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Discussion Starter · #1 ·
Might be a silly question, but I cant seem to find anything on Spirolox ring sizing for wrist pin retainers.

21mm wrist pin = 0.827"

So should I get Spirolox for a .840" wrist pin? htps://www.summitracing.com/parts/ros-4004-j/overview/

Or ones for a .812" wrist pin? https://www.summitracing.com/parts/jep-812-042-cs/overview/
 

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Front Engine Dragste
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The .812s will never work . . . you have an ID groove in the piston to accommodate for a retainer that is a larger OD than that of the wrist pin.

The .840s *could* work depending on the depth the groove is cut to
 

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BATSLOMAN GIVES NO FUCKS.
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who made the pistons? call and ask them what they recommend?
 

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Discussion Starter · #4 ·
China made the pistons. I think I am going to go a different route. I was going to use these pistons for $86: 97 01 Acura Integra Type R 1 8L DOHC Pistons Rings Set B18C5 | eBay

And these rods for $252: Acura 1 8L B18C1 B18C5 Integra H Beam Rod 5 430" A Set 4pcs w Arp Bolts | eBay

And a local machinist said they would machine the pistons for spirolocks if I supplied them for $60.

The beauty of this is that with $2/each spirolocks is that I am looking at $415 for pistons and aftermarket rods with ARP2000 bolts, and even more important those pistons have fairly mild JDM ITR domes (nearly flat top) but CTR compression height of 30.7mm. That would give me a compression of 12.23:1 without massive domes.

However, I think that would be too annoying, and it is likely I would have things not work together without further fitting.

This setup is $525: Nippon Racing Honda Civic Type R CTR Piston Scat Rod Kit H Beam Rods B18C 81mm | eBay

It comes with name brand rods, ARP2000 bolts, and CTR pistons already all assembeled and everything should already fit together correctly. Basically I would just need to sand the tops of these pistons, balance everything, and plastiguage the rod bearings without any machine work.

The downside of this setup is it costs $110 more, and the "CTR" pistons have a compression height of 30.4mm, which gives me a compression of 12.55:1, which is nice, but CTR domes, which is not.
 

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del Sol si '94
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Have the domes milled. I had my PG6b's shaved down. Plenty of thickness left in the piston crown.
 

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Discussion Starter · #6 ·
I am kinda going back and forth on it, so if anyone does know which spirolox I should use for a 21mm wrist pin I would appreciate it.

I like the 30.7 compression height ITR pistons for $86 better, the higher compression height and lower domes is definately going the right direction for me. Either Eagle or Scat rods with ARP2000 bolts are $330, machining the pistons for spirolox is $60 and spirolox themselves are around $20. Thats $496, which is slightly cheaper than the $525 preassembeled option, but more importantly I like the pistons better with the $496 option.
 
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