Engine oil cooler block off? Henry?

[78SCRSMAN]

I have an engine oil cooler that may be leaking. Can I simply cut off the cooler core and weld on a plate to essentially eliminate it? (I'm over simplifying, I know) Has this been done before? I will have a LARGE, front, center mounted cooler so this shouldn't be a problem.

[YTNUKLR]

You will need to block off the top two out/in-lets and get an adapter (Smart Racing has one) for the bottom oil inlet.

I would recommend a 2nd oil filter element over a block-off, and make sure you have a thermostat to the front cooler.

[pete3799]

Why not post a WTB thread. A good used cooler won't set you back much.

[78SCRSMAN]

Originally Posted by pete3799

Why not post a WTB thread. A good used cooler won't set you back much.

Well I did buy one from a Pelican that did not disclose the dent or what looks like a screw driver puncture/gouge. Needless to say, I'm not too happy. I'll give him some time to respond before mentioning his name. So far, no response.

[nocarrier]

Post a pic of the oil cooler, maybe it can be fixed.

[78SCRSMAN]

Originally Posted by nocarrier

Post a pic of the oil cooler, maybe it can be fixed.

I was told by a reputable source, they cannot be repaired if leaking. The puncture is in the core area. At the moment, I'm not positive that it leaks. It must be tested first. I just want to cover the bases first before I put good $ after bad. I looked at the unit sold by Smart Racing but am more interested in a less expensive route. Also, I don't see any reason for adding a second oil filter. Really, someone should just make a simple plate to seal off the oil passages and include a fitting or tube to feed the oil tank. It seems it would be simple and cheap to make. Perhaps I will be the first?

I would imagine I could either cut the lower portion off my engine T-stat turning it into just a cover/cap or just leave it be.

[78SCRSMAN]

How about this for a simpler solution: Weld the two cooler passages shut and use a smart racing adapter for the lower oil-in passage. Also cut the T-stat portion of the engine Thermostat off.
Anyone know if that would work?

[PFM]

The filter consul from the late motors is the better solution, many good engine builder agree it is one extra step in insuring a reliable motor.

Stay Tuned,

PFM

[KTL]

Ask Eagledriver (Andy) what he did. He blocked off the upper passages like Scott said, however kept the cooler in place. This allowed him to use the cooler's lower oil pipe to continue using the setup as normal, except the cooler is removed from the system.

Internal Thermostat and External Tank Question(s)?

[78SCRSMAN]

KTL,
That is a great thread! Just the info I was looking for. Thank you Very much. That confirms what I was thinking.
I have reviewed some oil circuit diagrams and was thinking of doing almost what Andy did. My version will be the light weight route. That is, I will hack up the cooler in order to end up with just the lower scavenge fitting. The rest of the cooler will go bye bye. The two pressure holes will get tapped and plugged using esentially, a drain plug and crush washer. To finish it off, I will make the necessary modification to the T-stat.

Just to address some of the other posters. My take on all this is: Porsche is notorious for add-ons. We have pretty much found out the engine cooler is not needed provided you are running a large cooler in front. No? Many have removed it in favor of the filter console. Well, I already have an oil filter so why have two? Kinda like, why do I need two oil coolers? The engine cooler is just a loop in the system and that loop can be removed and costs very little to do so. I see no good reason to spend $450 for all the stuff needed to fit the filter console when I can go buy a couple drain plugs and washers to acomplish the same thing. In my case, the guy that sold me the cooler for $65 and the 2 plugs w/washers shouldn't be more than $15, so all told, $80 for the oil cooler delete kit, if you will. I also get to subtract another 4lbs-11oz. I weighed it.

[Eagledriver]

Running the smart racing filter consol is actually a good idea. This makes sure the pressure circuit is clean even if something contaminates the tank. I didn't do it because I'm too lazy to figure out how to hook up my oil line from the tank without a cooler in place. (and I like cheap solutions).

I was originally going to weld up the oil holes in the cooler but the blocking plan was even easier.

-Andy

[78SCRSMAN]

Originally Posted by Eagledriver

Running the smart racing filter consol is actually a good idea. This makes sure the pressure circuit is clean even if something contaminates the tank. I didn't do it because I'm too lazy to figure out how to hook up my oil line from the tank without a cooler in place. (and I like cheap solutions).

I was originally going to weld up the oil holes in the cooler but the blocking plan was even easier.

-Andy

Andy,
I agree about the console but like I said before, I just don't think two filters are necessary. Not only that, these engines have proven to be reliable to 200K+ miles with the original filter in place. I highly doubt adding a second oil filter is going to change anything. Also, one thing to remember, Porsche added the oil cooler when the displacement went above 2.0. Then on the later cars ANOTHER cooler was added at 3.0. Then they decided to get rid of it, FINALLY on the 3.6, when they needed space for power steering? I am not sure whether they had two oil filters or just one on the 3.6. At any rate, I'm cheap too... that and I've already got one of each. (oil filter and oil cooler)

I think I'm gonna cut up the oil cooler and just use the scavenge tube. (That's the bottom portion of the oil cooler that connects to the "S" hose) I'm curious what you did to the T-stat. Did you gut it or cut it? Ho, ho ,ho...

Thanks,
Derek

[78SCRSMAN]

I just re-read YTNUKLER's post who also had the solution from the beginning. I guess I wasn't getting what you said when I first read it.
Thanks

[KTL]

Couple of things to add to the conversation.........

The add-on engine cooler is said to be most effective in low speed operation like idling or around town cruising where fan speeds are slow. In other circumstances it's cooling is less effecctive.

The auxiliary coolers are not add-ons, they're a must. Run a SC or Carrera at the track a bit and you'll see temperatures rise substantially, just like you'd see in low speed street operation on a very hot day. The reason the 3.6 is able to get away with no engine mounted cooler is due to the better efficiency of its auxiliary front cooler. Walt Fricke, who always seems to find smart, cheap & effective solutions to things, runs two of these on his 2.8 race car w/out an engine mounted cooler.

One thing to keep in mind about that engine-mounted filter console. It's not a SmartRacing-only piece. They just took the factory 993 piece and elaborated on it. They put a 15 degree tilt on the filter mount so a high efficiency filter like the System 1 filter can fit on the console w/out interference. So if one wanted to, you could install the factory Porsche 0 degree 993 console for the extra filter. I bet a smaller filter than the System 1 recommended by SmartRacing could fit on there? Maybe a Canton would fit.

The extra filter is certainly not a necessity. As you said, the pre-993 engines survive hundreds of thousands of miles w/out the filter in that location. But what it does do is provide some level of protection for the oil cooler in the event of an engine failure. This is obviously not something we should rack our brains to plan for on a street car, but it's not a bad thing for a race engine. No need to send all that bearing material to your expensive front oil cooler, which just adds more cost to your repair bill! Plus if one opts to remove the factory tank for a custom front-mounted tank (ala race car for better balance/wt. distribution), then you need to come up with a filter solution since we'd be removing the existing filter when we ditch the factory's tank in the rt. rear fender.

Lastly, here's the way to connect your factory oil tank to the engine when the on-engine cooler is removed and you've installed the extra filter console:

http://www.smartracingproducts.com/pdfdocs/911oilsystemoptions.pdf

It's just a matter of bolting on an adapter fitting & pipe extension to get the oil system re-plumbed back to where the factory S-hose ends at the engine. As Andy's pointed out in that other thread, you don't need SmartRacing's engine case "thermostat block off." Just gut the existing t-stat?

Just have to be careful with cold operation. Use of that console, no internal t-stat, and a stock 993 filter has the potential for a popped oil filter as neilca pointed out in the thread I linked. That's why SmartRacing recommends the 15 degree console and high efficiency filter- which can withstand very high pressures. However I thought the factory Mahle filters could handle a lot of pressure and when they can't, they run in bypass mode (actually I think these run in bypass mode alot under high pressure during track use) to avoid bursting? I wonder if the 993 factory filter doesn't have a bypass?

[78SCRSMAN]

Originally Posted by KTL

It's just a matter of bolting on an adapter fitting & pipe extension to get the oil system re-plumbed back to where the factory S-hose ends at the engine.

For this, I was planning to cut the "S" hose extension from the OE engine oil cooler and discard the rest of the oil cooler. The two pressure inlet/outlet(s) will be blocked by tapping the block and installing a threaded plug and washer. I WILL be using a SETRAB STD172 cooler up front. The RS front cooler scoop has already been installed in the front tub. My car will be mostly street so if I find traffic to be a problem (I doubt it though) I will simply add a fan and t-stat to the back of the cooler like the Carrera. One small fan should work fine for that.

[Walt Fricke]

Dereck

What's this about the 2.0 911 engines not having an engine mounted oil cooler? All four five of the sand cast blocks I have owned were cast and machined for the standard through 1989 engine oil cooler. And I'm quite certain they were not modified in order to do this before I laid my hands on them. Or did I read your post incorrectly?

78man: All you really have to do with the stock engine oil thermostat to modify it to bypass the cooler system (where you have plugged the cooler openings) entirely is remove the thermostat bits. Or more, up to the sealing area, if you want to.

It is a bit more tricky if you want simply to disable the thermostat so oil never bypasses the cooler passages - Porsche made a special casting for this for the 935, but with some machine work a stock part can be made to do this.

[78SCRSMAN]

Originally Posted by Walt Fricke

Dereck

What's this about the 2.0 911 engines not having an engine mounted oil cooler? All four five of the sand cast blocks I have owned were cast and machined for the standard through 1989 engine oil cooler. And I'm quite certain they were not modified in order to do this before I laid my hands on them. Or did I read your post incorrectly?

No, you read it correctly, I'm probably just mistaken. I have seen the fan shrouds without the passage for the oil cooler so my assumption was they just didn't have one. If that is not the case, I thank you for setting me straight. (I thought I had read it somewhere too?) I am planning on using the RS/RSR type shroud without the oil cooler passage. I hope I'm on the right track for this application.

Thanks for the info.

[Walt Fricke]

No, you are right about the shrouding - the earliest ones didn't have anything special to duct fan air to the top of the cooler. Then that was improved upon. But the cooler was there.

[KTL]

Agreed the bottom section of the cooler is a great donor if you have a junk cooler available. That'll work perfectly when retaining the S-hose arrangement with the stock tank. Might be a good idea to fabricate a bracket to support the tube, in the event something bumps it

You should be fine with the big 172 cooler. The reason it's so expensive is because it's a very good multi-pass cooler. I have a Fluidyne HX front cooler which is approximately the same dimensions as the Setrab 172 and it's not nearly as expensive due to its simpler single pass design. My 3.0L in the racecar has topped out at 210-220 on really hot days. My mixture was a bit lean at those times, so I suspect with my richer jetting the temps should stay below 210.

I don't think those fans are a huge benefit but I guess it can't hurt. To make it most effective would you need two fans to cover the majority of the cooler surface area? Plus you'll likely have a tough time fitting the fan between the tub and the cooler, even with the RS scoop/panel modification. On my '87 I had the factory Carrera cooler with the fan. I wired to the fan to the fog light switch to manually operate it. When temps would get up there on the track, i'd switch on the fan and I couldn't tell any difference with it on. Even when I turned it on right from the start I didn't notice any discernible temp drop on the gauge. Maybe the gauge sensitivity isn't good enough because that Carrera fan blows pretty hard!

[djpateman]

Originally Posted by KTL

On my '87 I had the factory Carrera cooler with the fan. I wired to the fan to the fog light switch to manually operate it. When temps would get up there on the track, i'd switch on the fan and I couldn't tell any difference with it on. Even when I turned it on right from the start I didn't notice any discernible temp drop on the gauge. Maybe the gauge sensitivity isn't good enough because that Carrera fan blows pretty hard!

I think that most such fans would be capable of several hundred feet per minute of airflow. Depending on the cooler installation and the ducting to & from it, the airflow when the car is in motion could be much higher. A front mounted cooler without much restriction should see airflow at roadspeed: 60 MPH = 5280 FPM. I'm sure that there are restrictions that slow this down, but my point is that above 10 MPH it would seem that the motion of the car would force more air through than the fans could when the car is at rest.