60Lx vs Nelson q40

60Lx vs Nelson q40 (Full Version)

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ecoliburger -> 60Lx vs Nelson q40 (12/28/2007 3:20:15 PM)
I see on Jetts site that the 60Lx is supposed to put out 20k rpm with the right prop. Will this engine have close to performance of a nelson q40? Reason I ask is I have a q40 plane that I would like to try the 60Lx in but I want it to go as fast as possible. I modified a Nelson to have a carb but it doesnt transition very well, wondering if the jett would be better.

fizzwater2 -> RE: 60Lx vs Nelson q40 (12/28/2007 3:52:02 PM)
The Q40 engine was never intended to idle or transition - the intake/exhaust timing is set up for high RPM, not user friendly operation. I can't comment on the relative speed, but the 60LX is probably designed to offer better throttle response. I'm sure Bob will have a response with a lot better information before too long, so don't take what I say as gospel. :)

rmenke -> RE: 60Lx vs Nelson q40 (12/30/2007 6:54:38 AM)
ecoliburger: I don't think the Jett 60 LX can keep up with a full out racing Nelson or Jett engine simply because the intake is restricted in size by the carb in the sports version. Some of the racing engines turn in excess of 24,000. You crank them up, needle, carry out to the runway and let it go. You have no control over the engine except shut off while flying, no such thing as a planned landing. You do learn to compensate, there are many ways and the approach varies. I have two 60LX's, one for backup ready to go. I can take a streemlined Q-500 type airframe, crank it on the stand and set it down to idle out to the runway. Takeoff and land like any other sport airplane. Idle and transition are far better than anything I have ever had except the 35, 50 and 90 Jett motors in other airplanes. You breakin a Jett 60 LX RICH, NO LESS THAN 18,000. Some of the guys say they are running 8.75 X 8 and 9 apc in the 22,000 range. My honey's have never seen a full lean her out run, and probably never will. So far, none of the area go fasters are able to keep up with this thing. Mine does have a advantage of a streemlined nose vs their box blunt front end. With the 60, you naturally can run more prop than the 40 will take, but not as much as you would think. Its not likely that I will have the opportunity to compair equal airframes. If someone wants to send me a flyable Q-500, I would borrow a new Nelson and check um out. I would not lug this engine down with a larger prop for sport simply as Dub Jett says keep them over 18K. Nephew does have a 60LX on a cut down Avi Star which is quite fast, so I know the 60 is able to pull a heaver frame at the required rpms. A 60LX, black pipe in a clean Q40 is going to run close to what the National racers are doing, close to 200 mph. Next question, can you handle 200 mph. Not nearly as easy as you would think, like gone in 2 seconds, For a outstanding fun airplane, you simply can not beat a Jett 60 LX, with black pipe. You need the stock pipe to break in according to Dubb last year. Try one, you wont regret it. If you are going to race, gotta have the 40 racing engines in any event. ENJOY-fellow speed freak

ecoliburger -> RE: 60Lx vs Nelson q40 (12/30/2007 5:00:06 PM)
Thanks, Probably not going to race it just want to go fast. I have a q500 with a jet 50, pretty fast. I have 2 q40 planes that I have yet to fly and dont like the idea of no throttle. I would like to be at least able to slow down a bit for trim adj or to stabilize my knocking knees. I realize the 60lx will probably not be as fast as an all out q40 nelson but if its with in 10 or 20mph top end I would be happy with that.

bob27s -> RE: 60Lx vs Nelson q40 (12/31/2007 4:42:17 PM)
Thanks for the help guys..... Hard to answer the question, since they are very different engines. Apples to oranges. The 60LX is more like the Q-500 engine than it is like the Q40 engines. That is more like oranges to grapefruits. Jett offers the QM40 engines with Red carb (sj-90 carb) on the front, primarliy for those "practicing" a bit for FAI or just sport flying. It does not "idle" per say (5000-6000 rpm?), but give some throttle capability and an engine shut off. We sell a lot of them over in Europe and Africa actually. So if your goal is just being able to slow the Q40 plane down a bit ---- it can be a good option. The QM engine MUST turn over 22,000 rpm at peak to run properly, even with the carb. Prop is still important. Sometimes hard to get the engine to stage back up if it drops below about 16,000 in flight - partly because the nelson plug tends to want to go out. Another great option ....... You already have the SJ-50 - put that on the QM40 airframe to start with. Quite a few older Q-40 planes are flying with sport jett power. A 8.5x7.5 prop or a 8.8x8.5 works great. Allows you to get use to the plane... full throttle capability for apprach and landing. Trust me....... great way to transition to the QM40 engine power. The 60LX is a sport engine. It has torque. It transisions and idles very well. And it has a somewhat broad rpm power band considering its nature..... it can turn anything from a 10x6 down to about a 8.8x8.5 - peak ground rpm target is between 17,500 and 19,500 rpm. It can turn the APC 10x6 up over 18K rpm. With the black q-500 muffler instead of the usual LX muffler, the rpm range is now the same as the Q-500 engine, where you want it to turn between 19,000-20,000 rpm at ground peak... and it now becomes a 428 class Q-500 engine that is very easy to run. So if you wish to pursue that option, it will be a few MPH faster than the SJ-50 you have now, but hard to quantify exactly how much. I hope this helps Bob

ecoliburger -> RE: 60Lx vs Nelson q40 (1/3/2008 3:13:11 PM)
Thanks Bob and others for the good info. Guess my final question is will the sj50 or the 60lxz spin a apc d1 carbon 7.4x8 type prop or would it be outside of the engines powerband? Also since the motor mounts I have are already drilled for the Nelson, does the sj50 or the 60 have a similar mounting dimensions? Thanks

bob27s -> RE: 60Lx vs Nelson q40 (1/3/2008 4:19:29 PM)
You could use the carbon prop QM40 props, but you probably would be better of using one of the D-1 Q-500 props when it comes to over-all performance. (At one time we did quite a bit of testing using the q-500 engines and props in the Q40 airframes - they move right along.......) Others flying the QM40 aircraft with the sport engines are using D1 type 8.8x8.5, 8.8x8.75 or taking the 8.8x9.25 and clipping it down to 8" diameter if they are concerned with ground clearance. Let me check on the bolt patterns. Current jett sport engines have the OS46 mounting foot print. I know the QM engines were different (matched the F1 ST40X), but that may have changed over time.

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