MrGray

iTrader: (1)

Hey, I'm not sure if this in the right place.If it isn't my apologies.
Can anyone recommend a Machine shop in Toledo Ohio?

I am replacing the head gaskets on my LG4 and figured while they are off, that I might as well get a pocket port done.

Thanks in advance.

MrGray

iTrader: (1)

bump

sofakingdom

iTrader: (1)

Pocket porting?

I'd suggest MrGray's Head Service. Just make sure when you drop your heads off, that they have this equipment right here, or an equivalent; and a hand-held die grinder such as can be bought for $20 from Advance or the like, and an air compressor such as one can rent from any rental place, including home centers and rental yards. A "shop" will charge you $200-300 to do that, while MrGray's can do it for a total of maybe $75.

MrGray

iTrader: (1)

Thanks for the reply.

2-300 you say?Man prices went up in the last 10 years or so...
Whats the difficulty, as far as doing it myself, ie how likely is it for a novice to screw it up?

Reason I ask, I have zero experience in any type of machining/modification.

I'm mostly a motor monkey and really don't want to cost myself money in the end for just a light refresher.

sofakingdom

iTrader: (1)

Instructions

The main object should be smoothing the flow path and contouring it to work WITH the overall shape and design of the parts, as opposed to "hogging out". The places where you get the biggest "bang", so to speak, are all of the rough and sharp steps and whatnot left behind when the factory just sort of ran their cutting tool down into the throat to make the valve seats; and in contouring the guide, NOT eliminating it, but rather blending it into the shape of the roof of the port, and making the part of the roof on the side of the guide toward the head bolt (the high-flow side) smooth and uniform; and in unshrouding the intake valve so that air can flow around the edge of it.

Try to leave the area right behind the valve roughly circular (it will have various funky lumps and other shapes back there from the casting process); you want the cross-section of the port to be NO MORE THAN 85% of the valve diameter. In other words, DO NOT try to make that "throat" as large as possible; that kills low-lift flow, because you want the incoming air to come down the port on the "common" side of the port, along the roof right there, be directed at the center of the valve, and flow along the surface of the back of the valve and outward into the chamber. Imagine taking a garden hose and shooting it into the intake port, and follow the flow of th ewater; you want the path that the water will follow to be as smooth and uniformly contoured as possible.

Some other little tricks include rounding off the "margin" of the valve (where the "vertical" surface around the edge, meets the "face" of it); rounding the back side of the valve where the edge of the seat meets the curved "mushroom" part of the valve; and removing ALL sharp or irreular edges from the combustion chambers.

Go slow. Attention to detail is more important than removing lots of metal. Approach it with the idea that you're working on FLOW, not CROSS-SECTIONAL AREA; keep the shape of airplane wings in your mind, NOT "hogging it out" as far as you dare before you hit water or head bolts or push rods or whatever.

On the exhaust side especially, it's worthwihile to smooth out the "short side" of the port, where the floor has to make a sharp curve. DO NOT lower the floor of the port however, on either side; just get that curve to be smooth and step-free, while removing AS LITTLE MATERIAL AS POSSIBLE. Remember, you can always remove a little more, if you need to; but it's REAL HARD to put it back.

The intake should be left rough, like how the sanding drum things in that kit will leave it. The exhaust side and the combustion chamber can be polished.

"Gasket matching" is by far the least productive part of the process, but amateur porters often think it's a big deal, because they can SEE it. I'd suggest leaving that part of the head alone in fact, if you get tired of doing it; there's little benefit to be had there, until EVERY OTHER DETAIL is optimized. Kind of like the people who take some low-compression, low-flow smogger turd, and "think" they're going to make it fast by unbolting stuff off the top and replacing it with new shiny stuff.... the parts you can "see" aren't where the benefits come from.

Perform the same operation to all 8 ports, and make them all the same; then perform the next operation to all 8, until they're all the same again; and so on. DO NOT try to complete one port, then start all over on the next one and finish it, and so forth.

Use a CD and a medicine dropper and one of those Nyquil cups or something, and anti-freeze solution so you can see it, to cc the chambers and ports; put a smear of grease or Vaseline on the valve seat to seal it. Cc all the chambers with the same pair of valves, as opposed to making all the chambers different to match different valves.

MrGray

iTrader: (1)

That has got to be one of, if not the most informative and straight to the point post I have ever seen on a forum.

Thanks a lot man, looks like I'm ordering a porting kit.