Engine temp help

[Diedrich]

Hi there,
I am new to the forum and need some help please. I have a 1970 Westfalia kombi with a few mods to the engine. When I travel long distance in my bus the engine temp keeps on climbing. I would like to know what I can try to keep the engine temp from rising.
Here is my engine spec:
AS41 case
69mm c/w crank
Engle 100 cam
Engle lifters
CrMo conrods
STD pistons and sleeves (85.5)
043 heads with the 9mm valve stems
009 Dizzy
Solex twin carbs
Sand seal at the pully
Full flow with spin on oil filter
30mm oil pump
Twin solex carbs

The oil sensor is at the type 3 dipstick blockoff on the universal case. The temp pushes up past 120 C when I run at 100 km/h at 3800rpm. the only solution is to stop and let the engine cool down.

Any suggestions will be appreciated. Thanks

[Max Welton]

You could be making too much oil pressure (which can bypass the oil cooler).

Max

[Diedrich]

You could be making too much oil pressure (which can bypass the oil cooler).

Max

Point taken, thanks Max. What do you suggest, should I try and run a 26mm pump? When I switched over to the Engle cam, I had to switch the pump because I had a dish camgear in there and had to change it to a flat one. I thought at the time pumping bigger volume would be better. In hindsight it might have been a stupid mistake. The odd thing is, in town driving the motor stays cool.

[fusername]

run the right oil for the weather and engine health (15 40 I would assume) and see if the oil temps drop. Since you have full flow already, an oil cooler should be an easy add on. what are the temps like where your at?

other solution, keep hte rpms down. 100 kph isn't flogging on it, but its not nothing. Dropping to a lower gear will not help lower the oil temp even tho the fan is going faster, all that spinning heats the oil still. Was on the road for 50+ hours straight, did some science along the way and learned that.

[Max Welton]

You could be making too much oil pressure (which can bypass the oil cooler).

Max

Point taken, thanks Max. What do you suggest, should I try and run a 26mm pump?

Oh, I wouldn't start throwing parts at it just yet. But you might measure your oil pressure at speed. Also tell us what weight oil you are using.

The odd thing is, in town driving the motor stays cool.

Not odd at all. Around town you aren't sustaining the sort of power needed to keep your vehicle moving through the air at 100km/hour. Heat is a byproduct of power output. It takes a certain amount of power to pump oil.

Also, oil pressure rises and lowers with engine RPMs. If you are bypassing the pump, it may only be when the revs are up.

Max

[Piledriver]

Also make absolutely certain the engine tin/surround seal is in ~perfect shape so you are not recycling hot air through the cooling system.

[Diedrich]

Thanks for all the advice and replies.
The oil I use is Castrol Edge Sport. It is a 10W-60 fully synthetic. Usually the weather is nice and sunny between 20 to 35 degrees Celsius. When I slow down to 80km/h, it takes longer but still heats up eventually.
All the engine tin including the hoover bit is there and seals nice and tight. A friend suggested I open the engine bay door and drive it like that and see if the engine temperature drops?

[Piledriver]

I'd dump some 5w-40 or even a 30 straight grade in it as long as it has sufficient zddp etc.
Unless you have a sloppy worn out engine and are desert running at WOT 5w-60 is ridiculous.
Thicker oil does not cool the engine better, but it may be bypassing the stock pressure based cooler setup, esp with an oversize pump. Check your pressure at various RPMs, over ~45 PSI the flow through the cooler will be minimal.

The ajar door setup may or may not help, that would tend to show up as high CHT.

Right now we are trying to fix an oil temperature issue, and the tar like oil can do that.

The stock oil cooler can be plumbed full flow with a proper oil tstat inline, relegation the stock system to simple pressure relief duty. (take note of the T4 upright conversion setups, esp The DTM with the inverted cooler)
An off the shelf cooler to block adapter can be crossdrilled and used as the return to block point to allow all this.

Volvo turbos used to have a very nice sandwich oil thermostat/ext cooler adapter, used a bimetal spring vs. a typical wax tstat element. (adaptable to an external oil filter mount)

A good synthetic oil will last 12K miles at >260F. I like Shell Rotella T6. (5W-40 synthetic)

[Diedrich]

Check your pressure at various RPMs, over ~45 PSI the flow through the cooler will be minimal.

Ok, I am going to install a oil pressure sender and gauge in the bus to see what pressure I am running and when. Maybe this will give an indication weather the oil passes the cooler.

[Piledriver]

Check your pressure at various RPMs, over ~45 PSI the flow through the cooler will be minimal.

Ok, I am going to install a oil pressure sender and gauge in the bus to see what pressure I am running and when. Maybe this will give an indication weather the oil passes the cooler.

I suggest a mechanical gauge, unless you have a sender/readout with a known calibration.
Many folks have seen VDO setups all over the place accuracy wise.
I consider them dash filler.

[Max Welton]

I suggest a mechanical gauge, unless you have a sender/readout with a known calibration.
Many folks have seen VDO setups all over the place accuracy wise.
I consider them dash filler.

There's no need to trust what other people have seen. That's just internet crew-chiefing. Just test your own particular gauge. Compare the VDO to a mechanical that you trust. If they match, you can trust the VDO.





Max

[Piledriver]

make sure to check the whole range...
Many vdo gauges read zero at 10-15 psi.

never trust a gauge unless you have tested it first... esp. VDO.
They are not precision instrumentation you can inherently trust.

Autometers are a little better... just a little.

...seen it myself way too many times to be "internet crew chiefing"

[madmike]

You can Install a Porsche gen. pully to speed up the fan

[Jadewombat]

My friend's stroker motor had head temps a little on the high side. We had to pull the engine for some reason. He had aftermarket heads and I noticed on the casting that one of the passage ways was not opened up like the stock heads. I used a long skinny drill bit, put engine back in car, dropped head temps 30 deg. F.