Don Terrill’s Speed-Talk

A car buddy and I were talking last night about the future of gasoline and that prompted me to visit the American Fuel and Petrochemical Manufacturers website and I saw something I’ve never seen before, a pitch to effectively raise the octane rating on our fuel so vehicles could raise compression a...

Inspect the oil filter, that'll tell you straight away.

We learned today a new ruling has been past that requires all cars from 2022 to have a gps, black box and camera system installed which enforces the speed limits on the driver. You can still go faster if you press hard on the pedal but you'll be confronted with a strong wistle type sound and it get...

Hello I have a Audi V10 engine from a Audi RS6 The engine is a 5.0L version of the engine in the Audi R8. It is turbocharged from the factory and made 570HP at the flywheel at 6500 rpm. I fitted bigger turbochargers and push the power to 803 HP at 7000 rpm at the wheels on my Hub dyno. At a race tr...

The comparison to F1 ports must be examined very carefully, any I've seen are quite smooth so you have to ask why. It could be down to port or engine speed, lack of sharp turn (large SSR). Although who would let a highly developed head, bulging with expensive and hard won secrets into the public dom...

<EDIT: Found it> One of David Vizard's books talks about guide clearance vs. power. I'll have to hunt it down for the actual numbers* but with his Pinto engine, power increased as clearance was reduced down to a small number, but then with some trick setup to permit really close clearances without ...

the right dampener will actually gain you power. i did a bunch of different Damper tests for Troy Coughlin's (Jegs) NHRA ProStocker in 1994 ATI , Rattler, Fluid Damper, etc. and then i personally did a bunch on various engines i had in my Shop -vs- no Damper you will always loose TQ and HP if you r...

It is very temperature dependent. I've run petrol engines on a % of paint thinners before now, whether they started or not from cold depended on the % of thinners to petrol, yet once they were hot they would run fine on a high % of thinners. Getting it running and keeping it running are two totally ...

It's a very old European engine so that is where you find the parts, it's not a problem to find double springs there which retain the OE seats and take 1/2" of lift.

Aluminium blocks have made cold clearances smaller than they once were with cast iron. Improved piston design has enabled the OEMs to tighten clearances there, sadly it's often lost with dumb and lazy after market ones. Go read an internet available workshop manual on an S2000 engine, Honda were run...

Won't the power drawn to turn an electric pump negate any gains from the vac it produces? How would an electric pump do that where a belt driven pump would not? I know several guys who have had good results with the electric pump made for Cadillac, one dyno test showed around a 50 hp increase with ...

Won't the power drawn to turn an electric pump negate any gains from the vac it produces?

Check your seats with some blue to check accuracy.

There are many different sizes of glass bead which all give different finishes, you could try sand too - at least it's cheap for testing purposes.

That's detonation.