Don Terrill’s Speed-Talk

That’s a way bigger hole than what’s in a QJ needle and seat assy.

My understanding is that cams with “tight” LSA’s(more overlap) can create tuning challenges with EFI.

Just something to consider.

Apparently………cost does not seem to be a reliable indicator of quality

The way I read it is not the valve seat angle +- 1 degree but the valve angle in relation to the deck. That’s my interpretation as well. The valve seating angles can now be anything you want. I would also consider something like a “bowl cut” done in a seat and guide machine as legal now. It’s just ...

The Ferrea RA IV valves are not tuliped.
They have a 12* back angle.

Perhaps some other supplier of Poncho RA IV valves are actually tulip shaped.
Or even a couple of used OE pieces.

I woulda had that epoxy all cured and shaped by now if I were looking to do that test.

The clay would be fine for a quick test, but if you wanted something sturdier, you could use epoxy or body filler.

Could be shaped in a lathe, or even a drill press.

The wear limit is .80mm , which seams insane. If that number (.80mm, which is .031”) represents the actual valve stem to bore diameter, then I agree that’s crazy. I just replaced some guides that had close to .020” clearance with .341” diameter stem valves, and they were severely worn. The new guid...

I think you’ll be hard pressed to find any flow tests on a factory SBC double bump head from the last 20 years, done on modern equipment, where the improvement from the rework @.200 lift is 82%. (Not to mention the 100%+ gain @.100) Taken at face value, his numbers can be compared to his numbers. Tr...

It’s like a dyno, and honestly you should only be comparing against your own. I agree. Here are numbers from a head tested on two different benches. It’s the same head, same port, same valve, tested on two of the same make & model bench(Saenz S-600). Intake flow(same port, same head): Lift———A—...

Steve, what you’re looking at(in my pics), thinking it’s a QFT-750……..is actually a bunch of QFT parts attached to a Holley retrofit main body…… https://www.holley.com/products/fuel_systems/carburetor_components/main_body_replacements_and_upgrade/main_body_upgrade/parts/134-300S I originally bought ...

They appear to be .615”

I put the carb tests here:

viewtopic.php?t=67952

When I was doing more carb testing years ago, it was when I had a SF-110 bench, so the actual test pressure was 10”, and was converted to 20.4”. I did a couple of tests at different pressures on the CFS carb today. Tested at 20.4”, then 28”, then 10”. The converted numbers are pretty close to the ac...

The SF carb testing adapter comes with a 4 hole spacer that has 1.687” bores. I found one that has 1.750” bores that I use for the carbs that use the 1.750” baseplates. I hadn’t done that test in many years, so I did it again today. On the HP950, using the adapter with the 1.687” bores dropped the d...