Leadfoot-RCU

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Just wondering if anyone could tell me about these engines and what kind of power output I could expect from them.

I will be building a Lyka Jet from the MAN plans and thought about this engine for it. Alternatively, I have a piped OS 46FX that I could use. Currently this engine is in my Long-EZ, and considering the untimely demises that some of these speed planes can meet, I was considering using a different engine to preserve the OS for the Long-EZ.

Thanks for the info and help,

Steve

HighPlains

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Was this a hopped up engine or stock st X-40?

What type of fuel do you want to run? They run great with a straight pipe of about 4" and 65% NITRO. Expect to burn a glow plug every flight, and burn up the piston/sleeve if you go lean.

On mild fuel (anything less than 40%) you have less power, but less likely to burn it down.

Try about 8 1/4" diameter with a pitch of 7 1/2. Try propping for about 22,000 rpm.

Leadfoot-RCU

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Here's a pic of the engine. As I said, I really don't know a whole lot about the engine, but would assume that it is modified since it has a Rossi carb mated to it.

No idea what type of fuel to use..... lol, not even sure if I could find 65% nitro in the first place!!

Stupid question, but say with 30% nitro, how much more power would this engine have over the piped OS 46 FX that I have??

Thanks for the help

HighPlains

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It looks like a stock engine, judging by the exhaust extractor, head shape, and screws holding it down. If you can get a sleeve timed for a pipe, then this should outrun the OS. Talk to Dave at Performance Specialties, as he might still have parts, as he also did some of these in an FAI version 15 years ago. 30% fuel should run great in any engine with the right head clearance without eating you alive on glowplugs. You might also check with Dubby at Jettengineering. He was flying speed before dirt was invented.

Or you might consider selling it on EBAy and just spend the difference on a Jett BSE 50.

Leadfoot-RCU

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Thanks for the help!!

I will follow up with both of the people that you have mentioned! Are you figuring that this engine is 15 or so years old?

Ahhhhh a Jett BSE 50, that would make the Lyka Jet move!

Steve

HighPlains

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Most likely around 15-20 years or so. I had 10 of them that I flew in Formula One. Still got a some of them in a box, crashes got the rest. Nelson .40's replaced them. Same bore and stroke as the tigre, but better breathing and general construction.

Jett 50 could make a brick fly. Landing might be a problem.

bob27s

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(Dub actually "build" all of the FAI X-40 engines for the USA team for a few years - [link=http://www.jettengineering.com/about/jettfacts.html]click[/link])

The one thing to keep in mind with that X-40, whether race prepared or not, it it needs fairly small props, and has to turn up a great deal of RPM to develop its power. In its day, properly modified, it was hard to beat for FAI or F-1.

Do you have a pipe for it? Exhaust extractor (short tube exhaust that goes over the o-ring) ?? Are there any hand-written markings on the crankcase ?

The X-40 Formula 1 engines I had were all Terry Prather modified. No carb, just the venturi - ran crankcase pressurized fuel system - modified props which were basically 8x8 - turned in the 22K rpm range. Outstanding engines. Sad part, is back then flying 1:20 on the long course was considered fast. Todays QM40 and Q-500 aircraft regularly fly below 1:10.

For F-1 I flew mine on 60% nitro. However, back in the late 80's early 90's there were a few experiments flying "sport forumula" where guy were using 15% fuel in the engine. That was an effort to 'save' F-1 from extinction. The X-40 ran fine on 15%..... needed lighter props, but they ran great, and didnt self destruct/melt plugs if you goofed up. I have no doubt it will run just fine on 30% heli fuel.

As noted, any of the Jett SJ or BSE engines can provide more performance, and would be substantially more user friendly.
(just for friendly info, I noted a 50 FIRE setup on the "bay" for a reasonable price. Looked ok in the photos)

Bob

george 5151

hi there what is the best prop to run on my x40 super tigre and the best fuel to run on it thanks

MJD

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Didn't they answer that already above?

bob27s

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First, look here http://www.rcuniverse.com/forum/fb.asp?m=2293699

Beyond that, there were all manner of varients for the X-40. Some modified. Some were run with pipes ----- for F1 we ran open exhaust with an extractor.

If yours is a box stock engine, just use regular 15% fuel and try one of the APC 7.6x8 QM40 engine props. Saves on having to make/carve your own 8.2x7.5 and will deliver decent performance.

If you might want a RE version tuned muffler for it, email Dub Jett and tell him the application.

HighPlains

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Brilliant Bob, this may be the best way to drill in information that I have ever seen.

proptop

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Wow...I think I'm having a "Deja Vu" experience man...[sm=spinnyeyes.gif]

DonStegall

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How mach are X-40's with the pipes worth?

What about a G40 and S40 with the pipes?