Cummins Marine Diesel Repower Specialists › Forums › Cummins Marine Engines › Blow by test QSB 5.9 305 values
Matthew.
Hello guys.
I am searching for exact values for blow by test for engine mentioned above,would really appreciated.
Thank you!
Hello Tony.
I was thinking for spray pattern like usual testing on older type of injectors,but if you are saying that not necessary,then better to leave it be.
Its just precaution to say so,to check some engine parts. Today i receive oil sample analysis,and oil is good for further use,and nothing seriuos found in oil,thats good.
Thank you.
QSB / common rail Injectors–They either work or they don’t–Testing will accomplish nothing unless you have a on-going symptom that points to an injector..
About 9 months ago I pulled a pair of QSB 5.9’s with well over 30,000 hours– All original except for some hang-on’s.. They were running daily in a sub-chapter T boat–He got a EPA grant to put in 6.7’s, otherwise they’d still in in the boat.
Tony
Hello Tony.
Engine starts great from cold,no problems at all. We have worries that engine has too much of a blow by,because of running hours.
I will do seatrial anyway,and measure at full load readings,just that i have some values written down.
Boat is now on dry,doing winter works,and skipper with owner wants to know condition of the engine itself.
One more thing,injectors,is it worth it to take them out,and be checked in diesel shop? Can they be rebuild or just new original ones?
This is what matters:
1) Engine starting when stone cold
–It things start easy in this condition, IMO, I would not even bother with the test.. Just sort out the CCV thing..
2) If you measure blow per the book, then engine hot and at WOT in gear / at full load….. No other loads/RPM matters..
3) Now ask yourself– Accurately measured blow-by numbers are on the “edge” or a tad above…-What’s your plan, or the owner plan? Remember question #1……………
Tony
Hello Tony.
Client wants that i do blow by test,its an sailboat,engine has over 10 000 hours on it,and it is saturating CCV filter quite a lot(Airsep one). That’s why i will remove that filter and put Enviroment o it,its simpler and cheaper.
I was thinking to write down values like engine cold,on idle,then on higer revs,engine warm etc..And to see how much inches i have depending on engine rpm’s.
NO.
2″ is a new engines.. 9″ is when you start to troubleshoot and decide if you want to look farther.. A good CCV system with easily mitigate 12-15″..Remember, these measurements are at WOT making full power…..How much time to you spend doing that?
If your engine starts easy when cold, consumes a quote oil oil or less per 100 gallons of fuel burned, I personally do not think any blow-by number is of much consequence as long as you can mitigate it with CCV.
Tony
Thank you Tony.
According to that table,if i have blow by greater then 2 inch of water,or up to 9,i should consider to do rebuild,if excessive blow by is noticed?
I have discarded Airsep from engine,and will install your Enviroment kit which i have already in workshop,and hoping that this will improve engine breathing.
Yes– I use them for various things.. The “MINI-HELIC” is better for the field as they are easier to deal with and 1/3 the $$..Accurate enough..
Tony
Hello Tony,and thanks for your help.
I have gauges from Magnehelic that measures in inches of water up to 40,please see photo attached.
Can i use it as well for testing?
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