Recent content by krswen

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

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 less than 4.22. Hence the cranking cylinder pressure, measured with a compression gauge will be...

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 the number I was referring to above is the peak cylinder pressure caused not by cranking compression...

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 of the MARC Technically Speaking reprints. I got dyno and flowbench data from the Piranio site...

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 your eyes off the road, I wonder if an experienced A driver who is sensitive to his engine sounds...

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, which if not extinguished, develops into what we call a "flame kernel". This then grows...

Does anyone know the rod length (center-to-center), piston pin offset (if any) and whether the cylinders are offset from the crank? Ken

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 on this site for info like cam lift tables etc. I think we have Fluent, but I've never used it. Ken

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 in the headspace of the upper tank seeking to fill the void created by the water pump impeller...

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 guy needs to get a life, right?) .... in the chapter on propeller theory; a single blade is the most...

somewhere I read recently that the latest WD40 isn't flammable, so won't work for this test ..... Ken

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

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 in the engine. Pumps are much better at pushing than sucking. If the suction gets too deep...

Hi Marc ... Alas, I don't have my A yet. Awaiting retirement (soon I hope). Then I certainly will do some experiments! Ken

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 pump is situated so that it pushes coolant into the engine, usually the block first, then through the...