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(Bear with me, I don't know exactly what I am talking about) I was advised by fellow VMFers when ordering a stroker kit to make sure that the pistons didnt "intrude into the oil ring area." I told the guy that this was a concern when I was ordering and he said that these pistons DO intrude but they include a shim somewhere on the piston that will prevent oil consumption. Does this sound correct? He said that they have built many strokers with these pistons and have never had a problem with oil consumption. Any help appreciated.
Thanks
 

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What you're talking about is the piston 'pin' protruding into the oil ring grove. Here's a pic to help visualize. My preference would be to not have the pin enter the grove.
Item number 2425399968 on EBoy
 

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The oil rings on a typical piston are the 3rd (or 4th) slot from the top of the piston, and are filled with two thin steel oil rings and a wavey separator in between. They scrape nearly all oil off the cylinder wall as the piston moves on its downstroke into the block.

On stroker motors, the piston connection with the rods is via a wrist pin (basically a large, thick piece of steel tubing). To help "fit" more stroke in the engine, these pins are moved closer to the top of the piston; in some cases, the hole for the wrist pin interfers with the slot for the oil rings.

You lose oil scraping efficiency with this interference; I doubt a shim can be inserted that would make this better. I would try to find a stroker kit that would not have this interference.
 

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Here's a pic of the SRP piston I'm running in my 331. It came with my SCAT stroker kit:

http://a7.cpimg.com/image/FB/52/15255547-731d-01920120-.jpg
 

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When the wrist pin hole intrudes into the oil-ring groves (Ring Land) it leaves a small portion of the oiling ring unsupported and susceptible to deflection, which then allows oil to pass buy, or not get completely scraped from the cylinder wall, and results in oil burning.

By adding a support ring, or "Shim" under the oiling ring, the area is then re-enforced and deflection does not occur, so oil burning doesn't happen.
 

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By adding a support ring, or "Shim" under the oiling ring, the area is then re-enforced and deflection does not occur, so oil burning doesn't happen.
Couldn't have said it better myself. The SRP pistons used by my 347 use this support ring and excess oil consumption has not been an issue.
 

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If potential oil consuption bothers you, Coast High Performance make 347 stroker kits with pistons that do not have the piston pin hole in the ring land. The trade off is that they use a shorter rod, which results in a slightly less desirable rod ratio.
 
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