90 amp bolt in alternator on an L-series motor

[Charlie69]

DanielC what is the top bracket off of in this picture?

 

[]2eDeYe]

I have a 90 amp alt on my 8o kc with an L20B. I used the v6 alt off of a d21 4x4. Easy to adapt pig tail if you save plug-end from donor. I 'machined' the water outlet flange  with a 3" Craftsman belt sander. Also cut a small clearance 'window' on top of alt housing..tight quarters but it fits. Paid $30 for a used alternator...better than new or rebuilt. EASY!! Fast..even the first time. WORKS!! CHEAP!

 

 

Keep an eye out for a ZX water flange, you will get a ton of clearance, 

[DanielC]

It is off something Nissan.

Years ago, I wore out the L-16 engine that came in this truck (1970 521).  so I did some price shopping, rebuilding time, and figured out it would be faster, and cheaper to get a (real) JDM engine.  It was a fuel injection L-18.   I did not know what I had, and so i just put the L-16 carb, and manifold on that engine, and ran it, for years.

Heartbreak story number one.  "I do not need or understand any of this fuel injection crap", so I turned in the four cylinder FI manifold in for scrap aluminium.

Then I let the engine sit without antifreeze, and it cracked the cylinder head.  A big valve, big port, peanut head.

 

So figure out the years of cars Datsun was using a fuel injection L-18 engine, and that is the upper alternator bracket.  The alternator was a internally regulated, about 60 amps.

[5t341tH]

 

Keep an eye out for a ZX water flange, you will get a ton of clearance,

what year 280zx?

[datzenmike]

Only from the 280z or the 280zx.  Here's why...

 

L 4 cylinders usually have a water cooled/warmed intake manifold and/or a thermostat housing water by pass, and there has to be a way for this water to get back into the system. Usually this is a small pipe that connects down to the lower rad inlet to the timing cover.

 

The 280z has the small by-pass return line cast into the aluminum inlet as well as a steel threaded fitting for the heater hose return. The 280zx has the small by-pass hose return as part of the steel threaded heater hose return fitting.

 

The L24 and L26 do not have the by-pass return fitting in either form and the 810/Maxima only have the steel threaded fitting for the heater hose.

[DatsunHiLife]

I am trying to wrap my sore brain around all these options!! :confused: Damn it feels good to be a newbie :poop:

[5t341tH]

Hey I just tried upgrading my alternator off a saturn. I first grabbed one off a 2002 SL because it seemed very clean. I got it tested and it works fine. I since did more research on here and found out I needed an early 90's unit. So I picked one up too.

'92 on the left, '02 on the right

I tried both combinations and the '92 unit doesn't clear the water neck very well. The '02 unit cleared much better. Just a bit of grinding on the bottom mount to have full sweep.

I have a question regarding wiring it. I know I need to wire the L and the S pins but the plug on the new alt doesn't go to L and S. It appears to go to F and L. How do I make it go to the S pin?

 

and this is the plug off the '92 unit. Its pins also go to F and L

The 2 plugs aren't interchangeable.

 

EDIT: just did some more searching and I think I found my answer. The F can be connected the same way as the S would be.

[JonU]

I'm so confused now. I'm looking for preferably a 80-90amp alternator that is internally regulated. Minimal fabrication on getting it mounted would be preferred. I don't mind messing around with wiring so that doesn't really matter. I've read that the Bosch units are crap and it seems there are a lot of options. Is it possible to take my current alternator to a shop and get it rebuilt to an 80 amp unit with internal regulation? I think a 60 amp might even be plenty for my car though. I'm not currently running halogen or HID lights and all the electrics are stock minus the electric fuel pump the previous owner installed. Once the car comes back from the shop, I'm contemplating on putting together a new harness. I understand that entails lots of time and work, but it couldn't hurt to replace and update what is now a 42 year old wiring harness.

[bilzbobaggins]

are the 240z alts already 60 amps?

[datzenmike]

I think all Datsun cars were at least 50 amp. (60 optional) 521 trucks 29-34 amp and 620s about 35 amp. the 720 were 50/60 amp. All alternators through '77 were externally regulated with a box on the inner fenders.

 

 

HID lamps produce more light with less power so no worries there. For your halogen lamps replace the wiring with a larger gauge from a kit. It uses the stock wiring to run relays with shorter runs and thicker wire for less voltage drop. Lights will be brighter.

 

Yes your 50/60 amp can be rebuilt to 80 amp but that's a lot of money for an extra 20 amp you won't really need. Cheaper to just buy a (used) 90 amp alternator and convert your car to internally regulated. I have a 100 amp '02 Altima alternator in my 710. Wasn't easy but it works. Paid $75 for it and two rear disc brake assys.

 

The king of alternator swaps would be the one from a '99-'03 nISSAN Quest / Mercury Villager. Why? Because they both had VG engines with a Nissan 120 amp alternator in them. Other year Quests had...

 

93-98 - V40 = Quest and Mercury Villager - 110 amp

93-98 - v40 = VG30E  = 1 sliding door made in TN = Mitsubishi 110 amp 
99-03 - v41 = VG33E = 2 sliding doors made in TN = Mitsubishi 125 amp
04-10 - v42 = VQ35DE = 2 sliding doors made in Canton MS = Valeo 130 is actually a 145 amp

 

96-00 - R50 = Pathfinder and Infiniti Qx4 as standard - 80 amp
99-04 - D22 = Frontier VG33e - 80mp
00-04 - WD22 = Xterra - VG33e - 80 amp

[JonU]

The king of alternator swaps would be the one from a '99-'03 nISSAN Quest / Mercury Villager. Why? Because they both had VG engines with a Nissan 120 amp alternator in them. Other year Quests had...

 

93-98 - V40 = Quest and Mercury Villager - 110 amp

93-98 - v40 = VG30E  = 1 sliding door made in TN = Mitsubishi 110 amp 

99-03 - v41 = VG33E = 2 sliding doors made in TN = Mitsubishi 125 amp

04-10 - v42 = VQ35DE = 2 sliding doors made in Canton MS = Valeo 130 is actually a 145 amp

 

96-00 - R50 = Pathfinder and Infiniti Qx4 as standard - 80 amp

99-04 - D22 = Frontier VG33e - 80mp

00-04 - WD22 = Xterra - VG33e - 80 amp

So this would be the best option? Not saying I would buy one, but if I can find this alternator, it would be the one to get? How much fabrication am I looking at to get it mounted into place on the L24? I can swap pulleys easily enough, but not sure about the rest.

 

[warrior4777]

Hey guys... A lot of great info here... but I'm confused. Please help...

 

I have a 72 510 with an L18. I have the newer style L20b mounting bracket that takes the 10mm bolts.

 

 What would be the best/easiest swap out? I believe I had a newer higher amped one from a 78/79 620??? (50 amp, I think???) But it doesn't keep up, especially at night. and forget running the heater and/or windshield wipers haha!

 

I have converted it to an electric fuel pump, electric cooling fan, and I have 80/100 h4 headlights. I am going to convert to HID very soon.

 

Then what do I do with the wiring??

 

Thanks!

[Kathos]

I dont know if its frowned upon or if its already been posted but here is a link that may help others. http://www.the510realm.com/viewtopic.php?f=2&t=11086

[datzenmike]

The '620 didn't go above 38amp.

[flatcat19]

I have/had a 38 amp IR alternator on my 521. Very underwhelming.

 

 

KA will be the next to be installed.

[datzenmike]

Room is at  a premium on the 520/521 and the 620 trucks. If you got the urge gato, re mount it on the distributor side where there's tons of room. There are threaded bolt holes over there. Just make a custom mount for it.

[flatcat19]

I think I'll be fine. Not worried.

[datzenmike]

Truck alternators are small. Higher output are larger and hit the grease fitting on top of the idler arm.

[flatcat19]

I have a KA alt already. There is barely a difference in size between the two. I had plenty of adjustment to go with the 620 alt.

 

 

I'll report back when installed.

[Charlie69]

Truck alternators are small. Higher output are larger and hit the grease fitting on top of the idler arm.

Not if you run a 1980 to 1986 720 chassis under your truck.  The steering gear box and the idler arm are on the outside of the frame making more room for alternators and AC compressors.

[flatcat19]

Then bring a 720 frame up here and get this 521 finished!!!

[datzenmike]

Not if you run a 1980 to 1986 720 chassis under your truck.  The steering gear box and the idler arm are on the outside of the frame making more room for alternators and AC compressors.

 

 

These two poets go together....

 

 

Room is at  a premium on the 520/521 and the 620 trucks. If you got the urge gato, re mount it on the distributor side where there's tons of room. There are threaded bolt holes over there. Just make a custom mount for it.

 

 

Truck alternators are small. Higher output are larger and hit the grease fitting on top of the idler arm.

 

The 720 truck alternators are like the larger diameter '70s Datsun car alternators. 50/60 amp output. I've tried both in a 620, they are not a good fit. By the time you get it positioned where you can swing it to tighten the belt it hits things. Had to install shorter belt first then mount the alternator. The KA alternator did look slightly smaller but I have not tried it in a 620 only my 710 sedan. I think they are 80 amp.

[J's 620]

I would like to confirm that a Saturn alt. works in a 620. It's the cs 130. I bought it from an alternator shop, got a shorter belt, replaced the grease fitting on the idler arm with a grease cap, and used a turn buckle thingy as my adjustable mount. Also used the 280 zx water inlet and lower hose to give it some room. Fit is tight but doesn't hit anything. Does this help anyone? Yes I know, put it in a build thread.... and post pics. I don't have a computer so......

[J's 620]

Oh and I had to shave down the alt mount that bolts to the block a weee bit. Just so the holes line up.

[flatcat19]

Don't need a computer. I post everything from my phone including pictures.