"Fan spacer" for L20B?

Engine, Transmission and related drivetrain.
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SteveEdmonton
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"Fan spacer" for L20B?

Post by SteveEdmonton »

Got another bit of a problem here. I've got a brand-new water pump that includes a fan clutch, and a fan that I was pretty sure would fit on it-- until I tried to put the two together. The spacing of the fan's mounting holes is somewhat wider than the hole-spacing on the fan clutch itself.

This diagram from the parts catalogue for the L20B shows a "fan spacer" that seems like it ought to account for the difference.
Fan spacer FSM 200SX p76 Jul2015.jpeg
Fan spacer FSM 200SX p76 Jul2015.jpeg (408.97 KiB) Viewed 2756 times
Problem is, I haven't got one of these spacers. So far I haven't found anybody in my area who can help me to either confirm this part's actual, real-world existence, or supply one. :(

I see that RockAuto lists a "fan spacer kit"-- Hayden #3960-- for a 1979 HL510 with L20B, and I'm guessing this is the thing I'm looking for. Without a picture though I really don't know for sure. (This is what it says: HAYDEN Part # 3960 Fan Spacer Kit: Fan Spacer For Standard Rotation Standard Duty Thermal Fan Clutch)

Info and advice is most welcome.
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okayfine
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Re: "Fan spacer" for L20B?

Post by okayfine »

If you google the brand and p/n you get images of what appear to be generic fan spacers. Might work, might not work.

All that said, are you sure you're going to have room for a fan clutch water pump, the spacer, and the fan clutch fan, and that your belt will line up?
Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson
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James
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Re: "Fan spacer" for L20B?

Post by James »

The spacer would have in impact on the overall depth of the fan - but would not alter belt location, as it is after the pulley. Fan Clutch could though…..
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SteveEdmonton
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Re: "Fan spacer" for L20B?

Post by SteveEdmonton »

Julian, I should have thought of that Google search myself, thanks for mentioning it. It turned up a more specific pic too I think, and no this Hayden part isn't at all the same thing shown in the factory manual. As you suggest, it would add quite a bit of depth / length to the whole assembly-- without necessarily even addressing the problem.

James, I see it that way too, that such a spacer wouldn't affect the belt alignment at all. And the fan clutch is fine in this respect too-- its pulley lines up perfectly with the crank pulley, just the same as the pulley for the stock L16 4-bladed fan.

This is vague of course without a specific citation to back it up, but I recall reading about numerous people using this clutch-type fan on L20B motors in our older 510s. I'm sure it's a totally standard "upgrade." If anybody knows otherwise I'd be glad to hear why it won't work. As far as I can tell at this point, the only real problem I'm looking at is finding this part #7 on the diagram above!
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SteveEdmonton
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Re: "Fan spacer" for L20B?

Post by SteveEdmonton »

Once more, with pictures... :?

Here's the fan compared to the water-pump pulley I want to mount it on. I've circled the difference in diameter at the four mounting-points.
IMG_6849 fan & new pulley.jpg
IMG_6849 fan & new pulley.jpg (197.05 KiB) Viewed 2707 times
As you can see, the holes in the fan's mounting boss are about 135 mm apart and those on the fan are about 102 mm apart.
IMG_6851 fan boss-size.jpg
IMG_6851 fan boss-size.jpg (155.11 KiB) Viewed 2707 times
IMG_6852 pulley boss-size.jpg
IMG_6852 pulley boss-size.jpg (147.41 KiB) Viewed 2707 times
I've got an old, somewhat beat-up water pump someone gave me that this fan does fit onto perfectly, and that pump looks like it would fit straight onto my L20B. However, I'm starting to wonder if maybe this whole setup is from a 6-cylinder L-series, because the diameter of the fan itself is 38 cm, while the diameter of the fan shroud on my 510 is 37.5 cm. Obviously, this particular fan won't fit my shroud unless I cut its blades shorter.
IMG_6853 fan diameter.jpg
IMG_6853 fan diameter.jpg (142.12 KiB) Viewed 2707 times
IMG_6854 shroud diameter.jpg
IMG_6854 shroud diameter.jpg (173.75 KiB) Viewed 2707 times
This leads me back once again though to the picture in the Nissan parts catalogue of a "spacer" that goes between the fan-clutch and the fan itself. It's #7 in the diagram earlier in this thread (Nissan p/n 21064-U6701). The catalogue I got this picture from, dates from Dec 1978 and covers the '78 HL510. That picture looks like I should be able to make this particular fan / water-pump combination work-- if, as noted above, I trim the fan blades a bit shorter to fit within my shroud.

Am I thinking my way through this correctly? Any information to help me figure out what to do here will be thankfully received.
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James
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Re: "Fan spacer" for L20B?

Post by James »

Does the fan fit inside the shroud? (not sure how it fits in a manner relative front to back). Meaning, while the fan may be bigger in diameter it might fit in front or behind the plane of the fan. I would get one of those spacers, and see how it goes…..
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okayfine
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Re: "Fan spacer" for L20B?

Post by okayfine »

Hey Steve, have you checked with a good NIssan parts monkey with your part number? Not necessarily a great chance of success, but...
Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson
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Re: "Fan spacer" for L20B?

Post by datzenmike »

Generally I have found the L20B clutch to be smaller than the later Z20/22/24 clutch fans.


Image

Image

What you need is an L20B plastic fan. Maybe yours was swapped long ago.
"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs
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SteveEdmonton
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Re: "Fan spacer" for L20B?

Post by SteveEdmonton »

Mike, that's exactly the situation alright. The fan on the left in your picture would do the trick. Maybe I'll have to post a WTB ad and see if I can scare one up.... Thanks!
'71 4-door
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