2.7 CIS w/Webers&Headers - Do I need a front mounted oil cooler? - Page 2

911pcars · 02-14-2003, 02:35 PM

[/b]"....It would seem to me that if you could channel some air in a duct to the engine cooler area it would be of benefit."[/b]

Well, there is a bunch of air going through engine oil cooler - from the engine-driven fan. I doubt you could get more airflow through it using the forward movement of the car (unless you were driving 1xx mph) or by using an auxilliary blower fan. I think it's a case of it not having enough surface area, otherwise there wouldn't be a need for another cooler, wherever one places it.

I should stick a thermocouple into the air shroud sometime and measure the air temperature forced in by the fan. I think it's not as hot as many might think.

Sherwood Lee

Rich911E · Rich911E's Garage

Thanks all for the help, but the three day weekend is over and I still have a two liter motor, but my dash is all back together and looking very nice. The 2.7 is still staring at me from its perch on the engine stand, but it will go in soon. I am reluctant to pull more than one thing apart at a time and now that I know it runs after my adventures in the electrical wiring under the dash, I feel more confident about pulling the engine.

Sherwood is right, more surface area is always better and this is one area that you want to make sure of. But I do think that there is some merit in the idea of forcing more air to the oil cooler as the factory modified the fan shroud to do just that.

I have two types of fan shrouds in my garage -- the early one is flat over the area leading to the oil cooler and the other one actually has an enlarged raised passage to channel more air to the oil cooler with a separate little duct. The duct is about an inch high by three inches wide. (I think this is the one that came with the CIS 2.7 liter motor?) If the factory thought it was worthwhile, perhaps it is worth investigating more???

While putting my dash back together, I was thinking of other ways to improve the efficiency of the air cooling system. There are a million leaks between the shroud and the top of the engine and the oil cooler. I think that improving the sealing around the fan shroud to the engine and oil cooler would improve the cooling efficiency. I bet that some high temperature foam sealing tape (like the weatherstripping kind of adhesive foam) would help.

Second, as I mentioned earlier, my engine is running headers I have block off plates where the heat exchanger tubes would go. Judging by the amount of air that comes out of the heater ducts at high RPM suggests that these passages bleed off a lot of air that would otherwise go to cool the engine. That was why I was thinking I might be able to get away without an external cooler with the block off plates. I also have the 11 blade fan.

I just need to get out there, put the stupid thing in the car and see what happens. If it gets too hot, I'll put the oil cooler in. I wonder if the guys who put the 2.7 motors in the 914s run external coolers? If a 2.7 can survive in that tiny engine bay without an external cooler, it certainly should do so in a 911.

Rich

Rot 911 · 02-18-2003, 09:09 AM

Quote:

Originally posted by Chuck Moreland
Rich, you might consider removing the battery box to improve airflow. Sherwood, although aluminum is used in AC plumbing none that I've seen run a solid aluminum line the length of the car. They are rubber hoses going front to rear.

Not to hijack this thread, but I respect a guy that will still give advice even though he knows the person he is giving the advice to is not going to buy his product. Thumbs up Chuck!

Rich911E · Rich911E's Garage

Kurt:

I do appreciate the assistance from anyone -- this board has been a real help to me and I have tried to pay the Board back by offering my experience and ideas, my house for Pelican parties, and spare parts (somebody out there has a free pair of doors and a 150MPH speedo).

Chuck helps out a bunch of people on this board all the time and I do value his advice. I would certainly consider the finned cooler lines that Chuck sells if this were a killer motor but until I can afford the engine, the finned lines are a bit overkill. For the moment, this is a budget project -- April 15th is looming!

Rich

turbo dave · turbo dave's Garage

I have just recently done this mod with Moorespeed of Austin, TX (2.7 with SSI's on an early car). We ran Aeroquip lines through the outer rocker panels, keeping the inner panels open for heating (yeah, I know, heat isn't a big problem in central Texas...)

We used a 993 front oil cooler, cut out the battery box. The oil cooler was cheap- only about $270 after my PCA $100 coupon from last year. Hasn't been hot enough to know how well it works, but Moorespeed has done this on much more powerful racing cars in the past, with great success.

turbo dave · turbo dave's Garage

Hmm, pictures didn't come through:

turbo dave · turbo dave's Garage

Let's try this again:

turbo dave · turbo dave's Garage

and another...

turbo dave · turbo dave's Garage

last one...

barlowdo · 02-18-2003, 11:08 AM

Dave,

What did you attach the hose clamps with ? Are they metal screws or did you thru bolt them ?

Don

Chuck Moreland · 02-18-2003, 11:14 AM

Dave

Can you show some pics of the 993 cooler in place? I'm interested in how you wedged it in.

turbo dave · turbo dave's Garage

I wish I could take credit, but the work was all Moorespeed. They did through-bolt the holders, and they had to cut away the battery box & slightly flatten the headlight bucket to fit the cooler. This is the only picture I have of the oil cooler in position:

scg · 02-18-2003, 06:33 PM

That looks nice and clean, Dave. See Rich...the aeroquip lines can be done well (I'm going that route on my 914). Go for the fan if you plan to get stuck in traffic.

barlowdo · 02-19-2003, 06:33 AM

I agree, it looks real nice. And thanks for the info on the thru bolts.

Don

Rich911E · Rich911E's Garage

I agree it looks nicely done. I think it may go that way as I just don't have the time for the hardline engineering project at the moment. The clamps are nice -- I don't believe our host sells them so I can mention that Aircraft Spruce and Speciality (www.aircraftspruce.com) sells them as "WDG clamps" in a variety of sizes.

Rich

keitho64 · keitho64's Garage

Scott

Your tag line says 914-6 2.7. Are you driving a 2.7 powered 914 now? What do you have for an oil cooler? Does it run hot? I am curious how much heat is produced from the 2.7 in the smaller confines of the 914.

bigchillcar · bigchillcar's Garage

rich,
were i you, i'd just give it a shot without the external cooler and see. i've been driving a stock '74 with the early exhaust sans pollution control, etc. for years in the heat of arkansas summers without killing the car yet. i think the early exhaust and absence of this equipment is the sole reason i've had no problems as you suggest. my aircraft mechanic likewise owns a '76 911 and he proclaims the motor to be 'basically an aircraft engine without propeller' and he's been in the business for 25 years. he's convinced me that mine can take the occasional strolls in the upper ranges. in summer heat it can vary between 220-270 when very hot. 240 is probably an average on a humid, 90-100 degree day. i don't track the car so i don't know what influence that would have, but i suspect it would be 'up'. the car is pampered, however and always sees regular maintenance in my garage. maybe every car is a little different, but unless i planned to track the car hard, i see no reason to change what has been working for 80,000 miles.
ryan

scg · 02-19-2003, 03:42 PM

Quote:

Your tag line says 914-6 2.7. Are you driving a 2.7 powered 914 now? What do you have for an oil cooler? Does it run hot? I am curious how much heat is produced from the 2.7 in the smaller confines of the 914.

Kietho64: I finished the conversion last summer without a front cooler, hoping that the mild Oregon climate would keep me cool. At constant speed (*any* speed so far) the car runs nice and cool at 180 degrees... but start using the right pedal as an on/off switch and the oil starts to heat up fast, forcing moderation

The car also overheats if it isn't moving (stuck in traffic, for instance)... but this is a bonus when I want to heat the garage

.

I'm currently installing a front cooler (Mocal 24 row w/fan and thermostat) to get rid of the heat problem... and I'm taking the lines up the center (aeroquip).

I really like the idea of bolt through clamps...

Rich: Thanks for the cool link for the clamps