After reading the alternator upgrade using the Leece Neville 90 Amp Alternator I did some on line shopping and purchased the LN-110-602 (8MR2069TA) from ASE Supply Company in Oregon. The price plus shipping was around $216.00. I appreciate all of the research and agree replacing the Motorola 55 Amp unit with the same size Leece-Neville 90 Amp unit makes for a no brainer!
The Leece-Neville alternator arrived this morning. Having the day free I responded to my boat, removed the old Motorola 55 Amp alternator and took them both to Gen Star, a local shop in Oakland CA that specializes in alternators, starters, and motors. My intent was to have them install an identical pulley on the new alternator leaving my old alternator intact as a spare.
Making a long story short the owner immediately told me the LN-110-602 was not a correct match for the old Motorola Alternator. He showed me the slight offset on the 2" foot which put the pulley about 1/8 to 1/2" difference between the two alternators. He also pointed out the shaft on the LN-110-602 was a metric diameter that did not match the Motorola. The solution for my unit was to either machine a new pulley which would make a close match or replace the front end of the alternator with an exact match to the Motorola. I opted to have the front of the alternator replaced for an exact match. The cost plus labor was around $70.00. The modification took about one hour.
One other difference was the attached regulator. I opted to keep the regulator for the time being. I may opt to add a three stage unit later.
The attached regulator did not have an exciter circuit. The option was to remove one of the leads and attach it to the hot lead on my battery isolator (battery #1) which in turn excited the circuit and turned on the alternator. Also the units is not a grounded unit. A separate heavy gauge grounding strap has to be attached to the negative post on the alternator and the other end grounded. This was all carefully explained to me by the store owner so there would be no problems when I installed the new alternator.
The owner suggested that with the right research he could find the exact match for the Motorola. He suggested the more correct unit was the LN-110-603. The foot allows for an aftermarket adapter/spacer that fits the 2" footing and allows for the correct offset. He further said the shaft size is the same as the Motorola. This unit also has an exciter circuit and the unit's shell is grounded. Both the 602 and 603 are the same price.
I returned to my boat and installed the unit without any problems. I have a battery isolator for my two battery banks. I connected the alternator's positive terminal to the + post on the isolator and the attached the one wire to excite the alternator to the isolator's battery #1 post.
After checking all of the connections I fired up the engine. I noted a good charge to the isolator's main terminal and showed no loss from either of the battery isolator's #1 or #2 terminals. I have a battery volt/amp meter for my battery banks. The meter showed a good flow of current both in volts and amps to the three battery banks. It should be noted there was a huge difference between the old Motorola 55 Amp and the new Leece-Neville 90 Amp alternator.
I would definitely suggest this project to everyone that has the old Motorola 55 Amp Alternator. As with the glow plug and wiring harness projects this is a something that will improve your electrical system...
Chris
Chris Stewart
S/V "24~7"
1984 Catalina 36 Tall
Hull #251 M25
(SF Bay) Alameda, CA
I used the 8MR2069TA, I wanted the 2" spool. The company I bought it from in Burlington, Ontario sent me two pulleys to try. One had a slight offset machined on it and it lines up perfectly, or at least as perfectly as I can determine. The pulleys were 5 bucks each. On our last boat we had a similar problem and the alternator guy was able to provide shims to move the pulley to the correct spacing. That only works if you have to move out though. The 3 ear mounting tab on the 2070TA was a problem on the last boat due to clearance in the engine box and I expected it might be with this one as it is tight in there. There was a difference in bolt sizes due to the metric/imperial change but that was easy to solve. This is on an M35A so there will be differences in the mounts and housings between it and the M25.
Edit: I just checked on Leece-Neville's website and viewed the side dimensional drawings for the 110-602 (8MR2069TA) and the 110-603 (8MR2070TA) alternators. The distance from the front of the mounting ears to the front of the fan where the pulley butts against is virtually identical. The 110-603 is .76" plus or minus .04", the 602 is .79" plus or minus .03". Therefore there shouldn't be much difference between them in that respect. It seems to me the differences are the metric bolts, the 2" spool vs 1" spool and the 3 mounting ears on the 2070 vs 1 on the 2069. I am going to buy a 2nd unit for a spare and thought I might get the 2070TA but now I don't think I will do that.
I have a Xantrex 3 stage regulator on it, it does what it is supposed to but it is a little complex to program if you need anything other than a standard charging profile. I had a Hehr Aqualine on the last boat and it was much easier to set up, uses pots instead of magnetic switches, but they are scarce and I'm not sure they're even making them anymore.
Bud,
Thanks for the great info. I am sure you are right on with your research.
Regarding the 602 vs. the 603. If you look at the foot of the 602 vs. the 603 you will notice the 602 is a 2" foot and the 603 is much smaller. The owner of Gen Star had the actual adapter for the foot for the 603 alternator allowing it to fit the 2" footing on the M25 allowing for a match up of the pullies. He installed it on a similar 603 unit he had in his shop to show me the offset matching the Motorola on the M25 Universal. With this adapter there is no need to use shims or to find a pulley that allows for the offset.
He did have several pullies that had an approximate offset to match my Motorola alternator. We took a look at a couple of pullies that seemed to match but after discussing the pros and cons I didn't want to take any chances. I chose to replace the front housing of the 602 for a perfect match. It cost me a few extra bucks but I wanted to err on the safe side. I figured with my luck the little offset would be enough for the belt to break when I really needed the engine... while the captain was on board.
And as I noted above unless you are going to install an aftermarket regulator the 602 has some slight simple modifications needed such as the exciter and ground which the 603 does not.
According to the owner there is an exact Leece-Neville unit to match the Motorola. He said given time he could do the research and find an exact fit. (Just for info for those that need to replace their old Motorola with the same Motorola model Gen Star has rebuilt units in stock.)
Chris
Chris Stewart
S/V "24~7"
1984 Catalina 36 Tall
Hull #251 M25
(SF Bay) Alameda, CA
I actually prefer the 2069 but install both. The problem is that I prefer machined pulleys, not the stamped ones, and cast pulleys are very difficult to find for the 2070 non-metric shaft. As a marine electrician I also much prefer an isolated ground alternator over a case ground.
The big problem is that Universal used a number of alts over the years, now days they often use Mando's, all with very, very similar case sizes. So on some engines the 2069 is a perfect fit and on some you may need to machine the pulley or alt foot and use a shim kit. The 2069 on our 86 C-36 was a perfect fit but on our 2005 C-310 I used the 2070 as that motor came with the Mando. The Mando BTW was off by darn close to 1/8" from the factory and I don't find this all that uncommon..
I have seen number of Universal engines with factory alts off by 1/8" or more in alignment....
You will often throw alignment out more choosing pulleys than with the alt case. Different pulleys from different manufacturers are usually all a little, well,.... different.
In my experience cast pulleys resist belt slippage far better than the stamped ones especially when you get over 70 amps or so....
-Maine Sail
https://www.marinehowto.com/
Chris,
I found this thread when I was searching on Leece Neville alternators on a Google search.
Thanks very much for the referral to Gen Star. John's a great guy.
Here's what I learned:
[url]http://c34.org/bbs/index.php/topic,7917.msg55085.html#msg55085[/url]
Thanks again,
Stu
Stu Jackson, C34IA Secretary, C34 #224, 1986, SR/FK, M25 engine, Rocna 10 (22#)