Macgyver

Hi.This is for all you guys that would like to see what A Rossi 105 Ducted Fan Engine looks like on the inside.I have also included some side by side comparision on my blueprinting and porting techniques. I will post about them soon.Take care-Mac Http://community.webtv.net/bolt34/Jets

mugenkidd

My Feedback: (94)

So how does yours perform compared to stock? From what I have heard here on RCU these engines aren't real reliable.

Macgyver

HI Mugenkidd,What I do to the rossi's to make them run are two things,lower the compression if you run nitro,two,three or four head shims,They have to much compression but they run fine on no nitro.With no nitro I use one to two head shims,mainy one shim.Now the carb I sharpen the low end needle becouse you can not fine tune the bottom end becouse it is ether rich or lean.Once you fix the needle the carb will not load up or lean out on take off.On the one I worked on I opened up the end(output) of the tuned pipe to 1/2" I.D. the engine did not over heat and carb tuned. better and the engine hit 23k rpm's.I found this out about the pipe from running the K&B100,temp was 358deg's and then i opened up the tuner pipe at the end(cut the stinger off) and engine ran at 256deg's and stoped blowing out the couplers and ran like A top! Take care-Mac

mugenkidd

My Feedback: (94)

hmmmm, very good information. So the K&B just needed a larger and/or less restictive pipe? I may try one out next time I see a new one cheap. Thanks.

Macgyver

This is what I did to the needle jet to make it transition right. The one the left is the needle I sharpened, or tapered. It made the engine run not rich or lean on the midrange. Take care,
Mac
-P.S. More pics to come.

Johng

My Feedback: (4)

I'd love to hear more about your experiences with the K&B as well. I have more than one I may try out in the not too distant future.

How do you get the head shims? Wherefrom?

Macgyver

Hi Jhonn,the K&B 100 I bought here on the net was $105 shipped and it did not want to run good and I know why people do not like the engine.I did some work on A Bob Parkinson F-15 reagle eagle with A K&B 82 Df and I reworked the piston and that engine was A great engine and I know now that's probably why Bob Violet used it as the KBV 82.I learned A lot from that engine and the difference from the 82 and the 100.The 82 ran good and had good compression and the 100 had low compression.Mine has the double bubble head and the way that they made the head was from the single bubble head and it lowered the compression down a whole lot.Does your's have the single or the double head button on it.If you have the single you are OK.I milled the double bubble button head down to bring up the compression and now I run it on no nitro but the engine would not run good before I did this now the engine running right but hot,358deg's and blowing the coupler on the second run and I got mad and cut the stinger off the pipe and the temp went down,256deg's and I could touch the engine after flying.I know now the compression makes A lot of difference on DF engine.To much on the Rossi 105 and not enough on the K&B100.I like these engines even though you have to do some work to them.When I cut off the stinger the KB 100 I still had plenty of richness on the inflite needle.
I will talk some more later,take care-Mac

mugenkidd

My Feedback: (94)

Mac, got another question and instead of posting a new thread I though I'd just ask you here. I just got another jet and it has a Rossi .81 package on it. Its an old George Miller F-8 crusader. Anyways I have heard that the Rossi's run good with the OS 91 carb. Well low and behold I have one of those laying around. The question is what do you think of this mod and what all is involved in this? Is it a strait bolt on or do you have to do some modifications to the carb? Also this plane is pretty light only 11lbs, what do you think about taking off from grass with the rossi .81 ? I am really debating on weather I should even mess with it or get an OS, but the rossi really doesn't look like it has that much time on it at all, and the compression is really tight. Well thanks in advance.

Michael

vasek

My Feedback: (4)

hi Mac,
i was just wondering why tinker with Rossi (or any other engine for that matter) and not use OS. Most posts i have read state that OS is the most (popular) efficiant/reliable DF engine...

is it the cost? do you have any affiliation with Rossi?
just curious.

Vasek

Terry Holston

My Feedback: (1)

I put a OS .77 carb on my Rossi .81 back in the 1980's, and it worked great. Had to make an adapter out of aluminum. A lath would have helped, but I didn't have one at the time. So, I just carved it out with a dremel and an electric drill. LOL

Macgyver

Hi,thank's Terry for jumping in here.I have not yet put A OS carb on A Rossi but it is possible.Do A search on carb and Email Jackjet becouse Terry and Jack is the only one's I know that has done this.Vasek,I like the Rossi's for the way they are built on the inside.Next to the BVM (Nelson)( Dubb Jet fan 90 engines are hard to find) Rossi's are next on the list.The piston rod,ports, fit and looks.I'm trying to get the 1.00 cubic inch engines to run right,I do not have any 90 size or smaller engines.That's all I have are the larger Engines.I have run smaller engines both the OS 77 and the K&B 82 but I wanted to find out why these 1.00 ci engines where having problems.I know now that it is mainly A pipe problem,the stinger,output hole is to small making them choked up with back pressure.As to buying shims I have not bought any so far as to date.I don't need to as I use no nitro fuel.The best pipe so far I have found is the big prather pipe or cut the stinger off.Michael,George Miller kits,Is your's A Byron pusher type or Danamax.The Byron spec's are Rossi 81,5% nitro,19,600-19,750 rpm's,pipe length,11-3/8",static thrust 11-3/4 to 12-3/4 pounds.Take care-Mac

Macgyver

Can you guess?

mugenkidd

My Feedback: (94)

Not sure on the engine in the pic Mac, but my George Miller F-8 is setup on the with the byron system. Thanks for the setup tips, how much oil do the rossi's like with the 5% nitro, I have some 5% nitro and 25% or 30% castor fuel at home,(don't ask I was going to mix it with some byron fuel for a Moki 210 I have) do you think that would work ok in the Rossi? Mac you may need to change your name to Rossi Guru


Michael

Macgyver

Hi Michael,The 25% should work I use 23 to 24 % oil.If it loads up ad some methanol and don't worry about the nitro content the Rossi should run on 3% nitro.if you would just sharpen the needle on the carb you should have no problem tuning the Rossi carb.The OS carb is A little bigger though it might give you little bit more performance.I have notice that all the engines from Italy have the same problems with the carb needle.Blunt needles and small inside diameter throats.That why I work on them.Your jet at that weight should perform realy good.Take care-Mac

mugenkidd

My Feedback: (94)

Hate to bother you again Mac, but I pulled the needle out of the engine, and it looks like it is already sharpened? Do they come from the factory with a constant diameter meaning that this one has already been modified or should I sharpen it some more, I took a picture but my cheap digital camera won't focus that well on it, I inverted the colors and you can see the point better, what I want to know is if this thing has already been modified? Also on the tuned pipe length, is that measured from the center of the glow plug to the highest point on the tuned pipe? Well thanks again

Michael

Macgyver

Hi Michael,That's looks like the high end needle maybe.My carb has only one needle, the high end needle is caped off for A remote needle.The one i'm taking about is the one that slides through the spray bar and when you twist the barrel to the open position it moves outward to open the little hole on the spray bar and you can see it from the back side of the carb when you take it off the engine and it is turnable with A screwdriver.If this is the needle you removed`you're ok.If you remove the jam bolt on the carb the barrel will come out and A liitle tension spring will come out also,don't lose,don't ask me why! and I have never seen one tapered so long.Let me know or disregard what I said.The pipe length is fron the plug to the fat part of the pipe.I have the instructions for the Byron F-16 and it states some pipe length info on the rossi 81,90 and the OS 77 and the 91. 11-3/4 to 12-1/4 lbs. of thrust the 81 in your jet sould be 1 to 1 ratio and it should kick butt.Talk soon-Mac

mugenkidd

My Feedback: (94)

Once again thanks for the info Mac, yes I had pulled out the wrong needle, I took out and was showing you the pic of the high end needle. I'm going to rebalance that byron blade so when I take the engine out to do that I'll also check out the other needle. If I can get a 1-1 ratio with this jet I should be in for a nice suprise, I'll post picks if I ever get it in the air. Thanks again.

Michael

David Eichstedt

My Feedback: (17)

Regarding the photo you posted looking for takers on "guess the engine:"

It looks like screenshots from the SKS video a few years back of Wolfgang Kluhr displaying his Russian Angstrom .91's that were used in his Su-27.

Am I close?

David

Johng

My Feedback: (4)

Hey Mac:

I regards to the K&B 100 having low compression - since you use 0% nitro, wouldn't that also indicate that the engine was designed to use more nitro?

Macgyver

Hi,David your right on the money,You get A free prize,send me your address and I will send you out something like two free Vinton O rings.John,the K&B100 on 15% nitro was still not enough nitro.I had to mill A heck of alot off the head to get it to run on no nitro.When you flip the K&B over before milling the engine had nothing but now it has about the same a the Rossi105 does and it runs right now.Take care- Mac

David Eichstedt

My Feedback: (17)

Macgyver,

Thanks for the offer, but I'm satisfied in simply having guessed correctly!

David

rulast1

Macgyver
I bought a used Rossi 105, Byro fan(pusher) and was wondering a starting point on pipe length? The pipe that came with sure seems to be small. Comments?

Macgyver

Hi,I know that the tuned pipe for the Rossi should be black.The pipe length from the plug to the fat part of the pipe should be around 12 1/8" .That should be A good starting point.Can you post a pic of the pipe.Take care-Mac

rulast1

Hi Mac
That is correct the pipe is painted black. It came setup with about a 11 3/8" pipe length. Lengthed pipe to 12"and seemed to help. Guess i will try a little longer. Pipe was getting real hot, started burning paint off! Sorry do not have a dig. camera to send a picture.

Thanks very much: Rodney

Macgyver

Hi Rodney,I will post A pic of the black pipe and it is made of medal not aluminum so if the pipe is the same as the pic I will help you fix your problem.The problem is not expansion but back pressure.If you would get A pipe of the same size as the output pipe and weld it to the other side of the tuned pipe so you would have two output pipes your pipe woud not become so hot becouse of back-pressure and it would make the Rossi 105 run like it is supposed to.When they started to make the larger engines they kept the same size stinger or output dimensions on the .60's size D.F. pipe and up so to me that did-not make any sense to me at all.The bigger the motor the bigger the stinger.The sound wave nocks the extra fuel mixture comming out of the engine and not the back pressure. Take care-Mac