Posted by cooperman on Saturday, August 2, 2008 @ 05:24 PM:
Hi all
In pursuit of sorting my engine I have fitted a Melling oil pump. Oil pressure now roughly 3 1/2 to 3 3/4 bar when cold, 3 1/4 cruise and dosnt drop beneath 2 bar when hot. Fantastic!.........however oil temp has jumped from approx 95 up to 105 deg .
Any ideas?
Thanks
Paul.
Posted by eugenio on Thursday, August 7, 2008 @ 04:40 PM:
Install an oil cooler, or if you already have it, chech all baffles for good seal over the engine cowl.
cheers
Eugenio
Posted by cooperman on Friday, August 8, 2008 @ 10:59 AM:
Thanks Euginio
Working on the baffling and looking into an oil cooler.
Just surprised to see an increase in temp with improvements in pressure. It has been suggested that this could be due to improved flow removing more heat from the engine?
Paul.
Posted by eugenio on Friday, August 8, 2008 @ 01:59 PM:
Maybe......
I have a RF3 with a regular Rectimo 1200 without oil cooler and with 1200+ hours, it never reach more than 95°C
I also have a RF4 with the same engine installation, with 6/700 hours also that was without oil cooler, but after a frightening flight over the sea and then over the Alps (From Fayence to Envie) with the oil temp never falling down 100°C, I installed an oil cooler and the problem was solved. (by the way it was the one Collin used from Envie to Gap)
Then I have my own RF4 with a 1600 that was at first built exactly like the 1200, but the second flight after having experienced a 110° C of temp and a nearly 0 PSI of pressure was imediately modified with a 26 mm oil pump and oil cooler, now it runs quite OK, and with an outside temp of 30+ °C I have a steady 85 to 95°C with nearly 3 bar.
I use 20W60 oil.
If you have not an oil cooler I suggest first of all install one.
ciao
Eugenio
Posted by Bob Grimstead on Thursday, November 20, 2008 @ 04:48 AM:
Hi Paul,
Francis Donaldson says beware over-filling a VW with oil.
It goes out along the push-rod tubes and collects more heat from the heads, making the oil hotter.
Seems like a good thing to me, but could that perhaps account for your higher temps?
Yours, Bob
Posted by eugenio on Friday, November 21, 2008 @ 02:58 PM:
Well, the first result of overfilling the engine with oil is oil spraying from the vent tube. Be sure that the first hour of flight you will spray out all the oil in excess.
What Bob says is correct, but also chromed valve covers dissipate less than black ones, and also a black engine case dissipate better than a clear one, lots are the things that works for cooling the engine.
Did you checked the temperature gauge? does it works fine?
Just for info, Limbach gives as maximum temp. 120°C and temperatures about 100°C are within range
ciao
Eugenio
Posted by cooperman on Friday, November 21, 2008 @ 06:35 PM:
Bob/Eugenio
I have been very careful not to overfill the oil. There has been no noticable loss by venting, none around the crankcase or seals. Chatting with Dave and Matthew recently I draw a possible conclusion of having glazed the cylinders when breaking in the engine - you may recall the first few months were troubled with relief and control valve problems and the engine was never really worked as hard as it should have done. I have consistently been using oil all summer now although temps are better at say 95 to 100 deg and pressure rock solid at 3 bar.
I will be taking the heads off next month and having the cylinders honed and will start again. At the same time I will be replacing the baffling. Subject to what temperatures I achieve I may fit an oil cooler - I have one and an adaptor to machine. The only question is what pressure the cooler will withstand - my oil pressure is nearly 4 bar when the engine is cold on a cool day.
Rgds
Paul.
Posted by Bob Grimstead on Friday, November 21, 2008 @ 06:51 PM:
Hi Paul,
Four bar should be no problem for a VW oil cooler.
Which adaptor did you use? The $30 Great Plains one? or the GP Sonerai one? or something else?
I ordered mine yesterday.
Yours, Bob
