Machined horiizontal grooves in piston skirts

[rocketracer380]

Have pistons with machined horizontal grooves in skirts I'm assuming they are for lubrication to hold oil on the skirts or cool pistons original application was circle/ dirt track olds v8

[SupStk]

I'm guessing you have some old school pieces there like Venolia or Arias.
Don't know there reason for those grooves but whatever it was, must not of worked because they quit doing it.

[piston guy]

+1 Antiques

[Frankshaft]

Well, look at Polaris h.o. 800 engines. Ski doo also does it, and has done it for awhile now. They have horizontal grooves on the piston skirts. It's marketed as new technology. I hate the when they use that word. Anyhow, it's deemed "new" and "improved". It was done to add reliability to the stock pistons. Funny how they take something old, and make it a "technology", and it's new.

[adam728]

Well, look at Polaris h.o. 800 engines. Ski doo also does it, and has done it for awhile now. They have horizontal grooves on the piston skirts. It's marketed as new technology. I hate the when they use that word. Anyhow, it's deemed "new" and "improved". It was done to add reliability to the stock pistons. Funny how they take something old, and make it a "technology", and it's new.

Polaris 800.

[roc]

Have pistons with machined horizontal grooves in skirts I'm assuming they are for lubrication to hold oil on the skirts or cool pistons original application was circle/ dirt track olds v8

Sounds like antique race pistons... do the have buttons on skirts too? If it's a serious race piston, "it's gotta have the buttons!"... so they thought 40 years ago.

[Newold1]

I realize that for novice and budget governed types that they sometimes have ownership and access to some older performance engine parts and they want to move these nearly antiques into their parts building and use them accordingly. Nothing wrong with that if they are willing to accept the facts that their ultimate final build will just be at those older antique levels. If you really want to improve and maximise the results of your engine builds and performance results then come into the present and try to use the newer better technologies especially in pistons, rods, rings, bearings, etc. I realize sometimes the excitement and joy of receiving almost free or gifted parts, but if you are on this site asking to find out how to get the best performance out of your engine you need to understand how and why these new improved parts were developed and produced to begin with! JMHO

[Krooser]

I'd sooner watch 50 cars race with old tech and used parts then 5 guys with the latest and greatest...

[pamotorman]

Well, look at Polaris h.o. 800 engines. Ski doo also does it, and has done it for awhile now. They have horizontal grooves on the piston skirts. It's marketed as new technology. I hate the when they use that word. Anyhow, it's deemed "new" and "improved". It was done to add reliability to the stock pistons. Funny how they take something old, and make it a "technology", and it's new.

Polaris 800.

is that on the exhaust side only ??

[MadBill]

In this app, would the exhaust be the non-thrust side?

[pamotorman]

In this app, would the exhaust be the non-thrust side?

i was more thinking of heat on the exhaust side needing the oil.

[Newold1]

Krooser I for one appreciate your comments, opinions and dedication as an Antique enthusiast! I am just an "old fart" who enjoys the latest science and technology in todays racing world. I try to be an "old dog "learning new tricks ! Heck, I never really learned all the old tricks !

[pamotorman]

when i was doing 2 strokes if the exhaust port had dividers i would dill .032 holes in the piston skirt in line with these dividers to allow extra lube in this area.

[Frankshaft]

when i was doing 2 strokes if the exhaust port had dividers i would dill .032 holes in the piston skirt in line with these dividers to allow extra lube in this area.

That's what the aftermarket companies do for the new liberty 800 pistons. On either side of the ex port, as they have one big hole for the ex port. Wiseco and Wossner do this. They leave the ridges off. They are also forged.

[LSP]

Have pistons with machined horizontal grooves in skirts I'm assuming they are for lubrication to hold oil on the skirts or cool pistons original application was circle/ dirt track olds v8

3 grooves?, 100 grooves?

Depends on how close you look I suppose.