348 alternator removal & rebuild

Okay boys, I just got off the phone with the supplier.

I called and asked them if there was a difference between the heat sinks for the RN-02 and the RN-10. I explained to the person on the phone how George's RN-10 was wider than the Transpo inside the cover. What they then did was to go and pull both the RN-02 and RN-10 rectifiers to compare the dimensions. When they did the thickness of the heat sink was the SAME?!?! They butted them up back to back and the only difference was indeed the size of the positive bolt post. They even double checked them and they were still the same outer same dimensions and thickness. Figuring that maybe it was made in a different country than George's I asked what the country of manufacture was. It was the same as George's, China.

So maybe the difference is between the Regitar and the Transpo, because as the supplier just informed me both the RN-02 and the RN-10 are the same dimensions. Of course with the only difference being the positive bolt posts, 6mm for the RN-02 vs 8mm for the RN-10.

 

The outer diameter for heat sink on the RN-04 is 103mm. So that would make sense that its smaller. The site also lists the RN-04 as being a replacement for the the Transpo INR739, and the rectifier that came out of my alternator is a INR736. The OD for both the RN-02 and RN-10 is 113mm. The RN-02 is listed as the replacement for the INR734, with the RN-10 being listed as the replacement for the INR736 which is the direct replacement for the rectifier coming out of our units. It would appear that the Transpo unit George posted has an OD of 103mm. Good lookin out Brian.

However I have the RN-02 in my alternator and I had no problems fitting the rectifier in. I also have had no running problems with it. I would rather have the larger 113mm heat sink because it will help to dissipate the heat better. As you guys know our alternator sits REALLY close to the headers and we need all the help we can get to keep them cool. Yeah I know it's only a 10mm difference, but as I said we need all the help we can get. The cooler they run the longer they will last. The larger heat sink will help give us this little extra dissipation. Especially since the stock units seems to fail so often I would stick with the 113mm OD of the RN-10 rectifier.

 

I told you.

Still have them rebuild it with the upgraded parts we have discussed here. USI regulator (VRH2005-4A), and the Regitar rectifier (RN-10), along with the new brushes.

 

That's it!

Here's the pic again of the cover on the back of my alternator. You can definitely see a difference between the two covers. Especially over the cooling hole above the regulator. Mine has 3 long slots, while George's has two openings. So it seems that the problem is actually the covers and not the rectifier. The RN-02 and the RN-10 will fit inside covers that are like mine. I'm now wondering if the covers on the back of the 355 alternators are the same as mine or George's?????
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I'm still searching but this one "could" possibly work? http://www.wai-wetherill.com/products/partimage.cfm?wai_num=39-8203-3
But like I said I haven't found it for sure.

Do you know what model number your alternator is?

 

YEEEEEEEEEEEEEEEEHAAAAAAW!!!!!!!!!!!!


I FOUND IT BOYS! I FOUND IT!!

After searching, and searching, and searching, and searching, I have FOUND what car uses the SAME alternator as ours does!!!!!!! Man I'm so excited. Okay, okay, calm down Ernie, calm down. Big breaths, big breaths.

Okay fellas hear it IS!

http://www.wai-wetherill.com/products/partimage.cfm?wai_num=1-1410-01ND

On this page they list all the parts used in the Nippondenso http://www.wai-wetherill.com/products/sresult1bom.cfm?ManufName=NIPPONDENSO&item=100211-617

It comes out of a 1991-1995 Acura Legend. It's a Nippondenso 1-1410-01ND or 100211-617. I called up an Acura dealer and got a brand new price of $346. The Honda part number is 31100PY3013. It's the same part number for a 2 and 4 door Legend.

The only difference I saw was that the Acura alternator uses a INR226 regulator as compaired to the INR220 that comes out of ours. But that's okay because I'll bet the INR226 is a little bit better than the INR220.

I then called around Pep Boys, Kragen, Carquest, and Autozone looking for '91-'95 alternators. They only sold rebuilt units and the prices ranged from $141 - $214. The stores I called had Pep Boys being the cheapest and Autozone the most expensive. The core charges for the old alternators were $70-$80, but got refunded when you gave them the old units.

So their it is guys. Now you don't have to get bent over at the Ferrari dealer for a brand new alternator. You can either rebuild yours, buy a rebuilt one, or even buy a brand new one on the CHEAP.

Long live the Brotherhood!!!

 

Done.

 

Okay I have some more good news.

Even though the regulator that is used in the Acura isn't the correct one I have found what CARS have the correct regulator IN220.

It is found in a:

1990-1991 Lexus ES250 2.5L engine code VZV21
1989-1990 Toyota Camry 2.5L engine code 2VZFE
1986-1989 Toyota Celica 2.0L engine code 3SGTE


The Toyota alternator part number is 27060-62040, -63020, & -63082. The alternator is a NIPPONDENSO 100211-830. Keep in mind this IS NOT our alternator. Those are just the alternators that use the IN220 Tranpso regulator that comes standard in the alternators for our 348/355's. So if you are looking for just the regulator those are the alternators that use the IN220.

Continuing.

I did a little more searching and found that there is a bit more heavy duty regulator. The number for that one is IN220SE. It is listed as being used in race cars, agricultural, and specialty. This one is found in a 1989-1990 Honda Prelude running the B20A block and the "S" series NOT the "SI". The Honda part number is 31150-PD2-014. But DO NOT buy it from the Honda dealer! I called up two different dealers and they wanted $211 for just the regulator! Screw that noise!!! The unit that the IN220SE comes of is a Nippondenso 100211-330.

Keep in mind fellas that these numbers are only for the correct REGULATOR.

 

You could be correct for your alternator. However, I am beginning to think that your alternator isn't the same as what the rest of us have. The reason is because the rest of the guys that have rebuilt their alternators using the parts we have listed haven't had any problems fitting the RN-10 rectifier, and only you have had the problem fitting it you your alternator. Plus the rear cover on yours is different than what is on mine. I had no problems fitting the rectifier with an OD of 113mm, yet your rectifier was 103mm. So maybe it's that your alternator is different than what the rest of us have?

Could it be that Ferrari went to a smaller alternator to save money during assembly? It wouldn't surprise me. Then they could charge the same outrageous price for the new part (which they don't even manufacture) = even more profit.

So maybe the one that I think is the same as what I have is indeed correct, but it just doesn't match what you have. If the Acura alternator I have found is bigger and it does work, wouldn't you want a bigger better alternator running in your car? Now I am pretty sure that this is the correct alternator. But even if it isn't, it's REEEEEALLY close, and the closest we have come to so far. Like I said the only difference I saw was the regulator, and I found what cars had the correct regulator.

In the event that you come across the exact match please share the information. If I am wrong I welcome the correction, because it gives us more accurate information to properly tackle the problem, so that we don't get stiffed buying way over priced parts from the dealer.

 

The rectifier that you listed INR739 comes out of a 1992-1993 non-turbo Volvo 940 2.3L, engine block B234F. But that alternator does not use anything else that is similar. The regulator used in that alternator is totally different than the ones I listed.

It seems that what they are doing is just matching up parts that they, which are also used on different alternators. So at least you now have some more information on what car the rectifier you have is coming out of. That way you can just go buy what you need for your rebuild at the real world price, and not the Ferrari price.

 

Yes it does. Nice work Georg!

So now it looks like there are three different alternators that where used in the 348. The AC Delco unit used in the early 348's (Motronic 2.5) & Mondial T's. Then we have the Nippondenso's that where the upgrade, with a large version (INR736 113mm rectifier) and a slightly smaller version (INR739 103mm rectifier). Although bought of the Nippondenso's seem to use the IN220 regulator.