OS 40 FP mods

Hi guys,
I am using an OS 40 FP in a Brodak Cardinal and am curious if there are any engine mods that are being used to cure the Run-away problems associated with this engine.
Dirty Dan, I remember a conversation we had up in Canada a few years ago and you recommended raising the transfers to accomplish this, could you refresh my memory again please? Thanks, -Todd

Hi Todd,
Ah-Ha! so you're a secret stunt flyer..... What's it worth to keep this quiet?

Probably the best answer is to send the engine to one of the specialists who have modded a gazillion of them. I have experience of the SSW & Muggleton conversions and both work very well.

Ther are many previous threads on this subject on this forum, and you'll no doubt get plenty of answers anyway.

It seems that the changes required to tame the FP series is more than just raising the transfer ports.

See ya next July!
Cheers, Dave

I have one that has an extra head shim and a venturi from an OS 25.
It actually 4-2-4's quite well.
I also have one that was reworked by Lew Wollard aka Silver Foxx.
Don't know what he does to them, but they don't run away that's for sure.

Lew Woolard's modifications work very well. He has a quick turnaround time and stands behind his engines. highly recommended.

On the other hand, you can run it stock, with a Mac's #6650 muffler and a flat pitch prop, per Scott Riese's setup. Mike Haverly ran his last Cardinal with this setup, except it was a Tower .40. I used this setup on a .46LA and liked it a lot. If you don't like the Mac's muffler, you should be able to run it stock in a rich 2 cycle with similar low pitch props...let it wind up. How's that Cardinal coming along? Post pictures! Steve

I taked to Mike Conner Last night and I told him, 11x4 with extra head gasket. NOW if you still have runaway try Another head gasket and all castor fuel. What I found out was the BEST FOR ME was 5%nitro with 25% all castor 11x4 top flight.
HOWEVER, the MAC'S pipe system works the best. To make it work for stunt you must re-time OR inlarge the intake port simple to do with a dremal tool.

Scott(stunt is fun)Riese

>BEST FOR ME was 5%nitro with 25% all castor 11x4 top flight.
>HOWEVER, the MAC'S pipe system works the best. To make it
>work for stunt you must re-time OR inlarge the intake port
>simple to do with a dremal tool.
>

Grinding away metal with a Dremel tool or equivalant is simple to do.

It's just hard to get it right.

Before I experimented with some engines, some of the older hands told me to expect to tear a few up until I got a setup that worked. They were right. Fortunately, my test bed engines were normally swap meet/used engines that I did not have much money in.

I send my new engines to Leonard. Now, if I could just get them back....

>
>>BEST FOR ME was 5%nitro with 25% all castor 11x4 top flight.
>>HOWEVER, the MAC'S pipe system works the best. To make it
>>work for stunt you must re-time OR inlarge the intake port
>>simple to do with a dremal tool.
>>
>
>Grinding away metal with a Dremel tool or equivalant is
>simple to do.
>
>It's just hard to get it right.
>
>Before I experimented with some engines, some of the older
>hands told me to expect to tear a few up until I got a setup
>that worked. They were right. Fortunately, my test bed
>engines were normally swap meet/used engines that I did not
>have much money in.
>
>I send my new engines to Leonard. Now, if I could just get
>them back....
>
>
>Regards - Bob Kruger

Bob it is nice to know that I am not the only one waiting for a engine to be returned. 14 months and waiting.

>>I send my new engines to Leonard. Now, if I could just get
>>them back....
>>
>>
>>Regards - Bob Kruger
>
>Bob it is nice to know that I am not the only one waiting
>for a engine to be returned. 14 months and waiting.

My comment was tongue in cheek humor. I occasionally kid my good friend Leonard about his backlog. He kids me back by putting my stuff at the bottom of the pile.

I have four engines modified by Leonard. All of them swing a larger prop and produce more thrust than any of the other mods I've had done on similar engines. Lew Woolard's are close, and his backlog is not as bad, so could consider him.

LAST EDITED ON Nov-10-03 AT 01:45 PM (CST)
 
>My comment was tongue in cheek humor. I occasionally kid my
>good friend Leonard about his backlog. He kids me back by
>putting my stuff at the bottom of the pile.
>

>Bob

I guess my engine just moved to the bottom of the pile?

Bob,

Have you tried modifying the piston like the sketches I sent you? I had the Mustang out late this season and the FP ran like a watch. I have another I'm reworking for my Jetco Sabre Stunt.

>Bob,
>
>Have you tried modifying the piston like the sketches I sent
>you? I had the Mustang out late this season and the FP ran
>like a watch. I have another I'm reworking for my Jetco
>Sabre Stunt.

Yep, did one on a Magnum 40 GP. Just a bit scary to do this on the piston. What prop combo were you running on it with your Mustang?

I ran an APC 10.5x4.25 with a narrow blade. Turns up tight but still 4 stroking and good breaks, very consistent.

>Have you tried modifying the piston like the sketches I sent
>you? I had the Mustang out late this season and the FP ran
>like a watch. I have another I'm reworking for my Jetco
>Sabre Stunt.
>Randy Ryan

Randy,
Could you please explain the piston modification you mentioned? Thanks.
DennisV

Dennis,

Because the plating around the ports is prone to peal if the port is cut, I decided I could change the port timing by cutting the piston crown in the bypass port areas by the same amout the port would normally be raised. In the case of the .40FP its .030. The also lowers the CR which we do anyway by adding head gaskets. It does however alter the squish clearnce on the average as well as the actual combustion I'm sure. It doesn't seem to make a hugh difference since both the port modified and the piston modified engines I've flown in the same model run near identically.

Randy,
Thanks for the reply on the piston modification. Sounds interesting. Do you also cut the piston by the exhaust port or only the transfer/bypass ports?
DennisV

Only the bypass ports, if you cut at the exhaust port you would defeat the purpose.

I have a completely stock FP40. With the small stock muffler, it has a perfect "stunt run"(I'm watching Windy's tapes ). a couple of weekends ago, I tried switching to a tongue muffler from another FP. The plane exibited the dreaded runaway problem! As soon as I put the original muffler back, it went back to 4-2-4 run!

I think my "mod" is the cheapest!

>I have a completely stock FP40. With the small stock
>muffler, it has a perfect "stunt run"(I'm watching Windy's
>tapes ). a couple of weekends ago, I tried switching to a
>tongue muffler from another FP. The plane exibited the
>dreaded runaway problem! As soon as I put the original
>muffler back, it went back to 4-2-4 run!
>
>I think my "mod" is the cheapest!
>
>Steven Yampolsky

If you are using the stock muffler (highly restrictive) to "control" the run and want to use the lighter tongue muffler, just tap the holes and insert short 4-40 screws until you get the run you want. You can choke it way down that way. You will definitely lose power, but you can easily equal the stock muffler that way.

Todd, I wanted to mention yesterday that you might have better luck with one of my NVA's that so many serious stunt guys like. In fact I will drop one of to you today on my way back through.
Joe

>If you are using the stock muffler (highly restrictive) to
>"control" the run and want to use the lighter tongue
>muffler, just tap the holes and insert short 4-40 screws
>until you get the run you want. You can choke it way down
>that way. You will definitely lose power, but you can
>easily equal the stock muffler that way.

How switching to a restrickted tongue muffler will make it better? If it is restricting the same amount as a stock muffler, won't it loose the same amount of power? The engine would sound louder as well, right?

I am using the earlier/lighter version of the FP muffler.

Since you mentioned the runaway problem with the tongue muffler, I am assuming that the choked down muffler is what is holding it back. You can do the same thing with the tongue muffler, just block off a few holes. When I started experimenting with those things, I was getting about a hundred rpm increase with every hole I added.

Is there a way to add more power without increasing RPM's or nitros? I'd like to try a 11x4 prop instead of 10.5x4.5.
when I tried 11x4, the engine 2-cycled as soon as I did a loop and it wouldn't come back to 4-cycle for two laps!

>Hi guys,
>I am using an OS 40 FP in a Brodak Cardinal and am curious
>if there are any engine mods that are being used to cure the
>Run-away problems associated with this engine.
>Dirty Dan, I remember a conversation we had up in Canada a
>few years ago and you recommended raising the transfers to
>accomplish this, could you refresh my memory again please?
>Thanks, -Todd
Todd I think I know the mod. you are asking for.Will look up after work and post or email , if I can find.

Todd,

I was probably just talking because the wind had died down. I don't know that much about the 40FP.

Truth be known, I assume what was being related to you was merely what I had been told by others, as I have never been a fan of the sort of rework--raising intake ports--we are talking about. Also not a fan of reduced-compression setups, although it may well be necessary for some motors. If Mike Conner says that's what he does, well, he pretty much knows what he is doing.

Personally, more and more I think a lot of people are making a mistake in just automatically tossing the stock O.S. mufflers. While this might not be the case with the 40FP or 40LA, I would want to have it proven to me at the field. The 25FP runs Killer with a stock muffler; I even use the little insert which is claimed to further reduce noise and which I maintain improves the run characteristics.

If balance is an issue, fine. The stock mufflers are heavy, granted.

I think Helmick and Scott had the best suggestion: Run the Macs pipe/muffler setup. Not only does it work in a superb fashion on an otherwise stock motor, there are several people in this area to give advice and help solve any problems you might have.

Is it true that you are on *TWO* FAI teams for the W/Cs in 2004? I think that's what Booker said, but he was off to chase a FF model as he said it.

Let me know if there is anything else you need. I might not have the answer--more than likely will not--but I can make you think I am right about most any subject. Heck, I'll even help your father out. If he asks very nicely.

I look forward to seeing you at the Stunt circles. You can (easily) whomp me in Racing and Speed; but I'll eat your lunch in Stunt.

Hoping your schooling continues to go well,

Hi Guys,
Thanks for all the info. Flew the Cardinal yesterday for the first time and that is a very nice model. Joe Just gave me the kit as a present when I graduated from Oregon Tech back in June, thanks again Joe.
Anybody have any idea for a tank size for a 40 FP? I'm using a 4oz tank right now and Mark Conner tells me I need at least a minute more of run time minimum. I'm using a stock FP 40 with a tongue muffler so maybe I'll have to try the stock muffler as everyone keeps recommending.
And yes, Dan, I placed on both the F2C team and the F2A team this year. Should be a fun and busy World Champs.
Anyhow, the model is pictured here. Thanks for all the help guys. -Todd

Go to 5% nitro and ADD a HEAD GASKET NOW!!! Dang it:o

Wow, congrats on making it to WC, in double!

I am using everything stock(venturi,muffler), 4oz uniflow tank and 10.5x4.5 prop. With this setup and 5% fuel, I can fly full pattern plus another 6-10 laps. With 10% fuel I tend to run out of fuel within 2 laps after I come out of the cloverleaf. There is nothing like an engine starting to sputter on loop 1 of a clover to get your heart pumping.

Oh yeah, that's with a 4-2-4 run, no leaning.

Well Todd, sound like you got it. In PAMP stunt news some time back had the mod. for the 40fp and 40la , I do like these mod. along with dishing out head and adding .020 to .030 shims. I get a great 4 2 4 run with good 15% fuel. I make all my parts and have fun machining them ,so Im not out much doing mod. to engine. Good luck at W.C. Jake

LAST EDITED ON Nov-11-03 AT 01:53 AM (CST)
 
Todd.
What solved my runaway problem was the opposite of what you might expect: Go to fuel with less oil. Standard 10/10/10 racing fuel cured my runaways pronto. I had been using 20% and 25% castor. Finally somebody told me that those engines don't like that much oil, and he was right. I guess the deal is that with too much oil, you have to set it too lean on the ground to keep it lit, then it runs away when it unloads. Anyway, I have used 10/10/10 for a long time now, no more runaways. I had fiddled with head gaskets, venturis, different props, all that.
--johnt
P.S.: For non-racers, I mean 10% nitro, 10% synthetic oil, 10% castor oil.

http://members.aol.com/
JohnT4051/
NorthwestCL.html

WOW.......Mine all HATE 10 10 10

Hi Guys,
Well, My dad, Mark Conner and myself all went flying today with the OS 40 FP in my Brodak Cardinal. After an email to Scott Riese and a phone call with Mark and Scott, we made all the suggested changes to the system. Let me just tell you that this model and engine work beautifully together. No runaway, no needle problems, airspeed at 5.3 laps on 62' wires (eyelet to eyelet), good tension and lots of fun.
My setup is as follows:
Brodak Cardinal, 41oz ready-to-fly without fuel
OS 40 FP, stock,
-.014" head clearance,
-Needle Valve assembly from Joe Just
Mac's Muffler
Uniflow 5.3oz tank filled with 115cc's for 7 min. flights
ThunderBolt Plug
APC 11 x 4 prop
GMA fuel, 10% nitro, 11% synthetic, 11% castor (Thanks John)
This combo worked extremely well and I would suggest it to anyone working with the OS 40 FP in a Cardinal. Thanks guys for all the help. -Todd Ryan

Todd, great going! I told you the NVA would be a winner! I think if I were able to fly stunt as well as you I would sell a bazillion of these great valves! Wish I could have been with all of you yesterday, but my plate was too full to get away.
Next Sunday?
Joe

Joe,

Hey, look here. I want to be a winner too.

Which is why I sent to you, via Stuka Stunt private message service, an order for two pieces, sized for the Fox 35. And two spare needles.

Don McClave says they're cool. And you know how badly I want to be both cool and a winner.

Anyway, check the little flag thing at the top of your screen.

>
>Anyway, check the little flag thing at the top of your
>screen.
>
>
>Dan

Dan...? what flag? I may be the most computer illiterate person you ever met. Flag? I don't need no stinking flag!Also there is no E-mail in my inbox from you.

Joe

JOE ...He means your in box on Stuka Stunt Works.
scott

Scott/Dan...Which one of you is putting me on? There is no "flag" or "inbox" that I can find! After an hour of searching and phone calls I am inclined to think your having fun at my expense.

Joe

>Scott/Dan...Which one of you is putting me on? There is no
>"flag" or "inbox" that I can find! After an hour of
>searching and phone calls I am inclined to think your having
>fun at my expense.
>
>Joe
>

They weren't, Joe, but if you want we could cook something up "just for you."

Go to the User_menu at the top of the forum. Then on the left you will see the in box.

Normally, if there is a new message for you in the in box, there will be a flag at the top left of the forum telling you that you have a new message waiting for you. You can also check in your preferences to have an e-mail sent to you to notify you when a private message is sent as well.

Thanks Leonard, Problem solved. I never go to the lobby, having things set up to open at the threads.
Joe

(whose only connection to anything electronic in the past was putting a battery in a flashlight) all this computer stuff is a puzzelment!
While seaking out the Dirt's message I did discover a couple of other messages, whcih are way too late to answer. My opologies for that.

Joe

Snippity, snip, snip

>While seaking out the Dirt's message I did discover a couple
>of other messages, whcih are way too late to answer. My
>opologies for that.
>
>Joe

Joe,

I see you (finally!) got my message, as your return was viewed this morning.

I surely hope that one of those messages which are too late to answer wasn't along the lines of: "Today you may have a very painful accident; do not go flying. If you must, have someone else start the engine."

Dan, no, nothing like that. Basically I had messages wondering if I could explain your columns in Stunt News to the Italian Stunt team in Macchia Val Vatori, Italy. For some reason my three day stay in that wonderful place a year ago has the locals thinking I either knew you or failing that could understand you. Alas!

Oh, by the by, your NVA's will go out Wednesday, Enjoy!

Glad to help.

Scott(did it again)Riese

Hi Todd,
I know there are several methods of getting good runs from the 40FP.
The very best ones I've had, IMHO, were reworked by Byron Barker. Plenty of power and a great run.
Haven't had a chance to run one of Len's "profile Special" 40FP but understand they do a very good job.
Probably the wet 2 cycle run with shims and proper muffler is the way to go if you don't want a full blown rework.
Bill <><