Don Terrill’s Speed-Talk

400 MPG? :lol: A 1959 Opel Olympia Rekord, (3 door station wagon), modified by Shell engineers, set a fuel economy record of 367 MPG at a test track at Wood River, IL in 1973. That same car is now for sale for $425,000. It might take a while to break even with fuel cost savings. And, yes it had a s...

Over 30 years ago, I was asked by a NASCAR team to blend a "qualifying" engine oil for them. The engine only had to last for 3min, 40 sec; it would be replaced by the race motor. I blended the lightest viscosity oil from stocks that I could find. They tested it and said it was too viscous....

I don't have a dog in this hunt...but those who do, might benefit from a quick read of:

NASA Reference Publication 128
Fastener Design Manual

It's only 100 pages long.

A carburator has actually an advantage over fuel injection, ... A carb has two advantages over fuel injection: it is simple, and it is cheap. They can run well in lawn mowers at a single speed. They do not run well across a wide rpm band. Every serious engine designer has incorporated fuel injectio...

Unfortunetly a real engine doesnt go by simple maths. To the surprise of many, all engines obey the laws of physics. Where do you think my data is wrong? A carburator has actually an advantage over fuel injection, ... A carb has two advantages over fuel injection: it is simple, and it is cheap. The...

Fuel economy mind game; anyone can play. Object is to build a vehicle that will obtain 400 mi/gal of gasoline. Frontal area = 8 ft^2 Cd = 0.23 Vel = 60mph Power needed = 2.5 hp @ 1500 rpm Bore = 46mm Stroke = 37.5mm Twin cylinder = 124.6 cc Baro =31.0 inHg Temp = 40F RH = 30 DCR = 16:1 BMEP = 13.02...

Fuel economy mind game; anyone can play. Object is to build a vehicle that will obtain 400 mi/gal of gasoline. Frontal area = 8 ft^2 Cd = 0.23 Vel = 60mph Power needed = 2.5 hp @ 1500 rpm Bore = 46mm Stroke = 37.5mm Twin cylinder = 124.6 cc Baro =31.0 inHg Temp = 40F RH = 30 DCR = 16:1 BMEP = 13.02 ...

I didnt understand freezing at school until in practice.. In general freezing occurs when the air is moist and the temperature is close to 0C. Think about what the sensors tell us and what happen when we adjust, or compensate fuel or ignition with things like MAF or MAP. Humidity increases the pres...

Engine Masters on MotorTrend did a test of engine oil viscosity using Driven GP-1 in 5W-20 and 20W-50. The test engine was a marine 454 BBC with a stock bottom end and quite a bit of age on it. They were mostly looking at the differences in viscosity and pressure at different temperatures, mainly 4...

The confusion here is sad to see. SorryTuner, that may have been my fault. I was not as clear as should be. An increase in water vapor does reduce air density. The reduced density affects all air components, i.e. nitrogen, oxygen. That would require a change in fuel mixture since less air mass is i...

Humidity has significant effect on O2 per unit mass of air. Increased humidity causes a reduction in overall air density; not the concentration of O2. Higher humidity = less O2 per gm mass. Not quite. Higher humidity = less mass of air; both nitrogen and oxygen are displaced by increased water vapo...

Tuner wrote: ↑Sun Jun 11, 2023 10:33 pm Does a MAF sensor compensate for humidity?

Yes. A change in humidity will produce a change in air density, which is read by the sensor as a change in mass flow.

A change in relative humidity from 0 to 50 will cause a reduction in air density from 1.20442 kg/m^3 to 1.18352 kg/m^3.

EGR is an inert gas which, when injected into the combustion chamber, will reduce chamber temperature. The reduction of temperature serves to reduce the formation of NOx. EGR has no effect on O2 readings. The primary source of ECR is from the exhaust port during the overlap period. A late closing e...

I've read/herd wider is better but couldn't say the exact width or if it's always better. Yesterday I ran a series of computations for flow areas for various valve seat widths and seat angles. I compared the aggregate flow areas over the lift ranges. The highlights: seat widths 45 deg 0.5 -> 0.75 =...

First of all I’m trying to promote Newen. The post was about how valve seat machining has changed. I could care less if anyone here on this forum buys a machine. It’s interesting the posts. One guy say use a machine center to do this job. Enjoy how you guys do your valve jobs. Like I said I could c...