Piston Squirters- 930 vs. 964
 

What's the difference between the 930 and 964 piston cooling jets?

Nobody? Figured there had to be some sort of difference, otherwise Porsche would have just carried the 930 squirter forward to the 3.6??

I was looking at replacing the squirters since my case is open for a COMPLETE cleaning. My 3.0L engine has a "new" 964 pump so I wondered if matching the squirters to the pump is advisable.

The 964 squirters flow more...... I have forgotten if they are dimensionally the same as the previous versions... or if add'l machining need to be done to fit them....

I have a bag of them somewhere, however things in my house are still discombobulated after Sandy..

Still doing inventory regarding what I tossed from my basement etc.

Kevin - I found my invoice from the squirters I purchased (from our host) in '06. They were for the 930.

These are the same OD, so they fit right into a case which came with the smaller orfice stock NA squirters from the pre-964 days.

Subsequently, on this very forum somewhere, I read or someone told me that the 964 squirter, while having a larger orfice than the older ones, doesn't flow as much as the 930 ones do - it has an intermediate size hole out its end. And that, except for forced induction, was all you need. Well, by that time my 930s had been installed, plus six of the suckers are quite expensive, so I wasn't changing. If ever I do this all again, I might use the 964s rather than the 930s - as long as I maintain the 964 cam oil line restrictors anyway.

For that matter, other than the fact that Porsche upped the orfice size for the 964s (and 993s?), I don't recall anyone asserting that for a 110 hp/liter 911 air cooled race motor you really needed the larger squirters.

Somewhere I may have recorded the orfice sizes - something like 1.5, 1.75, and 2mm (but don't trust that). Searching the archives ought to bring up the actual specs.

Thanks Tim & Walt for the response. I just don't trust flushing my existing squirters after almost every bearing in my engine got wasted and filled the entire eingine & its oil system with bearing debris. So as long as i'm removing the existing ones, I might as well look at other alternatives.

I'll do some searching with your name Walt. Thanks for sharing you've looked at this & post some numbers on it.

Aside from the larger orifice allowing more oil, I wonder if the spring rate is the same in all of them? Reason I ask is because one strike against the common squirters with an early/std. pump is that it takes quite a bit of pressure to open them as noted here by Grady Clay. http://forums.pelicanparts.com/911-engine-rebuilding-forum/335776-3-0-liter-upgrade-horsepower.html#post3163848 But using the smaller cam line fittings addresses that- at the expense of oil to the cam housings. I'd prefer to get as much oil up in the cam & head area as reasonably possible. The older engines ran the big orifice fittings without issue for a long time so I tend to think they're OK

I'm wondering if using the 964 pump, which has a larger pressure pump side than the std. SC/Carrera pump I used to have, activates the squirters sooner? I suspect no because the larger pump provides more volume, not pressure. Pressure is determined by the relief valve.

More pressure could be achieved by shimming the relief valve. Which I suspect is what the spacer fitting does on the later pumps? I bought one of those spacers to use with my "new" 964 pump. Incidentally I did not use the spacer with the last pump (because I wasn't aware of the spacer) and oil pressure seemed to be a bit lower than i'd seen with the old tried and true SC pump. Never shoulda sold that nice SC pump! ;)

Here are part#s, courtesy of Bill Verburg:

The squirters were introduced in '72 on the 2.4s. I can't find a separate part # till '78. All 911 n/a from '78 til '89 used 911.101.011.01 all turbos used 930.101.015.00, the 964 and 993 n/a used 964.101.020.00, 964 and 993tt and 993RS use 993.101.018.51. There are also oversize versions of each, flow is the same the case is o/s.


__________________
Bill Verburg

Here is what I typed into my personal master list of 911 engine parameters, gathered from sources ranging from factory manuals to internet assertions (though I have tried to keep to sources I trust).

Squirters: Introduced in 1971. Cracking pressure was 45-55 psi. Squirter orfice increased to 2.0mm on the 964-993 (also Turbo at some point?). Turbo cracking pressure about 3 bar (45 psi).

I am only certain that '71 was the first date, 45-55 is a reasonable figure for what it takes to cause the squirter to squirt, and the 3.3 and later Turbos had the larger 2mm orfice (also, from another post, they are longer and require that the hole be bored maybe 10-11mm deeper). And that the cam oil line restricters allowed the 964s to run a larger orfice /higher flow squirter.

Most of the Pelican discussion on squirters centers on how to clean them, how to remove them, and how to keep new ones in - good topics all to be sure, but not entirely useful for us Holiday Inn race motor redesigners.

Thanks for the additional detail Walt. So what you're saying is the smaller cam oil line adapter fittings are what allowed the later cars to run the larger squirter- to take advantage of the choke which keeps more oil down in the main oil pressure galllery. Because recall that one of the changes to the 964-based engine is that the cam towers have an internal oil feed to supply oil to the tensioners and the cam spray bars. No external cam lines on the 964, 993 3.6 motors, remember?

Kevin - you are right, the restrictor fitting isn't a part found on the usual 964, much less 993, motors. Caused me to peruse parts catalogs, and I now understand the oil flow there better. Oil for the squirters and cam bearings enters the cam carrier at the same place, but with different fittings entirely.

I found a posting which suggests that Porsche did decide to alter the oil distribution starting with the 964s, though, which the larger pump allowed. And that the fitting we know was used on the turbo of that era (still based on the 930 case), and then the one using 964 stuff, and finally the 993 turbo (for the same reason?). Parts catalogs show the old style chain boxes for turbos.

According to a post by Stephen Kaspar, Porsche kept the old 901 105 361 01 part number, even though this part is different (narrower oil passage) than earlier parts under that number.

http://forums.pelicanparts.com/uploa...1358302030.gif

This doesn't entirely answer the (sub) question. Bruce Anderson's most recent edition of his book gives these flow numbers, which I suspect Porsche released. However, since the restrictor attracted quite a bit of attention, a search using suitable terms here ought to turn up some authoritative information.

Yep the oil gets to the 3.6 N/A cam housings from the same case source- comes out of the case main gallery near the fan housing. However it is first introduced to the 964 chain boxes to feed modernized chain tensioners, and then on to the cam housings via a bridge fitting to get the oil to the cam bearings and valvetrain spraybars. I'd like to see the orifice size of that bridge compared to the debated cam housing oil feed adapter!

There's a few of the 964 3.6 upsides right there:

-no external cam feed fittings to debate
-no external cam feed lines to leak
-you're running oil pressure-fed chain tensioners, like it or not (eliminates the solid tensioner debate)

I agree w/you about the cam housing adapter fitting seeming to coincidentally arrive with the 964 turbo 3.3L M30.69 engine (1991 MY). I'd be interested to know when Porsche first truly introduced this revised part to production. Because at first glance it would seem the smaller orifice was used to match up with the 964 pump being used in the M30.69 which uses the older pre-N/A 3.6 chain cases?

Once the 964 3.6 Turbo (M64.50) and the 993 3.6 Turbo (M64.60) came along, those small orifice fittings were no longer needed since those engines use the 3.6 N/A chain cases w/internal oil plumbing.

So, what I think would be interesting to know is what the flow rate is for the old cam feed adapters with the big hole. If the 964 was deemed to have suitable volume of oil in the cam housings at 13L/min, then as long as we are at least providing that amount with the choked adapters, everything should be OK.

I like the idea of getting more oil to the pistons with a bigger pump and bigger squirters. But I don't want to under-serving the cam towers by simply choking the towers of oil via the smaller cam housing oil feed adapter.

When these restrictors were introduced, those of us (me, for instance) who are reflexively first adopters (with 911 go fasts and such anyway) jumped on it as sliced bread. Later along came some shop and other guys saying they didn't like the long term results. But I can't say that I've had bad problems. Got one race motor with them and an SC pump, and 125 or so hours didn't hurt the cam. Haven't had the SC apart since I made the change, so other than the fact that the motor still pushes the car to where it should be racing so the cam lobes can't have been worn down, can't say what things look like in detail there.

It would be nice to know those liter per minute or similar rates for the earlier stuff, though.

I've put in the restrictors, taken them out, put them back in again, ........ rinse & repeat ............. on my '87 and the '79 race car over the years. So i'm certainly not immune to the reflex too!! :D

Some believe in them, some don't. I know one builder who mentioned that he developed his own restrictor before Porsche started producing it. Other respected builders don't want anything to do with them, since they strongly believe oil to the valvetrain & head area is of utmost importance for cooling, where the air-cooled engine needs it most.

Eh, i'll probably stick with the old ones and not concern myself any more. With the bigger 964 pump (and the all important little spacer piece for the pressure relief valve) and 930 squioters, I should be just fine

Found a post from Grady that I recall reading in a tech document that Porsche produced, detailing the changes in the 964 and 993 engines.

http://forums.pelicanparts.com/porsche-911-technical-forum/255525-tubo-oil-pump-xlitres-per-min.html#post2286509

The 964 pump is also a high-quality large-capacity pump made of magnesium, with bearings for the pump shafts. The pressure pump delivers 65 liters of oil per minute: 17 liters are used for the squirters to cool the pistons, around 35 liters are used to lubricate the main and con-rod bearings, and the oil flow to the camshaft housing was reduced by about 50% to the 13 liters necessary to lubricate the camshaft bearings, valve guides and rocker arms. The scavenge pump has 1.84 times the capacity of the pressure pump to ensure a low oil level in the engine’s crankcase.

Oil to the cam housing reduced by 50%........ wow.

That exact same language, or something very like it, is in Bruce Anderson's 3d edition.

All no doubt stemming from something Porsche put out. The likes of you and me are not likely to be able to measure oil flow directly at all, much less how much goes where. I see it now: a 50 gallon barrel under the crankcase drain (though that would capture squirters pus bearings), and another under two hoses stuck into the cam housings with the return tubes blocked off, and another similar barrel mounted up high with a hose to the car's oil tank. Run car for a minute and measure what's in barrels with a stick and do the math.

Oh yes. The mess I could make doing oil flow testing would be SPECTACULAR! :D

930 pump
 

Can anyone explain why the 930 oil pump pressure side is rated at 100 l/min and the gt3 pump is rated at 83 l/min, they are both 51mm long gears, same diameter gears, same inlet and outlet port diameters? I have both on the bench in front of me, and do not see a difference in the pressure side. Thanks, Ken

As I periodically do, I put Bruce Anderson's 3d edition by my favorite reading spot. He says that when the 964 pump was introduced, the squirters were increased to 2.00mm. But he does not differentiate between the NA and T motors of that era (or the 993s).

He also says the restrictor fitting came out for the 964 turbo (1994, 1st of the 3.6s).

I may have gotten that chart from something Bill Verburg, moderator of the 911 forum, posted. In several posts he put forth all that is in that chart, but stated, for the 100 liter per minute, that he wasn't sure he remembered correctly. It may be as simple as that. Perhaps, as may be the case with the earlier pumps, that Porsche never put out figures until the 964s?

On that discussion one also finds a guy who measured oil flow when running a 3.8 RSR motor on a dyno - came up with 14 gallons per minute at 7,500 rpm. That's a whole lot of oil. There really isn't much, if any, room to make the oil pump package longer or wider, is there?. Did the 3.8 RSR use one of the oil return tubes as a second scavange outlet? Perhaps that was a less restrictive outlet system, using two?

Hello,
I know htis is a very old post but I was in a workshop yesterday and they had a couple of 964 engines apart. What I did notice is that the 964 has 2 sets of squirters. One on the block but also a second one on the crankshaft pointing towards the pistons. Maybe that's the reason why the flow rate is different?http://forums.pelicanparts.com/uploa...1641976267.jpg

Those circled locations are not squirters. They are the plugged ends of the passages in the crankshaft that allow oil to flow from the center of the crank, via the main bearing passages, to deliver oil to the rod bearings