03-12-2007, 05:34 AM
i was perusing around local machine shop's websites to check out prices and hopefully descriptions of some of this stuff, but i haven't heard of half of it. here's one website: ARI Racing Engines (http://www.engine-parts.com/machine.htm) i know what a port and polish is, but the other stuff leaves me scratchin my nuts. any responses will be appreciated, i'd like to know what they are, what they're for, and if they're worth it thanks
03-13-2007, 02:26 AM
Multi-Angle Valve Jobs --valve and seat faces are cut at certain angles. doing just 1 angle can cause bad sealing, valves and seat craking. multi angles are just several angles (usually 3) so the seating area of the 2 is smaller and it aids in flow.
Resurfacing -- nothing but machining the flat part that mates to the block back even
Valve Guide Replacement -- the valve stem rides in a sleeve through the head called a guide. these can become worn. they strip the head and drill these out, or push them out, and replace with new ones, engines that smoke ofter have worn valve guides. the engine smokes due to oil being drawn through the guides.
Port & Chamber Work (Polishing)== we all pretty much know what this is
Intake Manifold Milling --- making the surface that mates to the head flat again so it will seal.
Aluminum Cylinder Head Straightening --no friggin clue. suspect they are talking about milling it flat again
Installing Screw-In Studs -- on small block chevys and others with rocker arms, the factory uses pressed in studs. this removes them, taps the holes, and a screw in stud is placed. these arent apt to pull themselves out in race aplications like the press ins will eventually
Measuring Chamber Volume ---the head is faced up with all valves closed. the chamber is the bowl shape in the head. a plate...usually glass, is sealed with vaseline to the head. there is a hole for each chamber in it. a syringe or small graduated beaker is then used to add a fluid through this hole. its usually measured in cc's. whatever it takes to fill the chamber full is its volume in cc's
Aluminum & Iron Crack Repair ---done using a welding process
03-13-2007, 11:49 PM
lol, i was trying to keep everything fairly simple...think i may have overdonr it a little...
03-14-2007, 02:34 AM
actually, some more detail would be nice.
and also whats honing? i know what boring is, but not honing. and torque plate honing, line honing all that stuff. would any of this besides p&p, boring, and cnc actually do anything?
03-14-2007, 03:40 AM
boring is actually taking a cylinder in the engine block and making it larger, but it is kept slightly less than what is actually needed. its basically a rough cut of the cylinder to reshape it into a circle again and enlarge it slightly. usually done with carbide cutters.
honing is what is done to the cylinder to get it to its final size. uses either stones or a sandpaper like flapper. either one gets the final size and does a cross hatch patern on the cylinder walls from being moved up and down in the cylinder bore. the pattern helps the rings seat and gives oil a place to cling to and lubricate the rings until they seat and wear the walls smooth.
torque plate honing is nothing more than a thick steel plate with holes in it that is bolted to the top of the bloch to similate the head being bolted on. it keeps the block from relaxing while either boring or honing so the cylinders are straight.
line honing is done with a large bar. all the bearing caps for the crankshaft are bolted down and torqued and the line honing starts. it makes where the crank shaft rides straight in line. also used to make sure where camshafts ride is straight.
in short, not on a stock engine.
on a racing engine where alighnments can be very critical, yes if you dont want to break parts and want them to live as long as possible.