Automotive technician since 1991 I show how I do a valve grinding job (Lapping Valves) at home using a vacuum hose, drill & compound, don't over think it an...
ادامه مطلبTo allow more airflow into your engine, a camshaft is designed with a profile (or curve) that provides a specific amount lift to the valve. So in this issue, we're going to do some heavy bench racing and delve into camshaft basics. The better we understand how each of these terms affects an engine, the better armed we are to choose the best ...
ادامه مطلبGrinding valve seats with abrasive stones has been aound about as long as the internal combustion engine. In the early days of grinding seats, there were only two abrasive materials to choose from – General Purpose and Finishing – because seats were mostly made of a single material, cast iron.Click Here to Read MoreAdvertisement Today, […]
ادامه مطلبIn general, for street/strip engines, switching from a 1.5 (stock)-ratio rocker system on the A-engine to a 1.6-ratio rocker arm gains about .030-inch valve lift with the typical hydraulic cams. This change should yield gains similar to installing the next bigger camshaft except that the durations stay about the same, as does the overlap.
ادامه مطلب"The steeper valve angle will wedge the valve a lot harder," explains David Reher of Reher-Morrison Racing Engines. "Depending on the cam, it can beat up valve seats and cause metal transfer. You're not going to run a 60-degree seat on …
ادامه مطلبIn the process of producing engine valves, the valves are subjected to a first grind. Valves whose thicknesses are within the specification are ready for installation. Those valves whose thicknesses are above the specification are reground, while those whose thicknesses are below the specification are scrapped. Assume that after the first grind ...
ادامه مطلبEngine Porting and Polishing Order 24/7 at eastwood or call 800-345-1178 Step 3: Polish the Intake and Exhaust Valve-Guide Area You will fi nd sharp edges on your short-side radius.
ادامه مطلبthat after the first grind, 74% of the valves meet the specification, 15% are reground, and 11% are scrapped. Furthermore, assume that of those valves that are reground, 90% meet the specification, and 10% are scrapped. Find the probability that a valve is ground only once. Round the answer to two decimal places.
ادامه مطلبGrinding And Machining Finished Valve Seat Width. The seat width is important because, about 70% of heat transferred from a valve; goes out the seat contact area. The old rule of thumb used to be, to try to maintain a seat width of about .070″. Today's engines, have valves that are so thin; it is impossible to locate a seat that wide on the ...
ادامه مطلبwe use a "hot plate" arrangement with 2 electric burners on it that are directly side by side. electric coil type burner like on your kitchen stove. heat it till your spit dances arround (water boiling temp),, then knock out and knock in the new ones,, with the proper tools of course,, then let cool, ream to clearance, then valve job.
ادامه مطلبThe shape of the valves affects performance, and by removing material at the top of the valve's cap, you can improve airflow since you are reducing obstruction in the air channel. In addition to the valves, using titanium or high-strength valve springs will allow you to increase the redline on your engine, increasing your power band.
ادامه مطلبWARNING: Always read the engine and equipment manual(s) before starting, operating, or servicing your engine or equipment to avoid personal injury or property damage. See an authorized dealer or contact Briggs & Stratton if you are unsure of any procedure or have additional questions. Find all Engine Safety Warnings.. If you're looking for a specific solution …
ادامه مطلبLapping valves doesn't replace a valve job; however, it shows if the mating surfaces are perfect for each other. Some time ago, this is something we learned in auto shop. Without a doubt, its old school, yet you have to know how to lapping valves in the event that you need your motor to work at the highest level of efficiency. Lapping vs Grinding
ادامه مطلبYour valve springs should always be matched to the camshaft as closely as possible. A spring pressure that is too weak allows the valve to hang open and, worst case scenario, it could hit the piston. If the valves begin to float it will starve the engine of power and lead to excessive wear on the valves.
ادامه مطلبIf you want to grind your own valves, check around for an old Black and Decker, Sioux or Snap-on Valve grinding machine. They are cheap, cheap, cheap anymore since hardly anybody grinds valves on modern engines, they just replace the valve. New 350 Chevy exhaust vales run about five bucks each, you can't pay a machinist to grind them for that.
ادامه مطلبIf you get a much lower reading for one intake valve compared to the other intakes, you've found your bad lobe. The same goes for the exhaust lobes and valves. Remember, only compare intake to intake, and exhaust to exhaust; many engines have "split-pattern" cams with different specs for the intake and exhaust lobes.
ادامه مطلبLapping has been around for as long as engine building has been around. It's a very simple, straightforward procedure. All lapping tools work in the same manner. This means the tool is attached to the valve head, lapping compound is applied to the valve seat or the valve face and the tool is rotated left and right to lap the valve to the seat.
ادامه مطلبSpin the drill slowly to grind the valve in its seat. Work the drill in both directions, both forward and backwards. Slowly slide the valve in and out of its seat to move around the grinding compound. You will notice that after a few minutes, the valve spins with less resistance. The grinding compound will be worn down.
ادامه مطلبThe valve gear fitted to your engine will be either pushrod (OHV) or overhead camshaft (OHC) (See The engine - how the valves open and close). There are two types of OHC valve gear direct acting and indirect acting. The tappets on an OHC engine are usually adjusted by placing shims of a predetermined size under them.
ادامه مطلبTo grind the valves and head we need some grinding paste. The paste is simple enough – powdered carborundum suspended in a grease base. Buy a small tub and it'll last you a lifetime. The carborundum is a powerful …
ادامه مطلبLearn how to properly grind valves. Use the correct techniques for valve lapping by machining them.
ادامه مطلبGrinding the end of the valve stem to provide valve to tappet clearance (for example on the small block Kohlers) can be done at home on a bench grinder. Care must be taken to gind the stem square. I clamp a V block to the rest next to the grinding wheel, and use the side of the wheel.
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