Don Terrill’s Speed-Talk

Back-to-back dyno data on an otherwise same engine doesn't really tell the whole story. With/without data on an engine built to run without crankcase vacuum won't show much difference. With/without data on an engine built to take advantage of crankcase vacuum won't show much difference either, other...

It's a well sealed low-compression 355sbc, gapless rings, nitrous friendly cam (251/261 114lca). In the beginning back in 2012 with no pcv valve, the electric pump pulled 4"Hg in the crankcase on 12v. With the ballast resistor dropping voltage to 9.5v, it only pulled 1"Hg. Draw is another ...

OP has an electric pump in hand, not a belt driven unit. My journey started with a street/strip build that used low tension rings and went thru a lot of oil. Added the electric pump in an effort to improve oil consumption. I used off the shelf circle track valve covers that came with fittings welde...

If you look at the shape of the top/base, the tightest point between the two is at about 9" diameter. Let's say worst case the base/lid are only 3/8" apart on a 9" dia. That's about 10.60sqin of area at the tightest point, or about 1sqin more area than the combined total of (4) 1-3/4&...

Not an AVS2, but similar Carter carb. Rolled a hoop and made my own extreme drop base from an off-the-shelf drop base. Had to get creative with a throttle cable bracket which needed to come in at a steeper angle... https://grannys.tripod.com/shopmulecrossbar4.jpg https://grannys.tripod.com/shopmule3...

If you built a system that had two check valves made from a piece of plastic and 1" plastic ball bearing, with breather filters on top, then yes. What pcv valve were you running on that? I'm concerned that a stock one will open immediately at full throttle and I'll lose the vacuum that way Yes...

How long the pcv vacuum lasts when you go wot will depend on many things. Blow-by, how much vacuum was in the crankcase to start with, and how much volume there is inside the crankcase. You could add external volume to make your WOT crankcase vacuum last longer. Maybe plumb the inside of the roll ca...

During my obsession with cheap hyper pistons, I sprayed a street/strip 355sbc to around 700hp on 97oct pump gas. Piston/head with $90/set rebuilder hypers was around .090". Scat cast crank. It used $800/set Total Seal gapless "Advantage" low tension rings with gas ported groove spacer...

Real-world engine accel rates from a sealed crate engine class...
1st gear- 3685 rpm/sec
2nd gear 1674 rpm/sec
3rd gear- 818 rpm/sec
4th gear- 356 rpm/sec
Dyno won't really tell the whole story of a lighter rotating assy at 300/600 rates.

You can make an off the shelf PCV adjustable for idle air flow volume. Common sbc pcv valves come with a plastic 90 degree elbow on top, i threaded the top of that plastic elbow to add a small screw which serves to limit pintle travel in the hi-vacuum position. Here's a pic of that style valve cut o...

In your experience how much does the proper slip have to do with parts breakage? If you are dead hooking and effectively double the slip time, it basically cuts inertia discharge component of torque applied to the input shaft in half. For a drag racing application, proper slip is usually about keep...

The most important tuning aspect with a clutch car is the rate that the clutch pulls the engine down against WOT. If the clutch pulls the engine down too quick, you get an intense inertia release that either causes excessive wheelspin or bogs the engine if it doesn't break parts. That pulldown rate ...

If you have to use your foot to find the balance between too much clutch slip and not enough traction at the dragstrip, you likely still have some tuning to do.

Grant

Only the hit of the clutch is externally managed, the driver still launches the car with his foot. Not much driving skill difference between making clutch adjustments inside the bellhousing vs outside.

Grant

It's not so much about what clutch/converter you have, it's more about what the clutch/converter allows your engine to do. The more energy you can store in the engine's rotating assy before the clocks start, the more energy you will have available to move the car once the clocks start running. Those...