Hi guys,

I was wondering if the OS Max 40 FSR is the same engine as the OS 40 VF except its side exhaust instead of rear exhaust? Mr. Randy Smith if they are the same engine can they be set up to run the same way a rear exhaust does?? I believe ya would have to have a different type header? I wonder if the 40 FSR and the 40 VF would have the same intake??? Just another dumb question, thanks for your input Gary

They are not the same engine, they are very differant, However both can be made to run well for stunf, The 40FSR is also mostly ringed motors, although some of them were lap fit, The 45 FSR is the better of the 2 FSR engines, The VF is a larger heavier motor, and has never been ringed.
Since one is a side EX and the other is rear EX it is obvious that the headers would have to be differant, you need a side to rear setup for conventional inverted mounts on the 40 FSR

Randy

There's a distinct possibility the VF's were based on the later FSR which was ABC as both have the removeable front ends while the next OS version of their sport engines (OS-F) had a one piece crankcase. Whether their crank/port timings were similar though I have no idea.

Hi Brian

The 2 nickle plated (ABN) motors are vastly differant and none of the parts fit the other, OS went to a 1 piece case because of strenght, a 2 piece case is just not nearly as stable
In the 2 motors the  heads, piston/sleeves , cranks, bearings, rods, front housings, mid housings, backplates, and several other parts are differant and a new design, about the only thing they shared was the 2 piece case idea

Regards
Randy

Hi Randy,

Does the OS Max 40 FSR have the same power as the OS 40 VF?  If not how does the OS 40 FSR compare to the OS 46 LA? I'm not sure its worth fix her up for control line stunt and I did, would it be best to run it on a pipe or a muffler? I appreciate any information you can give me about this engine. I don't even have the spec. on her?

Thank You
Gary

Hi Gary

They both have about the same power when setup running piped stunt..although KAZ told me the 40 FSR was a much better setup...  I have setup many of both engines but I have not ran one on a piped setup, they do run well though as I have seen others flying ones I have setup
As far as power I have not tested the LA against the other 2 engines

Randy

Hi Randy,

Just got thru running the OS40FSR, wow, she likes to run hard, a lot of pull and when ya think ya got all the rpm's out of her, turn the nose up and the race is on. I wasn't sure what set up I should use, so I started out with a 10/6 prop using 0/20 than 5/20 than 10/20 and last 15/20. The engine ran very cool with each fuel, I believe the best was on 10/20. Prop seemed to small so I tried a 11/4 prop and it seemed to work out great of course I couldn't leave thing alone had to try a 11/6 prop. The engine seemed to pull the prop okay but didn't have the rpm variation that I had with the 11/4 prop. The engine doesn't seem very heavy, haven't weighted her yet, for the amount of power she is giving me. I would appreciate any suggestion you have about setting this engines up. At the moment I'm running her on the bench no muffler no pipe and not pressured.
Gary Anderson

Just got thru running the OS40FSR, wow, she likes to run hard, a lot of pull and when ya think ya got all the rpm's out of her, turn the nose up and the race is on. I wasn't sure what set up I should use, so I started out with a 10/6 prop using 0/20 than 5/20 than 10/20 and last 15/20. The engine ran very cool with each fuel, I believe the best was on 10/20. Prop seemed to small so I tried a 11/4 prop and it seemed to work out great of coarse I couldn't leave thing alone had to try a 11/6 prop. The engine seemed to pull the prop okay but didn't have the rpm variation that I had with the 11/4 prop.

   Oy Vey!  A 40FSR on a 10-6?!  WOW!  I would probably start with a 12-4 2-blade. This is a *much* stronger engine than a typical "stunt 40" by a long shot.

     The 40FSR was one of the first cases of people modifying engines for stunt, but mostly because they kept trying to run 6" of pitch - and that usually resulted in a good speed for the first few laps, followed by 8 minutes of 4.0s and holding on with  two hands!

   Paul Walker flew some test flights with a 45FSR and a 9-4 at the Reno NATs. And reportedly launched at about 15000 rpm.

     Brett

Gary

The motor is strong enough to fly anything a 40 VF will fly, the RPM range would be between 10,500 and 11,200 for a typical setup with a 3.8 to 4.2 pitch prop. Remember the motor will need to turn a higher RPM to put out the power needed to fly a 60 size ship
Don't try the 15,000 RPM setup....your friends will  NOT like the prop noise.

Randy

Hi Randy,

Thanks for the information. I couldn't sleep last night, so I got up and started playing with this engine. I found that the evo 36 venturie is a great fit for this engine. I have to make up a header for her and than I'll be ready for another test. I probably just roll a piece of stainless and make a pipe to test her. Does this engine need to be run under pressure? I don't remember seeing a pressure tap on the pipe system or header???

Yes you're correct I know most wouldn't like to hear an engine running that sounds like ya got the pedal to the metal with no load. I remember back in the late eighties when a lot of guys was using the system this way. It was funny to hear the engine wide open and the plane just cruising. Heat and smoke everywhere and not going anywhere?

I appreciate your help
Gary

No I would not recomend pressure for it, I don't really use pressure on any pipe setup

Randy

Hi Brett,

That big baby sounded like a very health 1/2 A. It wasn't enough load for the engine but the engine didn't get warm, could still put your hand on the bottom end, coolest running motor I've ever had. I even tried a 11/7 on her, maybe the one I have is tired, like me, but she didn't like the 11/7. She would sag when ya pointed the nose up, didn't get hot could still hold your hand on the bottom when she was running. After she ran out of fuel it still didn't get very warm. Brett is this the engine the guys where running small prop and running around 15,000 rpm's? I was surprised how well she pulled with the 10/6 prop. It pulled harder with the 10/6 than with the 11/7, I guess cause the poor baby was sagging with the bigger prop??

    That 9-4 15,000 is probably *not* the hot setup! 

     This is (or should be, if it's not worn out) a *very* strong engine - very strong. In the day it was a breakthrough increase in power over an ST46 - a huge quantum leap. It was a match for an ST60 as far as power goes. The problem was that it was very difficult to control using the techniques of the day (including everybody trying to run 12-6's or 13-6's on them), so the ST60 ended up being a much better and more tractable replacement - but it didn't perform a lot better.  11-7 is not the prop unless you want to go about 100 mph. The 7" pitch results in a large part of the prop being stalled on the ground, so and 11=7 on just about any engine is pretty gutless on the ground. And, you have to set it so slow on the ground that you aren't developing any power to speak of. A 10-6 is also WAY more pitch and way less diameter than I would try.

    Try a 12-4 Rev-up or similar to start - it should be able to handle that easily, and at launch revs of maybe 95-9600 or so. THAT will have some static thrust to it. That's the reason that the tuned pipe engines have so much pull on the ground - most of the prop is under the stall angle, so it's pulling, and you are developing a tremendous amount of shaft power because you are spinning so much faster. Check the in-flight speed and adjust richer or leaner to get about 5.2. If it's too lean (i.e sagging in the maneuvers) then trim about 1/8" of each tip until you get it unloaded enough to have a good speed but not sag. If you get down to 11" you might have either a modified engine or a worn-out engine. I hear that you can use a 40FP piston/liner in it but I don't know what if anything you have to do to make that work.

    I mostly agree with Randy that any airplane you can fly with a 40VF you should be able to fly with a 40FSR in good shape (presuming you can tame it). That means essentially any current 40-60 sized airplane you see, outside of the 80-style east coast monsters like the Patternmaster. Power was never the problem with FSRs -  it was controlling it. In a lot of ways, tuned pipes were applied to engines like the 40FSR to be able to harness the incredible power available with some semblance of controllability. In that sense, the 40VF is overall a much, much better stunt engine. 30 years ago, when the 40FSR was briefly the hot setup, most people had no good ideas to solve the controllability problems and the 40FSR was notorious for great (at the time) but very inconsistent performance, and screaming runaways. We are *a lot* smarter now and I at least know not to run 6" of pitch.

   I wouldn't recommend anyone go buy a 40FSR because there are much better alternatives. But, since you already have it, it's worth a try. If you can get it to run in a stable manner (which I think pretty much requires 4" or pitch or so and pretty good inflight RPM) and it's not worn it, it will be a great performer. But don't be too disappointed if you experience some issues.

     Brett



     

Hi Randy,

I ran some more test on her today using different fuels. We ran her on 10/22 wildcat using a OS A3 glow plug, she didn't want to run any slower than 11,700. If I tried to richen her up she would just start coughing. The next run I ran 5/22 Wildcat fuel using the OS A3 glow plug. With the same needle setting she fired up around 8,300. I turn the needle until she was running 9,700, (still a little rich) and when I turned the nose up she straight to 12,900. I believe she likes to run with less oil, around the 20%. What is your opinion, should it run on the 20% and am I using the correct glow plug? I appreciate your input, Gary (Man is she healthy, wow) At the moment I'm using a T/F wide 11/4, cause that's what I have on hand, will change later. Thank you

Hi Randy,

I ran some more test on her today using different fuels. We ran her on 10/22 wildcat using a OS A3 glow plug, she didn't want to run any slower than 11,700. If I tried to richen her up she would just start coughing. The next run I ran 5/22 Wildcat fuel using the OS A3 glow plug. With the same needle setting she fired up around 8,300. I turn the needle until she was running 9,700, (still a little rich) and when I turned the nose up she straight to 12,900. I believe she likes to run with less oil, around the 20%. What is your opinion, should it run on the 20% and am I using the correct glow plug? I appreciate your input, Gary (Man is she healthy, wow) At the moment I'm using a T/F wide 11/4, cause that's what I have on hand, will change later. Thank you

Hi Gary

You have a few things off, first all you need a 265 to 280 diameter venturie (restrictor) with a spray bar going thru it...DO NOT try to run and launch the plane in the 85 to 9500 RPM range, if you run a 11.5 x 4 prop you are going to be over 10,000 RPMs or you will be going too slow. If you  have a venturie with no bar thru it and it is as big as the EVO ones this is like using a 325 sized venturie in the conventional setups
The venturie you have now is NOT what you want to use, it is way too big.
Use to start 5 to 10% nitrofuel with 20 to 22 % oil I would use at least 1/2 or 3/4 synthetic oil, The OS plug would work but I would start with a T BOLT Big Bore 2 and 4 cycle.
Doing the above you will really close the gap between the extreme RPMs
As Far as props go the CF hand made ones are best, however you can also use these that are cheap
TF 12 x 4 cut to 11.5 or 11.3 inches
Cyclone 11 x 4.5 as is
Pro Zinger 12 x 4 cut to 11.3 inches

Randy

If you take the back plate off and have a "S" stamped on the counter balance you have the stunt version. The timing is a bit different on the crank then the R/C version and a little bit more manageable run.

Hi guys,

Well I'm still having fun with this engine. I got a pipe system off of evil-bay for very little money. Probably a waste of money but the pipe system seems to be working on this baby. I need to get the correct venturie, prop, glow plug and then maybe she'll be okay. At the moment she starts first flip and is running at 10400 rpm's level, when ya turn the nose up she goes to 11200 rpm's and she doesn't seem to sag any. Maybe this coming friday I'll be able to put her in the air. Wish Brett could be there, cause I'm sure he's correct and I would love to give him a laugh. I have the engine mounted on a close to sixty size ship. Its a home made junker I call My Mess after Larry's Mo' Best. The wing is design after the shark 45, fuse is Larry's Mo' Best, stab and tail area is just a pipe dream. The plane flys well with several different engines I've used on her so maybe she won't go a million miles an hour with the famous OS Max 40 FSR ABC. Ha Ha just having fun but I do like to see Brett smile!! Gary

Hi guys,
I'm back playing with the OS 40 FSR on Mac's Pipe System. I purchased a nva from Randy and it works very well. Last night I drilled out the engine to receive the nva. I used a evo 36 venturie which seems to work very well with the set up. Took the set up to the field to maybe put her in the air. Well before I would try and put her in the air wanted to bench run her. When she started up she has running around 11,000 and didn't want to needle. Rich help me tighten the needle set up, (I wasn't use Randy'sset up and was afraid to get it to tight). I decided not to play with her after the 11,000 run. The engine didn't mind running that hard, just wasn't what I has looking for. I had changed the pipe length by adding four inches to the pipe. Mr. Frank William told me I needed to add at least this amount to get the run needed for stunt. After getting home my son and I decided to bench her. With no more air leak's she started and was tacking at 9,100 and sounded very nice and pulling like a truck. We all know that the tank shouldn't be vibrating and yes mine was. I held my hand on the tank and believe it or not the rpm's dropped to 8,400 and the little old OS 40 FSR didn't seem to care what I did to her, she just wanted to run. Just seems like to me there is so many things that could go wrong and many many place to check before ya find the problem. I still have several things that Randy has told me that needs to be done before she ready but at the moment she's really  a sweet heart.

FWIW, Hunt, Pappas, and Rich Tower were running these in the NE for a while. If I recall Bob had his in one of the Genesis's(Sp?) Think he might have won the WC with one...

W.

I think you are correct, Ward-O!   I seem to remember a conversation with Bobby about that.  He had run the OS .40H (F-105), the ST .46 (originally in the Genesis .46), then switched to the FSR.  His "1980" Genesis" is also called the Genesis .40.  Haven't talked to him about the power he used it it, though.

It's funny that the Genesis .46 (Mk III?) plans show a ST .46 and it's noted that it is  "Rich Tower modified".  I think he switched to the FSR and used his homemade wooden 3 bladers for the Worlds.

Bill

Hi guys,

I had a little more fun with the OS 40 FSR. I used a Brodak 11/5 wide prop, 10% with 22%oil, same plane (61 ounces), flying on 62' lines, Lap time is 5 seconds flat, pulls like a truck. Launched her at 11,000 R's, she ran great couldn't tell if she was picking up R's when I pulled the nose up but she wasn't sagging. I test run her on the ground before and at 11,000 R's when I pulled the nose up, she would drop off 200 R's, so I richen her up maybe a 1/8 turn, R's didn't change but when I turned her nose up she gained 200 R's. Don't know why?? that just the way it seems to be working. The sound doesn't seem to change with either setting, just found this to be interesting?? Bill asked on this forum if it was worth purchasing this type and the OS SF motors, I have both engines and if ya set them up correctly you'll have a winner. I wanted one of the OS VF engines but that cost a lot more money and I don't believe you'll get anymore for your money??? If you follow what Randy tell ya to do with this engine I believe you will be a happy camper.

Gary

Thank You Randy,

I'll give that set up a try, should I run her around the same R's?? Would the bolly prop be the best for this set up and do you have the prop in stock?? Would I run around the same R's that I'm running now?? I found it very interest that I moved the needle valve just a bit and it didn't change the rpm's. Couldn't hear a difference in sound just gained a few more rpm's when I turned the nose up. At the moment I'm very happy with the engine. The other day I got to messing with her and set the needle to lean, believe it or not she was turning over 17,000 rpm's. The instruction state that the engine range is 11,000 to 15,000. I didn't realize that the engine could turn that many rpm's. The sad part was that the engine didn't seem to care, it was pulling so hard I was afraid she was going to rip out of the front end, she wanted to go baby, WOW!! I'm going to have to find a header that wraps around the engine so I can put her in a build up fuse. Randy do you have one of these headers??? I used the metal pipe and I used the carbon pipe and couldn't tell the difference?? When I was doing maneuvers you could see a very nice trail of smoke. I guess I'll either make a different header or build a plane so I can mount the engine on a degree. I sure like this baby, it flys a lot like a electric plane, even pull where ever she's at. Gary

Hi Randy,

I found something interesting, I hadn't installed a fuel filter, so I installed one and guess what? It changed the engine rpm's, the r's dropped 500 r's. I couldn't get the engine back to 11,100 rpm's. I guess the filter restricted the fuel to the venturie??? Wonder if I could install the .275 to make up for the filter (at the moment I'm using a .265)? I don't want to do much until I try the different props I have on order. I've found that the FSR is a very good strong engine and ya have to be very careful that you don't get it out of its happy mode. If you try one you'll be happy if!!! you listen to Randy about setting her up.

Thank You for Your Help Randy.
Gary

Hi

There  is NO reason as  fuel filter  would drop RPMS, did you install a fuel or  air filter??

Regards
Randy

Hi guys,

When she couldn't get the same R's that I was running before. I removed the fuel filter and the R's returned to normal. I wouldn't have believed it could do what it did but she did. I'm going to try a different fuel filter and see if it does he same thing. Brett could be correct that the filter has a air leak. I pressure tested the filter and she didn't seem to have any air leaks??? Don't know why it would make a difference, the filter seemed to be clear with good air flow??? I honestly think that the .265 venturie is almost to small and the .275 could help out. At the moment the engine is just running very sweet and pulling my plane just great. I don't believe I want anymore power but once I get the props I have on order I'm going to play with her. Every time I try something and it doesn't work on that sweetheart the group, at the field, keeps telling me leave it alone, its great the way it is. I believe this set up would fly my strega and out perform the engine I have in the strega. After I try a different filter I'll report back. I appreciate all your help.
Thank You
Gary

Hi Brett,
The engine dropped in rpm's and wouldn't go leaner, it would just start to quit. The filter is a two part with a mesh screen. I don't believe its the filter, I think you where correct about air leaks. I was going to try a different type filter today. The first flight the engine started and needled great without a filter. Took off and did the six laps went into the wing over when I came out inverted she quit. I tried to remove the fuel from the tank and the fuel wouldn't draw. Took the tank apart and everything seemed okay, fuel lines seemed okay. Only think I can figure is the clunk must have got stuck??? The next flight she was great? I believe I'm going to install a metal tank and change all fuel lines and install the new filter I have and try she. Every little thing makes a difference. Do you think changing the tank and lines will help. I checked all the bolts on the engine and they seem to be okay. I appreciate your input.
Gary

Bob Hunt did, in fact, win the 1976 World Championship individual crown with the Genesis powered by a .40 FSR swinging a home made three blade wooden prop he assembled himself using machined almuminum clamping washers which locked the blades (from Rev Up props as I recall) using a clever tongue and groove with the tongues in the washers and the grooves in the blades.  Typically Bobby clever and immaculately created.

I've said this before and still believe it to be true.  I don't think stunt has ever had a more innovative and competitively competent individual than Bob Hunt.  And in this event of a lot of such people, that's saying a lot.  We've been lucky to have him.

Ted Fancher

Hi Ted,
This is very true about Mr Hunt but don't forget about Mr. Ted Fancher. The articles you wrote and the help you have offered to many. Without your help and many others, this sport wouldn't be here today. I thank all that has made this possible for me.
snip

Gary,

That's very kind and thank you.

As I see it, however, I pontificate a lot (sometimes with some good stuff) but Bob has always put his effort where his innovation lead him and then offered the fruit of both to the entire stunt family at--always--bargain prices.  Plus, the guy can really fly these things.

Ted

Hi guys,

I'm sure the group is getting tired of hearing about my little OS Max 40 FSR but if ya get one be sure ya follow what Randy tells ya. I received the props and glow plugs from Randy the other day and yes I had to start playing again. I installed the T-Bolt glow plug that Randy told me to use. At the moment I'm using the thunder tiger prop recommended by Randy, ( 11/4.5) The pipe length is 18.75 as recommended by Randy. 10/21 fuel, setting the rpm's at 11,400 and ya can hear her unload in the air.  Weighted the plane again, 62 ounces. Lap time is 4.9 to 5.2 which is great for me. Line length is 63'. I've run five gallons of fuel thru this little baby and she is just getting better. Thank you Randy for all your help, I'm really enjoying playing with this baby.

Gary

Hi guys, I have 2 of these engines, both former RC jobs. I actually have the OS stunt venturies that were sold for these. I have no idea what the diameter is of these but I expect they are too large. Any way, I figure  that Randy can supply the proper size slugs so I have other questions.

First is there a side to rear tuned pipe manifold for these?
Second is there a relitively inexpensive 3 blade prop that would be suitable?

Next I'll have to find a kit this engine would be happy in that is of reasonable size but that has a pipe tunnel.

BTW. This was the only engine that I ever had that actually started without the battery attached. Very Scary.

Well I looked up pipe headers, and the selection available is rediculous. .75 inch header diameter is bigger than the piston. That is for the Mac and Hp headers, Hp makes a wrap around. The tumed pipe diameter suggested is 1.5 inches wich would be greatet than the fuse dimension. Any setup using that setup would be god awful ugly. The pipe setup as big or bigger than the airplane, might work on a full size 60 but is rediculous on a 40. So if this engine cannot be tamed without a monstrous pipe setup, I'll pass on the using this engine. Makes me wonder what worked back in the day for this motor, or did bob or kaz hang a butt ugly monster pipe off the side.

The Mecoa website still claims they have them.

http://www.mecoa.com/acc/pipes/hppipe.htm