Fabio421

Whats the story with piston squirters on the early 87's? Why were they added? Was Porsche planning a turbo'd S-4? Why were they deleted? HAs anyone had any problems due to having them on their car?

Joe '87 S4

Yeah, same questions here.

atb

Rumours abound Fabio, I don't know if anyone can definitively say.

The benefits seem evident, to aide in cylinder cooling.

But, they were likely removed because the added windage was causing crankcase ventilation problems with all of the aerated oil.

I've heard stories of some of the squirter block cars experience uneven oil pressure readings, but I haven't personally seen or heard of any major issues. My stroker build is using a squirter block. That should make for some interesting windage issues.

IcemanG17

Hmm......a good ???? My guess is cost....cheaper to make without it? That plus it wasn't needed , since the only turbo 928 engines were in boats

SwayBar

To be more exact, they are to wick heat away from the piston's crown, which means less heat for the top ring to dissipate to the cylinder wall.

daveo90s4

As I understand it, the squirters only become operational at around 4,000 rpm (about when flappy valve opens, coincidentally??). I have heard stories of the squirters system malfuntioining and still squirting at lower revs thus depriving big ends / main of oil. But I've never met anyone who has 1st hand knowledge of such a problem.

Vilhuer

They come operational when ever oil pump can produce enough pressure to open valves. Stated number is 4 bar. If valves do not function pump can never get pressure high enough to be on normal operating area.

blown 87

What number (vin) did they stop at?

tv

It was a new feature on a new engine. Then it was discontinued, seems to me that someone thought it was not such a good idea.

918-S

Another great topic. Anyone have a photo or diagram of the system?

heinrich

There are tons of posts on this topic, bottom line is nobody really knows. I (anectotal i know) remember reading that the squirters were added to all racing Porsches, like the 924 GTR's. The aeration problems are likely the ones that stopped this in the big V8 engine for Porsche.

heinrich

Correction, not windage -- AERATION. Apples and oranges.

Vilhuer

No one knows it seems but I think there isn't any sightings in VINs above first few 100s. Besides its more question on what engine number is last one and less about what VIN it happened to end up as engines were not assigned to VINs in sequencial order.

Fabio421

What adverse effects have owners of 87's with squirters seen due to aeration or is it just one of those things that are "common knowledge"? Does anyone have any pictures of these squirters?

heinrich

Oil sucked through the cam cover breathers into intake.