Thank you for doing this test and for doing it methodically. I look forward to the tests where you hold the intake constant while changing the exhaust (or vice versa). A request - any chance you have multiple runs with the same engine settings? I'd like to know what is the run to run variability so that when there are results for different conditions, we can have an idea of how much of the change is run to run variability vs the change in the condition. Thanks again!
Hey there good videos I have a old dynamite kart engine dyno the software is super old the company has gone out of business do you know of a company I can get newer software from to get mine going again
I have a question. I used to ride karts growing up, everything from trikes, yard karts. My pride was my dart kart. Anyway, I'm 53ish now and finally got a used PRC kart. The motor is a beast. Fastest engine in a kart I've ever driven. My question is, how do i tell what kind of motor. The guy said it's a cyclone but I'm unsure as he sounded. He said it is a stage 3. How does one tell about that without opening it up? So now I scour through the videos.
Hey Kirk, without seeing it it would be hard to tell. I would take a picture and post it on Bobs 4cycle karting forum. The best guys in the business are in there! 4cycle.com/karting/
This is great stuff. I've been really looking into optimizing my engines beyond the usual (float, clip, etc) and lash was one of the things I've been experimenting with. Thank you for sharing this. I've been doing some research (some of it from your posts on 4cycle and here) and it seems that there are two benefits to lash: increasing lash increases rate of opening of the valve, which can increase power; and changing valve overlap can move the powerband around. I tested this awhile back with my local tuner and we noticed that increasing intake lash noticeably increased torque but shifted the powerband to the left and we lost some horsepower. If I understand correctly, increased intake lash can *reduce* overlap because the intake valve doesn't open as soon as it normally would when the exhaust valve is closing, effectively reducing overlap. Out of curiosity, when you ran the tests for 0.06 and up, your AFRs shot up to near stoich. Would this be because the exhaust valve is opening later and i.e. allowing for more complete combustion?
YO thanks for the comment!! I also noticed the AFR change. I think it would be what you stated, maybe a fraction more amount air getting into the camber due to it opening later?? I think we'll learn a bit more once I get the lash testing done when I move just one at a time.
I will definitely attest that this engine is not down on power! Love racing with you guys!
Thank you for doing this test and for doing it methodically.
I look forward to the tests where you hold the intake constant while changing the exhaust (or vice versa).
A request - any chance you have multiple runs with the same engine settings? I'd like to know what is the run to run variability so that when there are results for different conditions, we can have an idea of how much of the change is run to run variability vs the change in the condition. Thanks again!
Black slide?
Hey there good videos I have a old dynamite kart engine dyno the software is super old the company has gone out of business do you know of a company I can get newer software from to get mine going again
I hear good things about the Company "YourDyno" though I personally have no experience with them.
I have a question. I used to ride karts growing up, everything from trikes, yard karts. My pride was my dart kart. Anyway, I'm 53ish now and finally got a used PRC kart. The motor is a beast. Fastest engine in a kart I've ever driven. My question is, how do i tell what kind of motor. The guy said it's a cyclone but I'm unsure as he sounded. He said it is a stage 3. How does one tell about that without opening it up? So now I scour through the videos.
Hey Kirk, without seeing it it would be hard to tell. I would take a picture and post it on Bobs 4cycle karting forum. The best guys in the business are in there!
4cycle.com/karting/
This is great stuff. I've been really looking into optimizing my engines beyond the usual (float, clip, etc) and lash was one of the things I've been experimenting with. Thank you for sharing this. I've been doing some research (some of it from your posts on 4cycle and here) and it seems that there are two benefits to lash: increasing lash increases rate of opening of the valve, which can increase power; and changing valve overlap can move the powerband around. I tested this awhile back with my local tuner and we noticed that increasing intake lash noticeably increased torque but shifted the powerband to the left and we lost some horsepower. If I understand correctly, increased intake lash can *reduce* overlap because the intake valve doesn't open as soon as it normally would when the exhaust valve is closing, effectively reducing overlap.
Out of curiosity, when you ran the tests for 0.06 and up, your AFRs shot up to near stoich. Would this be because the exhaust valve is opening later and i.e. allowing for more complete combustion?
YO thanks for the comment!! I also noticed the AFR change. I think it would be what you stated, maybe a fraction more amount air getting into the camber due to it opening later?? I think we'll learn a bit more once I get the lash testing done when I move just one at a time.
Sooooo, the Lamba went to 1.0 because the sensor died while doing the tests. Just finished tuning an IAME Mini Swift and had to replace the sensor.