944ja väntvõll ja kepsusaale probleemid

Porschede mootori- ja veermikuprobleemid.
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joonas
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Re: 944ja väntvõll ja kepsusaale probleemid

Postitus Postitas joonas » 28 Mai 2008 09:58

Lindsay Raicing OIL PAN BAFFLE KIT INSTALL
http://www.lindseyracing.com/mm5/mercha ... =OILPANBKI
Pilt

hellraiser
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Re: 944ja väntvõll ja kepsusaale probleemid

Postitus Postitas hellraiser » 28 Mai 2008 10:04

Huvitav, ma just kuskilt nagu lugesin just selle Huntley vastast juttu, et igasugune drilling ei tee midagi, samas tundub jällegi see Huntley versioon usutavam, kuna tal ei ole enam ühtegi ringi käinud.
Seega vist on kõige mõttekam tõesti see perp drill ära teha ja loota kõige paremale. Need pan baffle'd ja cranck scraper'id kindlasti annavad lisaks.
https://www.stuttcars.com/margus/
’08 Cayenne
Ex: ’83 944, ’86 951, ’01 911 Turbo


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laur4
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Re: 944ja väntvõll ja kepsusaale probleemid

Postitus Postitas laur4 » 28 Mai 2008 10:21

hellraiser kirjutas:Huvitav, ma just kuskilt nagu lugesin just selle Huntley vastast juttu, et igasugune drilling ei tee midagi, samas tundub jällegi see Huntley versioon usutavam, kuna tal ei ole enam ühtegi ringi käinud.
Seega vist on kõige mõttekam tõesti see perp drill ära teha ja loota kõige paremale. Need pan baffle'd ja cranck scraper'id kindlasti annavad lisaks.
Osad räägivad jah, et drilling ei aita väga palju. Samas loogiliselt peaks nagu abi olema nii Huntley enda versioonil (inertsi tõttu ei saa õli kanalite kaudu kepsusaaleni), kui teisele versioonile, kus õhk saab kergemini liikuda kui õli (tavaversioonil läheb ainult õhk läbi õlikanalite, kuid otsekanali korral peaks sinna ikkagi siis õli ka sattuma). Lisakanalite tegemine eeldab kindlasti korralikku õli (võibolla rõhk langeb) ja korras õlipumpa.
Foorumis rusikaga vastu rinda taguda, et minu variandi puhul pole ühtegi enam katki läinud on natuke kahtlane. Aga võibolla tõesti.

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Re: 944ja väntvõll ja kepsusaale probleemid

Postitus Postitas joonas » 28 Mai 2008 11:07


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Re: 944ja väntvõll ja kepsusaale probleemid

Postitus Postitas joonas » 30 Mai 2008 19:01

http://944spec.org/944SPEC/component/op ... itstart,6/

I have raced my 944 with success in temps to 105F both with and without an external oil cooler.

Here are some tips.

1)You need the stock system work to 100%.
By that I mean all working perfecty.
- It needs to be bled correctly as air is bad.
- It needs to run on distilled water and a bottle of water wetter. Any coolant reduces the heat disipation capacity of the system.
- All hoses must be 100% leak free, No leak at all as any leak will cause over heating. Get a pressure tester to check for leaks when cold.
- NEW Radiator - The stock 944 one is fine and works great, IF if not clogged up. Nearly all old orginal radiators will not cool enough on track due to accumulate debris both inside and outside. A few weeks ago I spend 2hr clearning dirt rubber debris from the front part of my radiator. I was blow it clean. This was a new unit 5 years ago and even with screen the accumulate debris was considerable. 20 year radiators don't stand a chance because they are often corroded inside as well.
- New waterpumps. Again old water pumps can be marginal and fresh on will help ensure 100% operation of the system.

Ok now that the basics have been done work on the rest of the system
2) For 944's cut out the bar that goes between the fog lights. Removing this will improve airflow to the radiator and thus improve cooling. You really need to install a debris screen of a sizeable opening to prevent rocks from hitting the radiator.
3) I assume all of you have ditched the condensers right.
4) Know "Normal" temps. Both early an late gauge don't have number markings. However even a well running car in 95 to 105F temps will run the final white line on either temp guage. These temps are only 210F or so and the car will race fine all day at these temps. Going past that for a short time is ok especially if you are drafting a bit.
5) Direct wired fans. When running in the very hotest times I need to have both fans going full bore. I have both fans wired to switches and the battery. This way I can control when they start and stop. Not using both fans will cause temps even during racing to increase in really warm weather
6) Front undertray. It help prevent the air from under the spoiler from creating a high pressure zone behind the radiator. If this happens it restricts some flow and increase temps.
7) External oil cooler. I noticed a drop of 10-20F water temps by ditching the stock oil cooler and going with a 951 oil cooler. In the old days running a race in 105F temps put the cooling system to the limit. I would run, but would run hot right at the limit of what I liked (just past the last white line). With the external oil cooler the heat from the oil does not go into the water system and as such there is less heat to dissipate so the water temps are down.

So those are ways to keep the cooling system operating.
When it comes to oiling and rod bearings.... see the next post.

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Re: 944ja väntvõll ja kepsusaale probleemid

Postitus Postitas joonas » 30 Mai 2008 19:02

Rod bearings and bottom end life.

Rod bearings are the only weak spot on these cars.

It is a long story as to why (roots in the 928 motor development really), but there is no one fix it solution. There are how a number of little things to be done to minimize the risk.

(In order of effort to implement)

1. Run oil to the full level never under full and never over full. So check the oil level before each run session.
Some motors burn oil and some do not. Most do at least a little but and letting the oil level drop is just asking for problems. Also overfilling the oil can result in increase oil frothing with is another source for issues. Make it your routine to check the oil level at each session to make sure it on the mark.

2. Run high quality heavy oil. Don't run anything less than a 20w50 oil or similar. Running thin oil to make hp is a great way to spin a bearing. I run AMSOIL 20w50 Series 2000 racing oil. It is alot more expensive than Mobil 1, but also holds hot pressure alot better. Also change the oil every 2-3 events. Old oil breaksdown more easily and gives less protection. I think the Redline racing oils are also good.

3. Fresh Rod bearings It is not easiest to do, but 20 year old rod bearings are often ticking time bombs. Years of use has opened the clearnaces and open clearnaces need more oil flow to maintain the oil film layer between journal and the bearing. Fresh bearings run a little close and as such need less oil flow and this give you more margin incase something bad happens.

4. Baffle the oil pan. There are many kits to baffle the oil pan by putting rather crude looking trap door in the bottom of the pan and putting ring around the oil pick-up tube. Doing this helps prevent the oil from getting pulled away from the pickup in long hard left turns. Keeping the oil level full also helps this issue, but a baffle is the best way.

5. External oil cooler. Either along with the stock one or just 951 system. Keeping the oil cool helps alot with making sure the oil can do its job. Hot oil is thinner and provides less protection as it seeps through gaps faster. On the very hotest days my oil temp runs to may 250-260F. Not great, but ok. The other thing to watch is oil pressure if you don't have a temp gauge. If it drops of from normal it is getting hot and running in clean air can help. I have run races where I close drafted a car infront to 20 laps and saw oil temps going up and pressure droppoing. So I began to pull out in clean air on the main straight and soon saw temps go down and pressure come up 0.5 bar in 2 laps.

6. Fresh main bearings. This goes along with rod bearings, but can only be achived when pulling the engines as the crank needs to come out do this. One critical thing to remember is that the supply for the rod journals comes from excess oil supplied to the main bearings. So old worn main meaings have less excess oil than tigher fresh main bearings. You will never spin a main bearing because the oil will starve the rod bearing long before the mains. Even so open main take away oil that should go to the rods

7. Cross drilled crank. The main journals are cross drilled, but in most cars the rods are not. I have seen a few rare cases where some motor seemingly have crossdrilled rods too, but don't count on it. Drilling the rods helps oil flow. You can do it 180 deg from the existing hole on all 4 or just #2 & #3. The reason for just 2 & 3 goes to oil flow on the entire crank and 2 & 3 are the weak flow points and it seems that doing just those two helps balance th flow.


I would say that 99% of all rod bearing failures are the #2 or #3. I don't believe I have ever hear of #1 or #4 bearing failure that could not be linked to a specific unique issue.

Also nearly all the rod bearing failures I have seen (I have seen plenty and experinced 2 myself) were a result of poor oiling practices (ie letting it get too low or using too thin of an oil), old rod bearings, build problem or failure of the oil pickup tube due to improperly timed balance shafts. (Hint if you have vibes at 3000 rpm or a cracked fuel rail your oil pickup tube could be craked too).

When driver follow the advice about thier cars and motors last a good long time in all conditions.

If I forgot to mention it I use distilled water an 1 full bottle of water wetter. Water is perfect as a coolant medium and the water wetter is in the for its lube properties not cooling aspects.

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Re: 944ja väntvõll ja kepsusaale probleemid

Postitus Postitas joonas » 17 Juun 2008 10:56

Ühe lahendusena pakutakse ka Accusump seadeldist.
Pilt

Kas keegi on sellise seadeldisega kokku puutunud?
http://www.cantonracingproducts.com/acc ... sumps.html

Edit.
Manuali link http://www.accusump.com/accusump.pdf/instructions.pdf

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Re: 944ja väntvõll ja kepsusaale probleemid

Postitus Postitas cmf » 18 Juun 2008 01:04

scraper, drill, baffle kit, 20w60 ester baasil kähkusõidu õli, max õlitase, suurem väline oilcooler, kepsusaale kontroll(vahetus) 60000km ja elu lill. (Kuna kepsu saale ei maksa palju, siis ise vahetaks koos rihmade ja rullikutega umb. 60000km tagant.)

Päikest, pidamist ja kuiva rada!
Kert
http://www.porsche9xxshop.eu
Porsched, Varuosad, Hooldus
CMF 52-55105

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Re: 944ja väntvõll ja kepsusaale probleemid

Postitus Postitas joonas » 19 Juun 2008 17:08

928 accusump paigaldus tagumisse "kaitserauda"
http://members.rennlist.com/louie928/92 ... nstall.pdf

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Re: 944ja väntvõll ja kepsusaale probleemid

Postitus Postitas joonas » 19 Juun 2008 19:51

Veel üks teooria.

Most of what I'm going to say is speculation on my part, so keep that in mind, but oil temperature is not the problem. I don't think that the oil pump pickup being uncovered in a turn is the problem either. When I had my oil pan off I did some experimenting and found that another problem occurs way before the pump pickup would be uncovered. The pump pickup is located in the center of the symetrical pan. If the pickup being uncovered was the problem, the 2/6 bearing failures wouldn't be occuring primarily in left hand turns. The problem appears to be oil foaming.

Louis Ott cut a hole in a valve cover and fitted it with a clear plastic window. A video camera was mounted to view through the window, and the car was taken out on the track. Everything was fine until the car went into left turns. When that happened the nice steady stream of oil turned to foam. This was even with an Accusump on the car. He has since found that his 2/6 rod bearings were almost completely gone, and is now rebuilding the engine.

What's apparently happening is that in a left hand turn the oil surges to the right side of the pan, and runs out of the sump and up unto the flat rear portion of the pan. This occurs way before the pump pickup is in any danger of being uncovered. The rotating assembly comes surprisingly close to the that upper part of the pan, and probably dips into the oil when it runs up there, whipping it into a foam. Because of the direction of rotation of the engine, the rotating assembly helps to keep the oil on the right side of the pan. There are also angled ribs molded into the upper flat portion of the pan to aid in getting the oil to move forwards into the sump. Those ribs also move the oil to that right side. The oil pump continues to pick up oil, but it's foamy oil.

There's probably no great loss of pressure indicated because there is pressure. It's just that it's a combinmation of oil and air pressure, in the form of the aerated oil being pumped. If you had 100psi of air in there and not a drop of oil, your oil pressure gauge would show 100psi. It doesn't know the difference between oil and air, it just measures the pressure. The 2/6 rod bearings appear to be the most suceptible to marginal oiling, so those are the first to go.

The GTS baffle does nothing to keep the oil from running up unto the rear portion of the pan. After taking a good look at things, giving it some thought, and experimenting a little, I think that the main reason for Porsche putting the baffle in the GTS was to help reduce windage and oil consumption through the breather system in the GTS. With the longer stroke of the GTS, compared to the 5.0 liter cars, this would have been more of an issue.

When I had my oil pan off I made a baffle to cover the entire sump area, with only a hole in the center for the oil pump pickup to fit through. That made a big difference in how far the oil can surge up on the right side before it runs onto the rear portion of the pan, and be affected by the rotating assembly.

I think that adding extra oil to the engine may actually help to make the problem worse by causing the oil to run up on the rear portion of the pan even earlier.

http://forums.rennlist.com/rennforums/s ... t=accusump

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Re: 944ja väntvõll ja kepsusaale probleemid

Postitus Postitas joonas » 01 Juul 2008 23:23

Juttu küll peamiselt 928 mootorist, kuid infoks siiski.
http://www.9xxfin.com/forum/viewtopic.php?t=87

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Re: 944ja väntvõll ja kepsusaale probleemid

Postitus Postitas joonas » 01 Juul 2008 23:28


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Re: 944ja väntvõll ja kepsusaale probleemid

Postitus Postitas joonas » 10 Veebr 2009 11:38

Accusump Installation - 924, 944, 968

I know of few topics that elicit such dismissive and strongly held opinions as that of how to eliminate the cause of #2 rod bearing failure in 944 engines. Some builders claim that the aeration of the oil in the sump is at the root of the problem. Others claim that the fault lies in the design of the oil journals. There is yet another school of thought that holds that it is essentially a cavitation problem in sustained left-hand turns. One thing is certain; this is a topic that brings out some remarkably vehement opinions.

I recently replaced the engine in my 1985.1 944NA. I didn't have any particular problem; I simply had 150,000 mi. on the engine (including a fair amount of track time) and was getting concerned about longevity. I had a variety of minor oil leaks (my floor pan anti-corrosion strategy) and was due to have the rod bearings replaced, along with the belts and rollers. I had an opportunity to acquire an engine with a warped head at a reasonable price so I started to do some research. I spoke with several engine builders about how to resolve the rod-bearing problem and how to improve the longevity of the engine in track usage.

Since I was the one paying for the rebuild, I tried to remove the rhetoric from the various arguments and reason it out for myself. I think that there is a valid claim to be made for all of these opinions. The conventional solution of adding an extra half quart of oil (to minimize cavitation in turns) only adds to the problem of foaming (due to crankshaft splash). There are some flow modifications that can be made to the girdle passages and the crankshaft passages. I had some of these done in the machine shop. We also did the best baffling job that we could. After some deliberation, I decided to add a 3 qt. Accusump, a Canton/Mecca spin-on oil filter housing and oversized external oil cooler. The Accusump is mounted in the spare tire well at the rear of the car. It is connected with an AN-10 stainless steel braided hose, via a manual shutoff valve mounted in the cockpit, to the top of the oil filter housing. The Canton/Mecca oil filter uses a replaceable 8 micron filter element. The oil cooler is a Setrab 625-10 unit mounted on the drivers side of the car behind the left fog light opening. The lines for the oil cooler run from a 951 oil cooler adapter housing that includes an integral thermostat and pressure relief valve (this replaces the original oil/water cooler).

In terms of where I sit in the rod bearing debate, I think that I have reached a reasonable middle ground. I know that I now have an extra 3 to 4 quarts of oil available at system pressure, should it be needed. I can also pre-lube the oil system before every start (most track cars are driven relatively infrequently and the first fifty to one hundred revolutions are without oil pressure to all of the bearing surfaces). I have minimized the aeration problem by locating the oil cooler as far for the engine as possible (giving the foam an opportunity to precipitate out) and run as fine an oil filter as possible.

After all of my research, I disassembled the engine and sent the pieces to the machine shop. I used a machinist (Dean Palmer of Palmer Automotive Machine, West Haven, CT) who had worked on a number of engines for Fairfield County Motorsports (Fairfield, CT), the premier Porsche preparation shop in the area. I had Dean do all of the machining that he would normally do for one of their track engines. I then asked Jim Reilly of FCMS to complete the assembly and installation. Due to some interruptions (a family move from Connecticut to California) I added the Accusump after the engine was installed.

I mounted the Accusump on an aluminum shelf that I fabricated in the spare tire well at the rear of the car. This puts about 25lbs at the rearmost point in the chassis, giving a slight improvement to the weight distribution. I followed the suggestion of the engineers at Canton Racing Products (manufacturer of the Accusump) and ran AN-10 hose from the oil end of the Accusump to an adapter fitting in the top plate of the Canton/Mecca oil filter housing. This hose runs across the rear deck, along the right side of the shifter tunnel and through a bulkhead fitting (located just in front of the glove box liner) to the oil filter. After hearing a number of stories about failed electric valves, I mounted a manual shutoff valve just aft of the shifter, on the passenger side of the shifter tunnel. There is a pressure gauge on the �air� side of the Accusump to allow you to set the precharge. I replaced this with a 90 degree 1/8 NPT fitting and used an AN-3 line to connect it to an air pressure gauge mounted flat on the rear deck. The present sanctioning body that I run with (POC) requires that I cover the Accusump installation so I fabricated an aluminum cover for the spare tire well and mounted it with jet nuts to the top perimeter.

The recommended precharge for the Accusump is normal ambient air pressure (14.7 psi). This results in the air pressure gauge reading actual oil pressure any time the oil pressure is greater that 14.7 psi. When starting the engine for the first time with the Accusump, have an assistant hold the Accusump with the oil end aimed up. This will minimize any air pocket that might be captured in the cylinder. Once it has been cycled in this manner, it can be mounted horizontally. The mounting brackets offered by Canton work very nicely. They are worth the money.

So far, these changes seem to be working well. At my last event at Willow Springs, the ambient temperature was around 110 F. My oil pressure ran 4.5-5 bar and the oil temp remained at 225 F. I plan on checking the rod bearings at 40-50 hours for wear. The oil system that I now have may seem like overkill, but at least it gives me peace of mind.

http://www.tech-session.com/kb/index.php?article=3

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Re: 944ja väntvõll ja kepsusaale probleemid

Postitus Postitas joonas » 19 Mär 2009 18:32


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