Forum: Model A (1928-31)
06-25-2012, 11:55 AM
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Replies: 38
Views: 19,756
Re: Why the insert fabric roof and not steel
I read somewhere that until the mid-thirties U.S. steel rolling mills could not roll sheet wide enough to span the top. Can't lay my hands on the source now though ....
krswen
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Forum: Model A (1928-31)
08-22-2010, 08:47 AM
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Replies: 40
Views: 14,343
Re: High Compression Head
Also, don't forget that compression doesn't start until the intake valve is closed, which is around 50 ABDC for the stock A. So the true compression ratio, as opposed to the "geometric" CR, is even...
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Forum: Model A (1928-31)
08-22-2010, 08:29 AM
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Replies: 40
Views: 14,343
Re: High Compression Head
Hi Terry .....
It turns out that when you compress a gas "adiabatically" (no heat loss), which is close to what happens during cranking, the pressure ratio is greater than the volume ratio. But...
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Forum: Model A (1928-31)
08-21-2010, 02:28 PM
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Replies: 40
Views: 14,343
Re: High Compression Head
OK .... some quantitative answers to your question about increasing compression ratio. I just finished tuning my Model A engine computer model. I was able to find valve lift tables in a back issue...
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Forum: Model A (1928-31)
08-08-2010, 05:59 PM
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Replies: 15
Views: 12,349
Re: Need For Manual Spark Advance ?
Hi Marc ....
This may sound strange coming from an engineer, but as slowly as things happen with a Model A (most of the time), and given the fact that you can adjust the spark lever without taking...
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Forum: Model A (1928-31)
08-08-2010, 11:56 AM
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Replies: 15
Views: 12,349
Re: Need For Manual Spark Advance ?
The use of automatic spark advance was a step forward, but still did not meet all the requirements for optimum combustion. A short review:
Combustion starts with a spark at the plug electrodes,...
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Forum: Model A (1928-31)
08-07-2010, 06:49 PM
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Replies: 3
Views: 1,426
some engine questions ...
Does anyone know the rod length (center-to-center), piston pin offset (if any) and whether the cylinders are offset from the crank?
Ken
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Forum: Model A (1928-31)
08-06-2010, 05:21 PM
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Replies: 35
Views: 6,447
Re: Thermostat data, not opinions
Hi PDXCougfan ...
I'm thinking of modeling it with GT Cool (part of GT ISE suite of programs), but first I want to get my GT Power engine model up & running. I'm sure I'll be pestering the folks...
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Forum: Model A (1928-31)
08-05-2010, 09:19 AM
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Replies: 35
Views: 6,447
Re: Thermostat data, not opinions
you're absolutley right ..... I fell into the same trap of loose technical language that I criticize my students for! There is no such force as suction. The flow is driven by atmospheric pressure...
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Forum: Model A (1928-31)
08-04-2010, 12:07 PM
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Replies: 10
Views: 2,314
This will be anathema to the purists ....
but has anyone ever made a fan shroud? Done right they can improve fan performance significantly.
Another interesting fact I ran across the other day in one of my aerodynamics textbooks (this...
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Forum: Model A (1928-31)
08-04-2010, 11:25 AM
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Replies: 5
Views: 1,945
Re: Carb Cough and fart
somewhere I read recently that the latest WD40 isn't flammable, so won't work for this test .....
Ken
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Forum: Model A (1928-31)
08-04-2010, 07:38 AM
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Replies: 35
Views: 6,447
Re: Thermostat data, not opinions
here's a link with a good description of how cooling systems work:http://www.arrowheadradiator.com/14_rules_for_improving_engine_cooling_system_capability_in_high-performance_automobiles.htm
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Forum: Model A (1928-31)
08-03-2010, 06:02 PM
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Replies: 35
Views: 6,447
Re: Thermostat data, not opinions
Hi Frank ....
Yes, the pump does suck somewhat on the circuit, but the radiator is on the far side of the engine. The pump has to suck water from the lower radiator tank through the restrictions...
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Forum: Model A (1928-31)
08-03-2010, 03:29 PM
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Replies: 35
Views: 6,447
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Forum: Model A (1928-31)
08-03-2010, 03:15 PM
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Replies: 35
Views: 6,447
Thermostat data, not opinions
I’ve been pondering the advisability of using a thermostat. Here’s why.
The Model A cooling system is very primitive compared to more modern cars. Today, when we design an engine, the water...
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Forum: Model A (1928-31)
08-01-2010, 03:23 PM
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Replies: 8
Views: 2,207
Question about parts books
In the early 60's I had a summer job as a partsman at the local Ford dealership. I learned a lot about how engines and cars are design by studying the exploded views in the parts books, which came...
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Forum: Model A (1928-31)
07-30-2010, 11:27 AM
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Replies: 7
Views: 2,369
Re: Any A Model kits made?
type "model a ford kit" into search window at ebay. Looks like ERTL, Lindberg, Revell and others have made kits over the years.
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Forum: Model A (1928-31)
07-26-2010, 06:28 AM
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Replies: 17
Views: 3,050
Re: Brumfield Swirl
You want the microturbulence in the mixture in the cylinder, not the port, although it is largely achieved through port geometry. The intake valve has already closed. The reason is as follows: once...
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Forum: Model A (1928-31)
07-25-2010, 06:32 PM
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Replies: 3
Views: 1,474
Re: Relative Humidity and Mixture Control.
At sea level and 15 degrees C (60 degrees F) fully saturated air only contains about 1.3% water vapor. At 85% humidity it would be 1.1%. The average Model A carb probably doesn't have the jets that...
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Forum: Model A (1928-31)
07-25-2010, 05:45 PM
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Replies: 17
Views: 3,050
Re: Brumfield Swirl
We started developing large-scale air motion in the cylinder called swirl and tumble in the late 80's. The way it works is that you shape the inlet port so that the incoming charge during intake...
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Forum: Model A (1928-31)
07-25-2010, 07:22 AM
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Replies: 3
Views: 1,474
Re: Relative Humidity and Mixture Control.
Actually, 85% relative humidity doesn't mean that the incoming air to the engine is 85% water vapor. It means that the air is holding 85% of what it is capable of holding at that temperature and...
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Forum: Model A (1928-31)
07-24-2010, 10:23 AM
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Replies: 5
Views: 1,871
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Forum: Model A (1928-31)
07-09-2010, 05:53 PM
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Replies: 18
Views: 4,095
Re: Introducing myself
Thanks for the quick response and kind words! What books would you recommend to increase my knowledge (the more technical the better)?
Ken
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Forum: Model A (1928-31)
07-09-2010, 05:26 PM
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Replies: 18
Views: 4,095
Introducing myself
Hi .. my name is Ken and I'm about to retire up in northern California. I'd like to get a Model A to piddle with. I'm a mechanical engineer with decades of experience restoring cars and...
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