turbowrenchhead Posted August 19, 2013 Author Report Posted August 19, 2013 I replaced the paper base gaskets with OEM base gaskets and I get 160 psi now. Only a 10psi drop. It has to be the pistons that are the variable. They are the same brand name but the there were differences in the construction of them. Quote
turbowrenchhead Posted August 19, 2013 Author Report Posted August 19, 2013 How much does 1cc in dome size change cranking compression? Quote
Dixie normus Posted August 19, 2013 Report Posted August 19, 2013 How much does 1cc in dome size change cranking compression? Roughly 10 psi Quote
Zillaguy Posted August 20, 2013 Report Posted August 20, 2013 Check your squish with a piece of solder also... 1 Quote
turbowrenchhead Posted August 20, 2013 Author Report Posted August 20, 2013 I have to get bigger solder. I only have .050 gauge and it doesn't catch. Quote
mike0chek Posted August 20, 2013 Report Posted August 20, 2013 if you want your gauge to read higher, just thread it into the head more. that could be why your snap on is reading higher. you want to thread your gauge as much as a spark plug. the snap on i used actually didnt even thread in as far as my craftsman, the craftsman couldnt even give me the same reading after many tests, the snap on was the same everytime. Quote
lms1977 Posted August 20, 2013 Report Posted August 20, 2013 if you replaced old worn out pistons and rings then there is your 30psi you are in question of possibly Quote
turbowrenchhead Posted August 20, 2013 Author Report Posted August 20, 2013 The old ones were not very old. Maybe 30 hours on them. I had 130psi on them right after the first rebuild. Quote
Coupelx Posted August 20, 2013 Report Posted August 20, 2013 Base gaskets are used to adjust squish and or port hights. rarely are they used to change compression. Quote
turbowrenchhead Posted August 20, 2013 Author Report Posted August 20, 2013 But they can change compression. The paper gaskets were .15 as opposed to .30 on oem's. That made a 10psi change. Quote
Coupelx Posted August 20, 2013 Report Posted August 20, 2013 Never said they didnt. just that it is not usually done that way. Quote
sprinklerman Posted August 20, 2013 Report Posted August 20, 2013 Never said they didnt. just that it is not usually done that way. ^^This. The reason being (besides everything already mentioned) is that it changes the MSV of the domes (which really is what dictates a lot of what fuel you can run, along with compression RATIO),,not JUST the kicking compression. Quote
Nieskes Posted August 20, 2013 Report Posted August 20, 2013 ^^This. The reason being (besides everything already mentioned) is that it changes the MSV of the domes (which really is what dictates a lot of what fuel you can run, along with compression RATIO),,not JUST the kicking compression. You have to remember 95% of people on this fourm dictate what fuel they run by what the kicking compression is, Why? I have no clue. Quote
turbowrenchhead Posted August 20, 2013 Author Report Posted August 20, 2013 I'm don't know how to calculate my real compression ratio. The only thing I have to go off of is my kicking compression. I imagine that is true with the other 95% of the other members. Quote
Coupelx Posted August 21, 2013 Report Posted August 21, 2013 This is why there are people who do this shit for a living. Figure out your squish and call noss machine or whoever gets you hard and discuss it with them. Profit with something not half assed. Quote
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