Don Terrill’s Speed-Talk

I saw an article about one of Lothar Motzenbacher's (?) cars, that was supposed to have a four-bolt 351 Windsor block. I didn't remember seeing anything about that anywhere else. I wonder if it was one of those... the author of the article wasn't an engine guy.

Older small block Chevys that had the little slot across and around one rod bolt (commonly known as the "spit hole") for oil to pass through. Various service manuals said they were for providing additional oil to the camshaft.

For a production Chevy small block, the only place I've personally seen with an internal water leak was a crack down in the lifter valley, usually in the middle unsupported area of the water jacket. Has the block you're looking at been clearanced for a stroker crank? Some water jackets go lower than...

Older Mopar V8s which might have one or more oversize lifter bores. Neither the dealer nor the local parts stores could get replacements. Probably no big thing after the internet. Oversize valve stems on small block Chevys, usually small-valve truck heads. Easy to get and in stock everywhere, they w...

Historically, one of the earliest popular stroker deals was Drew Backlund's 540, which was made by using the Ford 240-6 cylinder rod and an OEM crank stroked to 4.22". I did some 460 strokers with 240 rods; apparently more than one machine or setup was used for doing the oil holes in the crank...

That's a ground finish. The OEMs like to use something like a 10 grit wheel and feed it hard; that's where the tears come from. Depending on which factory they came from, small block Fords sometimes had broached main caps; the broach is essentially a giant file and leaves a very slight wavy finish t...

That inlet tract shape looks peculiar too.

I don't know if Ford officially changed their spec, but .0025" seemed to be normal for roller 5.0 blocks. Flat tappet blocks all seemed to be .001-.0015".

In my experience, street 289s have performed best with cams in the 108 range for sticks or high stall converters, 110 for stockish converters. Wide lobe centers seem to just flatten the power curve with no advantage anywhere. Even if you don't change the cam, degreeing the one you have would be a go...

Move the pickup opening to wherever it's most likely to stay in oil. For that matter, you can bend or relocate the whole pickup if that's what it takes.

Herb Adams destroked a Pontiac 400 to 303 CID to meet SCCA class limits in the late '60s. It used a 2.84 inch Moldex crank and 7.08 inch Carrillo rods.

I always grind my oil passages over so they line up with the slots in the bearing shells, but it's more a matter of pride in workmanship than knowledge it does anything necessary. I put restrictors to the cam bearings too, usually .062 or .078. You can just drill new, smaller holes in the cam bearin...

I've listened to all the exposition about bearing speed, oil heating, frictional losses, yadda yadda, but I've also taken apart a lot of 400 cores and never noticed any unusual main bearing issues, and I freshened up many 400 and 375 dirt track motors back when useable factory blocks were still a th...

Many of those dimensions were fractions... Lots of engineering and machining in the USA operated in fractional inches until WWI, when several Detroit automakers and other prime contractors petitioned the War Department to standardize on decimal inches to make dealing with subcontractors easier. Mos...

That page in my notebook is dated 1996, which seems like just the other day... for 11/32 stems: .060 Bill Mitchell .080 Sig Erson .050 Chet Herbert .080 Comp Cams .060 Crane .080 Clay Smith .050 Crower .060 Lunati .060 Ultradyne .080 Norris .080 Del West .080 Manley .080 Precision Products .062 Wolv...