WPS500 in cylinder pressure testing just getting started
it was mentioned in another post about snap on pressure testing equipment. I too have had issues with the snap on pressure testing transducer both with my pico scope and their vantage ultra. two things i noted that the actual pressures and anything below zero just didn't show accurately or in the case of anything below zero it didn't show at all.. I have since just got the WPS500 kit from Autonerdz and now everything is working much better. I also sat in on John Thorton's 4 hour class on in cylinder Pressure transducer testing so i now have a good foundation to start this journey. Below are 3 captures of a known good Ford fusion i had in my bay this morning. Gotta know what good looks like so i plan on starting a known good data base. I am still learning some mechanical terms and movement of the valves themselves so this will be a good tool for that as well. So going forward i will likely have lots of questions and also some wave forms on good vehicle to share. in one of the cranking compression waves i have measured the zero line to the bottom of the expansion line shows about 4 psi difference. So multiply that by two and 8" hg ? would the be considered cranking vacuum? any tips or advise for those who have been doing this testing for years would be appreciated for us oldtimers who once thought this would be a waste of time. Last for any one who still thinks that way i encourage you to watch John Thorton's or Brandon Stecklar's video training on this subject . " It just blew me away !!
brandon has a live webinar tomorrow through TST training
I was at his class for TST on Monday in MA. He did an awesome job. Great class. Well worth the time and cost.
Tonight Brandon is doing a live webinar. tstseminars.org
automotiveseminars.com/online-events…; you cant go wrong with training from John Thornton
I will let the guys with daily experience doing in cylinder testing give you advice on your captures. But I will add a shameless plug for Brandon! If you want some more training on this, Brandon Steckler will be doing his pressure waveform analysis class on November 9th at Daytona Speedway. Floridafoundations.com
unfortunately for this Alaskan that I wont be able to attend. But I am looking to try and get into one of his classes next year.
Richard, You beat me to it, Robert Chabot as Richard mentioned Brandon Streckler will be doing his all day full version of using the Pressure transducer next month down in your state of Florida. Click on the link in Richard's reply for more information. Hope to see you there.
Until I got comfortable with what I was seeing I would also hook up a vacuum gauge as well. Then I was able to interpret more what I was seeing. The vacuum gauge has been around for ever and if you know how to read one it will confirm what you are seeing in the WPS waveform.
I’m a vacuum gauge guy myself also found that if you use a vacuum transducer like “First Look” you can add that to another channel and see the vacuum pulls in the intake and see the pull when the intake valve opens as well missing pull in that area could indicate an intake valve not opening. I will post one with that as well tomorrow
It made it much easier for me to see How the scope pattern looked with the vacuum gauge.
Robert; Good evening Sir, I hope this email finds you doing well. I'm attaching a Technical Training Article I wrote on Chrysler's 4.7 Liter V8 Engine. The testing procedures might be helpful when it comes to understanding In Cylinder Pressure Waveforms. If you find this helpful I also have these written for GM's 3.6 Liter Engine and Ford's 5.4 Liter 3 Valve Engines. Good Luck and happy testing
The 4psi difference is expansion pocket void, as some call it, not cranking vacuum. The point where the intake closes is at “0” line. The bottom of the expansion stroke is -4psi(I’m going on your measurement here). Then the pressure rises up to 0 before the intake closes again. It is a more common feature on VVT engines because the intake valve closure is less degrees BTDC that the exhaust valve…
You just keep capturing known goods, so you can be the guy we go to when we need a known good reference. LOL. You might want to start capturing known good Euro models, I might need them.
automotiveseminars.com/online-events…; here is the Link for John Thornton's Pressure transducer class for anyone interested tstseminars.org/training-video… And Brandon Stekler's class as well Both top Notch and compliment each other with information !