Datsun Roadster Forum-311s.org

When sorting through my various parts from disassembling five or more R16 engines, I came across a crank pulley with a larger diameter: 5.9in (150mm) vs 5.1in (130mm). Picture distorts it a bit, but keyways and timing marks are identical. I believe the painted one is from my '67 1600, but I may have just painted the one in the best condition.
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Now it's possible it was on the 5-main R16 that came from a 411, but, again, not sure.

Anyone have any idea about the larger pulley?

Thanks.

Might be off a 520/521 or even early 620 series pickups. They had bigger pulleys.

Bwk2000 wrote: Fri May 27, 2022 9:47 pm Might be off a 520/521 or even early 620 series pickups. They had bigger pulleys.

Okay, but total mystery as to how I ended up with one. Those would've been J or L motors. Never had those vehicles nor a J engine. Had an L20b, but sold it years ago. Weird.

Of all the hundreds (who am I kidding … Thousands) of random spare parts I’ve had accumulating in countless boxes that have come and gone over the last 40+ years for dozens of vehicles, I’ve certainly had my share of finding “What the heck are these?”, “How did I end up with this?” and “Well, that’s weird.” random parts - I suspect your situation is similar.
Chalk it up to another of life’s great mysteries

Pete, it looks like an R411 crank pulley, they are a tiny bit larger than the early spl 1600 pulley.

I discovered yesterday that I have the two sizes of pulleys. The groove diameter is about 100mm and 130mm. The 130mm is listed as a second option in the 311 online parts manual.

According to what I read the larger pulley will run your alternator and water pump faster. Given that cooling is a problem at times with these cars I think I will go with the larger pulley. I'll have to jack the stroker up to see which it has. The smaller I think.

Note: I edited this since I had a mistake.

I got curious, and just went and measured the crank pulley on my '67 at approx. 5" OD,...not close at all to the larger 5.9" of the larger pulley. I also run the "Super Cooling" (smaller OD than stock) water pump pulley I got from Rallye decades ago.

I would bet that the pulley is from a car like the 411, true sports cars have reduced speed at the accessories to keep them from failing at high RPMs. Look at the alternator pulley for just about any “sport car “ and they make it larger to slow it down.
Dave

Perhaps, but it is in the roadster parts manual. To me that makes it a roadster part and maybe the 411. The online 411 manual does not list this pulley.

The small one has the same part number as the 1500.

The Online Parts Manual shows "SPLU" for the smaller(?) 130mm pulley.

I think SPLU means a different market. Anyone know for sure?

for USA & Canada:

symbol SPLU is SPL311-U (from Oct '67) Datsun Sports 1600 with EMISSION CONTROL AND SAFETY DEVICES

symbol SRLU is SRL311-U (from Oct '67) Datsun Sports 2000 with EMISSION CONTROL AND SAFETY DEVICES

Jon

I have always been told SP Left hand drive United States.

!30mm is the bigger pulley.

Well....crap. Did I put the wrong pulley on? Is this going to bite me later, or much ado about nothing?

I stand corrected on the pulley size. I was going by groove diameter. They are measured by outside diameter.

Based on the parts book the larger pulley which is 150mm is the stock. The 130mm is offered to slow down the water pump and alternator.