25 Plain Bushing Shoot Out

Which one makes the most power? OS FP, OS LA, Thunder Tiger GP, Brodak, Am I missing any? I think the Brodak is the only one that isn't nickle plated. Do any of them have a boost port?

MM

>Which one makes the most power? OS FP, OS LA, Thunder Tiger
>GP, Brodak, Am I missing any? I think the Brodak is the only
>one that isn't nickle plated. Do any of them have a boost
>port?

I don't know for sure, but aside from the somewhat neutered 25LA, don't they all have boost ports? The FP does for certain, and I would guess that it's one of the stronger of these engines, *run as intended*.

Nickel VS. chrome doesn't make any difference for stunt applications. Treated properly, either will last long enough.


Brett

Can only talk about the 3 I have direct experience with.. Don't see much difference between the FP and LA as far as run goes. The FP will edge out the Brodak in sheer power but the Brodak is allot more stunt friendly.

Choice would depend on the airplane and type of flying you want to do. My choice for our triathlon is an old iron piston FP because it's fast and will hot start. I give up a little in the stunt event but make up for it in the race. For the Mirror meet where stunt performance is most important I use a Brodak 25.

The Magnum 25 and TT25 are all clones of the FP-25, parts will also interchange. The only difference is the TT is a bit more powerful,and the Magnum is not quite as well machined. The standard venturi on the TT is a sprinkler type,same as the ST-G21, spray bar is off set to either the inside of the venturi or outside toward the prop, I think the Magnum may be as well? The FP spray bar goes thru the middle of the venturi

>Which one makes the most power? OS FP, OS LA, Thunder Tiger
>GP, Brodak, Am I missing any? I think the Brodak is the only
>one that isn't nickle plated. Do any of them have a boost
>port?
>
>MM

Power and usable power are two different things. The FP, LA, and Thunder Tiger GP are all the same in bore/stroke and timing. (hmmm.) The biggest differences will probably depend on tolerances, deck height, and especially venturi used (along with the needle valve size on the FP/LA.) I do not know the specs on the Brodak, but the real question is "what are you intending to do with it?". As Brett points out, nickel plating is just fine at the rpms we run them and with the fuel (oil content) we use.

>"what are you intending to do with it?".


Maximum straight line speed with largest venturi opening possible.


MM

quote "Maximum straight line speed with largest venturi opening possible"
If they are the only critera then the FP 25 with the ABN piston and liner (has the boost port) or better still fit the Thunder Tiger GP 25 ABC piston and liner (drops straight in); bore the venturi out as large as you can or fit sprinkler type then convert the head to take a Nelson plug. Lastly, enlarge the gas passage in the crankshaft. Run at least 35% nitro

Ployd in OZ

>quote "Maximum straight line speed with largest venturi
>opening possible"
>If they are the only critera then the FP 25 with the ABN
>piston and liner (has the boost port) or better still fit the
>Thunder Tiger GP 25 ABC piston and liner (drops straight in);
>bore the venturi out as large as you can or fit sprinkler type (snip)

I agree with the first part...the FP or Thunder Tiger GP will be equally stronger for maximum straight line speed. However...

The criteria is the "largest venturi opening possible." It is not the "largest possible venturi opening". The largest opening possible is the one that will still give you adequate fuel draw and proper mixture. Go too large, and you will need to revert to pressure feed on the fuel, and then, again, there will be a limit. A "sprinkler" type won't help...the fuel just basically comes into the venturi through the closest hole to the needle body anyway. And it won't gain you power. So you are going to have to experiment here.

I don't think opening the center bore of the shaft is going to help--might even hurt with fuel draw. You could change timing and other stuff, but it sounded like you were looking for a stock engine. And if you are changing timing, be prepared to experiment and ruin engines.

"Maximum straight line speed with largest venturi opening possible"

Mighty strange requirement to be asking CL Stunt folk about.

But if you are serious buy any top-line 3.5cc (.21ci) RC car motor.

You will surely get what you are asking for...

Dan

>"Maximum straight line speed with largest venturi
>opening possible"
>
>Mighty strange requirement to be asking CL Stunt folk about.
>
>But if you are serious buy any top-line 3.5cc (.21ci) RC car
>motor.
>
>You will surely get what you are asking for...
>
>Dan
>

This is the Stuka Stunt Control Line forums, not the Stuka Control Line Stunt forums.
A distinction with a difference.
Definitely a stunt "lean" here, but it is by no means restricted to it.

Pat Mackenzie

>>"Maximum straight line speed with largest venturi
>>opening possible"
>>
>>Mighty strange requirement to be asking CL Stunt folk
>about.
>>
>>But if you are serious buy any top-line 3.5cc (.21ci) RC
>car
>>motor.
>>
>>You will surely get what you are asking for...
>>
>>Dan
>>
>
>This is the Stuka Stunt Control Line forums, not the Stuka
>Control Line Stunt forums.
>A distinction with a difference.
>Definitely a stunt "lean" here, but it is by no
>means restricted to it.
>
>Pat Mackenzie
>
>
>
>
Whoa! A little touchy tonight, aren't we?

I don't recall mentioning the name of the site, nor do I see where I made any sort of incorrect statement. I certainly didn't say anything as foolish as there being "Definitely a stunt 'lean' here..." as we clearly do more than lean in a Stunt direction on this site!

In any case, assuming the application has been clearly stated, I am the first to give a really good answer. And I went so far afield as to cite RC car engines...speaking of this site not being restricted to just CL Stunt!

Dan

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

And in review I see where the original question was in reference to plain bushing engines.

Rather than erase what I now see as an incorrect reponse, I hereby retract said response.

But one could still buy a honkin' 3.5, pull the bearings and replace them with bushings...

Dan

Hmmmmm, there is this word in the title that comes right after Stuka.... Actually a 25FP on a tuned pipe could go fast...

>Hmmmmm, there is this word in the title that comes right
>after Stuka.... Actually a 25FP on a tuned pipe could go
>fast...

And quess what I have prepped, hope to fly this weekend: A 25FP breathing into a spun-aluminum tuned pipe!

Actually, I hope it does not go too fast.

Dan

I had a little airboat with a LA10 (actually a FSR, then a FP, then a LA that the liner peeled and I replaced the engine again) with a Macs tuned pipe that picked up a BUNCH of RPM! If I remember correctly, with a 7-3 APC it was 19400. I bet the 25 comes alive

Enya makes a couple of nice 25's. One has an iron and steel traditional p/s setup. And the other has an aac p/s setup. The neat thing about them is they both come with front venturi and flexible nva direct from the factory all ready for C/L without rework!

>Enya makes a couple of nice 25's. One has an iron and steel
>traditional p/s setup. And the other has an aac p/s setup. The
>neat thing about them is they both come with front venturi and
>flexible nva direct from the factory all ready for C/L without
>rework!

Any of the engines you mentioned plain bearing?

Is there an Enya web site somewhere?

Thanks.

Bill Lee

>>Enya makes a couple of nice 25's. One has an iron and
>steel
>>traditional p/s setup. And the other has an aac p/s setup.
>The
>>neat thing about them is they both come with front venturi
>and
>>flexible nva direct from the factory all ready for C/L
>without
>>rework!
>
>Any of the engines you mentioned plain bearing?
>
>Is there an Enya web site somewhere?
>
>Thanks.
>
>Bill Lee


Yes and yes

web site:
http://www.enya-engine.com/index.htm

plain bearing .25 C/L SS25S
http://www.enya-engine.com/ListCL_J.html

plain bearing .25 R/C AAC SS25 AL-CHRO PL W/SNV
http://www.enya-engine.com/ListAP2CYL_J.html

Pat MacKenzie

>And in review I see where the original question was in
>reference to plain bushing engines.
>
>But one could still buy a honkin' 3.5, pull the bearings and
>replace them with bushings...
>
>Dan
>

Would you please name names.
The committee would like the full nomenclature' of this alleged engine. Also, it's birthplace.

>Whoa! A little touchy tonight, aren't we?
>
>I don't recall mentioning the name of the site, nor do I see
>where I made any sort of incorrect statement. I certainly
>didn't say anything as foolish as there being "Definitely
>a stunt 'lean' here..." as we clearly do more than lean
>in a Stunt direction on this site!
>
>In any case, assuming the application has been clearly stated,
>I am the first to give a really good answer. And I went so far
>afield as to cite RC car engines...speaking of this site not
>being restricted to just CL Stunt!
>
>Dan
>
>"Some of my friends have found it best to cut their
>Prozac in half."
>
>


Thanks for making my point.
Even the self professed "Stunt" guys on here have a vast background to draw on and come up with answers to non-Stunt questions.
Even those whom ( as we all do on occasion) have failed to read the original question

I got an email suggestion from someone who is "not going on Stuka for love nor money".
I wonder why he might have that attitude?
Thinly veiled-under the guise of humour- personal attacks perhaps?


Anyway, he suggests that the BigMig 25 is, as he put it, "a real monster".

Pat MacKenzie
(Smilies added just for you Dan)