Radial Anti Detonation Grooves

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bsfc9

Post by bsfc9 »

Erik, can you tell us alittle more about incorrectly made pistons? What exactly was the problem? I've heard through the years about JE having design issues above the top ring. I do have to add, I have never experienced these supposed problems. I have used quite a few sets and will continue to use them until someone provides concrete evidence of a design problem(not pictures or stories of a scuffed bore or piston top). I have seen power increases in back to back dyno tests between JE and another brand.

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Post by Barry_R »

Erik is correct on several points.

Wiseco is the only North American piston company that does in house forging from bar stock. Everybody else purchases semi-finished blanks from Aluminum Precision Products or Precision Forge.

Wiseco and JE are sister companies - but the relationship can best be described as "tenuous"- it took several years before they even stopped hating each other...

Warren uses (or used, I don't keep up) Wiseco - they make an extremely good product. I've had to wait on parts while his were on the machine.

Those grooves above the ring land are - in my view - more decorative than funcional

There is no "silicone" in pistons...
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Post by Racer7088 »

Ed-vancedEngines wrote:Erik,
Do you know that you are talking about the same company? Wiseco JE

Maybe they do make their own forgings, I don't know. Most Piston companies I know of buy the forging blanks from aluminum companies.

Ed
They are not the same company but are owned by the same company now so big difference. Wiseco makes most of their forgings in house.
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Post by Racer7088 »

Scott Smith wrote:Just because they have a sticker on the side of their car don't mean they run the product. :lol:

Do you think Warren Johnson really runs a Fluid Damper? :lol:
I know that WJ really has run and does run Wiseco pistons a hell of a lot and so do some of the guys here that have worked there. Of course like all PS guys he will try everyone's pistons to go faster and has as have all other PS teams. WJ does not use a Fluidamper though even though he has the stickers.
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Post by Racer7088 »

bsfc9 wrote:Erik, can you tell us alittle more about incorrectly made pistons? What exactly was the problem? I've heard through the years about JE having design issues above the top ring. I do have to add, I have never experienced these supposed problems. I have used quite a few sets and will continue to use them until someone provides concrete evidence of a design problem(not pictures or stories of a scuffed bore or piston top). I have seen power increases in back to back dyno tests between JE and another brand.

Mike
Yes most of JE's stuff is totally awsome and has always worked flawlesly for me and with the stuff we got at the other shop. We had some where the skirt had a lot of barrel and the top ring lands were very little pulled back as compared to a normal piston and the top land dug into the cylinder and wore pretty crazy right away and JE told us they were not the right lands for that skirt and the problem was handled so nothing bad about JE really.

They do seem to have some pistons where the ring lands are very close and the crown rides aginst the wall or almost does more so than others on some of the weirder inboard pin boss stuff I have seen and used lately. It seems like these sometimes have problems and you can't run too much clearance on them.
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Post by Racer7088 »

Damn, I didn't see your stuff till now Barry! I was going off the other page!

I have seen some deals where the pistons were overheated and those "ridges" touched and wore away a little without lifting the ring land where I think a regular smooth land would have melted or galled more but I don't really know if that is true. The ridges do look sparkly and cool! I know some PS people want them and some don't care.
Barry_R wrote:Erik is correct on several points.

Wiseco is the only North American piston company that does in house forging from bar stock. Everybody else purchases semi-finished blanks from Aluminum Precision Products or Precision Forge.

Wiseco and JE are sister companies - but the relationship can best be described as "tenuous"- it took several years before they even stopped hating each other...

Warren uses (or used, I don't keep up) Wiseco - they make an extremely good product. I've had to wait on parts while his were on the machine.

Those grooves above the ring land are - in my view - more decorative than funcional

There is no "silicone" in pistons...
Erik Koenig

Houston, TX

http://samracing.com

http://HKRacingEngines.com
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Post by automotive breath »

From Wiseco frequently asked questions

What are the anti-detonation grooves on the top ring land for?

The Anti-detonation grooves prevent carbon-buildup from locking
up the top ring. They also help keep the air and fuel in suspension.
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Post by nastyrs »

i just ordered a set of the je nitrous pistons .. they have those same grooves above the top ring land.. i can take some pictures if you like ...

i also just got a customers car in that melted 4 pistons from nitrous related issues .. and i do beleive they are the same piston .. i will have it all the way open soon .. i can get pictures of what all was destroyed in the motor as well..
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Post by automotive breath »

nastyrs wrote: just ordered a set of the je nitrous pistons .. they have those same grooves
above the top ring land.. i can take some pictures if you like ...

i also just got a customers car in that melted 4 pistons from nitrous related
issues .. and i do beleive they are the same piston .. i will have it all the way
open soon .. i can get pictures of what all was destroyed in the motor as
well..
I'd like to see pictures of the melted pistons and the cylinder heads from
the same engine. Did it run lean?
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Re: Radial Anti Detonation Grooves

Post by ptuomov »

There’s a pretty good explanation of how the groove in the top land works to protect the top ring groove from detonation. The groove buffers the large amplitude pressure waves that mechanically break the top or bottom of the top ring groove.

The reason why car factories don’t use it is emissions, instead the top land is made very narrow now and the volume is minimized.

Mahle piston book describes 105 hour continuous detonation test with low octane fuel with and without the groove, and why it’s not used nowadays in production cars.

I’d post a photo but the site doesn’t accept iPhone photos without processing, which is asinine in year 2018.
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Re: Radial Anti Detonation Grooves

Post by DCal »

Not Wiseco, but Cosworth. At least Cosworth in Torrance Ca. is the one who sent us (and other piston companies) a registered letter that we were to Cease and Desist from machining multi-grooved top lands. Told us it was patented which was a joke and they went out of business shortly after that.
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