Tony

Fact or fiction on the S4s??

Ive heard that some of the earlier S4 motors actually had them and that subsequent motors didn't but still had the holes for the squirters to be installed...later blocks had no such provisions??

Ive searched the 968 forums and found a part number..from Kelly Moss actually.

1) I was wondering if any one can provide PROOF that the S4s did have them installed.....if so up to what engine#/build date?

2) There is a picture on the 968 board showing the area where they are installed but i cant quite make it out?

3) Is this an item that can be done "after market" on the engine. Im learning so far that anything is possible, just takes time and of course $$$ to some extent.


Just curious.

I dont have access to PET...is there any reference to them in that?

Lizard928

Tony do a search on the board, Adam (atb) had a thread on this awhile ago and there we pics on it as well, and the reason as to why it was discontued

Tony

Found it LIZARD..under "87s4 Performance Sleeper" by Adam. I dunno why i didnt find it earlier??

Anyway, i cant recall now if my block has the same holes in it or not. Ill have to check when i get back. Plus even with the holes, i think they have to be bored to the jouranls to get there source of oil...ill have to look at that also

They dont look hi-tech. Marc T states they were disc. for windage and hot oil pressure problems? To me it seems they are just a hole for oil to be routed to the underside of the piston. The squirters in the newer cars seem more refined, they have checkvalves in the squirter to allow oil spray only under higher rpms/oil pressure. Some pages iIve read say the piston temp can be lowered as much as 120'

Anyway, thanks.

Doug Hillary

Hi,
Tony it is fact not fiction and yes considerable temperature can be removed from the piston area by using jets. Estimates of temps from this region suggest 650-800F - maybe more so your temperature extraction estimate is possible

I suspect something like a 15w-40 HDEO diesel lubricant would do the task best. That is why I use Mobil's Delvac 1 - 5w-40 synthetic in mine

This practice is very common stuff in heavy diesel engines. Ultra high compression pressures/high turbo boost and high placed top rings treat their crosshead pistons to considerable thermal stress

In MY87 the 5 litre block had oil spray jets pressed into the upper crankcase section
These open above 4bar oil pressure and spray onto the bottom of the piston crowns
Bores were drilled into the main bearing journals to supply oil to the oil spray jets

I do not know if and/or when they were omitted

Regards

Chris

Well the replacement engine for my 87 (which has an MY87 date code) is a non sprayer.

Maybe they deleted the same time as the flip up spoiler ....

Chris

Scott M.

Tone;

A dude named Clark Fletcher on the 951 board did considerable research into this last year or so. He was trying to do a 3.0L turbo. Maybe look him up for application data.

Keep up the good work, O' guinea pig.

Scott

atb

I'll take a closer look at my block, but I it appeared that there were two check valves on the center main. If these were the sprayer inlets, they would activate when pressure become high enough at the center main journal to open the two spring loaded valves in the squirter journals which must then feed through the block to the squirter orifices. I haven't checked it out real closely as of yet, I'll do it some time over the weekend and provide more detailed pics.

Fastest928

If you need them we can get them...a stock porsche turbo/968 part!

A very limited number of 928 had them installed. Porsche eliminated them due to too much windage from oil splashing.

Good for dry sumped engines, or ones with very deep sumps.....or boosted one.

Marc
DEVEK

Fastest928

...oh, cracking pressure is 3 bar.....45 psi

Marc

Chris

I stand corrected, I just pulled the pistons and their are the squirters !

Chris

GoRideSno

ATB, Mark,
In the interest of us figuring out when the piston oil squirters where deleted, what are the vin #s of the cars your engines are from?

Andy K

Doug Hillary

Hi,
Marc@DEVEK - can you please provide the data ( Porsche Service Bulletin Nos etc ) to confirm;

a) that only a limited number of S4 engines had them, and,

b) that the operating pressure is 3bar and not 4bar

Thanks

atb

My squirter block came from '87 S4 #0731, which I believe would make it halfway through the run of that model year. The owner said the build date on the car was 10/86.

atb

....by the way... this car was also the original home of the folding wing that now lives on the tail of my '88. (see avatar). Is there a correlation?

Doug Hillary

Hi,
Marc@DEVEK - a few days ago you made these comments in this thread:


"A very limited number of 928 had them installed. Porsche eliminated them due to too much windage from oil splashing.

...oh, cracking pressure is 3 bar.....45 psi

Marc"


To increase the humble level of my knowledge AND TO ASSIST OTHERS I asked for confirmation as follows;


"Hi,
Marc@DEVEK - can you please provide the data ( Porsche Service Bulletin Nos etc ) to confirm;

a) that only a limited number of S4 engines had them, and,

b) that the operating pressure is 3bar and not 4bar

Thanks"


Marc, can you please deliver the goods!

Thanks