How hot is too hot for a 356?

[neilbardsley]

I drove my car down from Daventry to London in the middle of the day yesterday so was a little more conservative, with the speed, than normal as it was a very warm day! I was cruising at about 70mph with my rpm just under 3000. I was somewhat perlexed by not having a red zone on my oil temp gauge. However, it appears that I'm not the only one to ask how hot is too hot!

{So why did Porsche take the temperature numbers off the gauge? Perhaps they got tired of anxious owners asking "How hot is too hot?".}

http://porsche356registry.org/resources ... o-hot.html

My tempature seemed to sit around the 180 mark. Which according to the article is about right.

[Bootsy]

My tempature seemed to sit around the 180 mark. Which according to the article is about right.

If that's the case I'd not worry and just drive!

[KEVFITZ]

Just for information :
I have a newly rebuilt 1720cc 356B engine just run in at 2000 miles with a full flow filter fitted and I monitor my oil temp with a VDO dipstick temp probe and I note my oil temp at 80-85 degrees c at normal ambient temp cruising at about 70 mph rising to 100--110 degrees c at high ambient temp (22 degrees +) at 70 mph.

Prior to rebuild the temp read 90+ degrees at 70 mph at normal ambient temp and 120 degrees c at higher ambient temp.

Always used VDO dipstick on all my aircooled vehicles...

If a 356 is running hot trust me you will smell it !!!!

Regards

[neilbardsley]

Thanks I wasn't too worried since it moved just over half way (180F) but it had continued going higher I would of started to have got concerned. I as said it was just the lack of red line that made me ask some questions.

I've started using Motul Oil which I've been assumed by Mike Smith is pretty good stuff (I found it at quite a nice price on ebay).

[40 scout]

Just ran my back from Le Mans - at 90 + smelt warm when pulling in for a fuel stop, 85 ish fine.

Agreed you will smell when it's hot !

I have a new Ali oil cooler from Andy Prill, very good, gauge very rarely rises above halfway, highly recommended.

Steve

[mycar]

I`m intrigued by the VDO dipsticks Kevin, do you have a gauge on the dashboard ?

Regards, Mike.

[Mike Smith]

First Check that your Gauge and Sender are `Actually` giving you the correct reading

The numbers are still there but you cannot read them, they are VERY small and tucked up high almost under the bezel

100 C is OK

If everything is calibrated properly the needle will be vertical

If you are running hot there is a reason

• You have a small oil pump engine and you are pushing it too hard
  Lack of oil
  Worn Valve Guides and/or Rings
  You have the early Fan - (Less Blades)
  Externally the Oil Cooler is blocked with crud
  The Head and Cylinder fins are blocked with crud
  Ignition is retarded

If you have the the Fan Housing with the Wire Gauze on the inlet - A later Fan Housing with the Involute entry will help
The New Aluminium Oil Coolers will Help

The ambient temperature will, of course, affect matters and everything becomes more relevant as your motor ages - bit like us all really

[KEVFITZ]

Hi Mike (Mycar)

The bundle is available from most VW parts suppliers for about 55 quid (try Machine 7) and comes with dipstick probe which is wired to a vdo 55mm gauge. You can fit where convenient e.g under dash or in period chrome gauge holder

I use a reproduction gauge holder which fits round the steering column and gives a neat fixing without and drilling...try aircooled accessories .A repro of a 60's american holder for about 45 quid.

I use my oe dipstick for oil checks but you can score the vdo dipstick for oil levels.

Very accurate..checked with boiling water against NHS clinical thermometer.

Standard kit for VW boys.

Regards...is yours on the road yet ?

[mycar]

No.

Though I managed to have a good look at the damage this weekend and draw up a shopping list.... I'm not sure the old girl is going to be back on the road this summer.

Thanks for the VDO info, it sound like a great idea, perhaps if I'd had one fitted I wouldn't have cooked my engine.

Cheers, Mike.

[neilbardsley]

1) So because my car is a 1956 it probably means that the temperature is measured in the slump so no need for a dipstick thermometer?

"Keep in mind that on mid-1957 engines and later, the gauge measures the oil temperature after it goes through the cooler, which means that the sump temperature is probably at least 20 degrees hotter (earlier engines had the temp sender located in the sump). A "dipstick" style thermometer inserted in place of the standard oil dipstick will verify that the sump temperature is hotter than the gauge reading (assuming both intruments are calibrated correctly!)."

2) I also have an aluminium cooler but I don't see how that helps keep the temperature down more?

3) What is a full flow oil filter?

[KEVFITZ]

Hi Neil,

The aluminium oil cooler has a bigger internal cooling matrix surface area compared to the standard item despite having the same overall dimensions...I believe it is up to 1/3 bigger area.

I have a Precision Engineering full flow oil filter fitted as an addition to the oe canister oil filter(which is at best only a bypass oil filter..i.e it does not filter all the oil all of the time ) takes about 2 hours to fit.

The full flow includes bigger oil pump gears ( so better/faster circulation) and bolts on to the tacho drive cover plate on the oil pump.It includes an oil filter canister which filters all the oil all of the time ..it slightly increases the oil capacity as well.
It fits neatly on the engine and has an exhaust heat shield.

Downside is you will have to fit an electronic tacho as the cable drive is removed.
Check out Andy Prill website for details on full flow system
Exchange electRc tachos are available from PRS regards KEVFITZ

[KEVFITZ]

Neil,

Just to clarify: the aluminium oil cooler we are talking about is an aftermarket improved item which has a better cooling capacity as I explained due to the matrix design and construction.

Again try Andy Prill or PRS for details/price.

If your oe cooler is clean and oil tight it will do a good job but if it leaks best to replace with the improved version rather than oe style.

Regards,

KEVFITZ

[Burma-Shave]

Highest I have seen is 3/4 up the gauge, whatever that is, on the Nurburgring at the DDK Euro trip..it was very hot weather at the time. Usually it stays on the left side of the gauge, on UK motorways etc., which I have read is where it should stay most of the time.

I have the full flow mod (which I think is a no brainer if you drive your car plenty), and clean stock (I think) oil cooler. I probably could have a better seal around the motor, and also, for the track I should have fitted the blanking plates that delete out the carb pre-heater horns, as I suspect they let a little heat through even when the thermostat has closed the flaps. You could maybe check your own horns if you have them..(insert joke here.)

An alternative to the VDO gauge is a 'mainely' dipstick+gauge combo, which I have - it helps you double check/calibrate your in-car gauge (although you have to lift the engine lid to check it of course), and is cheap and easy. Its a bit like a meat temperature checker! Only downside is that reading the oil level accurately is a little harder than the stock 'stick, as the shaft is round not flat.

See here http://mainelycustombydesign.com/

[Hendrik Moulds]

Neil,

If your engine is well and regularly maintained then it should be fine as it is, especially as it is running at around the right temperature at the moment.
You don't need to go for the full flow oil filter unless you drive your car hard (like Johnny does!).

In normal driving for me the temp is between a 1/3 and 1/2 way. The hotter the day the higher it goes!