Thermostat

Ron · Post by **Ron** » Tue Apr 10, 2001 2:28 pm

So guys, who runs a thermostat and flaps in their upright conversions? Jake, if not why? My theory is not in a high perf motor as they were designed for a very low compression with all exhisting tin work in a very enclosed area. A higher CR motor is going to heat up faster anyway, correct? Thoughts?

Aircooledbreeze · Post by **Aircooledbreeze** » Tue Apr 10, 2001 7:01 pm

No provisions on the Sharpbuilt Upright

Joseph · Post by **Joseph** » Wed Apr 11, 2001 1:15 am

Ron,
Mark Falls here in Portland has thermostatic
flaps on his DTM. He also has CIS FI. Check
it out by going to Gary Miller's site and
scrolling down past "prices". There a good pic showing how Mark did it. The thermostatic
flaps are controlled by the stock thermostat.
In Marks case, its turned backward but in the
same "blow" for the same response. Mark
could have made the set of flaps smaller and
kept the oil cooler air housing in its normal
location. Flaps only control the lowest op
temperature. A simple fan change can raise
the op temperature in cold weather (using a
pre '71 or 40HP fan). A CHT also monitors
the engine to determine if its too cold.
Check out Marks Falls work.
See http://www.millerfi.com
Joe
Oregon Performance Products http://www.spiretech.com/~opshroud

Tarnx · Post by **Tarnx** » Wed Apr 11, 2001 11:33 pm

As I was poking around the Porche pages I discovered that Porches don't run thermostatic flaps. Or so the page stated. Apparently the engines that use the big round fan, what we call the porche fan use only an oil thermostat. The stock bug engine needed all the help it could get. A powerful porche engine may not have needed the benefit of warming up as much. If the engine is cooled 70%(I think)by the oil it probably doesn't need or use the thermo flaps once it warmed up.

Joseph · Post by **Joseph** » Thu Apr 12, 2001 8:00 am

Tarnx,
You read right, the 911 does'nt have an air
warm up. The 911 does'nt use oil to cool off
70% of the engine's heat- Thats what the fan is for. Most of the heat generated by the
engine travels to the surfaces of the heads
and cylinders not to the oil. The cooling
medium is air (directly cooling the exterior
of the engine) and oil is a carrier of heat
that indirectly carries some heat from part
of the head surface (the cool side), some of heat on the walls of the cylinders, and
all the heat from the bottom of the pistons.
Not a great deal of heat is generated by the
surfaces of the bearings as long as an oil film is maintained.
So in terms of where all the heat goes, little is carried off by the oil. You could
check this out. Take an engine with a head
temperature of 350F and run the oil line into a 55 gal drum so that the oil would remain at
ambient temperature (and absorb all the heat
transfered to it). If what you stated is true and 70% of the engine's heat were absorbed by the oil, the head temp would drop to 105F or about the temp of a good hot tub.
All water cooled engines would HAVE to have
an oil cooler (and they don't) since the
water coolant would only absorb 30% of the
engine's heat.
I think that oil helps in the heat removal
job, but more like 10-20%. And I think we have had this discussion before.
Joe
Oregon Performance Products http://www.spiretech.com/~opshroud

Aircooledbreeze · Post by **Aircooledbreeze** » Thu Apr 12, 2001 3:42 pm

OOPS! My Type 4 consultant (Chris) has just informed me that I am a complete dolt and have no business advising anyone on anything!LOL! You CAN adapt a thermostat to the Sharpbuilt upright kit. He says it ain't easy, but it can be done. I stand humble and corrected!

Tarnx · Post by **Tarnx** » Fri Apr 13, 2001 12:29 am

No Joe we did not have a discussion you slammed me with your opinions with out asking how or why I came up with the information I did. The major point of these forums is to investigate possibilities and alternatives. The mere suggestion of a possible solution may lead an individual to formulate a solution based on their needs. No one can anticipate all the possible permations.

Joseph · Post by **Joseph** » Fri Apr 13, 2001 1:30 am

Tarnx,
Stating that you "think" that an engine gets
70% of its cooling by oil is not a mere
suggestion of a possible solution. Or a
possible permutation. Its an unfounded
statement made by you. If you would like to
support the statement you made (not with just "I think"), I would like to hear all about it.
Joe
Oregon Performance Products http://www.spiretech.com/~opshroud

Paul Illick · Post by **Paul Illick** » Fri Apr 13, 2001 6:37 am

I read and re-read Joe's post, Tarnx, and don't see where you got slammed. I've heard that "air-cooled motors are 60-70 percent oil cooled" too, but think where VW put cooling fins, and why there? And how much of the engine oil actually goes through those areas? Joe's in the air-cooled business, so think about how many times HE'S heard that statement. If it was me I believe I'd be wishing that misinformation would go away, too. No harm.

Ron · Post by **Ron** » Sat Apr 14, 2001 12:17 am

Wowser. Once, again, I post something that starts a "heated"(yes, that is a pun) discussion. I'm just thinking and listening. I, too, and been working on aircooled VWs since I was 9 yo. But still don't have all the answers that I want. Thats why I look to others. Thanks, everyone.