killshee Posted March 18, 2009 Report Posted March 18, 2009 how do u measure squish and how do u fix it. i keep going thru head gaskets. but i dont thing its my head bc i had a stock head then went to a coolhead and still happining??? i dont even know were to start. Quote
bonbon Posted March 18, 2009 Report Posted March 18, 2009 To measure take a piece of solder, bend it so it can go through your spark plug hole and put it against the side of the cylinder (parallel right on top of the wristpin so you don't get any rocking in the piston) and turn the motor over slowly once. You should have a squished piece of solder that you can measure the thickness with a micrometer. Quote
killshee Posted March 18, 2009 Author Report Posted March 18, 2009 i dont understand? i know im retarded Quote
killshee Posted March 18, 2009 Author Report Posted March 18, 2009 so what is it exactly that im measuring? i posted about the head gasket problem and someone told me to check my squish Quote
LS1Inferno Posted March 18, 2009 Report Posted March 18, 2009 take a piece of solder ( like for plumbing) and bend it into the cylinder through the spark plug hole, and make sure you put it up against the cylinder wall above the wrist pin. and turn the motor until its SQUISHes the solder. pull it back out and measure ho thick the squished solder is. Quote
bonbon Posted March 18, 2009 Report Posted March 18, 2009 Your measuring the distance between the top of the piston and the outside edge of the dome. The part that has a slight angle around the edge then comes up to a larger chamber where the spark plug is at. Quote
bonbon Posted March 18, 2009 Report Posted March 18, 2009 The squish band is the outer edge on this dome. It's that part with the pitting on it in this picture. Quote
killshee Posted March 18, 2009 Author Report Posted March 18, 2009 so it gets squished between the piston and the head? is the a correct measure ment for this? or should they just be even on both sides? like how do i know if my squish is bad and how do i fix it? Quote
bonbon Posted March 18, 2009 Report Posted March 18, 2009 so it gets squished between the piston and the head? is the a correct measure ment for this? or should they just be even on both sides? like how do i know if my squish is bad and how do i fix it? Yeah the solder gets squished between the piston and the head. I can't remember the number off of the top of my head but I think it is something like .035" or .040". Hopefully dajogejr chimes in I know he knows quite a bit about it. Quote
killshee Posted March 18, 2009 Author Report Posted March 18, 2009 ok im gunna go see if i can try this out and see what i get! bbiab give me like 15 min Quote
killshee Posted March 18, 2009 Author Report Posted March 18, 2009 ok i did it and the have to b like .40 - .45 the tool i have only goes to .35 but its just a lil bigger than that. they do look the same tho like ones not any bigger than the other. does it matter if u measure on the outside edges or inside edges? bc i did them on the outsides. it it posible to just put copper wire in the groves for the o-rings or no? Quote
bonbon Posted March 18, 2009 Report Posted March 18, 2009 Outside or inside doesn't matter, as long as you do it parallel to the wristpin so if there is any rocking in the piston you still get an accurate measurement. Like I said I don't know too much more about it, at least not enough to recommend things to people. Quote
dajogejr Posted March 18, 2009 Report Posted March 18, 2009 You want around .045 or so. Close enough works for 2X4's framing in a door or a window. A digital Mic is cheap, you can get one at Harbor Freight for around 20 bucks. You're not a machinist...so you don't need one accurate to .0000001 inches. I use .065 solder with a resin core (smashes easier than a solid piece) Pull both spark plugs, push down on the kick starter one time nice and easy, that'll turn the motor over at least once or twice. As said, it is critical you place the solder left to right instead of front to back, because the piston rocks front to back a hair due to the pivot point on the wrist pin bearing. There are two ways to fix it. And each is dependant on your motor. You can either run a thicker (more squish from raising the cylinder and head) or thinner (less) base gasket, or you can have different domes cut based on your deck height. Deck height is the amount a piston sticks out of the bore when it's at top dead center. Playing with different base gasket thickness can be a good or bad thing. It alters your port timing, in other words...how soon your piston pulls an intake charge of fuel/air into the cylinder and how fast the exhaust charge gets spent out the exhaust port(s). If you keep spitting head gaskets or Orings, and your squish is within reason (Say .042 to .050 on average) I'd say you either have an uneven/warped cylinder and/or cylinder head. Wait... You have a cool head and are using a head gasket? Or are you talking about the Orings. If you're using a flat head gasket with an aftermarket head, there's your problem. Quote
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