Oil Squirters and Turbo oiling

[Supra_Villan]

I'm doing a rebuild, and i bought an na block thats been bored 20 over with a balanced crank and je 8.4:1 turbo pistons, brand new freeze plugs, new oil turbo oil pump and all that jazz. I will be putting it in my 89 turbo and ill be using a 60 trim ct26, but anyway, the NA blocks don't have oil squirters, do i NEED these? I will be using an oil t-stat with a filter relocation, and an rx7 oil cooler also. But i also heard that there is no place in the block for an oil send to the turbo. Is this true? i was told if there is not, to tap into the oil pressure regulator, and i will be using the turbo oil pan, so i don't believe drain will be a problem for me.

 

[MmmBoost]

ok, the oil squirters are used to keep the piston temperature a bit lower. they are not absolutely required in a turbo configuration, however take note that most turbo engines have them. the oil send port is there, but its not drilled or tapped for the banjo bolt (m12x1.25). also, the drain is on the side of the block, and like the feed, the boss is there but its not drilled.

 

[zachm611]

I dont think they are necessary. iirc the turbo a's didnt have them.. and there are plenty of people na-t with out problems. I asked this question a long time ago and i got a bunch of mixed answers one was saying forged pistons are a must.. but im not sure so i'll let the pros tell you for sure. lol

 

[Adjuster]

While I have not looked at a set of NA rods, I belive that they are the same as the Turbo ones.

If that is true, the rods have a hole bored in the upper shoulder area and corresponding hole in the bearing that sprays oil up onto the thrust surface of the bore, and the under side of the piston too. So in effect, all 7M's have squirters, but not dedicated ones that do nothing but spray up under the pistons like the Turbo does.

Pistons are really a question of how much boost your going to run, and how long you want your motor to last. Stock stuff is not forged, but it will hold up to pretty good power, say 400hp easy with a good state of tune, and the right fuel mods.

But, any piston is going to fail with a poor state of tune, and cast ones just fail under less stress than the forged ones do. Melting down the ring land of a cast piston is just too easy when you are pushing the limits of this motor.

So again, it goes back to your budget, and your power goals.

Good luck.

 

[IJ.]

Greg: The "cut along dotted line" Rod squirters miss the underside of the piston totally so only lube up the thrusts

 

[Doward]

One of many reasons to get rid of the stock rods

 

[supramic]

im glad i found this i was just thinking of this for a build idea.

 

[D-Dayve]

I thought I'd throw in my $0.02 on this...

The 2G DSMs had problems with their oil squirters getting stuck open because of crud in the oil. This causes them to get stuck open and since they share oil passages with the thrust washer, the thrust washer sees less oil, starves, wears through and causes the dreaded DSM "crankwalk".

I'm not sure where the supra block gets oil from for the squirters, but if you have crappy squirters, you run the risk of having the same problem.

Most high HP guys toss out their squirters because they are looking for every last hp out of the motor. As the piston moves down the bore 8000 time every minute, that little bit of oil actually impedes the piston's movement, and adds mass to the piston as it's being accelerated. In simple terms, it takes more effort to move the piston, so less hp to the wheels.

Oil squirters are good because the oil cools down the piston, making it less likely to detonate or pre-ignite the mixture in the chamber being compressed. So, if you're running higher compression or your combustion chamber is prone to detonation, the chances of a hot piston lighting off your mixture at the wrong time is reduced by running squirters. Unless you're hitting quite high horsepower levels, this usually isn't a problem.