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”
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”
I’ve always said, “If it spins, then it likely needs balancing”. When going for that last bit of detail in blueprinting an engine, then camshaft balancing comes into play. How much is it worth you ask? Continue reading “Camshaft Balancing”
Here is a list of items that are contributing factors for a flat tappet camshaft (new or otherwise) and/or lifters to experience a premature failure. Continue reading “Camshaft and Lifter Failure Causes”
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”
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”
The aluminum heads continue to impress and even more so on the engines built to be daily drivers. A case in point here is an alumi Continue reading “Not A Race Engine But Maybe It Should Be – 318″ Ford Y-Block”
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”
Because an engine may be borderline in regards to the compression ratio when it comes to ignition timing or fuel octane requirements, it’s important that all values used in the compression ratio calculation be as accurate as possible. This includes the head gasket volume which many times isn’t stated on the package or in any reference material. For a conventional or mainstream engine where the fire ring in the head gasket is perfectly round, the hole size in the gasket can be measured and the volume calculated appropriately. But the Ford Y-Block has an irregular shape to the fire ring seal which throws special nuances into the measuring of this volume. But there’s no need for guess work when it comes to obtaining this volume value as it can be derived by doing some simple measurements on an existing head gasket and then performing a little bit of math. Continue reading “Head Gasket Volume Calculation”
Rear cam plug installation on the Ford Y-Block engines dictates that it not be installed so deeply that it actually interferes or contacts the rear of the camshaft. Besides the obvious wear issue that can occur at the face of the cam plug, detrimental wear at the rear side of the cam thrust plate can become evident or in a worst case situation, the thrust plate itself can break. Continue reading “Rear Camshaft Plug Installation”