SR20 crankshaft pulley measurement

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onsight512
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SR20 crankshaft pulley measurement

Post by onsight512 »

Does anyone know what the offset is, from one pulley to the next, on the stock crankshaft pulley on an SR20? If the three of them are not symmetrical to each other, the ones I'm really interested in are the two closest to the engine block.
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sfdaugherty
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Re: SR20 crankshaft pulley measurement

Post by sfdaugherty »

I might be able to help you but need a much more complete explanation of what you are looking for. I have an S14 sitting on an engine stand but may have my S15 pulley on it. I'd be willing to take some measurements but need to know exactly what you want. Knowing why you need the measurements might help me understand also.

Shannon
69 2000 SRL311-10088 (Type 4 Solexes)
68 SR20DE SPL311-18735 (SR20DE S15 Autech)
68 2000 SRL311-01179 (Restoration underway)
68 1600 SPL311-20462 SOLD! After 41 years in the family
onsight512
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Re: SR20 crankshaft pulley measurement

Post by onsight512 »

sfdaugherty wrote: Fri Oct 05, 2018 10:34 am <snip> I'd be willing to take some measurements but need to know exactly what you want. Knowing why you need the measurements might help me understand also.

Shannon
Thanks Shannon. I’m typing on my phone, so I can’t attach any photos but...

My car has an S14 with a Subaru Justy alternator that was swapped in by the previous owner. He made a bracket, “similar” to what Michael Speadbury sells. The bracket he made broke and I thought it’d be a good opportunity to buy one of Spreadbury’s kits, so I did.

I then discovered that the PO had cut the two ‘front pulleys’ off the stock crankshaft because he would have had to modify the front crossmember for clearance.
Since my crankshaft pulley only has the single pulley, I can’t use Spreadbury’s kit as that setup uses the middle pulley.

Since the PO did modify the frame on the passenger side of the alternator for clearance, I’m wondering if by redrilling the bracket from the kit, I might be able to avoid having to buy a new crankshaft pulley and modifying the front crossmember.

I’d need to offset the new holes in the bracket, towards the rear of the engine, the difference between the middle and rear pulleys on the stock crankshaft pulley.

I know Michael makes his kit to move the Subaru alternator so that the middle crankshaft pulley is used, but since the PO has already made some room in the frame on the passenger side of the engine, I think I might be able to use the single pulley that I have now. I could be wrong, but for the sake of drilling three holes...
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Re: SR20 crankshaft pulley measurement

Post by GoldHawg »

If you decide you need a pulley, I can provide you with one from an S15. I ended up taking mine off so I could use my new AC kit. I would NOT redrill Michael's kit. I ended up selling Michael's kit myself because I've gone with an alternative alternator setup that I made on my CNC plasma setup, but I can tell you it took me weeks to get everything lined up perfectly. And Michael makes a great kit--if you are thinking you're good w/Justy there is no better option. I'd buy an S14/S15 pulley and call it a day. I got a used S13 DET harmonic balancer off another forum shipped for $40--shouldn't be too much problem.
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sfdaugherty
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Re: SR20 crankshaft pulley measurement

Post by sfdaugherty »

Jeff: it sounds like he doesn't have room to fit a full sized pulley.

Shannon
69 2000 SRL311-10088 (Type 4 Solexes)
68 SR20DE SPL311-18735 (SR20DE S15 Autech)
68 2000 SRL311-01179 (Restoration underway)
68 1600 SPL311-20462 SOLD! After 41 years in the family
GoldHawg
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Re: SR20 crankshaft pulley measurement

Post by GoldHawg »

Not sure I understand why. As I recall from Michael's SR20 install, you don't even have to cut the front crossmember, but it just makes it a bear to get in and out if you don't cuz of the oil pan. Nevertheless, the crossmember slopes down toward the back, and there is plenty of clearance. I have attached several pictures of mine (yes, the crossmember is clearanced, but it is well below where the 2nd and 3rd pulley go. The first picture is of my S15 HB that I replaced (temporarily) with an S13 DET. I swapped for the DET style to get 4 ribs on the outer pulley vs 3 for my AC. Note that the picture with the straight edge is at the front of the crossmember, which is the highest point as it goes across. Hope this helps.
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onsight512
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Re: SR20 crankshaft pulley measurement

Post by onsight512 »

I'll reply in more detail later, but yes, I lack the clearance for the full stock pulley. I'd imagine it's because the engine in my car is located lower &/or slightly more forward as compared to Jeff's car (and most other SR20 swaps). The previous owner fabbed his own motor mounts. Maybe that's part of the reason.

Jeff, is the S15 pulley the same as the S14? If so, I'll gladly take you up on your offer. I'll pm you.

And I'll see about getting a photo or two that shows my (lack of) clearance.

thanks,
Chris
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