Recent content by panic

The SAE (Society of Automotive Engineers) viscosity (grade, not weight) is, by definition, thickness (resistance to flow). It’s the time in seconds for a given volume of oil to pass through a sized opening, not the oil’s lubrication properties. A single SAE number (without the “W”), or...

The Holey 390 CFM is the smallest 4160 type (throttle discs are 1-7/16”, venturis are 1-1/16”) is a popular, practical square-bore single 4 bbl. choice. However, there are (at least) four variants of the 390. The preferred one (List 8007) is for small V8 & six-cylinder, a different one is for...

On strokers in the Harley-Davidson flathead engines: I have some comments in Word .doc form, email me for copy.

"I use the 1.72 Chevy builds in the street engines instead of a cam.... adds a little more air, but doesn't kill low end torque"" I agree

Is the spark @ full retard? Try advancing it a bit.

It appears that some performance cams for the Ford have fairly late intake valve closure ABDC. IMHO this is done for a good compromise between torque and peak power. Engines with relatively low static CR may gain some torque by advancing the cam 4°.

The KR comparison is a bit misleading. The engine has a low bore to stroke ratio, which gives good compression (compared to the reverse): 2.745" bore by 3.8125" stroke. However, the valve seats (which in the Ford are angled toward the bore) are angled away and flow badly due to the cam...

Mistake in the video: the intake valve closes AFTER the piston reaches the bottom of the stroke (ABDC). IMHO minimum safe piston to head clearance is .035".

I prefer 3/8" minimum screen to floor

Running with the choke on too long or rich cruising (high vacuum, low throttle) mixture puts carbon in the oil

THOSE REQUESTING A COPY OF MY POTVIN CAM SPREAD SHEET: i NEED YOUIR EMAIL ADDRESS. THANKS.

Some interesting mods have been made to the Kohler 16hp flathead engine

I've written an Excel spreadsheet containing the data for the Potvin 3/8 and another for the Potvin Eliminator. This includes how the events are calculated and some comments bout each. PM me for a free copy.

I have found that the low CR of the KR race engines required very strange cam events. A sample: Intake duration 310° Opens 65° BTDC Closes 65° ABDC Intake CL 90° ATDC The exhausts are all 30° smaller The early closing point keeps the CCP and low speed torque up When do hot Ford cams close...

The 1929-73 Harley-Davidson 4-cam flathead engines: small engine VINs are D, R, W, G, K & X, big engines are V & U (750, 900, 1200 & 1300cc) The 1936-2000 single-cam pushrod OHV engines: a.k.a. knucklehead, pan head, shovelhead E & F (1000, 1200, 1340cc)