TheSamba.com :: View topic - Is it Necessary to have thermostat and ring?

Mon Mar 15, 2010 7:45 am

EverettB wrote: Bezzer wrote: Yes you can put it back, and you did, keep an eye on it. If the ring fails, and they can, it will overheat your engine.
If it fails, it fails open so how would that overheat your engine?

I know of a few "crusty engine" startups where the pivot was seized and the ring couldn't open.... and the engine overheated. Rare, and just ignorance of someone checking the right things before hitting the road. It is a pretty fail proof system though.

My take is that you should run with it. I do, and infact check the ring after running a while, or hit the T stat with a heat gun just to make sure it is working. But I also arrange my socks on the shelf by hue. :wink:

That being said, I think there really is no harm in running without it, as stated many times, your engine will just not warm up as fast.

Mon Mar 15, 2010 10:43 am

A very interesting and erudite discussion I must say. A word on technique to the wise. When you install the ring, take the fan belt off so you can rotate the fan, loosen the clamp bolt on the throttle ring shaft so you can move the ring through it's full range. Spin the generator with one hand while moving the ring back and forth in it's range adjusting it's location with the two 6mm mounting bolts until it does ot rub at any extension. You cannot imagine how irritating a rubbing throttle ring can be.

Don

Mon Mar 15, 2010 3:12 pm

I have experience with this issue on a 40hp which may still be relevant.

In the late '70's and early 80's I drove a '63 1200 in all sorts of weather in upstate Vermont. I noticed that on cold days, less than 20F, the ring would never open completely. In fact, when it was below 0F it barely moved off the rubber stop at all no matter how long or hard I drove. In the summer, in this same car, the ring would open completely, almost to where the top of the ring would contact the insulation board on the firewall so I beleive it was adjusted correctly.

My current '63 which is also completly stock behaves exactly the same way.

Based on the above, the ring serves more than just for speeding up the warm up time. It seems to me that the ring is critical to keep the engine at something close to normal operating temperature in cold weather

Mon Mar 15, 2010 3:33 pm

pav266 wrote: I have experience with this issue on a 40hp which may still be relevant.

In the late '70's and early 80's I drove a '63 1200 in all sorts of weather in upstate Vermont. I noticed that on cold days, less than 20F, the ring would never open completely. In fact, when it was below 0F it barely moved off the rubber stop at all no matter how long or hard I drove. In the summer, in this same car, the ring would open completely, almost to where the top of the ring would contact the insulation board on the firewall so I beleive it was adjusted correctly.

My current '63 which is also completly stock behaves exactly the same way.

Based on the above, the ring serves more than just for speeding up the warm up time. It seems to me that the ring is critical to keep the engine at something close to normal operating temperature in cold weather

That is true. 24 years ago I ran a '68 Beetle as a daily driver (no flaps or T stat) and I had an oil temp gauge with a peg value of about 120 or 140F I think. I used to drive it to NH or VT to ski when the temp was near zero, and the oil temp never got off the peg! I ran a thinner oil, but still not good. Then I ran installed the flaps (the later equivalent of the cooling ring) and controlled them with a bike cable connected to them so I could control them when I drove the car while watching the oil temp gauge. Even with them closed it was hard to get that engine up to temp when the high for the day was "4". Not sure I ever put the T stat on, I don't remember.

If you drive in cold (sub freezing) temps, you absolutely need the setup...

Mon Mar 15, 2010 4:29 pm

johnshenry wrote: pav266 wrote: I have experience with this issue on a 40hp which may still be relevant.

In the late '70's and early 80's I drove a '63 1200 in all sorts of weather in upstate Vermont. I noticed that on cold days, less than 20F, the ring would never open completely. In fact, when it was below 0F it barely moved off the rubber stop at all no matter how long or hard I drove. In the summer, in this same car, the ring would open completely, almost to where the top of the ring would contact the insulation board on the firewall so I beleive it was adjusted correctly.

My current '63 which is also completly stock behaves exactly the same way.

Based on the above, the ring serves more than just for speeding up the warm up time. It seems to me that the ring is critical to keep the engine at something close to normal operating temperature in cold weather

That is true. 24 years ago I ran a '68 Beetle as a daily driver (no flaps or T stat) and I had an oil temp gauge with a peg value of about 120 or 140F I think. I used to drive it to NH or VT to ski when the temp was near zero, and the oil temp never got off the peg! I ran a thinner oil, but still not good. Then I ran installed the flaps (the later equivalent of the cooling ring) and controlled them with a bike cable connected to them so I could control them when I drove the car while watching the oil temp gauge. Even with them closed it was hard to get that engine up to temp when the high for the day was "4". Not sure I ever put the T stat on, I don't remember.

If you drive in cold (sub freezing) temps, you absolutely need the setup...

Absolutely agree. The last 2110 I built is barely reaching 180 degrees with the full thermostat system in place. This is with the mild GA winters and after an hour long drive at 70-80 mph. I can only imagine how it would in a fare in a truly cold climate.

Mon Mar 15, 2010 4:55 pm

I just took my car out for a spin today, didn't work it very hard and it was about 55 degrees F out. The ring was about 1/4 inch off the rubber bumper when I got home, so about half way open. I forgot to check the temp. range of my thermostat before I put it back together, but I'm pretty sure it's the later style range (65-70C?) that all the newfangled flap style motors use. Mine was adjusted with the heat gun method on the thermostat, 1 inch gap with the thermostat fully extended.

Fri Mar 19, 2010 9:00 am

I know Jake Raby is a VW God, who else could assemble an engine blindfolded at age 11... His claims are outside the realm of mortal man thats for sure.. There was a mere mortal that spent the bucks to investigate this years before Jake got out of diapers... Gene Berg's technical articles details the VW cooling system and brings up salient points not found anywhere else including of St. Raby.... Sometimes things go full circle the latest fuel injected 75-80 German VW engines had returned to a fixed throttle ring behind the shroud... Search this topic to reveal a seperate thread on the advantages of using this later shroud for dual port applications.... Original question ???? yes always install all the cooling pieces regardless of what some backwoods mechanic thinks he knows better... Most of them are too stupid to understand why its there, how to rig it so it becomes easier to make up a bullshit reason to remove the cooling system..... Would you disable or remove the thermostat on your new Ford?????

Jim-

Fri Mar 19, 2010 9:55 am

Zundfolge1432 wrote: yes always install all the cooling pieces regardless of what some backwoods mechanic thinks he knows better... Most of them are too stupid to understand why its there, how to rig it so it becomes easier to make up a bullshit reason to remove the cooling system..... Would you disable or remove the thermostat on your new Ford?????

Jim-

That is probably the best, most accurate statement in this entire thread!

Fri Mar 19, 2010 11:27 am

Quote: There was a mere mortal that spent the bucks to investigate this years before Jake got out of diapers...
How many of them are still developing today? Where will they be in 25 more years?

Fri Mar 19, 2010 11:38 am

Zundfolge1432 wrote: Would you disable or remove the thermostat on your new Ford?
Perfect.

Fri Mar 19, 2010 11:43 am

Who here has ever worked on a Pinzgauer, Haflinger or Porsche 911 engine??

The Pinzgauer and Haflinger are aircooled engines that were designed for the Swiss Army for operation in the Alps, neither of those or the 911 uses any sort of flaps to control engine temperature. Just an oil thermostat. The 911 all the way through the 993 generation never used flaps or a T stat- FYI.

Not to say that is a good thing, but it does make you wonder... These are of course not ACVWs, but they do have aircooled engines of similar composition.

Fri Mar 19, 2010 12:35 pm

A short time ago, I posted a link to an article about Mira Slovak, a pilot who flew his Fournier RF-4D across the Atlantic Ocean in 1968. That airplane was powered by a 36hp VW engine converted for aircraft use. I seriously doubt that it had a thermostat either, as most of those aircraft engines had exposed cylinders and heads cooled by the prop wash.

If you read Mr. Slovak's article, there is a passage where he became worried about a strange drop in oil pressure while cruising at elevation. Eventually he opened the window and stuck his hand out to feel that he had encountered a thermal air inversion (warmer air), which put his mind at ease, knowing he has a wide range of oil pressure safety due to excellent design of the motor.

What I get from all this is that of course, thermostats are not required, and in some cases you might be marginally safer without one as it eliminates one potential source of a system failure. But aircraft engines and military vehicle engines do not necessarily need to perform in the same manner as consumer automobiles. VW did what they could to extend the life of their motors within their design concept, while making it as easily drivable as possible and the thermostat helped them achieve that goal. Aircraft motors (and I expect military vehicle motors) get torn down, inspected and rebuilt on a regular schedule, far before anything wears to the point of failure, unlike many car motors which get driven until something breaks.

Fri Mar 19, 2010 12:53 pm

Quote: unlike many car motors which get driven until something breaks
A general lifespan for a 911 engine is 200,000 miles, except some of the odd years with inherent issues.

FWIW, the 356 engine and 616 engine both used a system very similar to the early type 1 throughout their production years, even after VW had swapped to the integral flaps inside the shroud Porsche retained the ring on their pushrod engines.

But when the 911 was introduced the thermostat was omitted. Odd.