Bringing it back to life again, is removing squirter better for supertech pistons as well?

I wasn't planning on removing them but still confused after reading the whole thread...

I'm going to use motor for street application and light track duty

The consensus in the Mitsubishi world is that oil squirters are needed in high output engines with cast pistons, but if you build an engine with forged pistons they are no longer needed, and removing them increases oil pressure to the bearings. The difference is that Mitsubishi's have very robust cooling systems whereas the Miata cooling system is marginal at best. The piston oil squirters remove a crap load of heat from the combustion chamber and I would not remove them on a Miata for this reason alone.

Keith

<edit> Didn't realize this was a necro-thread. Hope my reply wasn't already covered 4 years ago!</edit>

I removed them the engine stays drastically cooler on the track . Oil pressure is much better rings cylinder walls, bearings and everything had about 4 times the life span on a 300+ hp track car after removing the oil squinters. Combustion heat goes out the tailpipe and spins the turbo rather than into your oil. Ceramic coated piston tops on forged pistons I think are desirable with removing the oil squirters though.

The oil squirters are typically there to cool the bottom of the piston to reduce chances of detonation, pre-ignition, and annealing. A forged piston will help combat some of this but only to a point. Professional race teams will use a rockwell hardness tester to measure the hardness of the piston in the as manufactured condition (or obtain numbers from the manufacturer since they likely used a heat treatment coupon for verification) and during tear down inspection at the end of the season will measure the hardness in as many locations as they can to determine if annealing was happening and where. They'll also visually examine the piston crown with a microscope for signs of pre-ignition or detonation. If they find signs of either they will make changes during the next season's engines to combat the issues. This might be re-aiming the squirters, changing the jet size, adding additional jets, adjusting oil pressure, adding coatings to the piston crowns, changing the geometry of the piston, examining fuel distribution in each cylinder, etc....

Unfortunately a better cooling system can only do so much, changes to the coolant system won't change the length of the vector required for the heat to be dissipated to the cooling jacket, the center of the piston will always have the longest heat path so smaller diameter pistons are less prone to thermal issues, forged materials have better thermal conductivity and strength, thicker piston rings have higher contact with the cylinder wall for conducting heat away, etc.... of coarse all of these things have trade offs.

If people who have access to hardness testers can perform hit maps of the hardness of their used pistons and be willing to provide specifications such as the manufacturer of the piston and engine specs it will be far more helpful to help people to decide what actions to take regarding their oil squirters.

I recently considered removing my squirters after one of them came loose (10+ years after my initial build) and broke a piston. I eventually decided against it.

IMO, the benefits of removing the oil squirters are:
-if you have a stock oil pump, it will increase bearing oil supply. If you're running upgraded gears with a shimmed relief valve, you'll get much less benefit. The only problem with this is... if you can get to the oil squirters to remove them, you can get to the oil pump and replace it just as easily.
-if you have a stroker kit (bbundy for example) or some similar setup that has an oil control ring that intersects with the wrist pin area, you'll get less oil usage. If you are running pistons with stockish geometry, you won't get as much benefit because they don't eat oil in the first place. That's my experience anyway.
-if you are suffering from elevated oil temps, your temps will go down because the oil won't be cooling the pistons. This is a mixed benefit IMO, kind of like the increased ability to move around the cockpit you get from not wearing a seat belt. If you're in a situation where you don't suffer from oil overheating or you are in a situation where you worry about heat in the combustion chamber more than the oil, removing them will have less benefit.

If you're running an N/A build with stock oil pump and forged pistons (why would you do this?), this is probably the mod for you.
If you're running a stroker build with coated pistons, this is probably the mod for you.
If you're not experiencing oil pressure/oil heat issues on a turbo car, this is NOT the mod for you.


I'm in the situation where:
-I have a shimmed boundary engineering pump
-I have never come close to having oil overheating problems with my current cooling setup. I had overheating issues like 10 years ago, at which point I parked the car for a few months, upgraded my radiator and fans and installed an oil cooler setup with a fan.
-I have wisecos with stock wrist pin location and I've never had oil eating problems with the sprayers
-my pistons aren't coated
-I like not having detonation problems.

Even before my current rebuild, I never had any of the problems that this fixes. So I kept them.

There is another thread here about the Pro's/Con's but before ever reading that thread, I kept them in my build. In retrospect, I think I'm alright with leaving them in because I, like Always Broken, am running a shimmed BE pump so pressure is not an issue. I wanted to do everything I can to reduce the chances of detonation as this car in it's current form is my daily. Hence the 8.6:1 CR as well.

If this was a beater build I'd do something like Downmented and just go balls to the wall, probably still keeping the squirters.