mender Posted March 6, 2019 Report Share Posted March 6, 2019 (edited) 1 hour ago, turbogrill said: Areation (or whatever it's called) is just a function of time right? So if you change oil after 8hours it's unlikely the oil has gone bad? The oil itself isn't really affected but the bearings need a liquid to form the hydrodynamic wedge and keep the crank off the bearings. You can also get micro-erosion on the bearing surface from the expansion of the air bubbles but that's very minor compared to the damage from contact. Edited March 6, 2019 by mender Quote Link to comment Share on other sites More sharing options...
Team Infiniti Posted March 6, 2019 Report Share Posted March 6, 2019 9 minutes ago, Ronh911 said: This is the problem, aerated oil, I use a HUGE oil cooler and we very rarely see oil temps over 190. But the crank causes the oil to separate and form layers on #2 and the way that its fed the air/oil layer reaches that bearing before the heavy oil layer. That's why I never put an accusump in the car, it's not going to help this separation problem. How would a dry sump heal the issue? Quote Link to comment Share on other sites More sharing options...
Ronh911 Posted March 6, 2019 Author Report Share Posted March 6, 2019 9 minutes ago, Team Infiniti said: How would a dry sump heal the issue? Engines naturally will create oil/air intermix from the oil pump itself to the oil sloshing, oil hitting moving parts etc. 944 cranks exacerbate this situation greatly so the real key is to keep as much air out of the oil as possible. Dry sumps keep that oil away from moving parts and also allow the oil/air to separate in the oil tank. You can also get a combination of scavenge pumps that will remove the oil AND air out of the crankcase. An additional air/oil separator can be applied to the suction and pressure pumps to further keep the air out. Just received a quote for all the parts $3800 1 Quote Link to comment Share on other sites More sharing options...
karman1970 Posted March 6, 2019 Report Share Posted March 6, 2019 Can you knife-edge the crank and install a windage tray? I helped a friend do this with a 240Z SCCA car. Quote Link to comment Share on other sites More sharing options...
Team Infiniti Posted March 6, 2019 Report Share Posted March 6, 2019 (edited) The Porsche issue is sort of special Briefly thought we were going to experience a similar problem with the infinity V6 but it doesn’t cause any issues under 7000 RPM. The answer for my non-problem would’ve been re-drilling the oil passageways within the crankshaft Edited March 6, 2019 by Team Infiniti 1 Quote Link to comment Share on other sites More sharing options...
Ronh911 Posted March 6, 2019 Author Report Share Posted March 6, 2019 4 minutes ago, karman1970 said: Can you knife-edge the crank and install a windage tray? I helped a friend do this with a 240Z SCCA car. I'm having the crank cross drilled now on #2. We use a windage tray/crank scraper/pan baffle currently (all claimed). Quote Link to comment Share on other sites More sharing options...
Ronh911 Posted March 6, 2019 Author Report Share Posted March 6, 2019 6 minutes ago, Team Infiniti said: The Porsche issue is sort of special Briefly thought we were going to experience a similar problem with the infinity V6 but it doesn’t cause any issues under 7000 RPM. The answer for my non-problem would’ve been re-drilling the oil passageways within the crankshaft We redline at 6800 but try and shift by 6K, unfortunately peak power is at 5800 so we tend to overshoot 6K. 1 Quote Link to comment Share on other sites More sharing options...
mender Posted March 6, 2019 Report Share Posted March 6, 2019 15 minutes ago, Ronh911 said: I'm having the crank cross drilled now on #2. We use a windage tray/crank scraper/pan baffle currently (all claimed). Cross-drilling doesn't always work, especially if the problem is upstream. The main benefit of a dry sump (ignoring ground clearance) is the 5 gallon sump that gives the air time to separate from the oil. Extra oil capacity in a wet-sump system does the same thing but it's not likely that a person has room for a five gallon oil pan. Wings and trap doors work very well. Quote Link to comment Share on other sites More sharing options...
Ronh911 Posted March 6, 2019 Author Report Share Posted March 6, 2019 3 minutes ago, mender said: Cross-drilling doesn't always work, especially if the problem is upstream. The main benefit of a dry sump (ignoring ground clearance) is the 5 gallon sump that gives the air time to separate from the oil. Extra oil capacity in a wet-sump system does the same thing but it's not likely that a person has room for a five gallon oil pan. Wings and trap doors work very well. That's why I didn't have the crank drilled years ago. Porsche actually used a cross drilled crank in the 83 944 but only that year. All others are single drilled. If Porsche thought they could fix this problem with a cross drill they would have implemented this, it would have been a cheap fix/update. That's why I don't have high hopes on it working/helping. 1 Quote Link to comment Share on other sites More sharing options...
ablesnead Posted March 6, 2019 Report Share Posted March 6, 2019 The factory 911 sump tank was more to address the ground clearance issue in my opinion....we ran a Petersen swirl tank in my GTU car...I'm sure that the increased volume would offer a small benefit , but air bubbles travel so slowly in the oil that , the extra capacity would marginal for that purpose...The swirling action on a Petersen tall sump tank visibly reduce's the aeration substantially...the tank volume gives a greater swirl area..a lot of people over fill the tank in my opinion... Quote Link to comment Share on other sites More sharing options...
Black Magic Posted March 6, 2019 Report Share Posted March 6, 2019 Questions, Is the general thought that the crank aerates the oil in this motor? Probably from the very tiny pan to crank clearance? Do you have oil pressure data on track? Registering any dropouts at all ? Stock volume pump? What is high rpm oil pressure (blow off of return spring) Possible solutions... Raise motor in car, run much deeper pan with even more volume. Like 2 gallons. It will deaerate then, I run 8 qrts in the neon. It takes alot of true aeration to make a difference, since the oil pump pushes the air into suspension. This is not the same as a uncovered oil pickup, where there is simply no flow. Dry sump systems still often have a reasonable amount of aeration in the oil and they don't go boom. Do these motors have problems with pumping the oil up into the head? Could you restrict head oil flow, increase pump relief pressure, to help? You need to log oil pressure vs rpm as a minimum, to at least make sure you aren't getting partial drop outs. Quote Link to comment Share on other sites More sharing options...
wvumtnbkr Posted March 6, 2019 Report Share Posted March 6, 2019 9 hours ago, ABR-Glen said: You bust his balls for having a swap, so he takes it out to put the unreliable engine back in that he was trying to avoid, and now you want him to swap again, nice Maybe he could trade fuel capacity for a dry sump Well, when you put it that way... I am understanding, but not sure if dry s umps belong in this series. Quote Link to comment Share on other sites More sharing options...
wvumtnbkr Posted March 6, 2019 Report Share Posted March 6, 2019 23 hours ago, Ronh911 said: You’re right Rob they are cubic dollars but I would actually be ahead right now if I didn’t need to replace 3 engines. There IS a major flaw in the design of the 944 crankshaft and oiling system. Thanks for the feedback. Btw, this is an awesome response. Thank you for understanding I was not attacking you and only giving my opinion. Well done. 1 Quote Link to comment Share on other sites More sharing options...
wvumtnbkr Posted March 6, 2019 Report Share Posted March 6, 2019 What about a vacuum pump? The vacuum should help get rid of the bubbles? Just a thought out of left field. 1 Quote Link to comment Share on other sites More sharing options...
Team Infiniti Posted March 7, 2019 Report Share Posted March 7, 2019 It’s all over the Internet, #2 bearing failure is unique to this car, as said earlier, there’s nothing definitive in the way of a fix 1 Quote Link to comment Share on other sites More sharing options...
BeastZ06 Posted March 7, 2019 Report Share Posted March 7, 2019 An (expensive) dry-sump assembly is 100 pts, same as a cam and springs, so the value is probably good or too low. (currently 2 dry sump cars in my garage/yard and would like more!). Without looking into 944 oiling system issues, if an extensive windage tray/scrapper/oil pan isn't working, I would think a "dry-sump assembly" would have to include a scavenge pump and storage tank. Maybe a more Chumpie way would be an excessively large 2 gal "oil catch can"/oil sump (rules 9.11.1.1 say min 1 qt) that gets it's oil supply from cylinder head drains and the oil pan/block, but still uses the OEM oil pump with a modified pick up, just need a bit of ground clearance and baffles/check valve(s) to help the gravity flow? Quote Link to comment Share on other sites More sharing options...
mender Posted March 7, 2019 Report Share Posted March 7, 2019 Figure out how to mount one of these on your external oil cooler lines: http://www.spintric.com/ 1 Quote Link to comment Share on other sites More sharing options...
Originalsterm Posted March 7, 2019 Report Share Posted March 7, 2019 "We didn't pick your car" Seriously though, this is a problem I remember from my Porsche days and part of the reason I chose to not race one. I remember scouring pages and pages of ideas on the Rennlist forum years ago, so many theories and expensive band aids to try and cope. I don't recall a bulletproof solution at the time, but hopefully there is something available today since those engines are getting scarce and even more expensive to replace. My first Chump car cost less than my last 951 rebuild. 1 Quote Link to comment Share on other sites More sharing options...
Black Magic Posted March 7, 2019 Report Share Posted March 7, 2019 (edited) Can also look into boring the rods out to fit clevite H bearings. Might decrease the sensitivity to low oil delivery and rod geometry change from flex. Maybe the H bearing is cheaper as well, and you could just good at rod bearing swaps. Still leaning towards big pan. lots of oil capacity, drilling your crank oil feeds bigger. Edited March 7, 2019 by Black Magic Quote Link to comment Share on other sites More sharing options...
Scott Posted March 7, 2019 Report Share Posted March 7, 2019 On 3/6/2019 at 12:42 PM, Ronh911 said: We use a windage tray/crank scraper/pan baffle currently (all claimed). Curious what the points values were associated with those components? Is it just a material cost? Quote Link to comment Share on other sites More sharing options...
Ronh911 Posted March 7, 2019 Author Report Share Posted March 7, 2019 30 minutes ago, Scott said: Curious what the points values were associated with those components? Is it just a material cost? Yes, all materials cost. Quote Link to comment Share on other sites More sharing options...
Rodger Coan-Burningham Posted March 9, 2019 Report Share Posted March 9, 2019 Many a 944 engine has been torched due to this #2 rod bearing issue. One of several reasons we gave up on the platform, but a swap would have been in the works were it not for our baby being totaled at a lemons race (driver crested a hill and a big stupid Nash was crossways in the track. A good reason we shouldn't have been there anyway). Here is another issue that once got us: Quote Link to comment Share on other sites More sharing options...
mhr650 Posted March 11, 2019 Report Share Posted March 11, 2019 Just FYI regarding points, now dry sumps are 100 points, in 2014 they were $500….. Quote Link to comment Share on other sites More sharing options...
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