A question for those who belive in the stock VW oil temp thermostat

[Jon]

Most people use the stock cooler and as a result the VW oil temp thermostat, do you do so because you like the cooler or the thermostat?
If you could have the stock thermostat working with an external cooler would you like that? Or is the stock thermostat overrated and to small to cope with the big oil pumps/rev's we use today?

Any thoughts?

[Lids]

I had to modify my header to clear the thermostat, but i have since ditched it.  And don't run it at all.  flaps are held in the open position.

[Jon]

Hi Lids!
Perhaps my text isn't the best, but I'm talking about the rearmost oil piston inside the engine case. That does the job of a oil thermostat.
Sorry ;-)

[Lids]

I use them, but have adjustable ones.  Are they in the aftermarket scat and autocraft cases?

I am thinking of removing the oil pickup in the sump and replacing it with a collecting pan that is then rerouted into the case via the same gallery.  Hope this will reduce the risk of oil pressure drop off due to foaming.

[Jim Ratto]

I use stock VW spring, 1500S style piston (grooved) and adjustable plug (to adjust tension on spring).
I run 20W50 oil, and have "heard" that 30mm pumps and heavier viscosity oils make the oil run hotter, as the piston goes into "cold" position, and bypasses cooler, even when oil is hot. Somewhere I have the specs for the load of the stock spring... but anyway, I turned the adjuster "in" until the plunger beneath spring was about .040" higher than stock plug. A few things to note here: a) this is a different setup than I had ran in the past (using stock bypass plug and spring setting), b) the use of a 20W50 oil is a "new" item in my motor as well, at least since about 1999 or so, when I ran out of Kendall Green GT1 (I'm using Castrol Syntec for older engines, with additional ZDDP, about 1300ppm...not legal to go in catalyst "new" cars), c) my compression is about .6 higher than it was in last engine, though it has about 10 degrees more duration @ .050 now too. Anyway... two points here.
My current 2165 has yet to exceed 200F, and I would say for 95% of its driving (somewhat hard, different situations, i.e. sustained highway @ 4000-4200 rpm, hard driving through steep canyons in Santa Susanna Hills, 2nd gear to 6000-6500, third to 5500, wide throttle angles, city street driving up and down the gears, but light load.....all at anywhere from 70-95F ambient lately), the engine runs just under 180F. My last 2165 running a slightly thinner viscosity oil, and a tad lower compression,ran slightly hotter, never really running under 180F, and on the freeway, same rpm, same type of weather, would nudge 210F. So either cranking up the bypass spring has forced a larger % of oil in galleys to go thru doghouse... OR the increased duration has "freed up" motor, maybe on blowdown stroke.... allowing cooler pistons, cyls and heads? I don't know, really. But something is working. 
BTW I run a Setrab "twin fan" cooler up next to transaxle, fed by 2 50mm hoses from scoop under RH torsion housing.
Hope this helps...

[Jon]

Thanks Jim!
Changing viscosity and flows will probably change the timing on the valve (read temperature). Thats probably why it is so hard to find thermostats with information about opening temperatures....
Myself I would love to use the stock thermostat but I don't fancy the stock oilcooler. I'm looking at a work-around.

[Jim Ratto]

Thanks Jim!
Changing viscosity and flows will probably change the timing on the valve (read temperature). Thats probably why it is so hard to find thermostats with information about opening temperatures....
Myself I would love to use the stock thermostat but I don't fancy the stock oilcooler. I'm looking at a work-around.

 

I considered doing the following a while back, in an effort to force as much air to heads as possible:

Use a doghouse configuration shroud with "B" fan (the wide one, from 1971- VW # 113119031B), but remove stock cooler, and in place, use one of those RAPID COOL adapter blocks like Baja Bugs used in the 70's that goes where stock cooler went, and from there route AN-8 lines to a big cooler with a fan(s) under the car, kind of like my Setrab. Then... block off ductway to original cooler or the exit from duct from cooler. This way positive pressure would be built from block off, and force MORE out the next path of least resistance, through bottom of shroud to heads and cylinders. Just thinking though...  seems like it would be easy enough to do and with a good job sealing, I bet you'd run coooler heads and cyls.
Any thought JHU?

[Rennsurfer]

No pun intended, but cool idea, Jim. Also, look at Rayburn's rig if you haven't, already. Quite the trick lil' system.

[Jim Ratto]

No pun intended, but cool idea, Jim. Also, look at Rayburn's rig if you haven't, already. Quite the trick lil' system.

Well maybe I missed something on Rayburn's monster... I know he has a trick breather setup. Not sure about cooler...

[louisb]

Actually, I seem to remember reading some where that you would get less cooling with out the oil cooler there due to turbulence. It seems the VW engineers were pretty good at designing the fan housings and set everything up to work just so. Start monkeying around with it and you mess up that fine German engineering. But I don't have any proof, so it could just be more internet facts.

--louis

[Jim Ratto]

Thanks Jim!
Changing viscosity and flows will probably change the timing on the valve (read temperature). Thats probably why it is so hard to find thermostats with information about opening temperatures....
Myself I would love to use the stock thermostat but I don't fancy the stock oilcooler. I'm looking at a work-around.

 

I considered doing the following a while back, in an effort to force as much air to heads as possible:

Use a doghouse configuration shroud with "B" fan (the wide one, from 1971- VW # 113119031B), but remove stock cooler, and in place, use one of those RAPID COOL adapter blocks like Baja Bugs used in the 70's that goes where stock cooler went, and from there route AN-8 lines to a big cooler with a fan(s) under the car, kind of like my Setrab. Then... block off ductway to original cooler or the exit from duct from cooler. This way positive pressure would be built from block off, and force MORE out the next path of least resistance, through bottom of shroud to heads and cylinders. Just thinking though...  seems like it would be easy enough to do and with a good job sealing, I bet you'd run coooler heads and cyls.
Any thought JHU?

oh and to add, the stock thermo-bypass in case would regulate when cooler saw the oil, just like it does for doghouse (instead of running cooler in full flow line, cooling all oil 100% of the time).
If you block off the air to the cooler, I believe it would have to come out somewhere else, right? Block the duct going TO the cooler then,

[Jon]

Then... block off ductway to original cooler or the exit from duct from cooler. This way positive pressure would be built from block off, and force MORE out the next path of least resistance, through bottom of shroud to heads and cylinders. Just thinking though...  seems like it would be easy enough to do and with a good job sealing, I bet you'd run coooler heads and cyls.

That is esentialy what I do on my engine, no stock cooler, just a block off where it used to go. And a B fan inside a stock VW 36 hp housing. It works, but then again I havent done any back to back testing.

My setup does not have a thermostat, so I want to add one... what im thinking is to mashine a piece of aluminum to replicate the section of the case where stock sits, and use all VW measurements and hardware such as bung spirng and pistone. that way I could place it next to may setrab.
I just need to figure out if its a good idea, and if there are any real benefits over doing it the "baja way".

[Jim Ratto]

Then... block off ductway to original cooler or the exit from duct from cooler. This way positive pressure would be built from block off, and force MORE out the next path of least resistance, through bottom of shroud to heads and cylinders. Just thinking though...  seems like it would be easy enough to do and with a good job sealing, I bet you'd run coooler heads and cyls.

That is esentialy what I do on my engine, no stock cooler, just a block off where it used to go. And a B fan inside a stock VW 36 hp housing. It works, but then again I havent done any back to back testing.

My setup does not have a thermostat, so I want to add one... what im thinking is to mashine a piece of aluminum to replicate the section of the case where stock sits, and use all VW measurements and hardware such as bung spirng and pistone. that way I could place it next to may setrab.
I just need to figure out if its a good idea, and if there are any real benefits over doing it the "baja way".

if you need some stock junk to test it (bypass spring, piston, plug...etc...) let me know, I'll sponsor your testing. 

[Rennsurfer]

Well maybe I missed something on Rayburn's monster... I know he has a trick breather setup. Not sure about cooler...

It's fairly new and rather trick. Not the cooler. An enhancement, if you will.

[Jim Ratto]

Well maybe I missed something on Rayburn's monster... I know he has a trick breather setup. Not sure about cooler...

It's fairly new and rather trick. Not the cooler. An enhancement, if you will.

Guess I'm drivin to Fullerton tonight.... 

[Jon]

if you need some stock junk to test it (bypass spring, piston, plug...etc...) let me know, I'll sponsor your testing. 

Thanks, but its going to be long time before I get out on the roads again... winter is just around the corner

Can you see any benefits over doing it over the other option?
Might incorporate the stock valve spring into a filter holder... With a extra safety valve for those cold mornings....

[Jim Ratto]

if you need some stock junk to test it (bypass spring, piston, plug...etc...) let me know, I'll sponsor your testing. 

Thanks, but its going to be long time before I get out on the roads again... winter is just around the corner

Can you see any benefits over doing it over the other option?
Might incorporate the stock valve spring into a filter holder... With a extra safety valve for those cold mornings....

I think your way would be "cleaner"... no holes in shroud and front tin for oil lines, and no doghouse duct to block.
If you can machine a manifold to duplicate the stock bypass, with relief port etc... I think that would be cool. But does that spring react ONLY to oil temp?

[Jon]

I belive that VW intended it to direct hot and cold oil, but are you thinking about problems related to flow?

[Jim Ratto]

I belive that VW intended it to direct hot and cold oil, but are you thinking about problems related to flow?

no I just wonder how much ambient temp in case (from cylinders and heads) affects that spring. If the "spring/valve" was isolated away from motor and the heat from heads, mufflers etc... do you think it would react differently? I'm don't know.... 

[Jon]

That's worth thinking about, how the piston expands in relation to the new "housing" could be different. But I believe the oil would heat it up to close what it sees in the case. And it could still probably use a adjustable bung... to dial the system in... it would just bolt on if the manifold was done exactly like the case.

[Jim Ratto]

That's worth thinking about, how the piston expands in relation to the new "housing" could be different. But I believe the oil would heat it up to close what it sees in the case. And it could still probably use a adjustable bung... to dial the system in... it would just bolt on if the manifold was done exactly like the case.

Very cool. You know I am not going to sleep tonight now, thinking about this.

[Jon]

I'm already loosing sleep over here...   As a additional bonus you could skip having the block machined for full flow, as you could use the bore that used to contain the spring and valve to plumb the oil back into the case...  CSP sell the hardware to do that

[Diederick/DVK]

sorry to go offtopic (i do find this interesting to read, though i have no experience on this myself)
but do these csp fittings fit into single port cases as well?

[Jim Ratto]

I'm already loosing sleep over here...   As a additional bonus you could skip having the block machined for full flow, as you could use the bore that used to contain the spring and valve to plumb the oil back into the case...  CSP sell the hardware to do that

looks like this Bugpack part we used to have on the shelf for years and years, nobody knew what to do with it. 
Once we figured out what it was, it worked well on this autocross 84 x 94 motor we did for this nice old bald guy.