What if 1 piston does not have its squirter ? 1988 3.2
 

Hi,

I need your thoughts on this...what would happen if one piston does not have its squirter ? doesn't matter if you forgot to install it or it came loose years later (that last thing of course will damage more internally...)

but how would the oil pressure behave ?

The piston squirter's have a dual purpose, one obviously to lubricate, and two to cool the pistons, so in extreme conditions I would guess that the cylinder may run hotter than the rest, possibly leading to a partial or full seizure of the cylinder.
Also the oil pressure may be affected somewhat too.

If you forgot to install it, you'd have a pretty big internal "leak" but i'm not sure how much that would affect pressure. I'm guessing a LOT.

There's a reason you're asking...

indeed, the reason why I'm asking...

had made a post (some years already) ago about a sudden drop of max. oil pressure that is not linked to the electronics, pressure relief valves, ...

the only thing that it could be by elimination, is that one oil squirter has come loose and found its way to - well, I don't know if it got crushed in the oil pump or it got caught in an oil filter...

I'm running a good pressure until 3.2 bar (coincidence with it being a 3.2 engine), so 1 bar /1000 rpm until at somewhere 3000 rpm where the rpm further can go up, but not the pressure...

Strange thing: the car runs great, starts at first try, and oil temp practically never gets above the lower white mark (running Swepco 306 15w-40 of which I was told it's very good at keeping the temps down).

Have never measured exact cylinder temps when engine hot, but the fact that the oil is not getting toohot, wouldn't you think then that that one affected cylinder remains 'cold' enough ? a hot cylinder would make the oil hotter too, no ?

I lacked the money to get the engine open, so assumed that I only lost one squirter, that its out the system now, and that that one cylinder is getting more oil (bigger opening) but not at the same pressure than the other 5.

I know I'm taking a big risk, but now some 5000 miles later (and a nice trip to Le Mans Classic later) I feel like 'hey maybe nothing is bad as long as I do not presistently drive in the 5,000 rpm range...

If you have decent presssure at idle them I doubt you lost a squirter. They are staked in and cannot come out.
I'm not sure if a stuck oil relief piston might be something to consider: others more experienced will know.
Have you tried another oil pressure sender? or perhaps an external oil pressure tester to confirm?

yes on the last 2 questions, first bought a new oil sender, then bought a manometer (or how do you call that exactly in English)
the mechanical measuring of the oil pressure told the same story...good from 0 to 3.x bar but nothing above...

re-installed (after adequate measuring) the pressure relief valves and springs etc...

it started happening after I had the heads redone...but not the day after (I only noticed it 'some time after') so maybe it's linked, maybe not...

Oil consumption is ZERO, so the 'heads redone' thing was very well done...

suppose someone dropped a screw or so in the engine while re-installing the heads, and the screw passing the oil pump that damages the pump ?...did find soms metal flakes on the magnetic oil sump screw...but nothing dramatic - I thought...

I do change oil frequently...so maybe the sum of all metal was dramatic after all ?

can an oil pump internally get damaged and therefore perform worse ?

Depending on the size of the screw, anything bigger than 1/2 inch and you will be doing an engine rebuild complete with new pistons and head(s)

It seems from what you have explained that the oil pressure relief valve is opening too soon, which could be an indication of a partial blockage somewhere.

A loose piston squirter won't make it through the oil pump pickup screen, but it would likely end up on the case drain plug magnet. And I doubt that a leak that big would keep the oil pressure warning light off at hot idle.

If the low oil pressure started after the top end was done, is there a chance that the cam housing restrictors were changed? It should have the ones with the groove in the body.

https://www.pelicanparts.com/More_Info/90110536102.htm?pn=901-105-361-02-OEM

There's much controversy on the size of the restriction, but a Porsche bulletin came out with the restricted fittings and the original style is discontinued. They believe in the update that much.

Squirters are very restrictive. If one came out, I think you'd experience little oil pressure no matter the rpm. Fact that there's pressure up to a limit... can't see that being a missing squirter. Might be interesting to get engine to op temp and shoot a thermometer at each head. If there was any great difference among them, that would be food for thought.

I did install a (way) smaller restrictor and that did lift the max rmp up from 2.8 to 3.2 bar as from 3,000 rpm...did not mention that earlier in the post but the original problem of max rpm was at 2.7 to 2.8 bar

that new restrictor did thus raise the max pressure to 3.2 bar...but I can't make up anything closer to a final verdict

will buy one next week...indeed I will want to know this in the near future...

what do you guys normally buy ? just the cheapest internet version you can find ? or better from a reputable brand ?

Just a thought, have you checked the oil pick up and screen, could it be partially blocked with something ?

No I have not...can I check this without opening up the engine ? small camera ?

I paid $40 several years ago for one. Only used it a few times. Exactly how accurate it was in terms of a temp reading was less important to me than making comparisons between multiple targets---like variations between cylinder temps. Just looked out of curiosity and prices range between $18 and $240 on Amazon. Personally, I'd not get the cheapest or the most expensive.

Not really, because of where the oil pick up pipe and strainer are tucked into the case.
This video should help you get a better understanding.
The oil pick up pipe scavenges the oil from the case and returns it back to the tank, however; if there is an issue with the pump being able to return the oil quick enough, then I guess there is a possibility that there may be a lack of oil in the tank for the pump to build the correct pressure.
Mind you, that would mean that there would be quite a build up of oil in the case!
https://www.youtube.com/watch?v=u9mTtilsJJE

not to say you didn't explain what you are seeing well, but it might be helpful to see a video showing a cold start with camera on the gauge as well as the manual pressure gauge you added to the motor while you are revving the motor up some.

Indeed that would be a good start! :)

ok, working abroad for the moment, will try to find the necessary info by the end of the week...