tomcat

How does the use of piston sprayers and coatings affect required piston clearances? Do you have to tighten up on normal clearances because the piston no longer expands so much?

CcanDo

Tomcat,I repute you as knowledgeable engine person and feel you and your products are making a positive contribution toward the quest for engine durability and horsepower.Keep up the good work.For those without your expertise,they may want to follow the piston manufactures recommendations.

Raylar

The Duramax diesel has an interesting piston spray oiling system also. The cast piston has a chamber in the crown and the spray oiler is pointed to a small bottom entrance hole. the oil squirt is timed by location and sends a big shot of oil up into this cavity to reduce piston crown temperature. As for piston coatings there seems to be a lot of varying opinions and applications among engine builders. Some now feel that in non-shortburst motors that its better to let some of the cylinder heat migrate into the piston and keep the combution temperatures under better control to eliminate detonation from todays pump gas. I think each type of motor use will actually determine top coatings and skirt coatings. For longevity the anti-skuff skirt coatings and piston oilers seem to be the best overall direction. You can believe these GM engineers have more thermocouples, sensors and telemetry on their development engines than anybody in the industry. If you can add timing on todays fuels, eliminate detonation and gain the torque this gives you a tremendous opportunity to transfer this technology into todays higher horsepower marine motors, where slightly more compression and torque will certainly be a benefit. Just some thoughts.

Ray @ Raylar

tomcat

CcanDo: Thanks for the kind words, but I don't consider myself an engine expert; I just ask a lot of questions. I'm always interested in learning about any related systems and modifications that might allow a supercharged engine to perform better and last longer.

Chris mentioned new JE blower pistons designed to be used with oilers in the pin and skirt area. Why there? For lubrication purposes as opposed to sprayers for cooling the top of the piston? Any more info available on these pistons?

CcanDo

Ray@Raylar has an interesting webb site.www.raylarengine.com One of the items within the site displays Mahle pistons.Mahle is considered on plane with JE and CP.Nykasill is a Product Mahle is understood to have knowledge of.Nykasill is used to coat the cylinder bores.Ray,in your opinion,how would coated pistons and nykasill bores work together?Also,are you aware of carbon fiber blocks in development?

Raylar

Have not heard of any carbon fiber blocks in the marine trade. There might be some hitech raod racers and formula 1 guys playing with that but I would think the costs would be off the page! As for Nykysil and coatings Mahle is probably well ahead of anybody in the piston business and I know they have done a lot of testing on ceramic coated rings and such as well as exotic piston alloys. Our new pistons are the 2618 alloy with special treatments and they are proving to be wonderful pieces. I get pretty fresh info but they don't keep us in the inside loop on the newest stuff. I believe their putting most of the testing and technology in diesel pistons as well as extremely lean burn technology right now. As with any of the material improvements, they seem to trickle down fairly quickly and I look forward to PRI this year in Orlando for some new updates.

Ray @ Raylar

Jason3603

I know this is an old thread but wanted to see if this has became more common in bbc supercharged applications in marine engines. When this thread was started a few people stated oil sprayers were for the extreme high end build. Are there any kits available?

Strip Poker 388

iTrader: (6)

http://www.keithblack.com/racing_kbblocks.html

Hot Stepper

I can't vouch for the marine industry but in automotive this is becoming standard practice across almost every manufacture. One interesting point in regards to the oil squirters/jets or whatever the term of the week is that they all have a preset pressure opening so that the main bearings are not starved of oil. numerous designs some bolt into the main oil gallery, Ford and VW no have angle drilled pockets in the main bearing area and have a small drop in part captured by the bearing. Even seen them on a 103ci Harley engine. Primary purpose is to keep the piston cooled.

CcanDo

The piston sprayer technology has been around for some time. John Deere used piston sprayers in some of their farm tractor engines and etc.

The solution we have used is a fixture that bolts on, same as a main journal cap. There is a provided sleeve the precision drill uses for alignment. The drill is then drilled through the main web to the piston bore. A die grinder is used to channel a galley from the as cast machined oil hole to the new orifice galley. A tap is used to create threads for an orifice. Variables dictate the orifice measurement, but basically, a dry sump system is one group size, while wet sump is another.

Beyond piston sprayers, piston tolerance, piston alloy, piston coating, rings, DLC wrist pins and oil volumn/pressure are considerations. Piston sprayers may be useful in all engines, not just forced induction. Vacuum under 10" may also compliment the solution, especially when using a greater crank to rod ratio. NOTE: Subject to adding lifter and rocker sprayers, the oil pump capacity should be further increased.