| Author | Message | ||
| Frank K Lipinski (Kaz)
Junior Member Username: Kaz Post Number: 195 Registered: 11-2002 |
12 | ||
| "The Don" (Mlemus)
Advanced Member Username: Mlemus Post Number: 3829 Registered: 8-2002 |
Frank, Was it a 12mm or 14mm allen key on your drain plug? M | ||
| Frank K Lipinski (Kaz)
Junior Member Username: Kaz Post Number: 193 Registered: 11-2002 |
 OK thanks everyone...all is good... | ||
| Mitch Alsup (Mitch_alsup)
Member Username: Mitch_alsup Post Number: 526 Registered: 4-2002 |
"Can anyone with a 355 chime in if their psi is on the high side until the oil warms up? Don't know if it's always been that way and I never noticed, or might have something to do with my oil change." Yes it does ride the high side until warm. In fact, if you drive down the road at (say) 55 for a while, the oil will stabilize at 190 dF. Then take her up to 80 and the oil temp will actually drop to 175 dF (or so) and the pressure will rise by 3 PSI (or so). | ||
| Dennis (Bighead)
Junior Member Username: Bighead Post Number: 88 Registered: 2-2003 |
Frank wrote: >Dennis...I believe the hash marks are 15 psi ea..correct me, anyone, if I'm wrong.. >Question..right after an oil changed I noticed something. On a cold start, after 2-3 minute warm up, when I start to drive the pressure is about 85-87 psi. When the oil warms up to normal temp, the psi holds at around 70. >Can anyone with a 355 chime in if their psi is on the high side until the oil warms up? Don't know if it's always been that way and I never noticed, or might have something to do with my oil change. _________________ Generally, yes, Frank, oil pressure will read high until everything is warmed up properly (oil will flow more freely at operating temp). Hence the caution in the manual(s) to measure oil pressure at 100 degree C. As for the hash marks... I dunno if 15 psi is correct for each unmarked one. And the math ain't simple either. There are three numbers; 0, 70 and 140. Unfortunately, there are NOT an even number of hash marks between those numbers! As a rough measure, I use the "thicker" unmarked hash marks between the numbers at being 35 and 105; the "thinner" hash marks would then be 17.5 each, EXCEPT that between "105" and 140, there are TWO hash marks. Doh. Since the margin of error on the gauge is probably in excess of 2.5 psi, I wouldn't worry too much about it. vty, --Dennis | ||
| Rob Schermerhorn (Rexrcr)
Member Username: Rexrcr Post Number: 525 Registered: 11-2002 |
Great job, good info Dennis! | ||
| Frank K Lipinski (Kaz)
Junior Member Username: Kaz Post Number: 189 Registered: 11-2002 |
Comment and Question... Dennis...I believe the hash marks are 15 psi ea..correct me, anyone, if I'm wrong.. Question..right after an oil changed I noticed something. On a cold start, after 2-3 minute warm up, when I start to drive the pressure is about 85-87 psi. When the oil warms up to normal temp, the psi holds at around 70. Can anyone with a 355 chime in if their psi is on the high side until the oil warms up? Don't know if it's always been that way and I never noticed, or might have something to do with my oil change. BTW - 6000 RPM test holds good at 80 psi. Thanks - Frank | ||
| Dennis (Bighead)
Junior Member Username: Bighead Post Number: 87 Registered: 2-2003 |
THE ANSWER! Sort of. Keep reading.... Previously, I wrote: >WHAT is "factory specification" oil pressure for a 355? The owner's manual reads, "Under NORMAL conditions, with the engine running at 6,000 RPM and oil temperature at 212 degrees F, oil pressure should remain between 72 and 87 PSI. It is normal for oil pressure to drop below 4.5 bar if the engine is hot and left to idle." Quoting the ever-helpful Robert Ziino: > I have heard from a Ferrari mechanic that you can on the 1995 F355 cut the > oil pressure relief spring 3/8 inch to decress the oil pressure at high > rpm--it is way to high( 90-100lbs).The later cars had lower oil pressure and > this increased hp. He has done this to alot of cars and he has also found > that most F355, 75% of them, do not have full throttle. Also, he increases > the holes in the O2 sensors with a screwdriver to get a better reading at > idle and make the car smoother at idle. The also-helpful Al Chelini added: >Decreasing the oil pressure to a more conventional value sounds like a good idea. >If I remember my engineering/math correctly, cutting a spring actually makes it *stiffer* - it's basically just a coiled torsion bar. It brings to mind the '60s guys who cut the springs for the low riders and wound up with a stiffer ride. The shorter working length makes the pressure go down, but the spring stresses go up and more prone to break over time. >Unless you're absolutely set on the 3/8" dimension cut, I wonder if just installing a newer version (a factory engineered spring) would be a good way to go. I suspect that it would be wound with thinner wire but keep the overall length the same at 4.55", unloaded. >The part number for a '95 spring is 137614, but my parts book was published in '95, and consequently won't show a newer version. Anyone out there have access to a newer p/n? >Indeed, the manual states that oil pressure should be 80-96 psi at 6000 rpm with oil temp at 100 degrees C. It goes on to say that "when the engine is warm and idling, a pressure of less than 4.5 bars (66 psi) should be considered normal." Could they be more vague? The implication is that the engine will survive just fine on a lower pressure. >Also, I wonder if one has to drop the engine to replace this spring, or can the just the sump be dropped - in one's home garage? ________________________ My mechanic (and very good friend) John Tirrell of Independent Ferrari Service and I spent this afternoon figuring out this puzzle. I was concerned because my oil pressure gauge was reading on the (very) high side. Interpolating the hash marks between the marked ones (70 and 140 psi) on the dial, I was getting roughly 105+ psi at idle and 115+ psi at 6k rpm (all with the engine properly warmed), running 15w-50 synthetic. From experience, John knew (and had heard from many sources) that 355s tend to run with high oil pressure. We fired up two other 355s he was working on, and each reported similar high pressures. Note that there is an apparent discrepancy; the owner's manual allows for between 72 and 87 psi as "normal" pressure at 6k rpm, while the service manual references 80-95 psi (essentially, one bar of difference). First, we wanted to eliminate the possibility of a faulty sender, so we hooked up an external gauge. Nope, same readings. So we decided to change the stock spring with a new spring -- as Al suspected, there IS a new part number, but in typical Ferrari tradition, the SPECS on the "new" spring were the same as the specs reported for the old one. Visual inspection of the springs didn't help much, so we went ahead and tried the swap. The swap was relatively easy (no need to pull the engine!); just pull the plug (right where the center underbody panel ends). Be careful of the hot oil; you'll drain several quarts. We swapped the springs, replaced the oil, and . . . the pressure actually went slightly UP with the new spring. Damn. So, like Bob Ziino's mechanic, John proceeded to cut the spring, about two coil lengths, or just under 3/8th of an inch. He replaced it, filled the oil again, and fired it up. Results? It now reads about 70 psi at idle, and about 87 psi at 6k rpm. So, the problem is apparently fixed! If your 355 is running high oil pressure, consider this as a potential solution. Of course, your mileage may vary.... vty, --Dennis . | ||
| Rob Schermerhorn (Rexrcr)
Member Username: Rexrcr Post Number: 482 Registered: 11-2002 |
I believe what Ferrari and other engine manufactures are telling consumers is lighter weight oil reduces parasitic drag (friction) and improves efficiency, power, fuel economy, and component life. IMO, the days of large bearing clearances to "free" up HP, and consequential requirement to run 50 weight oil, are long gone. Talk to a NASCAR engine builder. Sure, some are still clinging to heavy oil, but the savvy know that designing and building a system that takes advantage of the frictional characteristics of light oil will build a winner every time. On the other hand, Ferrari mandated use of 10w-60 Helix for 360 Challenge. IMO, that was an insurance policy for them until they collected enough data for component life. Side note: we blew two engines in 2000 (tossed rods) but never received definitive reasons. | ||
| Mitch Alsup (Mitch_alsup)
Member Username: Mitch_alsup Post Number: 479 Registered: 4-2002 |
My 1995 manual indicates that 10W40 is the correct oil. Research corroborates that synthetic oil has very stable viscocity with respect to temperature. In fact, synthetic base is a natural 5W30 without any polymers that alter the viscocity with temperature. Dino oil is straight 30W30. 0W60 is more spread than I can accept without more evidence. I agree that the dash guage is only a faint approximation of the real pressure, but it is better than nothing. | ||
| Frank K Lipinski (Kaz)
Junior Member Username: Kaz Post Number: 169 Registered: 11-2002 |
Hey Mitch - or anyone else with a 355...brings up a good question... Manual says use 5-30! ...and so far that's all I used. Mitch's idea sounds reasonable. I live in Florida and can't see the need for the 5 end ...and the 30 seems would be too light for the heat the engines put out. At the car show 2 weeks ago I was talking with Tim Stanfords brother who says 15-50. I want to switch to 15-50 but just hate to do anything against what the dealer/factory suggests. These guys are skilled engineers and must have a defenitive reason for their suggestions. Anybody have comments? Yes, I did a search and came up empty with specific 355 oil use. Thanks FL | ||
| Rob Schermerhorn (Rexrcr)
Member Username: Rexrcr Post Number: 480 Registered: 11-2002 |
BTW Mitch, I spoke with a Mobile engineer in the eighties shortly after Mobile One came to market. FWIW, he mentioned to me that the true viscosity properties were so wide that the label "5w-30" and "15w-50" were marketing decisions in that Mobile believed they'd scare the public marketing a true 0W-60 oil. Basically, they put the same stuff in every bottle regardless of label. I am only relating a conversation. I just know it's good stuff. | ||
| Rob Schermerhorn (Rexrcr)
Member Username: Rexrcr Post Number: 479 Registered: 11-2002 |
First of all, to be certain, one must use a real Bourdon-tube pressure gauge. I make adapters using the original oil pressure sender's base, taping for AN or NPT adapters to plumb the mechanical oil pressure gauge. If I saw about 75 psi @ 6000 rpm, all is well. 90 psi @ 6000 is indeed too much assuming the oil is up to operating temperature (at least 100oF, better at 150oF). Idle pressure may drop to 15 psi, no big deal, no load. The factory dash gauge is inexact, but suits your purposes fine for relative pressure readings while driving. | ||
| Mitch Alsup (Mitch_alsup)
Member Username: Mitch_alsup Post Number: 477 Registered: 4-2002 |
In my 95 F355; using a 50%50% mixture of 5W30 and 15W50 Mobil 1: I get just over the unmarked hash line on a well warmed engine, and midway between the unmarked lower hash line and the 70 PSI line at idle. On a cool day driving down the road at 75 in 6th gear: oil pressure 3 needle widths above the unmarked hash line, oil temp 160dF, water temp 185dF. using 10W40 Shell Helix I get just at the unmarked hash line at revs and midway between the lower unmarked hash line and 70 PSI at idle. A track day generally subtracts 4 PSI from the high pressure point (about the width of the needle). | ||
| Dennis (Bighead)
Junior Member Username: Bighead Post Number: 79 Registered: 2-2003 |
Ok, this discussion of high and low oil pressures for a 355 have gotten me thinking... WHAT is "factory specification" oil pressure for a 355? In a similar vein, can anyone tell me what the heck the hash marks on the 355 oil pressure gauge read as? Mine is marked with 70 and then 140, but the hash marks in between are not evenly spaced.... The owner's manual reads, "Under NORMAL conditions, with the engine running at 6,000 RPM and oil temperature at 212 degrees F, oil pressure should remain between 72 and 87 PSI. It is normal for oil pressure to drop below 4.5 bar if the engine is hot and left to idle." I know that it varies according to load and conditions, but can someone chime in with the voice of experience? I've heard reports that 355s suffer from a fair bit of high oil pressure. Robert Ziino wrote: > I have heard from a Ferrari mechanic that you can on the 1995 F355 cut the > oil pressure relief spring 3/8 inch to decress the oil pressure at high > rpm--it is way to high( 90-100lbs).The later cars had lower oil pressure and > this increased hp. He has done this to alot of cars and he has also found > that most F355, 75% of them, do not have full throttle. Also, he increases > the holes in the O2 sensors with a screwdriver to get a better reading at > idle and make the car smoother at idle. Al Chelini responded: Robert, Decreasing the oil pressure to a more conventional value sounds like a good idea. If I remember my engineering/math correctly, cutting a spring actually makes it *stiffer* - it's basically just a coiled torsion bar. It brings to mind the '60s guys who cut the springs for the low riders and wound up with a stiffer ride. The shorter working length makes the pressure go down, but the spring stresses go up and more prone to break over time. Unless you're absolutely set on the 3/8" dimension cut, I wonder if just installing a newer version (a factory engineered spring) would be a good way to go. I suspect that it would be wound with thinner wire but keep the overall length the same at 4.55", unloaded. The part number for a '95 spring is 137614, but my parts book was published in '95, and consequently won't show a newer version. Anyone out there have access to a newer p/n? Indeed, the manual states that oil pressure should be 80-96 psi at 6000 rpm with oil temp at 100 degrees C. It goes on to say that "when the engine is warm and idling, a pressure of less than 4.5 bars (66 psi) should be considered normal." Could they be more vague? The implication is that the engine will survive just fine on a lower pressure. Also, I wonder if one has to drop the engine to replace this spring, or can the just the sump be dropped - in one's home garage? While we're at it, shouldn't the relief valve spring (p/n 109980)also be changed, since it's still looking for 96 psi? ___________ So, anyone care to chime in? Rob S? Grazie! vty, --Dennis |