South Texas Speedway Posted May 13, 2015 Report Share Posted May 13, 2015 It has come to my attention the way Compression was checked at the last race was not normally the way STS has done it in the past. I am reviewing the procedure for checking compression. As soon as I have time to review all the facts and procedures I will place the procedure on this site. I should have it up by Saturday at the latest. Ken Hobbs Link to comment Share on other sites More sharing options...
ks2290 Posted May 13, 2015 Report Share Posted May 13, 2015 I believe it should be done the way IMCA says to do it. Link to comment Share on other sites More sharing options...
Bigdogracing777 Posted May 13, 2015 Report Share Posted May 13, 2015 Stick the gauge in the rear. Duct tape nose and mouth and blow really hard!!! Do it three times and get a round about reading no more complaints!!!! Link to comment Share on other sites More sharing options...
BobbyJack Posted May 13, 2015 Report Share Posted May 13, 2015 imca does not say to remove all spark plugs and hold throttle wide open, neither do sts rules? thanks for checking into it. Link to comment Share on other sites More sharing options...
dirtracer99 Posted May 13, 2015 Report Share Posted May 13, 2015 By removing plugs and opening the butterflies you will come up with increased compression throttle should be at idle location and only one plug pulled which is replaced with a compression tester. Link to comment Share on other sites More sharing options...
ks2290 Posted May 13, 2015 Report Share Posted May 13, 2015 Agreed we would still have money and trophy if it was checked the correct way. Link to comment Share on other sites More sharing options...
BobbyJack Posted May 13, 2015 Report Share Posted May 13, 2015 10-4 WHAT HE SAID Link to comment Share on other sites More sharing options...
postell4270 Posted May 13, 2015 Report Share Posted May 13, 2015 We at sos just pull one plug and crank over 5 full rotations Link to comment Share on other sites More sharing options...
Bluebayouracing21 Posted May 13, 2015 Report Share Posted May 13, 2015 It bottles my mind everybody wants to go by IMCA but when you say to sanction the track everyone says no that's funny right there Link to comment Share on other sites More sharing options...
top_shelf_12 Posted May 13, 2015 Report Share Posted May 13, 2015 Not sure about the IMCA but that's the way I've heard of compression checking for as long as I remember. (One plug and the bumps) but we'll see what the track officials come up with. Sorry to hear about the dq, it was a hell of a race and clean. Link to comment Share on other sites More sharing options...
Josh38racer Posted May 13, 2015 Report Share Posted May 13, 2015 I'm wondering why sts use different procedure than 99% of other tracks.. Opening throttle squirts gas causing a wet test plus it will still make 10 to 15 more pounds with throttle wide open.. Link to comment Share on other sites More sharing options...
Josh38racer Posted May 13, 2015 Report Share Posted May 13, 2015 I just hope common sense will prevail... To me its a no brainier.. But I'm little biased. .. Lol thank you Ken for looking into this. Link to comment Share on other sites More sharing options...
poorboy Posted May 14, 2015 Report Share Posted May 14, 2015 Neither way is wrong or right but needs to be done the way every track does it. Ken will figure it out. Link to comment Share on other sites More sharing options...
WaerRacing00 Posted May 14, 2015 Report Share Posted May 14, 2015 What is the maximum? Link to comment Share on other sites More sharing options...
Josh38racer Posted May 14, 2015 Report Share Posted May 14, 2015 170 Link to comment Share on other sites More sharing options...
Josh38racer Posted May 14, 2015 Report Share Posted May 14, 2015 My car is legal for sos but 5 over by sts procedure.. Something is wrong here.. 5th place may not be big deal but it is to me. Link to comment Share on other sites More sharing options...
ks2290 Posted May 14, 2015 Report Share Posted May 14, 2015 Blue I said IMCA cause thats the way most every track checks it plus with u theres not much mind to bottle or boggle if thats what u meant. If it was checked the way others tracks check it we would have been legal. Link to comment Share on other sites More sharing options...
Josh38racer Posted May 14, 2015 Report Share Posted May 14, 2015 I agree 100% Link to comment Share on other sites More sharing options...
South Texas Speedway Posted May 14, 2015 Author Report Share Posted May 14, 2015 Update: I am finding this to be much more interesting then I previously thought. A few items I have found are below. These will be apart of my final findings but may or may not be the final decision. The reason you check compression has a lot to do with the way you check compression. If you are looking to see if you might have a bad motor or cylinder then it does not matter if the engine is warm or cold, air filter is on or off, if all or just one spark plug is removed or if you open or close the throttle. The only thing you look for is drop and or a change in compression from one cylinder to the next. However, if you are testing the motor to get a true compression ratio all engine builders and true technicians I believe agree you must follow different steps. The compression rate is determined by how many molecules are in cylinder compared to the pressure generated by the piston moving up and down. Any physical or environmental element that affect how many molecules or movement of the molecules will affect the compression. So if you were to test a motor with the throttle closed then the size of the carb will play a role in the compression rating. All carb's stay open to some degree even when closed so there will be a variance in the reading. This means that also how much fuel is applied during testing or right before will also play a role in the compression test. (Flooding the engine before testing). Other items that can affect the reading are humidity and temperature. I am unsure if removing one versus all of the spark plugs play a role in the rating. I am also unsure if the speed at which the cylinder moves plays a role. More testing is needed. I am still reviewing data and will make a decision this weekend. Thank you all for the patience. Ken Hobbs Link to comment Share on other sites More sharing options...
ks2290 Posted May 14, 2015 Report Share Posted May 14, 2015 It is believed that the speed of the rotation also increases the compression. Therefore removing all 8 spark plugs allows the engine to rotate faster. But that is just what i have found Link to comment Share on other sites More sharing options...
cperry115 Posted May 14, 2015 Report Share Posted May 14, 2015 Link to comment Share on other sites More sharing options...
cblgdc Posted May 14, 2015 Report Share Posted May 14, 2015 Track or tech guy post his procedure of testing, and then there is no discrepancy . Link to comment Share on other sites More sharing options...
ks2290 Posted May 14, 2015 Report Share Posted May 14, 2015 Kevin thats what we are all waiting for. Link to comment Share on other sites More sharing options...
cctxracer Posted May 14, 2015 Report Share Posted May 14, 2015 Ford Motor Company procedure copied out of service manual. Compression Test — Compression Gauge Check Make sure the oil in the crankcase is of the correct viscosity and at the correct level and that the battery is correctly charged. Operate the vehicle until the engine is at normal operating temperature. Turn the ignition switch to the OFF position, then remove all the spark plugs.Set the throttle plates in the wide-open position.Install a compression gauge in the No. 1 cylinder.Install an auxiliary starter switch in the starting circuit. With the ignition switch in the OFF position, and using the auxiliary starter switch, crank the engine a minimum of 5 compression strokes and record the highest reading. Note the approximate number of compression strokes required to obtain the highest reading.Repeat the test on each cylinder, cranking the engine approximately the same number of compression strokes. Link to comment Share on other sites More sharing options...
Josh38racer Posted May 14, 2015 Report Share Posted May 14, 2015 This may be true for Ford.. It still isn't the way the majority of the mechanics, engine builders, and all tracks that I've spoken to do it.. That what is the whole point here.. The common standard seems to be 1 plug, 5 hits, no throttle..hello why should sts do it different.. Jmo Link to comment Share on other sites More sharing options...
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