To disable cooling flaps or not, The endless debate Options

[Jack Standz]

That is unusual and am pretty sure never heard of a Tetra before (IMG:style_emoticons/default/biggrin.gif) .

So, the plural is Tetras? (that I've heard of before)

[JamesM]

@jamesm
Would you share your microsquirt tables?. I’d like to try your lean burn on my 2056. I’m curious what they look like.

Using my VE tables will do absolutely no good as you have a different engine and injection parts....

But here is the wizardry as far as igniting and AFR targets go.... copywrite me (IMG:style_emoticons/default/biggrin.gif) and im not responsible if you blow up your motor (IMG:style_emoticons/default/beerchug.gif)

Not fully refined to my liking but nothing ever is. This is the same setup I used on the test drive from Utah to California were I managed 37mpg and never saw over 350 head temps, most of the time they were below 300, on a bone stock 2.0 motor.


A couple things to note about tuning to these targets: First is that it is a bit more difficult to dial in your VE table vs a smoothly blended target map. You will notice the abrupt transition and uneven progression of load bins at 74, 75kpa. This is intentional and part of the magic to keeping the engine in areas running the coolest. The non linear nature means the engine ever sees the AFRs that cause the highest temps

You will need to have all your engine states/vacuum thresholds/switch points defined properly for the vacuum signature of your specific engine as well or you may wind up with drive ability issues, and depending on how different the vacuum profile is of your motor you my even need to change the load and or RPM at which the transition from cruise to load occurs.

[JamesM]

@jamesm
Would you share your microsquirt tables?. I’d like to try your lean burn on my 2056. I’m curious what they look like.

When dialed into the targets the VE Map winds up looking something like this.

And if you have ever looked at what the fueling curve (keyword curve) for d-jet looks like it becomes very obvious why you can only run like this with a fully mappable system.

The parts of the curve that we are abruptly transitioning over though, those are the areas that generate the most heat.






Ignition table to match.
Where the fuel map instantly transitions the lean burn, the advance immediately increases in step

[930cabman]

That is unusual and am pretty sure never heard of a Tetra before (IMG:style_emoticons/default/biggrin.gif) .

So, the plural is Tetras? (that I've heard of before)

German air cooled (rear engine) beast from the 1930's or so

plural would be (IMG:style_emoticons/default/screwy.gif)

[Krieger]

Do folks have any insight as to why the air-cooled sixes don't have a similar mechanism to the T4 for thermostatically controlled cooling airflow?

I remember seeing this question asked in some other thread or forum, but don't recall if it was ever answered (or I just forgot (IMG:style_emoticons/default/sad.gif) ).

The 911 has all aluminum case, cylinder and heads. Type 4 has cast iron cylinders. Expansion rates are different. This is a factor.

[73-914]

That is unusual and am pretty sure never heard of a Tetra before (IMG:style_emoticons/default/biggrin.gif) .

So, the plural is Tetras? (that I've heard of before)

German air cooled (rear engine) beast from the 1930's or so

plural would be (IMG:style_emoticons/default/screwy.gif)

Tatras were Czech (IMG:style_emoticons/default/stirthepot.gif)

[Superhawk996]

Do folks have any insight as to why the air-cooled sixes don't have a similar mechanism to the T4 for thermostatically controlled cooling airflow?

I remember seeing this question asked in some other thread or forum, but don't recall if it was ever answered (or I just forgot (IMG:style_emoticons/default/sad.gif) ).

The 911 has all aluminum case, cylinder and heads. Type 4 has cast iron cylinders. Expansion rates are different. This is a factor.

Well except for 2.0’s-2.4L’s . Magnesium case. Cast iron cylinders, just like T1 and T4. Biral cylinders mixed in there on 911 E and S variants.

2.7L still had Mag case.

3.0L was introduction of aluminum case to the 911 engine.

But you are correct, the more dissimilar materials you have the bigger your thermal expansion problems are that lead to broken head studs, pulled case threads, leaking heads, etc.

We are fortunate the T4 had an aluminum case from the start.

[Jack Standz]

Yes, was thinking about the old cast iron and biral 911 cylinders as well as magnesium versus aluminum cases.

Also, some Type IV motors are now being build with aluminum cylinders ("nickies"). In fact, aren't all RAT motors using nickies now?

BTW I appreciate the info on the Tatras. And, no I had not heard about them before. A 2.5 liter 90 degree aircooled V8 making 240-250 HP. That's amazing, especially for it's time frame.

[Superhawk996]

Julius Mackerle designed that v8 engine and later in the 60’s wrote the definitive engineering text on air cooled engines. 2nd edition became available in an English in 72’.



Want to know how much force a bellow type thermostat can exert on cooling flaps? It’s in there.

[930cabman]

Julius Mackerle designed that v8 engine and later in the 60’s wrote the definitive engineering text on air cooled engines. 2nd edition became available in an English in 72’.



Want to know how much force a bellow type thermostat can exert on cooling flaps? It’s in there.

Great discussion, I have that Mackerle book somewhere, great information

Is anybody making an air cooled vehicle these days?

[Superhawk996]

Is anybody making an air cooled vehicle these days?

No unless you count something like Morgan or Singer.

Air cooled engines died in the 90s for US, Europe and Brazil when they could no longer meet increasingly stringent emissions imposed on the OEMs. The last air cooled Beetle was 2003 in Mexico.

[wonkipop]

Do folks have any insight as to why the air-cooled sixes don't have a similar mechanism to the T4 for thermostatically controlled cooling airflow?

I remember seeing this question asked in some other thread or forum, but don't recall if it was ever answered (or I just forgot (IMG:style_emoticons/default/sad.gif) ).

The 911 has all aluminum case, cylinder and heads. Type 4 has cast iron cylinders. Expansion rates are different. This is a factor.

Well except for 2.0’s-2.4L’s . Magnesium case. Cast iron cylinders, just like T1 and T4. Biral cylinders mixed in there on 911 E and S variants.

2.7L still had Mag case.

3.0L was introduction of aluminum case to the 911 engine.

But you are correct, the more dissimilar materials you have the bigger your thermal expansion problems are that lead to broken head studs, pulled case threads, leaking heads, etc.

We are fortunate the T4 had an aluminum case from the start.

at least in the 914 and the USA.

first year of T4 engines in 68 were mag alloy cases - used in 411.
not exported to the USA.

not sure why they changed but just as well they did - as you say superhawk.
presumably durability issues?
but i guess at first they were trying to keep engine weight down?

[Jack Standz]

Is anybody making an air cooled vehicle these days?

No unless you count something like Morgan or Singer.

Air cooled engines died in the 90s for US, Europe and Brazil when they could no longer meet increasingly stringent emissions imposed on the OEMs. The last air cooled Beetle was 2003 in Mexico.

One example of an air-cooled vehicle still be produced and available in the USA. Also, L-Twin, Desmodromic distribution, with 2 valves per cylinder.

https://www.scramblerducati.com/en-us/bikes/icon-dark/

[Dave_Darling]

Deleting the T-stat and flaps [emphasis added] ...

Deleting the flaps has very well known effects. High oil temps, because you allow the cooling air to bypass the stock oil cooler. We've seen it dozens of times.

--DD

[wonkipop]

just getting back to tatras for a moment.
and to amuse @Superhawk996 because he is a man of taste as well as tech savvy.


where tatra was going but the old iron curtain economic model wasn't panning out.
the final fling of the 603. 603X. they got a running prototype up.


your regular four door!!!!! and this was in the 60s. in a communist economy for farks sake.


the power plant package. yeah.


check out the bottom drawing!!!

----------

recently the bottom drawing was turned into a cad model in virtual reality.



remind any of you of anything?
a corvair meets a 911.
or is a corvair a part tatra and so is a 911.
who cares. because all three of them were good.
esp the second generation corvair. what a car.
those checks were trying to go somewhere.
in the same general direction as the air cooled kooks from stuttgart.
and the fan fans in GM out there in michigan. (IMG:style_emoticons/default/beerchug.gif)

its what i love about the germans.
sitting on the edge between the east and the west.
the old berlin wall.

[Dave_Darling]

*Czechs. Tatra is and was a Czech company.

I'd sell organs to get a Tatra....

--DD

[wonkipop]

*Czechs. Tatra is and was a Czech company.

I'd sell organs to get a Tatra....

--DD

checks ---- as in check mate. (cold war lingo).
bit like rustkis. as in corrosion.

we speak rhyming slang down here in north antarctica. (IMG:style_emoticons/default/beer.gif)
you guys are septics. as in septic tanks. as in yanks. WW2 lingo.
its affectionate of course. (IMG:style_emoticons/default/smile.gif) (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beerchug.gif)

but yeah. i'd probably consider cutting a leg off rather than losing an organ for a tatra.
it would be good. never actually seen one in the metal.
don't think there are any down here.
there might be but never ever seen one.
and if there was one i would love drive it. (IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beerchug.gif)