Don Terrill’s Speed-Talk

mag2555 wrote: ↑Mon Feb 05, 2024 4:24 pm but in a running engine that does not have a highly drafted intake port they produce less power since they clog off the bowl as rpms go up.

Would you please define "highly drafted intake port"?

One way to size the primary might be the following. Take the boost pressure that you intend to run at peak power and compute the pressure ratio to atmospheric pressure. For example, if you're running 0.5bar boost, this ratio would be 1.5. Next, take your target power in hp and divide it by this num...

For me, the piston temperature is about piston strength. Aluminum loses strength rapidly above 200 degrees C . . . and according to the previously referenced paper from Mahle, page 19, figure 1.4, a typical temperature for the lower surface of the top ring groove is 227 degrees. ASM lists the yield ...

For a particular fuel, auto ignition is caused by a combination of three variables ... time, temperature and pressure. Increasing throttle position increases cylinder pressure, low engine speed increases the time available for auto ignition, and charge temperature will be higher at low engine speed ...

Thanks

Krooser wrote: ↑Mon Mar 29, 2021 10:50 pm

4sfed wrote: ↑Mon Mar 29, 2021 10:23 pm What kind of cleaning power do your units have?

I cleaned the valves out of my race motor in 30 minutes without touching them with any abrasives...looked new. Used Simple Green and water

Thanks, what really I'm looking for is the power in watts.

What kind of cleaning power do your units have?

Unless you plan to make them yourself, you can buy a set from Mini Mania.

The difference in expansion coefficient is not a problem. I have used steel main caps on aluminum blocks with good success. The combination can also be found on some Cosworth race engines.

From this paper ...
http://www.f1-forecast.com/pdf/F1-Files ... P2_08e.pdf

"the flow rate oil injected was slightly higher than 10 l/mim"

That's a lot of oil.

In general, the purpose of an oil squirter is to cool the piston. They are designed to direct a stream, not a spray, at the bottom of the piston crown, not the cylinder walls.

I have no idea if NASCAR teams use them.

The carbs have a rubber bushed support rod, but the typical soft mounts between carbs and manifold aren't needed.

BTW, I printed a couple ring squaring tools today. Thanks to whoever suggested that ... great idea.

here's a view of the model of the ring squaring tool I had came up with, for a reference I tried to attach the .STL but says that filetype is not allowed here this puts the ring about 3/4" down the bore. You're going to have a difficult time printing that design in one piece with FDM because o...

The problem with epoxy is its coefficient of expansion. If that's your choice of repair method, I'd recommend looking for for one that is aluminum filled to match expansion rates as closely as possible.

This is an excellent candidate for a weld repair. Clean the surface all the way to the bottom of the flaw with a cabide burr, weld (100% penetration), finish the weld within 0.010 then peen the weld with a round nose punch. Unless it's peened, a weld will have a residual tensile stess ... which coul...