Torquey 283Q I'm building a 283 small-block for my S-10 pickup. It's a basic rebuild with a stock crank, stock rods, and 0.040-inch-over cast pistons. What type of heads do you suggest? I was looking at the World Products S/R Torquer, but I was told that the big 2.02/1.60 valves are not meant for the small bore of the 283. Is this true? They also say that the heads don't come with guide plates and they have to be machined to the thickness of the guide plate to be used. I have a set of Comp Cams 1.6:1 roller rockers I'd like to use, but without machine work, will I have to go with self-aligning rockers? This is just a street engine I would like to run on pump gas. Darren BurtVia e-mail
A With the price of gas comes the fuel-conscience engine buildups: The smaller the engine, the less fuel and air for each stroke.
In short, yes, you would have a problem with standard World Products S/R Torquers. But don't fret; they have something available specifically for your application. World realized the popular S/R Torquers wouldn't work with the small bore of the 305 small-block. The standard bore comes in at 3.740 and World built an S/R Torquer 305 (PN 42650-1), which features 58cc chambers, 171cc inlet ports, and 1.94/1.50-inch valves. If you order the assembled head, it comes with springs for hydraulic flat-tappet camshafts with a max lift range of 0.560 inch. With the smaller combustion chambers and the smaller valve size, they fit nicely in your 0.040-over 283 bore size, which comes in at 3.915 inches. You're right that the heads don't come with guide plates. However, it would be much cheaper to have the rocker-stud pedestals machined down to the thickness of the guide plate than buy new self-aligning roller rockers.
With the redesigned combustion chambers in these heads, World recommends using 350 head gaskets. If you haven't decked the block, which brings the pistons up to zero deck, we would recommend going with GM head gasket PN 10105117. This gasket is 0.026 inch thick and has a bore size of 4.100 inches. Many of the aftermarket gaskets come in at a large 4.166 inches and would be quite oversized for your 283 bore. For more information, contact World Products at 810.939.9628, or online at worldcastings.com
Inches Of What?Q I have a question concerning how carburetor cfm ratings are calculated and whether the ratings advertised are accurate. Are they calculated using the same standards as cylinder head figures, like 28 inches of water at X amount of valve lift? I have always been told that straight-leg booster carbs flow more than the down-leg boosters, which flow more than annular boosters, yet they are all rated with the same cfm. The butterfly diameters and venturi sizes I assume are the same. I have never seen anybody actually put a carb on a flow bench and measure cfm. I bracket race and I think this info would help your readers choose the right carb the first time. This is not a transbrake car. I use a pneumatic cylinder via a delay box to actuate the throttle.Tyler MurdockHenagar, AL
A We've all used different systems when we couldn't afford a transbrake transmission. Back in the late '80s I used a throttle-stop timer with a small taillight bulb strapped to the top of my steering column. When the top bulb on the tree would come on I would release a button that started the timer. When the light on the steering column came on I would stand on the gas! It took me about a year to perfect this combination, but one day at I had three perfect lights, and in 1991 I won the TNN/ Centerline ET finals! Later I used the same setup you're running on my El Camino to race Big Bucks Bracket races when I didn't have a race car running.