Oil squirters for n/a build
 

Keep them or block them off?

~1.9 VVT motor, 11:1 CR, rods, SUB lifters, BE VVT pump, 949 superdamper etc.

What say you?

I am leaving them out for my new motor. It is supposed to make a tad more power.

To clarify, this motor will run for more than 14 consecutive seconds at a time and a planned MTBF of ~10k miles on trackduty.

Yes I am aware of that. And so you know, I plan to do some Sebring tracking with my motor and not just jaunts down the quarter mile.

It is a common mod to tracked BP motors.

Reliability says, leave them in.
Power goals say, leave them out.

If I were you, I'd leave them in. In that way, you can always say "I kept the oil squirters" when you lap times suck.

Laptimes will suck anyway, might as well go for broke this time

Id say leave them out. But I do believe using ceramic coated piston tops are an important part of the equation when doing so.

Even in a naturally aspirated motor? There are a ton of high reving motors that do not have oil squirters out there. And I doubt that ceramic coatings are on a healthy percentage of them.

I was under the impression that the oil ring grooves on a stock bp piston was specifically designed for squirters, and that a typical aftermarket piston's ring groove is designed in mind for motors without squirters.

I believe the thoughts on aftermarket versus stock pistons is correct.

I also think the ceramic coating significantly changes how heat is transferred from the combustion chamber to the piston and the need for removing heat from the bottom of the piston.

I suspect the coating could be worth more power wise than just blocking off the squerters for several reasons.

No way no how would I leave them in. You will have less "windage", your oil pressure will be better, if you are NA you have ZERO need for "piston cooling" anyway.

Based on my witnessed change in engine running on the track behavior I think removing oil squirters and ceramic top pistons did more for keeping the thing from running without overheating than any cooling mod I ever did.

My reasoning comes to these points.

1) Less combustion heat is transferred to the engine by way of the pistons.
2) The pistons don’t develop hot spots as easy thus you get better knock resistance.
3) Better knock resistance means you can run more timing which means lower waste heat is generated to begin with.

After spending years trying about every trick in the book to try to keep 200-250 hp 1.6l then 1.8l engines cool on the track currently My car will run pretty much continuously without going thermally unstable whale making ~350 hp. And it made a big difference with the 2.0l engine when I swapped to ceramic pistons and took the squirters out with basically no other changes in setup.

Another benefit in my book is the engine maintains higher oil pressure for added safety.

On an NA engine I still think you will gain some knock margin and be able to add some more timing, make more power. Might also be able to loose some cooling system weight. Possibly go to a little Honda Civic size radiator that would keep things stable.

How do you plug the oil ports after removing the squirters? I have a 2001 engine on the engine stand now, waiting to go in my 95 R-Package.

C

I went to the hardware store and bought flange head bolts with the same thread and installed them reusing a crush washer plus red locktite.

Exactly how I did mine too. ACE Hardware racing supply.

Thanks guys.

And thanks Oscar for bringing up the subject. Your timing was on the money. :)

C

I left mine in, but it's my first build.

Fifth build and beyond however... :)

I’m curious how well it works without the ceramic coated pistons.

Obviously the extra oil was meant to pull heat out of the pistons. But I might suspect the ceramic barrier coating on the top of the piston prevents more heat transfer than the extra oil ever was taking away. Some scientific studies suggest the ceramic might be reducing the amount of heat transfer through the piston by 15% or as much as 40%.

I will not have the slugs coated. I was asking since apparently only the FM wisecos are clearanced for the squirters and off the shelf wisecos would hit them. Not sure if entirely true, but if removing them frees up some power I figured why not.

Last I checked FM's don't work with stock squirters.

In the FWD SR20 world, USDM engines don't have squirters, while SR20VE's do, and their oil temps run allot hotter on the track. That heat your taking out of the pistons has to go somewhere, and it goes into the oil.

C