In the early stages of planning a -6 conversion for our 914. The engine will be from a '73 911E. It has Webers (really wish it had the original MFI, but it doesn't) and have new 2.4 S pistons for a small compression bump and original E cams. From most research, looks like it's on the hairy edge of needing a front cooler, oh, and we live in north Florida, so it does get HOT here! So, started trying to plan out what's needed for keeping the engine cool.

Dug out the oil cooler last week and found it has a good bit of corrosion especially at the seal boss.
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Also, it's been patched previously in it's lifetime.
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Just can't trust using this on a new build, so trying to decide the best option, and looks like there are many.

1. Buy a new factory cooler, do the mod for the inlet line and drive it.
   pros - simple and straight forward.
   cons - new coolers are pricey, not sure of adequate cooling.
2. Use a good used factory cooler, do the mod for inlet, and drive.
   pros - same as 1. Also saves a little money.
   cons - same as 1, but may have less confidence in a used cooler.
3. Buy a new non-factory cooler, do the inlet mod, and drive.
   pros - Also much less expensive than a new factory cooler.
   cons - same as previous. Can these aftermarket coolers be trusted????
4. There's also a 914-6 cooler available new, but it's not factory.
   pros - same as others and this option won't require any mod on the inlet.
   cons - Also pricey and still not sure it'll cool enough.
5. Do one of options 1-4 AND add a front cooler.
   pros - most likely to keep oil cool.
   cons - more work running lines, hoses, cutting and mounting cooler. More cost.
6. Skip the factory cooler, install a bypass, and just run a front cooler. Read more than one build thread here and see this option is popular.
   pros - Bypass with filter seems like a great idea. Oil will be cool.
   cons - Same as 5.

There's many other options too, but these are the one's that have bubbled to the top. I appreciate any input from those who know what works! Just trying to plan and start accumulating all the parts that'll be needed, and deciding on which route to take for proper oil cooling is intimidating to say the least.

Thanks,
Dan

I would not use that cooler. I just sent a factory 6 cooler to a local shop this morning to be cleaned.. They can't guarantee that if any metal is within that'll all be cleaned out.
With that said I know the cooler came from a running engine when it was parked. The engine did lockup from not being properly stored. I flushed the cooler with kerosene and didn't see anything of a concern. I will wait til I hear back from the shop to decide on to use it or not. I do have a new aftermarket 6 oil cooler on hand. They aren't cheap but way cheaper then having to tear down a newly rebuilt engine. With that said I'm leaning towards the new cooler and I'll save the other for a future project.

As for the front cooler it wouldn't be a bad idea. Some will say run it as is but you live in a hot and muggy climate so take that into consideration. Also the stop n go traffic you get there in sunny Florida... In the past I've run front oil coolers on 2.4 and up engines.
No issues with heat unless stuck in traffic(no fans at the time). We do not see heat like you here but it still hits 90's throughout the summer.

LMK if you want info on the cooler that I purchased.

Thanks for the fast reply Luke. Agree 100%, the cooler I have is not an option. About the best deal I could find for a new non-factory 914-6 style cooler is from Germany. Not sure there's any customs fees or not on top of the already high price, but yea, it's not cheap. AA lists one, but it's a good bit more than others that are out there. If you don't mind, certainly message me with whatever information you have. Again, there's many options and just trying to narrow down what makes the most sense.

Dan

#6. It’s costly but a sure thing. It can be done on a budget if you run braided or flex line to the front.

I agree with Mark- number 6 is the ticket.

Honestly, this option has the most appeal. I've read through one of your build threads and it's truly inspiring! What great work. I'm just a little concerned about some parts. I found the Taormina-racing bypass plate with filter and it looks like it's still being sold, but not for sure. I've also read about using the 993 filter console (993-107-057-01) but can't understand for sure how to handle the oil inlet fitting using this. There's the oil union adapter (964-207-317-00) but it doesn't look like it would mate properly with an older 911 case. So is the Taormina-racing bypass plate really the only option? Also, what to do with the oil thermostat? Guess it could just be left as is, but seems it'd be better for oil to pass through the new filter all the time.

Thanks very much for the recommendation,
Dan

Taormina-racing bypass plate - yes, this is the one to use.
There are smarter minds than mine when it comes to oil routing questions.
I was also told by a pro Porsche race car mechanic that I didn’t need a remote thermostat if I was starting the car in warm weather or my garage and taking it easy for the first 5-10 minutes. After all, it’s the same oil that is directed to the oil cooler on the engine, just bypassed to the front of the car.
Buy the A/N kool tool and easily make the lines yourself. A large Setrab cooler with a fan pack is less than $500 and you can remove the rubber plugs in the nose and the metal plugs in the trunk (held in by seam sealer) and not have to cut up your car. We ran the supply line up the passenger long and the return line down the driver side and it was very easy. Not true to the GT look but it just depends how far you want to go. The rockers cover much of it up anyway.

But this is just me. There are many ways to skin this cat.

Thanks for the recommendation Michael. I've read through Mark's build thread, but didn't see yours until now. Wow what a beautiful car! Now I've gotta find a free hour or 2 to read through your thread . So many helpful people here.

Dan

Thank you Mark. You're being modest, but I'll tell ya, after reading your build thread, I have a lot of confidence in your recommendations. Agree, I'll plan to make at least most of my own lines. Most likely plan to use a thermostat for a front cooler, assuming this is the option that ends up being taken. There's been numerous cases of people talking about a blown cooler from thick oil when cold, so probably wouldn't want to take the chance.

Dan

Mocal makes a great thermostat.
I would be interested in what type of performance you get out of your 2.4e. I am planning to do a similar build once I find a 2.7 crank to replace the 2.2 crank, I plan to go with Webbers and the e cam.

Hi Dan,

I got my oil coolers from PMS. Here's the links to what I'm gonna be running in my 6.
I'm going to be using a T-stat housing made by Troutman which uses a 911 engine mounted t-stat. My front cooler will have a triple fan setup as well. I'll be still running my engine mounted oil cooler as well.

https://patrickmotorsports.com/collections/...-901-107-059-03

https://patrickmotorsports.com/collections/...14-207-m491-pms

Thanks for the recommendation Pete. In all honesty, it'll likely to be at least another 6 months before I even begin stripping the car down, and with rust repair it'll be a couple years if I'm lucky before I can report anything. I'm just trying to get all the ducks in a row and right now stuck on the best oil cooling solution. You'll likely be driving before me!

Dan

Thanks Luke. I had seen PMS' front cooler setup, but didn't see they sold a 914-6 cooler. That's about the best price I've seen for it too.

Dan

I have a few 6 oil coolers. Pm me

When I rebuilt the engine in our 73 MFI T, I used 2.4 S pistons and cylinders and E cams along with E MFI. It was a very strong motor. I would give up about 2 car lengths going up the back straight at Watkins Glen to my rich friends in their 73 RS’s. Remember, this was the mid 1980’s when the 73 RS was a $30k track car. You’ll be very happy with it. We ran a factory loop and it was fine for the two of us running back to back and cool as a cucumber on the street.

Charlie

Very impressive Charlie! Thanks for the encouragement and info on your cooling method. Would have been nice to have picked up a couple of RS's back in those days, but then $30k back then was still a nice chunk of change. Heck, I was still in college at that time, so couldn't have even thought about it.

Dan

After reading this section of a post, it definitely sparked some thought,....



So, yea, our 914 has "factory" air. It's front floor is already cut out for the AC condenser.
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No plans on trying to keep the AC after doing a -6 conversion. Measured and the housing for the AC condensor setup is about 16-1/2" wide and it's around 17" deep.
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Has anyone tried mounting an oil cooler here?????? It wouldn't get nearly as much forced air flow while driving, but maybe fans would compensate to provide adequate cooling. Doing this should alleviate any front end lift problems as compared with the typical front cooler setup.

Dan

This is what I used on my 2.7 MFI engine transplant into a 914 chassis.

https://www.stoddard.com/sic10705901-90110705901-sic.html

It is "supposedly" a high efficiency cooler.
All I can tell you is that this cooler is all I've ever needed up here in Oregon.
It could be totally different story if you're driving in 100F heat a lot.

BTW....I sent this NEW oil cooler out to Pacific Oil Cooler for them to clean it and more importantly pressure test it before installing in my newly rebuilt engine. I thought that was good insurance.

Thanks for sharing this. I'd seen that one during searches. The only thing that looks like would make it "high efficiency" is maybe it has more webbing (not sure the proper term) between the passages to increase surface area. Looks like it has 7 inner passages which is the same as the original coolers, and can't see that it's dimensions are larger. I'm sure your engine is stronger than this one, so it's very good to know it does the job. Looks like there's another option now.
Seriously, thanks for ensuring this as a good option.

Dan

Just a note from someone whom has a 2.4 s spec engine with no engine cooler and the cooler deleted like mepstein links. I ran all summer in stop in go traffic 90 plus degree days with no issues. Worked perfectly for me. I run a big RSR sized cooler up front though. No fans

Fans are easy to add later if you need them.
Ben has a good handle on this stuff.

Agree Mark. Ben is actually the reason that's pushed me decide to go with this -6 vs sticking in a 283 Chevy. When he offered the great deal on the -6 sheet metal and then the oil tanks, that's what tipped the decision for me. Couldn't help but look at this a a sign.

It's all becoming fairly clear, but still confused on a few issues. Biggest question remaining is how to deal with the present engine thermostat. Assume it's best for oil to flow all the time through the new filter. With the thermostat, it'll flow straight to the engine until warmed, and then divert to the filter. I've found posts over on Pelican and Rennlist that show swapping the thermostat for a 964 and or 993 part that fits where the thermostat would go. Looks like this part has a couple of variations with one extending down into the case to block off the upper port (seems right) and another that just sits on top since it looks like newer cases were machined without the passages for straight oil. Both have threaded openings for sensors. I guess the part that extends will work, but is it easier to modify the thermostat so it'll just stay in the fully opened position?

Dan

Likely this will be common knowledge for many members here, but wanted to share findings regarding the thermostat. Received a very helpful explanation from Mr. Fricke at Pelican and here's the deal.

They're pretty easy to disassemble. Found a socket that would fit inside and used a clamp to depress the spring, then use a pick to remove the snap ring. Here's the thermostat disassembled.
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The thing that makes it all works is the plunger on the top of the piston that's marked Magic!. Haven't found any specific details, but assume this is using the wax method where heat melts a wax inside. In this case it causes the inner plunger to extend when heated.

In the "cool" position, the plunger is pressed in by the force from the lower spring and the piston is in the fully upward position. The upper cavity is open, and the lower closed, so all oil passes directly to the main oil galley and none to the cooler.
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When the oil heats up, the magic plunger extends, pushing against the lower spring and forcing the piston to move downward. When fully extended, the upper cavity is closed and the lower cavity is fully open so all oil passes through the cooler. In normal operation the piston is gonna be somewhere in the middle modulating up and down and keeping the oil temperature close to a constant temperature, assuming of course the cooler has adequate capacity.
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The goal is to have the thermostat in the position where all oil goes through the cooler (or future to be filter). One option is to buy the 935 bypass plug that has been mentioned numerous times, but don't have a part number and so far can't find one. It looks like 930 107 767 02 sensor cap may work (not sure this is the same as the bypass plug mentioned or not), but I haven't read anywhere for sure to confirm this part fits, and it'll have two sensor holes on top that'll need to be plugged, plus they're around $100. If I had a tig, the upper cavity could be filled in, but unfortunately don't have one. After a little thought, all that's really needed is a means to keep the piston in the position where the main oil galley cavity is closed and the cooler/filter cavity is open. It just so happens that 1" conduit fit perfectly inside the top of the piston. Jackpot! Measured and found it needed about 30mm (1.18") length to act as a block so the piston was always in the lower position.
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This acts the same as the plunger being in the fully extended position. The only other thing I'd like to do is find a shorter and weaker spring for the bottom since the original will be compressed tightly with the piston in this position.

Dan