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Posted by: peteinjp Mar 7 2023, 06:45 PM

My 2.7 get up to about 230F in the summers and I'm looking to try everything possible to keep the temps down a bit. I am planning on installing a front cooler but that is more of a project that I can handle in the short term.

So does the GT style double grill actually help cooling significantly? Any other mods that can increase cooling- different fan or pully etc?

230 seems to be a high but acceptable limit but sure would like to have a little more wiggle room.

Other weeks- will check the timing to ne sure its spot on. Also will try going back to the initial rich mix on the MFI.

Pete

Posted by: mepstein Mar 7 2023, 06:51 PM

It’s easy to check. Go for a drive, get it hot, check temps, remove the lid, drive some more and check temps. The lid removes in 5 minutes.

Posted by: r_towle Mar 7 2023, 06:56 PM

These (this concept) may help




Attached thumbnail(s)

Posted by: NARP74 Mar 7 2023, 07:04 PM

Do you have floor pan air deflectors installed? Mine did not make it back on the car after reassembly by the PO. I bought a set and installed them. Looking to see what gains I get in cooling if any this summer.

Posted by: peteinjp Mar 7 2023, 07:16 PM

Good point on just removing the lid. In fact now that I think about it I've already done that when I was tuning the MFI and I think it made no difference.... I'll try again.

Love the louvers!

Yes I have the lower deflectors installed.

Pete

Posted by: BillJ Mar 7 2023, 07:24 PM

Off topic but damn that is gorgeous silky blue paint with sexy curves.

Posted by: nditiz1 Mar 7 2023, 07:25 PM

I have a 2.4 installed with carbs (now PMO). In the hot summer or even on an extended highway drive she'll creep up to 230. I don't like it that hot either which is why I'm mounting a front oil cooler, hopefully soon. I have a GT grill and the flaps. I have tried everything to keep it cool on its own, but it's the nature of the 6 in a 914.

Posted by: r_towle Mar 7 2023, 07:46 PM

Well, it is an oil cooled car

Posted by: mepstein Mar 7 2023, 08:26 PM

If you have an engine sound pad, make sure it’s not obstructing the flow in front of the engine fan.

Love the blue color on that car.

Posted by: Superhawk996 Mar 7 2023, 08:29 PM

What oil temp would make you happy?

Posted by: altitude411 Mar 7 2023, 08:48 PM

what are you running for your front valance?

Posted by: peteinjp Mar 7 2023, 09:40 PM

This is a good question. Not really sure how hot is too hot. What’s the general consensus on this? Searching around there are lots of opinions… but generally its said that high temp = shorter engine life.




Stock valence

Kinda thinking of running a finned tube in the rocker panel until I can go all the way with a front cooler and making the rocker cover louvered for some air flow. That may even be enough to get temps down.

Pete

Posted by: mepstein Mar 7 2023, 09:43 PM

Perry/ironhillrestorations has a good thread about an oil cooler mounted in the rear quarter. Mirror image to the oil tank. It might be enough to make an appreciable difference.

Posted by: Nate W Mar 7 2023, 10:21 PM

If your 2.7 has the earlier pulleys like mine (116 crank ,95 fan pulley) you could change to 80-89 set up (127 crank, 83 fan). I was reading that the ratio is 1.67 to 1 instead of 1.3 to one which seemed to give about 9 percent more airflow (1500 vs 1380 CFM). I’m thinking about doing this to my 2.7 which I haven’t installed so I have no temp data. Roth sport has the pulleys in all the sizes.

Posted by: peteinjp Mar 7 2023, 10:26 PM

That is an awesome thread- but getting it down with the fender on and the engine might be a serious challenge. On the other hand working up a loop cooler for that location seems do-able...

http://www.914world.com/bbs2/index.php?showtopic=333474&hl=fender%20oil%20cooler&st=0




Good to know. the engine was actually built by rothsport and I'm planning on contacting them with some other questions so I'll ask about this as well.

Pete

Posted by: mb911 Mar 8 2023, 06:12 AM

How the engine mount is installed and how well the seals mate up has a huge effect on cooling. That is why I suggest not using the PMS or naroscpae mounts as they mount the engines lower in the car per instruction and the pushes the fan to close to the firewall and does not seal well as they sit about 3/4” to low in the chassis

Posted by: nditiz1 Mar 8 2023, 07:06 AM

My personal preference is 210. Whether 100f out or 80f. Cruising for hours on the highway at ~80 mph.

Heading to the NEG3 last year, I could actually raise or lower my temp by how fast I went on the highway 65-70 mph kept the temp ~210.

Posted by: Superhawk996 Mar 8 2023, 07:30 AM

Look at the oil temp gauges which vary from early to late. Knowing that standard design practices is to have a gauge run near mid scale. Also know that the 914 oil temp gauge was rescaled in 1974 because Americans aren’t familiar with the operation of air cooled / oil cooled engines and the fact that they run hotter oil temps than water cooled engines.

Where did Porsche expect oil temps to run?

Posted by: nditiz1 Mar 8 2023, 07:45 AM

I know you posted this question and pic before.

The 911 runs at 210 all day long. The mark on the 77 gauge is directly in the middle. The 914 is using a GT style gauge with 100C (212F) in the middle.

210 seems right to me

Posted by: GregAmy Mar 8 2023, 07:56 AM

To the original question...I sincerely doubt the single-grill lid creates any significant restriction to cooling airflow on a street car. On an always-7000-revving engine? Sure. But I do doubt that on a street car.

That said, I did Sergio's GT lid conversion on both my 4-banger street car and my 4-banger 2056cc race car*. The former because it looks good and the latter because...well, I looks good and is lighter and my race car lid is pinned and gets removed for service... - GA

*I also removed/trimmed all the external horizontal sheet metal on the race car, to improve airflow and access/serviceability.

Posted by: mskala Mar 8 2023, 08:03 AM

Many years ago I did some controlled experiments in semi-hot weather to see the effects
of the lid removal and some other things like having holes in the tin where hoses used
to be.

I'll need to find the thread, but the oil temp does go down when you remove the lid, and
probably will be similar with the double grill lid.

Posted by: Superhawk996 Mar 8 2023, 08:03 AM

210 is nice but not so easily achievable with the 2.7L without an external cooler. However, looking at the gauge you posted, there is no need to be excited with excursions to 250 under high load / high speed. Agreed?

For OP - question, what is the real difference between 210 and 230 in terms of engine life and oil life? 20 degrees is basically a 10% variance.

Posted by: mskala Mar 8 2023, 08:10 AM

Link to the post where I show temp difference with/without lid
http://www.914world.com/bbs2/index.php?showtopic=256870&hl=oil%20%20temp&st=20#

Posted by: Craigers17 Mar 8 2023, 08:16 AM

I also put Sergio's GT lid on primarily because it looks good, it's lighter, and mine is fastened with hood pins, so access is better(pretty much the same reasons as Greg).

That said, drive your car around for a half hour or so, and then pop your engine lid and see how much heat comes flowing out....even 5 or 10 minutes later. When you have a double open grill vs a piece of sheet metal and a plastic rain tray, there's absolutely no doubt that you are holding more heat in that space. I'd say it's theoretically possible that even that amount of heat could contribute to higher head temps. Maybe someone's already done the R&D. Anyone here with an aftermarket head temp sensor and a stock lid that they aren't afraid to remove could do some simple controlled tests.

Posted by: Olympic 914 Mar 8 2023, 08:40 AM

This thread may have some useful info.

Under trunk temps, with under trunk oil cooler.

http://www.914world.com/bbs2/index.php?showtopic=347282&st=0

At this time I was running the regular engine grill with raintray, /4

Have since acquired one of Sergio's double grill lids, and switch to it in the hotter months.

Have not done this same test comparing the single grill lid /w tray to double grill lid.

Maybe someday.

An under trunk oil cooler may work for you @http://www.914world.com/bbs2/index.php?showuser=25723

less work than the front mount.

I used a Setrab 119 fanpack cooler but they have larger ones that may give you better cooling.

That said, I'm very happy with the setup I have now. Oil temps are reasonable on the hottest days.

Posted by: DRPHIL914 Mar 8 2023, 08:58 AM

I dont have a /6 but i have a performance tuned and built 2.1 running highe compression, and you know 2.0 motors run a bit hotter anyway, but i found that without a aux oil cooler , with long highway drives evey at 3500-4000rpm head temps were fine but oil temps were wanting to go to 230-240, and same with a 90 degree day idling in traffic more than 30 minutes, even with the cooler but the fan not working this past week in florida at Amelia, then i got the fan wired back up and it made a big difference, which goes to the discussion of trapped heat uder rear trunck where my cooler is located. I still would like to have it more at that 210, so i am considering a larger aux oil cooler and i have Sergio making me a GT double grill lid too. We get really hot and humid here in SC and Florida. SO my question would be if i leave the cooler where it is, what brand/size cooler should i be looking at. also is there a difference in the mechanical temp triggered thermostat in that adaptor for these aux coolers? are most of the 180? i dont know for sure what mine is, it was installed by Tangerine about 4-5 years ago and did great on the stock 1911 motor but i feel like i need more oil flow or surface area for better more effective cooling.
- sorry to OP for the hijack .

Phil

Posted by: DRPHIL914 Mar 8 2023, 09:25 AM

@Olympic_914

what cooler are you using? mine is not as deep/thick as yours, would this help me get down to that 210-215 , switching to a double ? I have a fan and its definitely a must.

sorry just re-read the other post and saw you already answered that - Phil

iu think what i have now is a series 6 or very similar, and wonder if the 119 would be better than what i have or as you stated , could go to the double unit butdont know it will fit in that location.

Posted by: Olympic 914 Mar 8 2023, 10:19 AM

@http://www.914world.com/bbs2/index.php?showuser=11106

The Setrab Series 6 is a longer cooler than the 119 I have which is a series 1 (119= 19 row)

Looks like the series 6 25 row will fit without a lot of problem and they have a fanpack version also.

I still have my stock cooler installed, a sandwich plate without a thermostat and a remote thermostat , the setrab 119 unit is in addition to that. did Chris leave your stock cooler in place or eliminate it in favor of the remote cooler?

Setrab thermostat > https://www.pegasusautoracing.com/productdetails.asp?RecID=32981

Posted by: DRPHIL914 Mar 8 2023, 10:38 AM

stock cooler with sandwich plate just like you . i currently have an adjustable rheostat i have it set to come on at 200, i think it turns off ( the fan) at 180 or 185. i think my sandwich plate has a built in thermostat but i dont know for sure i would have to ask Chris but i was thinkg about if it does not , have one that opens at 180.

Posted by: dr914@autoatlanta.com Mar 8 2023, 10:41 AM

we did a study with a 914 3.0 six GT replica with front GT oil cooler with and without the stock engine lid on the car at the Atlanta Motor Speedway for many laps each, and there was no difference

Posted by: GregAmy Mar 8 2023, 10:46 AM

Emphasis mine. Something I had not considered, as I've always run "sans" rain tray so my statement was based on single-versus double-grill only.

There's a thread around here where I took a 4-thermocouple barbeque tray bluetooth thermometer to check temps inside the engine compartment and under the rear trunk; I was fighting an oil cooling problem (turned out to be an engine problem). I found that the upper area of the engine while underway was within 2-4 degrees of ambient; it's all about airflow.

Problem with checking when you're stopped is that there's much less more engine induction and cooling airflow demands, so it tends to heat sink.

Use one of these to do direct back-to-back comparisons of upper engine compartment airflow, with stock lid and raintray, stock lid w/o tray, and double. I'd be interested if there was much difference, $25 or so with click-coupon...but if someone in CT wants to borrow mine for testing you're welcome to it...won't say bad things about you if you buy me a beer... - GA

https://www.amazon.com/gp/product/B076QDC5VL

Posted by: Eric_Shea Mar 8 2023, 01:13 PM

Pete,

1. Low Pressure flaps are $20.00 and a great investment. We put them on everything.
2. I like the GT lids and there was a thread herein that gave some great figures.

The front cooler is a great idea for that car. We have quite a bit of real work experience with 2.7's. Love that motor for a 914. I wouldn't let a 2.7 leave the shop without a front cooler.

Posted by: r_towle Mar 8 2023, 01:35 PM

I agree, there was a thread someone did long ago that measured temp difference between the two deck lids. It may not be simple to dig up.

rich

Posted by: peteinjp Mar 9 2023, 08:05 AM

Thanks all- great info and ideas for sure. Cooler is the way to of for sure with the front cooler being ideal.

Its interesting to me that most think that 210F is acceptable. In reading factory literature it often refered to operating temp as 80C (176F) for MFI tuning so I was thinking that was kind of the ideal but in retrospect they were probably referring to the minus operating temp. Then there is the idea that breaking 212F is a good thing to help any condensation evaporate... So is 230 considered high but acceptable?

I think I might try as an interim system running the lines for a front cooler but just putting in a trombone type of deal in the front fender. If 230 is not terrible then it would be interesting to see how much I could drop the temps with such a simple system. IF this did work it would keep all the frunk space and keep things simple and clean under the rear of the car. Heck if I added some louvers to the rocker cover I might be able to get enough of a drop in temps without even going to the front wheel well. Maybe used some finned tubing?

Pete

Posted by: jim912928 Mar 9 2023, 08:34 AM

Well, the trombone setup works for my 3.0 SC….I’d say give it a try and let us know. I don’t run a 2nd cooler in my 3.2 conversion and hit 230 on hot days…would love to lower temps and not have to cut things up.

Posted by: Superhawk996 Mar 9 2023, 08:39 AM

Written in 1973 - based on Dyno oil - modern synthetic will tolerate 300F easily before thermal breakdown becomes a concern.

Posted by: zoomCat Mar 9 2023, 08:39 AM

The believe the factory internal oil thermostat activates at 80c, so it’s the most easily maintained temp for testing.


From the manual:

Posted by: Eric_Shea Mar 9 2023, 08:51 AM

Hey Pete,

I think "operating temperature" with regard to the manual means the engine has now warmed up and is no longer in a cold start type mode. This is when you can start to tune things like carbs and MFI.

I'm my experience most street 911's run at 210. 240 starts to cause me concern and 250 is pull over time. This has been widely parroted and published from Bruce Andersons extremely thorough 911 book.

With front coolers, our cars seem to stay at 180-200. When pushed at the track, 200-205. This is when the lightbulb comes on and you can see how the factory won these endurance wars of attrition.

Posted by: Root_Werks Mar 9 2023, 11:34 AM

Good write up on different configurations.

I'm lucky, my six won't need a dual grill.

Posted by: VaccaRabite Mar 10 2023, 09:51 AM

I've used all three variants (GT grill, stock / no rain tray, stock with rain tray) and there is not really a difference in temps that I can find with a street car for either heads or oil temps.

Where is makes a HUGE difference is noise coming into the cabin. For longer drives, the GT grill really lets a lot of noise out of the engine bay and into the cabin. Earplugs needed.

Stock - no rain tray cuts that down some, but I still wanted ear plugs on longer drives.

Stock with the rain tray you could hear the passenger in the car. Considerably more tolerable on longer drives.

Bearing in mind I have a SETRAB aux cooler and fan pack to help keep my oil in check on a hot 2056. I don't need the fan pack for most drives - but for some of the camping trips with bikes on the car and every inch of the car PACKED the fans were really helpful once the engine heat soaked.

Zach