Oil flow at original cooler

[GARRICK.CLARK1]

Hi. Is the oil flow at the original cooler mount supposed to flow INTO and OUT OF the cooler from a cold start up. I don't think the oil on mine is flowing to well at this part of the case.
Engines been running for years ,but I've always thought this is happening with my motor. I don't have the cooler fitted ,its a csp mount with a loop pipe, I have just changed this mount for a cooler delete mount that still loops the oil internally to get rid of the pipe work to neaten it up a bit.
P.s I use 20/50 oil

[Deefer66]

I think the colder thicker oil increases the pressure so valve opens to bypass cooler at the start.. but I could be wrong!

Robbed from Samba a while ago

[GARRICK.CLARK1]

Yeah, plus these motors in a bug take a long time to warm up ,keeping the oil thick for longer, i'll try some 15/40 next time

[rwk2]

That diagram is not entirely correct, oil pushes the piston down approx 12.7 mm at high pressure (60-70 lbs plus?) (cold start) before oil is relieved to sump when cold, thru two slots on the sides of the bore, at that point the main galley can get oil directly from pump before going to cooler, the groove around the diameter of the piston maintains pressure when piston is less then 5 mm compressed (not relieving,warm), oil from main fills groove and pushes back on the piston, counter acting the oil pressure acting on the piston top from the pump directly. This maintains a constant pressure in a T4, as pressure drops or oil thins, piston moves up forcing all oil to cooler and reducing the oil volume acting on the groove in piston. Filter and cooler always have oil flow, filter is protected by it's own bypass and one in its mount, cooler is protected by the bypass function of piston, oil is still in cooler just not flowing at high pressure due to piston being pushed down, spring is the controlling factor as to pressure required to relieve piston and maintain pressure. As we all know piston to bore clearance is similar to bearing clearance (.002-.003) and when worn out allows more oil to flow out around piston from both main galley and top, (from pump) constantly, reducing overall pressure. When the groove in the piston reaches the relieve slot at approx 5mm plus,the piston top also is relieving into main galley creating a open path to relief, very small however but relieving none the less. So the operating range or tolerance of the piston is around 4 mm, this allows for a build up of errors in mfg.of the engine, variance in spring ect. I did a scale sketch of it (blueprint) I'll post later.

[Voskhod02]

Thanks for the information, I remember that my grandfather always had issues with cold oil and starting the engine in winter, I've marked this thread in my bookmarks and saved the picture for further use!

[dstar5000]

Or a weak spring...

Don

[wreck]

use a Mocal thermostat sandwich plate , use a well shrouded oil cooler that is tucked out of the airflow with a thermoswitch on the fan . Also plug the bypass in the oil filter housing . The oil will heat up quite quickly .

[MegaRookie]

A bit the same as what Wreck mentions, but the Ahnendorp thermostat/oil cooler mount also works very good:

https://www.ahnendorp.com/VW-Typ-4---Po ... ostat.html

[Eddie010]

A bit the same as what Wreck mentions, but the Ahnendorp thermostat/oil cooler mount also works very good:

https://www.ahnendorp.com/VW-Typ-4---Po ... ostat.html

I use one of those, but for some reason it is not warming fast...
I don t know what the time should be for the oil to heat up...???

Damn those things are pricie nowdays..

[wreck]

there is always a little flow through the thermostat to the cooler , if the cooler is in a place that gets a lot of air flow, it will still cool the oil .

[dstar5000]

20W50 SHOULD NEVER BE USED IN A VW ENGINE, EVER!
A NEW VW ENGINE REQUIRES 10W30 ONLY. WHEN THE
ENGINE GOES OVER AROUND 100,000 THEN YOU CAN SAFELY USE
THE 15W40.

DON