (popular ZF-to-Cummins gear on this site) is a 10 degree down angle gear. I am surprised to see the 63a is a 7 degree down angle gear?...not that this would effect the installation in a 31, I just don't know.

That is confusing to me (what's new). Typically smaller gears are either no down angle, or 10 degrees. When you get into 400+HP ranges, the gears commonly go to 7 or 8 degrees....because they are going into larger boats and the shaft angles are not as steep.

jziegler · Post by **jziegler** » Aug 27th, '09, 22:47

If you go hear and click on ZF63a, you get a spec in PDF

http://www.tadiesels.com/hurth.html

Down angle is actually 8-degrees. So far, I need to confirm if engine is water cooled and gear angle. Thanks guys. This is the info I am looking for.

Joe

scot · Post by **scot** » Aug 28th, '09, 07:28

Yup...8 degrees.
Interesting HP ratings for a gear that size. At 5500 rpm the 63 is rated over 500hp.

Bruce · Post by **Bruce** » Aug 28th, '09, 07:43

The pleasure rating is a joke.

I've seen those style gears explode under way less rated HP. Its due to torque and loading.

I'm more inclined to believe they are rating that gear for gas engines.

I wouldn't use that gear on anything above the 220 Cummins or the 315 Yanmar. That would be the limits IMO.

I've changed a bunch of 85 gears that were behind 370hp Cummins.
They just blew apart upon acceleration each time.

8 degree down angle in the 31 is just fine.

The 28 is where you need the 10 to get the nose down to clear the hatches.

In Memory Walter K · Post by **In Memory Walter K** » Aug 28th, '09, 08:06

They will be water cooled (salt). Make sure they're FRESH water cooled (anti-freeze). Walter

scot · Post by **scot** » Aug 28th, '09, 10:09

Bruce,

When I say "interesting"...that's my way of saying, what you said. But i'm always in the minority as relates to gear selection so I keep my marine gear opinions to myself. If I were going ZF behind a 6B, I believe I would want the 220A's.

Personally I like heavier, "under-rated" cast iron gears. I have had very good luck with this philosophy.

jziegler · Post by **jziegler** » Aug 28th, '09, 17:54

Scot, Thanks for your opinion. I was going back and forth on the gears also. The 63a vs. the 220. My Cummins rep for Florida assures me the 63a will be fine. It is easy to convince me since the 63a is about $2K less than the 220 or ~$4K for two. I can use this savings towards shaft change, props, and strut work.

I am trying to make sure engines are fresh water cooled. I am pretty sure they are and the Cummins rep says I also get all the fluids with the engine like oil, coolant, etc.

Are there any other questions I should verify with the Cummins rep befor I purchase. I am very appreciative for any and all advise from you all.

Bruce, I still hope you will help me with the engine change out. I hope to get the engines this fall and start serious work beginning of 2010.

Thanks again. Joe Z

jziegler · Post by **jziegler** » Aug 29th, '09, 21:40

I didn't mean to start a controversy about environmental rules! I am just trying to make sure I purchase the correct engines and props. Please, any advise on this is greatly appreciated. Joe Z

bertram31.com

Last Minute Jitters Before Buying New Engines & Gears

Last Minute Jitters Before Buying New Engines & Gears

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