Has this ever been attempted?

Are you meaning in regards to spraying oil to the underside of the piston crown to reduce the piston temps. If so, then yes.

56er, this is common practice in the diesel industry; also applicable in high boost extended usage turbo applications .....the benefits would be relative to the usage; what were you thinking about???.....fats

Unless the piston is under some fairly hard stress it's not worth the trouble. The original rod squirters did some good.
Not that easy to do - there isn't much excess pressure/volume in these engines (certainly not in the pre-54 engines). You have to tap into a source at full system pressure or it just drools, and there's a big distance from the main bearings to the bottom of the skirt due to the very tall piston, long rod and long stroke.
A single hard line could be attached to the block ( screwed to the open areas next to the main caps) and plumbed into the pressure line between the pump and the block (metered with a restrictor), and individual jets aimed at the walls at an angle.
Probably better to modify the pump cap, and take pressure off the bypass valve port so that it never reduces system pressure. Way too much work, chances of failure, etc. unless you need it.

I agree with panic, there are certain engines that this type of mod is better suited for than others because of their oiling system. Since you didn't say which engine you were inquiring about, if you are considering this, you will need to take that into account before attempting it.

It's a 292 that I'm turbocharging and hitting with a 150 shot, looking for 550-600hp. I don't have the block in front of me (it's getting torque plate honed) but I was just thinking that maybe I could tap into that line that oils the lifters (the one where you put the copper tube in leo's book) and angle the squirters up, but I am not familiar enough with the geography to know if that would work. I was looking around on an LS1 site for turbo info and there was a link to someone who had done it on a small block chevy. It had part numbers and some techniques I thought maybe I could adapt. It seems to make a big difference for piston longevity and detonation resistance on the LS engines. I was just curious how it had been done and if it actually made a difference on our engines.

Also, my rods have a little beveled hole in the top of the small end. Is this a wristpin oiler or is it some sort of piston squirter? The more I learn, it seems the less I know.

It sounds as if someone has floated the small end of the rods before. I've seen where Porsche claimed to have been able to reduce the piston top temp by almost 400° by using oil spray to cool to bottoms of the pistons in high boosted LeMans turbo engines back in the 70's.

At least the 292 has a high-volume pump available, so dropping the rate to the mains isn't a big deal.
The lifter gallery wouldn't be my first choice, though. It's (almost) system pressure, but each tappet is a leak so the pressure goes down with the distance from the feed. You can compensate by using progressive squirt sizes, but IDK how to tell how much the rate will decay across the 12.
Are you thinking of tapping the inner wall of each tappet bore directly?
The ideal spot for this is really as high up on the wall that the skirt stops just above, which requires major plumbing (like sinking a tube into the block casting). If you don't need the squirter to actually protrude from the wall, it can be as high as (perhaps) 1/8" below the oil ring @ BDC.

56er,
I can't speak intelligently about a gasoline engine, but on a diesel engine the aim of the piston cooler is of extreme importance for component longevity. For example, if the cooler is not aimed properly, then the sleeve and ring wear is actually worse than having low piston cooler pressure due to the heat transfer across the piston - one side of the piston gets hotter than the other and severely scores the liner and creates uneven ring wear which also creates even more sleeve scoring. I know from talking to engineers for Mack that alot of engineering and testing is involved in proper piston cooler volumes, aiming and piston design inorder to keep the 'runoff' oil coming off from the piston out the path of the 'squirter'. Every manufacturer has tools designed to align the piston cooler.
I have no idea how you would determine proper 'squirter' alignment and volume, runoff from the piston, and let alone bottom piston design.

One thing to consider, if you can come up with a way to install coolers, is that several diesel manufacturers have, for 2010 emissions engines, designed a valve in the oiling system that changes the flow rate to the coolers via an ECU controlled solenoid depending on engine load and injection pressure. They have gone to this for the sole purpose of increasing fuel economy. Mack/Volvo claim an additonal one to two tenths of a mile/gallon increase in economy due to horsepower savings from oil pump parasitic draw.
But I'm confident that if you can get some 'squirters' functioning that you could use the same concept, in reverse, to only cool the pistons at proper time just prior to and during the nitrous shot.

Sounds like a great project. I'd love to see this in action. Good luck.

If you want to cool down the piston inject some methanol.

Some examples:
http://www.alcohol-injection.com/

http://www.alkycontrol.com/

http://www.coolingmist.com/


MBHD

I took apart the 250 in my garage today to see what the layout is, and I think the oil passage for the lifters is too high up to use, plus you would have to drill at into the side of the cylinder wall. I have short pistons and long rods so that might be possible, but I am apprehensive about hitting water. And, I have a snow performance alky kit my brother gave me, which requires way less work to install. Especially if getting the oiling wrong makes it worse. I'm not completely shelving this, but I am going to study on it a bit longer before I attempt anything for sure.