LA 25 Strokes

you folks that don't want to piddle around trying to find used FP 20's for the hot profile setup, take another look at the LA 25. I dug up Mike Pratt's suggestions for the engine he used on his Primary Force design while I was building the pictured plane for Brodak's last week. I pretty much followed his suggestions and the motor runs like a top.

OS needle valve assembly
.231 i.d. venturi(matches the area of Mike's suggested .25 venturi and ST needle valve, ~ .05 sq.in.).
Sig 10/20 fuel(50:50 castor:synthetic) with 6 oz. extra castor oil in a gallon

APC 9/4 prop
stock baffled muffler.
two head gaskets(just on general principles. Several other local motors run fine with the stock head clearance)

GRW 3.25 oz. chicken hopper tank mounted 1/8 in. above the engine centerline. I tried a Sullivan SS-4 set up for two clunk uniflow, but it simply wouldn't work. Quit lean early three times in a row. Strapped on the GRW and it worked. After I have some more fun with the plane this way I'll fiddle with the plastic tank some more.

The motor runs the whole tank down to the last two laps at whatever setting you launch at- rich 4 cycle all the way to a fast 2 cycle.

The only real problem with this setup is that you have to fiddle around either making or buying a smaller venturi. The stock OS venturi seems to be .262id. With the OS needle(~.08 sq.in. area) it tends to run away into a 2 cycle no matter what you do on a larger 500 sq.in. plane like this.

Sigh...

Phil, I don't deny that your 25LA is working nicely, and I am certainly glad you are having fun with it.

But you have just presented the 25LA as a suitable alternative to the 20FP when you have no experience with the latter.

Once again, the 25LA is a nice sport motor, it handles a wide range of props, fuels and models. Might even make a decent contest motor, especially for those hanging to the holy grail of 4-2-4 runs by their finger tips, trying to apply this sort of thinking to small-bore motors.

But I can assure you in the most emphatic terms the best 25LA on the planet would not have been able to pull my modded Skyray 35--powered by a stock 20FP--to a win in Expert PA at Stuntathon a week or so ago.

I mean, there were pretty decent 25LA-powered models at this contest. All deserved to be in P-40, which is where they were. No one even considered trying to fly such a model in the windy, turbulent conditions we had on Sunday. I believe the model I used in Expert gave me less trouble in the wind than did Jerry's 40VF-powered, and piped, SV-11.

What you have done here is obviously well intended. But it is also a lot like saying a very mildly tweaked Fox Mk IV is suitable for use at the upcoming Bladder Grabber where Nelsons and Foras will dominate. Only in an alternate universe is this true, of course.

Dan, I am tired of hearing that the 20 FP is God. I have never owned one and never want to. The 25 is so much more motor for the same weight and size.

Yes, Brett got the 20 to work. I am not arguing that point. But the 25 can be set up just as well to deliver more power.

End of story. Let us let other people talk, OK?

SNIP----But I can assure you in the most emphatic terms the best 25LA on the planet would not have been able to pull my modded Skyray 35--powered by a stock 20FP--to a win in Expert PA at Stuntathon a week or so ago

AAHH DON'T think so. Plenty of .25LA'S out there that work and can pull your plane around....and win.

Scott

"But you have just presented the 25LA as a suitable alternative to the 20FP when you have no experience with the latter."

Well Dan, I do have experience, a lot of it, with both motors and I agree with Ferocious about the 25LA being a great alternative. The difference I see is that the 25FP is slightly more powerful when compared to the 25LA. I think the 20 FP is a good running motor but no better than the numerous 25LA’s that I own and run every weekend.

“But I can assure you in the most emphatic terms the best 25LA on the planet would not have been able to pull my modded Skyray 35--powered by a stock 20FP--to a win in Expert PA at Stuntathon a week or so ago”

Wrong again Dan, my Skyray is powered by a 25LA and I practice the pattern with it during the week, plenty of power and runs great every time. I run the LA/FP with the stock muffler, tongue muffler, stock muffler with the cone removed, and no muffler on the Voodoo and they all run great, I couldn’t ask for better. I think everyone know’s you really like the 20FP, but how many times to we have to read about it. Stop pimping the 20FP like it’s the only motor to run, enough already, your scaring the children!

Hey John!
Looking forward to seeing you in October, if not before.

I think it is a matter of what "type" of engine run is preferred. The LAs and FPs that I have watched, and flown, do have a *little* bit of difference in how they produce their power. The small bore FPs have the closest run to a pipe motor that I have encountered with a small engine when the stock set up, with the cone in the muffler is used. Having said that, I have seen some very good running 25 LAs.

Their is a difference, but it all comes down to personal preference and what you have, or can get!

Aaron, and I, will be at the field for the next club meeting, if at all possible to fly with y'all.

For everyone else (present company excluded), this is beginning to sound like the old "pipe vs. ST 60" debates of years ago. hahaha
Bill <><

Sounds good Bill, looking forward to it.

Yep I agree there is a small difference, but once you add the APC 9x4, they all run great. Of course I got that idea from Brett, I thought it was crazy when I first read it but they work!

I think Steve F was running the 25FP on is Tomahawk, how could it get any better than that??

Yeah, I got to fly Steve's Tomahawk w/ 25FP, and it has the muffler with the cone in it. A GREAT flying combination! He launches at 11,000 rpm, and the ship stays a constant speed at all times, through all manuevers. I was talking with him last night and the Tomahawk was a topic of conversation.
Alex Courtney was flying a 25LA in his combat plane at Brodak's! Aaron flew it and he said it was real easy to do the pattern with it.
Bill <><

The whole point of the 20 FP "experiment" by Brett was to find a stock set-up that would run out of the box. That said, you can also do that with other engines, but don't try to use the same prop on all of them or run them the same way. The 25 LA will turn bigger props than the 20 FP. Don't compare them with the same prop or the same rpm. Compare them with the prop and rpm that works best.

And then, if you are willing to make a few changes (again, Brett's whole idea was to run something "out of the box" and changes were not in his program) you can change the muffler with the use of a smaller venturi and get the same kind of run. You can use more prop with a less restrictive muffler, since it is the highly restrictive muffler that is choking down the power and keeping it from running away. Or you can go to a smaller venturi with the same muffler and go to a smaller prop--but that is counter productive.

I have heard a lot about the "stock" set up on Phil G's Magnum 36. But it is not "stock" in that Phil had to add a venturi. There is nothing wrong with adding a venturi to an engine that doesn't have one or even changing the one that came with it. We can learn from those who have done so.

There are all sorts of ways to run these things, even with a few simple changes like mufflers and venturis and props. Just be ready to experiment. Remember, the guys running the PAs and the RO-Jetts are changing mufflers (pipes and pipe lengths) and venturis and props all the time seeking to find the combination they like. And once they find a combination, it can become repeatable. So there is nothing wrong with learning from each other. (Remember, "This is one way to run it." It is not, "This is the only way to run it.")

And yes, as much as I hate to say it because I do not like the quality, a properly set up LA 25 will out run a properly set up FP 20 any time, any day, any where. There are all sorts of good set-ups that have been shown to work. But if you are still trying to run with the same prop at the same rpm with each engine, you are on the wrong track. Witness our use of a 12.5 x 5.5 Bolly on a modified 35 FP. You need to look at where that engine will develop its best power.

You can run the PA at a 16.5 inch pipe setting. But don't expect to run a big prop on it. You can run it at a 17.75 inch pipe setting and turn the bigger prop. But don't, then, expect to turn it at the same rpm that it was running it at 16.5. Same engine, set up differently, but a big difference in what it will do (and there are people who like both sides of the fence.)

This whole hobby is about choice. We each have our likes and dislikes. There are no absolutes. I like what I like. You like what you like. We can learn from each other. And we can all have fun. Let's do that, and not say, "You have got to do it my way."

Sigh, Sigh, Sigh.

I don't think you get the point Dan. I don't want to spend the time bidding on old FP's on Ebay, hunting down P/L sets etc. Seems to me you just were raving about an FP 20 that needed a new P/L.

The point is, I bought a new LA 25(not very expensive, really), dropped in the correct size venturi(Per Mike Pratt)which is an admitted problem. The stock one is a bit too big for big planes. Put in a couple OS head gaskets, and went out and flew. It runs great! Sixth flight was an official at the Brodak meet. I'm happy. A day or so to build the plane. Three days of sanding to make the paint purty. Sweet!!

You are planning to fly your FP-20 powered SkyRay in expert at the Nationals, right? We'll all be watching.

Ok guy's let me try to add a little something to this subject. I have run both the FP 20, FP 25, and the LA 25 on various models. All were very good motors for the type of models I was flying. All were stock engines (no additional head shims) running Sig Champion 10% and 15%. Many of you do not know me (because we haven't meet yet) and that's OK, but just ask anyone who does and they will tell you I know what I am talking about. Listed below are some of my findings on these engines.

FP 20: Great engine on smaller models like the Skyray 35, Ringmaster, Flightstreek, and others this size. Equipped with a stock muffler and APC 9" x 4" prop is a wonderful combination that is worth anyone's time to fly. However, the FP 20 fell short when installed on a larger model like the P Force. It didn't have it at the top of the circle. Close, but just not quite enough.

FP 25: Another wonderful engine (forget the 4-2-4 break) when set up to run at a wet 2 cycle. This engine has more power than the FP 20 but likes to run the same high RPM setup. It handled the P Force just fine with the extra punch that I needed at the top. I set it up a number of ways with different mufflers, venturis, and props all with good results. The best was with a stock muffler (C/L type) and a .245" venturi and a Bolly 9-1/2" x 4-1/2" with the pitch reduced to 4". Fuel tanks were a problem at first with the engine going lean in the overheads and four leaf. This was cured by using a GRW 3 ounce uni-flow tank that was only 1" thick. This cured the problem (the chicken hopper GRW worked almost as good).

LA 25: This engine gave me fits at first and I wanted to smash it with a large hammer, but I was determined to make it work on the P Force. It was my fault for not using the same setup as the FP 25. I was sure it had less power and tried to run the larger venturi and a tongue muffler to make up for it. Wrong! Did I say I tried to run the stock needle valve? Wrong again. This was a joke from the beginning along with a backplate that was sucking air. After sealing the backplate with silicone, replacing the needle valve assembly, installing the same .245 venturi, and back to the stock muffler (baffle removed) it started to work. It wouldn't pull the Bolly as well as the FP 25 but it was close. I tried the APC 9" x 4" and a cut down 10" x 4" to 9-1/4" x 4" APC that worked pretty good but still not as good as the FP 25 and the Bolly. Then I shortened the line length to 60" (eyelet to eyelet) and bingo it came into its own. I also reduced the pitch of the Bolly to 3.8" and now it all came together. The P Force was now just humming along doing its thing. In the end both the 9" x 4" and the cut down 9-1/4" x 4" APC props were 90% to 95% as good as the Bolly so if you are not into carbon props use them.

The end conclusion is the all the engines can be made to run very well but it is more than just the engine. It is the combination of the engine, venturi size, prop, airplane, line length, and tank. So don't settle for just an OK engine run. Work at it! Change a few things to find the right setup for your model.

GREAT SNIP>>> The end conclusion is the all the engines can be made to run very well but it is more than just the engine. It is the combination of the engine, venturi size, prop, airplane, line length, and tank. So don't settle for just an OK engine run. Work at it! Change a few things to find the right setup for your model.

Mikey

Yep. Thanks Mike Glad you posted this. IT'S the combination of things that make a ENGINE-PLANE set-up work!!!

Scott(I keep saying it)Riese

From Mikey:

"Then I shortened the line length to 60" (eyelet to eyelet) and bingo it came into its own."

My man! Way rad! But I tried 5' lines once and with much less success than you claim.

Wouldn't it be easier to just install real long leadouts?

To All,

While Mike and I are both saying the same thing when it comes to the 20FP, it just shot straight across Scott's head for reasons I do not understand, although lack of familiarity with the concepts being discussed do come to mind.

As several of us have said, the 20FP with BB T-U is a dynamite engine to use on *almost any* 400-inch profile model. Mike lists three, lets the rest go with "...and others in this size."

Thus it is absolutely true that a great many profile models out there, from kits to plans to ARFs all fly so closely to the same capabilities that the differences can hardly be measured, let alone demonstrated.

When we have such a situation, a great many models to work with, the models themselves become much less a factor in ultimate success, the powerplant becoming paramount.

Does this apply across the board? Of course not, witness Mikey's very specific setup to two different engines, both powering the very same design.

In these two cases, Mike has developed an engine/prop/tank/fuel/model package that works and I will be robbing all of his ideas this evening.

But with the 20FP this is *not* the case. Assemble the motor per BB T-U. Run it as we have said. Bolt it on nearly any 400-inch profile banging around in your attic. Be prepared to amaze yourself.

There is no fiddling involved, no tailoring each engine to each model. When I use the same 20FP on my first ARF, the second, my Soup Combat Streaker, even my blimped-up SIG Skyray, there are no changes whatsoever made.

In short, when talking about a specific category of CL models and the 20FP, it truly is all about the engine itself.

Hey guys, what a great thread! Very good info as usual. But I think I,LL stick to my original plans, and go with the "BB-T-U set up on my streak. DirtyDan has made a very compelling argument here, and In this case I think she is right. Welp, of to find an FP-20 for me!! < Paul

Dan, what part of NO! don't you understand? GIVE IT A REST WITH THE STINKINGT 20 FP!

No, I do not want to hear you say another thing about it. Brett started a thread and you hijacked it to the point he asked me to delete it. you then started a thread of your own. I let you go while you ranted on and on and on. Now someone mentions the 25LA and you hikack it back to the stinking 20 FP.

The last time I signed off on you and you started with the private messages. But you never bothered to listen to me when I answered. You do not care what anybody says, you just twist their words and go on. I finally told you I would give you the last word but I would no longer read those private messages because you do not quit. You sent me three more, none of which I have read.

I do need to read the threads on this forum, however. But I don't have to listen to this 20 FP rant.

And, for the record, I have never owned one. That does NOT mean I have never seen one or run one. I have had several that I have reworked for others. I have seen them run stock and I have seen them run reworked. And a properly set up 25, stock or reworked, is better than any properly set up 20, stock or reworked. I have seen them, run them, measured them. But I have never owned one.

End of story with the 20 FP. Let someone else talk about their engines.

>Dan, what part of NO! don't you understand? GIVE IT A REST
>WITH THE STINKINGT 20 FP!
>
>No, I do not want to hear you say another thing about it.
>Brett started a thread and you hijacked it to the point he
>asked me to delete it. you then started a thread of your
>own. I let you go while you ranted on and on and on. Now
>someone mentions the 25LA and you hikack it back to the
>stinking 20 FP.
>
>The last time I signed off on you and you started with the
>private messages. But you never bothered to listen to me
>when I answered. You do not care what anybody says, you
>just twist their words and go on. I finally told you I
>would give you the last word but I would no longer read
>those private messages because you do not quit. You sent me
>three more, none of which I have read.
>
>I do need to read the threads on this forum, however. But I
>don't have to listen to this 20 FP rant.
>
>And, for the record, I have never owned one. That does NOT
>mean I have never seen one or run one. I have had several
>that I have reworked for others. I have seen them run stock
>and I have seen them run reworked. And a properly set up
>25, stock or reworked, is better than any properly set up
>20, stock or reworked. I have seen them, run them, measured
>them. But I have never owned one.
>
>End of story with the 20 FP. Let someone else talk about
>their engines.

Some of my friends have found it best to cut their Prozac in half.

Let me ask you a question: What about a web site dedicated to folk talking about CL models and engines, this resulting in people actually talking about their models and engines do you not understand?

The accusation that I twist the words of others has grown very tiresome, not to mention being completely without merit. I believe you to be guilty of projection.

Hugs and kisses,

>(snip) The end conclusion is the all the engines can be made to run
>very well but it is more than just the engine. It is the
>combination of the engine, venturi size, prop, airplane,
>line length, and tank. So don't settle for just an OK
>engine run. Work at it! Change a few things to find the
>right setup for your model.
>
>Mikey

Mike, your conclusions are "right on". Sometimes you can run different engines the same. Sometimes you need to change things. I would bet you could get the LA to put out more than the FP just by working with it. But think different prop, etc. And if you change mufflers, be ready to change venturis. Or props.

And also remember, that one engine in a lot may be different from another. The deck heights on stock motors vary quite a lot, so the LA engine you have may not be the same as the LA the next guy gets. You may need to make slight differences between engines. But your last sentence says it all: "Change a few things to find the right setup for your model" (and your own flying style--my addition).

SNIP....While Mike and I are both saying the same thing when it comes to the 20FP, it just shot straight across Scott's head for reasons I do not understand, although lack of familiarity with the concepts being discussed do come to mind.

WELL that's a slap in the FACE! NOT KOOL. Familiarity with concepts?
I understand engines BETTER then most. I have LOTS of case and points. NOW there has been NO discustion here in this post about about understanding how an FP-20 works. It's not that hard. VERY SIMPLE. In fact why and what's the big deal? It's an engine thats not made anymore and you can find them on E-Bay for $40. I'm not into attacking anyone's personal points. I agee with what "MIKE SAID".
I think it may be your style of posting. Get to the point so us SLOW people can understand what the HELLo your getting to. ANYWAY it's you saying "IT'S GOD" that I question. ANYWAY I think this FP-20 BS is done on my part and I won't post anything more about what I found out FIVE years ago!! NOTHING NEW.

Scott(Hay rocky watch me pull a rabbit out of my hat)Riese

Sadly, even after a very full Saturday of flying, I must report there is nothing to report.

My buddy with the two 25LAs failed to show up, even though I had assorted venturis, props, head shims and fuel with me.

I have, however, been working on my 25FP per Mikey's input. The Skyray 20, currently powered by an unmentionable--albeit quite nice--engine may well benefit from the extra grunt. Not only is it 34.5 ounces, the airfoil is 1/8" thicker (LE sheeting and capstrips) than stock Skyray, this plus big tips resulted in 450 square inches, about halfway between your average 400-inch profile and Mikey's Primary Force.

Next weekend. Maybe...

"Which brings us to Circle Burner. He does have the requisite equipment, has made his judgements based upon flying results. Good job! He and I disagree, as I have worked with all the same engines as he, but that's, like, totally fine with me."

Dan, disagree is to strong of a word. We just have slightly different views on a few engines that's all. I'm going to spend some more time with the 20FP to see what I'm missing. The good thing is your motors are running well for you and mine seem to be good for me, so we both can be happy about that!

However, all of the engines we are talking about can be considered quality products and all run very well.....maybe some a little better than others.

>"Which brings us to Circle Burner. He does have the
>requisite equipment, has made his judgements based upon
>flying results. Good job! He and I disagree, as I have
>worked with all the same engines as he, but that's, like,
>totally fine with me."
>
>Dan, disagree is to strong of a word. We just have slightly
>different views on a few engines that's all. I'm going to
>spend some more time with the 20FP to see what I'm missing.
>The good thing is your motors are running well for you and
>mine seem to be good for me, so we both can be happy about
>that!
>
>However, all of the engines we are talking about can be
>considered quality products and all run very well.....maybe
>some a little better than others.
>
>John

John,

I agree that "disagree" is stronger wording than was wise.

But still the point is that you and I have a fair amount of experience with all three of the engines being discussed. In addition, I am going to try some more stuff with the 25LAs being used by a good friend, you're going to fiddle some more with the 20FP.

When we slap our mutual positions up against those that don't have **any experience at all** with the prime mover in these discussions, it is so hard to assign them any credibility whatsoever, and yet still they keep coming back with a whole host of negatives and that-can't-be-so statements.

You're my kind of guy, one who truly is open-minded, I will be most interested in hearing about your further use of the 20FP.

Man, I knew we'd never hear the end of it if we let Dan win at the Stunt-a-thon. This will give him material for at least another month...or until he get tromped at Vancouver.

>Man, I knew we'd never hear the end of it if we let Dan win
>at the Stunt-a-thon. This will give him material for at
>least another month...or until he get tromped at Vancouver.

Randy,

A month? Only thirty days?! I'm gonna ride this for **at least** a year.

Even if I have to take a pass on the B.C. contest...

Weenie.

>You're my kind of guy, one who truly is open-minded, I will
>be most interested in hearing about your further use of the
>20FP.

*Whomp*

That was the sound of me falling over sideways in my chair when I read this.

Iskandar,

Your comment says a lot more about you than it does about me.

Please refrain from confusing empty-minded with open-minded.

Phil,

Have you put the new Gotcha on the scale? And if so, did you happen to weigh the difference between nude and painted (referring to the plane of course, since the weight of the nude pilot isn't all that helpful).
Also, sharp looking paint scheme. I've always liked sunburst or whatever you call those stripes. It's good to know that a 3-day finish can give you a purdy plane, something nicer than a beater but with much less investment than a pro finish, for those of us with crash rates are still too high for a super finish.

Scott,

I don't seem to recall seeing you at Stuntathon. I don't believe you have ever seen my Skyray 20 fly. I do not remember casting aspersions on your set up of the 46LA for Gary Nelson.

How about you bring a 25LA--tricked-up or not, I don't care--to the next contest. While you sit in a very nice camp chair, one of three I won at Stuntathon, the piece reserved for you having been for first place in Expert PA, I'll give it a test-drive or three. We can even go back and forth on the same model, my engine, you and I fly; your engine, we both get flights.

Might be a most illuminating experience for you...

DEAR DAN,
Time out. WHERE DID I chastise YOUR FP-20? I did not. YOU SAID YOUR 20 are BETTER THEN THE 25 LA. I pointed out the there are a lot of .25 LA’S out there that are doing the job very well. YOU CAN’T make a statement like “mine engine is better then yours because I won a contest. The flyer has something to do with that. YOU’RE a good flyer…MAYBE it’s the set up and not just the engine?
AS for the STUNTATHON I just couldn’t make it. That’s my fault…

Sorry DAN if your 20 is that good and makes you a better flyer GREAT. I just don’t think it’s the engine. It helps, but you have skill and determination to be good at what you do.

Scott(got an 20 FP to try someday)Riese

>Scott,
>
>I don't seem to recall seeing you at Stuntathon. I don't
>believe you have ever seen my Skyray 20 fly. I do not
>remember casting aspersions on your set up of the 46LA for
>Gary Nelson.
>
>How about you bring a 25LA--tricked-up or not, I don't
>care--to the next contest. While you sit in a very nice camp
>chair, one of three I won at Stuntathon, the piece reserved
>for you having been for first place in Expert PA, I'll give
>it a test-drive or three. We can even go back and forth on
>the same model, my engine, you and I fly; your engine, we
>both get flights.
>
>Might be a most illuminating experience for you...
>
>
>DEAR DAN,
>Time out. WHERE DID I chastise YOUR FP-20? I did not. YOU
>SAID YOUR 20 are BETTER THEN THE 25 LA. I pointed out the
>there are a lot of .25 LA’S out there that are doing the job
>very well. YOU CAN’T make a statement like “mine engine is
>better then yours because I won a contest. The flyer has
>something to do with that. YOU’RE a good flyer…MAYBE it’s
>the set up and not just the engine?
>AS for the STUNTATHON I just couldn’t make it. That’s my
>fault…
>
>Sorry DAN if your 20 is that good and makes you a better
>flyer GREAT. I just don’t think it’s the engine. It helps,
>but you have skill and determination to be good at what you
>do.
>
>Scott(got an 20 FP to try someday)Riese

Scott,

You, like a lot of people, have experience with only one or two of the engines being discussed. Of course I called you on your statement of: "AAHH DON'T think so. Plenty of .25LA'S out there that work and can pull your plane around....and win."

And, above, you just can't admit that someone with the experience of running all three might know something you do not: "I just don't think it's the engine."

Scott, this is not a problem and is easily resolved by you bringing something which is not a 20FP to compare with what I am flying. My challenge to you is still in effect. Do you accept?

Dan

An edit as I sit here drumming my fingers waiting for Scott to take up above challenge. Or not, your choice Scott. It would be fun, you know.

I am serious, Dan, give it a rest.

>I am serious, Dan, give it a rest.

Can I assume this is why posting N.10 is, somehow, "missing?"

>>I am serious, Dan, give it a rest.
>
>Can I assume this is why posting N.10 is, somehow,
>"missing?"
>
>Dan
>

YES!!

>>>I am serious, Dan, give it a rest.
>>
>>Can I assume this is why posting N.10 is, somehow,
>>"missing?"
>>
>>Dan
>>
>
>YES!!

Tsk, tsk.

Shame on you.

BIG SNIP>>>>And, above, you just can't admit that someone with the experience of running all three might know something you do not: "I just don't think it's the engine."

Clarify “ALL THREE” ???
I’ve run my OS-20FP and set it up FIVE years ago! I don’t have time to build a plane for it right now. MAYBE next summer.
Challenge: Your Plane, no matter to me. Give me Four Practic flights…HUMMMMOK TWO that’s all I need don’t want to wear it out…….LOL

NOW Back to what I said IT’S NOT THE ENGINE it’s the whole package CAN you accept that. I’m not bad mouthing YOUR 20FP Just your statement “it’s the engine”.

FP 20’s run good…HOWEVER, there are some FP-25 and LA’s that are just as good. NO better no worse.

SO…How’s the weather. Been good here. Been testing my new ship OS-25 with a pipe so far so good. Got lots to do. Got to get ready for the AIRSHOW here in Portland. Meetings and things..OH did I tell you I’M RETIRED

Scott(can do that in TWO Flights)Riese

Thanks Ken. An appropriate question. Much better than "he said, she said" about engines. My whole point on engines was that the FP20 is out of production. The LA 25 is not and is readily available, no hunting. If you can't afford a slightly smaller venturi from our host here, a piece of brass tubing will work to choke it down too.

The Gotcha Streak weighs 895 gr.(31.6 oz.) oily wet after a flight. That is about 2 oz. heavier than one done with a quick and dirty finish-spray some Tempera on the foam and cover with the SLC. The extra 2 oz. does make the turns a little less snappy, but they are still pretty darn good. The paint is much easier to clean up after flying and I am sure will hold up a lot better. Long live Rustoleum!!

I did extend the nose 1 in. to get the balance forward with the lighter engine. The stabilator does a nice job of ignoring minor changes in balance, like it is supposed to.

>Thanks Ken. An appropriate question. Much better than "he
>said, she said" about engines. My whole point on engines
>was that the FP20 is out of production. The LA 25 is not
>and is readily available, no hunting. If you can't afford a
>slightly smaller venturi from our host here, a piece of
>brass tubing will work to choke it down too.
>

snippety, snip, snip...

Agreed. We need quick and ready access to engines suitable for our event. The 20FP is indeed out of production, although I continue to maintain there are tons of good used pieces out there. The lone 20FP, of four bought over the last few months, that has not been up to specs needs only a new piston/cylinder set ($24.95) to be like new. C'mon, it was purchased for a mere $10.00! And even now is usable, albeit with 15% and 20% fuel, the latter kinda taking the edge off the goodness in ways I do not quite understand.

Still, the long-term objective is to come up with a currently available engine which meets some sort of benchmark in performance. In my view, the benchmark has been set by the 20FP with the BB T-U.

Others are free to disagree, more power to ya. In fact, maybe Phil has come up with the next-step setup, which is exactly why I whittled out a venturi to his specs last night, cut a bunch of head shims, all for a friend's two 25LAs.

While not mentioned for weeks, I have not totally given up on the 25FP, nor have other people whom I am in contact with on an infrequent basis.

The primary difference--maybe the only one, as many of us seem to be headed in a direction which results in better performance for profile models--is that quite a number of naysayers have no experience with the 20FP.

Again, that is fine as far as it goes. But to make claims which have not been verified by direct comparisons between various powerplants is hubris of the most extraordinary sort.

We'll be flying Phil's setup this weekend...

Phil,

In reviewing your setup for the 25LA I see where you've spiked SIG 10% fuel with some castor. Is this common, is it necessary, do I have to mutilate some spare fuel in order to fully replicate your results?

Rick has been using 10% Powermaster and SIG 10% in his 25LAs without any apparent problems, by the way.

We've been spiking the fuel for LA engines with castor because we find it runs "better". More castor seems to give a smoother run, less rpm variations, smoother break, if the engine breaks at all.

Have fun. Your results may vary.