Shroud flaps

Last week, when I took my IM for a drive (outside temperature was a couple of degrees below freezing), I noticed the oil temperature never reached 180 degrees F., and the cylinder head temperature stayed at 200 degrees F. Note that my shroud doesn't have the stock thermostat regulated air flaps that sit between the shroud and the cylinder heads.
I'm wondering how harmful this is for the engine. Also, is anyone else on this forum driving their air cooled speedsters, without shroud flaps, in this cold weather?

Ron,

Take a look at my Eberspacher BN2 thread. I am wondering the same thing. When i built my baja bug in '91 most people would tell you to remove the flaps and t-stat. Now everything you read is saying go back to the original set up. Im planning on installing the flaps and a t-stat in lieu of the gas heater (for sale if anyone wants it). The hope is the motor will get warm enough to produce heat, and warm enough as not to produce excessive wear.

im going to piggy back on your thread and ask what temp thermostat people are running on a larger engine pushing these very light cars?

Ricardo Baerga had the same problem (although how "cold" can it get in Puerto Rico?) and ended up installing the t'stat and flaps and had instant better heat control. In fact, it runs colder in summer with the flaps installed, as well as warming up faster in the winter and holding temp better around 180-200F.

I think Ricardo's article is on here somewhere.

.
Berg and Muir have both said keep your flaps and thermostats working.
Cold will kill an engine slowly

I discovered my stat had gone US recently but they do fail in the open mode so all is safe. Original types can be hard to find but the BUS DEPOT in Penn. State sold me a nice one for about $60. Being new to this gig, I'm looking just about everywhere for tips and tricks and everything I've read says keep the cooling system intact.

Awesome Powdercoating sells them
http://www.awesomepowdercoat.com/thermostat_flaps.html
If my tranny gets worse and I have to pull the engine I'm going to install a set of shroud flaps from A.P.
This is something I should have done with the original build.

There is a thread over on the samba about someone found a company to build new thermostat bellows with old parts grafted on.

Some people convert to the Mexican new design. Those fail closed instead of the preferable open.

Awesome Powdercoat is that company that can get them rebuilt and the cost quoted was $100.

Paul,
Give me a call sometime - I am sure my local engine guy may have a couple around his shop.
Dale

Will do Dale, thank you! Was thinking about heading over to the junkyard, then was thinking about it being in the thirties outside. I also need to take a crayon rubbing from the back of a stock fanshroud so that i can drill out my SCAT shroud.

If you do get a salvage yard thermostat, make SURE you get the mounting bracket with it. The actuator rod is a bonus, too, as they're both unique and scarce as hen's teeth.

"Cold will kill an engine slowly"

Dave--what would you say are unacceptably cold CHT and Oil temp numbers? I see all the time that heat is an air cooled engine's enemy
but would like to know more about cold.

Regardless of the temperatures outside, I make sure the engine oil temperature is at least 160 degrees before I rev it or drive anywhere. Sometimes, especially these days when its colder out, it drops below that while I'm driving.
I've got one of the RAT shrouds on a Type IV, but I would think the principle is the same for a Type I. You have to let your oil heat up before it can do its job effectively.
Someone here had a problem with a non-Wix oil filter grenading on cold starts -- unknown if it was from revving a cold engine or not, but these engines absolutely seem to need at least a three-minute warmup.

Almost forgot ; Hoover too !!
http://www.vw-resource.com/vanes_thermostat.html

Geez! That Hoover's a righteous dude!

I'm with Cory. 140-160F before you smoke it out of the garage. In fact, for you Jack, treat it like a Continental air-cooled aircraft engine and a 3-5 minute, feathered-prop, idle warm-up before you taxi will get you to around 150F+ oil temp and you'll be fine. CHT is nowhere near as important in the winter as oil temp because you have to get the oil warm to flow well before it can lubricate well.

If the engine is really cold and you're running relatively thick oil (anything over 30 wt in the Winter), the oil will be like molasses when cold and won't do a very good job of being slippery, so the bearings and rings and such will wear a lot (relatively speaking) until it warms up and the oil flows better - especially the splash up into the barrels to lube the rings. Also, most "full flow" cooling systems take the oil directly off the top of the oil pump, then through the filter and cooler and THEN into the gallery where the oil pressure-limiting valve is. That means that you get full oil pressure from the pump to the filter and cooler and THAT might rise to 300 psi on cold days with 50 wt oil and THAT can cause your oil filter to explode from the pressure.

It ain't pretty...

YOU, Jack, have a Type IV, however, which has the filter and such properly installed after the pressure-limiting valve so filter detonation is not an issue, but cold, thick oil is still a problem until it gets warm so the info above still applies (get warm, then taxi). Jake knows about both road-bound and airborne engines so he may shed some more insight here. We'll see!

Hope this helps.....

gn

Dont go off the deep end with warmups either .
Aircooleds also warmup MUCH faster than aquabuddas ! So immediate LIGHT UNLOADED driving warms the engine faster.
http://www.vw-resource.com/warmup.html

Those of you with both OT and CHT gauges got the knowin ; Heads heat up waaay faster than the oil , wintertimes

I'm with Rob and Dave.

Hop in, start it up, let it smooth out for a minute or so (remember....most of us don't have the benefit of chokes so the intake manifolds have to get sort-of warm before it'll move without puking) and then tentatively drive it off. This will be a bit better if you tend to run "normally rich" but it should be OK once you get under way no matter what.

Remember, too, that the VW service manual recommends SAE 10W-30 below 50 degrees F (10C) and 10W-20 below 20F (13C)

gn

Does that suggest that if I use 20W-50 in the winter, my engine will finally stop leaking oil???

No, that's a designed-in feature.

Hi Gord; I'm here....thanks for keeping my name alive in these pages; I just lurk occassionally. Yes; the car runs cooler with the system. Last month my girlfriend and I drove to stay at the old Ramey Air Force Base on the Northwest side of the island (as a side note; Kirk Duncan was stationed there for a while in the mid '60's when he was in the service). It's mostly highway driving and we were doing between 60 and 70 miles sustained in 80 degree plus weather and it worked wonderfully. If there's something that I'm glad I did to that car is install OEM fan housing and cylinder/cooling tin with the full factory thermostat system. Gene Berg has said in his technical papers that the system accounts for 12% less engine wear as compared to without the system. In a place like Canada I would definitely install the OEM system; after all engineers, especially German, wouldn't design and put something into a car that wasn't needed...that's the way I look at things.