Modifying the Holley Teapot four barrel carb for late model distributors

The Holley model 4000 four barrel carburetor that came as original equipment on single four barrel equipped 1956 and earlier Fords, Mercurys, and Lincolns is not up to its full potential when used with the ’57 and up Y-Block distributors. Continue reading “Modifying the Holley Teapot four barrel carb for late model distributors”

Y-Block, 585HP without a supercharger or other form of power adder

While a dynamometer is a great tool for sorting out engine combinations, there are those instances where some of the data provided conflicts with other data also being recorded.  A case in point here is where the EGT’s (exhaust gas temperature) do not match up with the results of the oxygen sensors. Continue reading “Y-Block, 585HP without a supercharger or other form of power adder”

Cylinder Head Milling for a 1cc Reduction

In the course of milling cylinder heads for a specific decrease in combustion chamber volume, it becomes necessary to know exactly how much a cylinder head must be milled for a 1cc (cubic centimeter) reduction.  Continue reading “Cylinder Head Milling for a 1cc Reduction”

Milling Heads for a Horsepower Gain

Over the years I have heard a variety of numbers from 2% to 10% for what a point in compression ratio is worth in regards to horsepower output.  The ten percent value obviously sounded a bit exaggerated while the two percent value sounded a bit on the small side. Continue reading “Milling Heads for a Horsepower Gain”

A Tale Of Two 330 Inch Y-Blocks

I recently had the opportunity to assemble a pair of Ford Y-Block engines that were very similar to each other and then dyno test each.  Both engines had the same bore and stroke, the same camshaft grind, and the final static compression ratio (SCR) on each was very similar. Continue reading “A Tale Of Two 330 Inch Y-Blocks”

Carburetor Spacer Testing

While Glen Henderson’s 337” Y was on the dyno, a variety of two inch tall carburetor spacers were tested.  The results were more than interesting and re-enforces why different combinations of parts are tested.  The baseline test for this was no spacer and then there were three different styles of 2” tall spacers put into place and evaluated. Continue reading “Carburetor Spacer Testing”

Four Barrel Carburetor Testing on The Y

I recently had the opportunity to dyno test a variety of carbs on a stock ECZ-B intake.  The engine itself is a sixty over 9.2:1 cr 312 that has stock (unported) G heads.  The camshaft being used is a Crower Monarch grind with 238° duration at 0.050” and 0.400” lift at the valve.  Advertised duration is 280°.  While the camshaft is ground on 110° lobe centers, it’s installed in the engine at 2° advance or at 108° intake lobe centerline.  Aftermarket 1.4:1 rockers are being used.  The exhaust used for this particular test is a set of Reds (might be old Hedmans) headers running into 2” lead pipes ~4 foot long with no mufflers.  The test range was 2500-5500 rpms.

The original ½” four hole spacer was used under the carbs in those instances where the carb bores were not too large for the spacer.  Where the carburetor bores were too large, the spacer was changed out to either a 1” Moroso or Wilson four hole spacer with matching larger bores.  The Moroso spacer had slightly larger bores than the Wilson spacer but both created a lip or shoulder within the bore where the spacer met the intake.  Just another variable that must be considered.

The performance of the carbs were looked at from several different perspectives which included peak HP and torque, average HP and torque, and a calculated score.  The score is derived by adding the mean (average) HP and torque together, dividing by the cubic inch of the engine, and multiplying by 1000.  A score gives a better indication of the overall performance of the carb versus just looking at the individual peak values or averages.

The carburetors tested are listed in descending order from best to worst as based on their dyno test scores. Continue reading “Four Barrel Carburetor Testing on The Y”