Extreme Speed Prop Planes Discuss the need for speed with fast prop planes (Screamin Demon, Diamond Dust, Shrikes or any REAL sound breakin'''' plane)

What engine will make my p-51 scream??

Reply

Old 08-02-2003, 08:20 PM
  #1  
Steven H
Member
Thread Starter
 
Join Date: Apr 2002
Location: Longview, WA,
Posts: 71
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default What engine will make my p-51 scream??

I have a .40 size modeltech p-51. Currently running a .61fx. I need to pick up the pace. what engine and prop combo should I use to reach the absolute max speed with this plane? I really, really, want it to scream!

Thanks

steve H
Steven H is offline  
Reply With Quote
Old 08-03-2003, 02:17 AM
  #2  
FlooredCOBRA
Senior Member
 
Join Date: Aug 2002
Location: Hampton, GA
Posts: 1,551
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default What engine will make my p-51 scream??

Try putting a pipe on your .60 to get power up.

Since it is a 40 size plane try a hot .40 size engine instead of the sport engine. They make much more power and can spin a lot more rpm's. Bigger is not always faster in some cases.
FlooredCOBRA is offline  
Reply With Quote
Old 08-03-2003, 02:22 AM
  #3  
daven
Senior Member
My Feedback: (1)
 
Join Date: Dec 2001
Location: Waseca, MN
Posts: 8,455
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default What engine will make my p-51 scream??

I had a 61FX on my Kyosho Spit, and it really didn't come alive until I put a Jett .50 on it.

That is what I would suggest.
daven is offline  
Reply With Quote
Old 08-03-2003, 03:49 AM
  #4  
Razor-RCU
Senior Member
My Feedback: (50)
 
Razor-RCU's Avatar
 
Join Date: Mar 2002
Location: Mira Mesa, CA
Posts: 5,405
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Agreed-

You need RPM's not displacement-

A Jett-50, YS-45 (Piped), or Rossi-53 would make that plane a monster....

A Rossi-60 or older YS-60 and full pipe would be crazy- and if you want more you need to be looking for DF engines-

I love that question "How do I make my mustang scream!" I mean a YS-63 would move out, but the 2 cy. engines above will be both fun and un-nerving!

Keep us posted!
james
Razor-RCU is offline  
Reply With Quote
Old 08-03-2003, 12:24 PM
  #5  
ewspears
Senior Member
My Feedback: (12)
 
Join Date: Sep 2002
Location: Ocala, FL
Posts: 242
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default What engine will make my p-51 scream??

Razor is Right ON!!!

YS 60 would be optimum, If you can find a good one, It has a couple of advantages over the Great Rossi 60/61 in this application.
1) It will let you move tank aft for balance.
2) It is 1.7 OZ Lighter than the Rossi.
3) It won't require a head shim for 15-20% NITRO.
Use 10X8 Rev Up or APC if you can't find the RevUp. Use Macs #1160 Tuned Pipe 16.5" (Glow Plug to end of converging cone.
Expect 16400 RPM on the ground (15%) and considerable increase in the air.

Several posters will undoubtedly tell you to use MVVS 49 but I GUARANTEE; The above setup will be faster and have better throttle response than a MVVS 49!

Next step (borders on lunacy) would be a Rossi 81DF Engine or if $$ no object Jett 90.
ewspears is offline  
Reply With Quote
Old 08-03-2003, 12:55 PM
  #6  
ewspears
Senior Member
My Feedback: (12)
 
Join Date: Sep 2002
Location: Ocala, FL
Posts: 242
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Correction to earlier post

Just went back and checked my test records on YS 60 FR (This was a cleaned uo engine with 160 degrees exhaust duration).

Change the following;

Change the #1160 pipe length to 17.25

Turned APC 10X8 16870 on the ground
ewspears is offline  
Reply With Quote
Old 08-04-2003, 01:05 AM
  #7  
Steven H
Member
Thread Starter
 
Join Date: Apr 2002
Location: Longview, WA,
Posts: 71
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default What engine will make my p-51 scream??

Thanks a ton for the idea's. I would like to stay away from large tuned pipes because of the appearance. I have seen the Jett pipes they look good to me. Would the Jett 50 make that big of a difference? Or should I just go with the Jett 90 and get it over with?

Thanks,

Steve
Steven H is offline  
Reply With Quote
Old 08-04-2003, 02:53 AM
  #8  
Flyboy Dave
My Feedback: (21)
 
Join Date: Mar 2002
Location: Pinon Hills, CA
Posts: 13,775
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default If you don't want to break the bank....

....a Tower .75 would honk pretty good....

....especially for a hundred bucks....
Flyboy Dave is offline  
Reply With Quote
Old 08-04-2003, 04:45 AM
  #9  
Razor-RCU
Senior Member
My Feedback: (50)
 
Razor-RCU's Avatar
 
Join Date: Mar 2002
Location: Mira Mesa, CA
Posts: 5,405
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Good advice all around-

Dave loves his Tower-75, and he's right for a hundred bucks...

3 Things:

1. Yes! The Jett-50 WILL make a big difference-

2. If you can afford the Jett-90, that is a whole other deal... Serious mods would be in order to keep the firewall and motor together tho- glassing the center of the wing, tail filletts etc.

3. If you want your "stang" to SCREAM you need to consider tuned/quiet pipes- They are long and non-scale but you asked for Screamin' right?

If you want something without a major pipe the Jetts fit the bill- The Tower-75 turns some pretty good RRR's from what I understand- (Super-Dave)

A MVVS-77 might be good as well (?)

How about an OS-91VRDF?
Razor-RCU is offline  
Reply With Quote
Old 08-04-2003, 05:12 AM
  #10  
mglavin
My Feedback: (31)
 
Join Date: Nov 2001
Location: Elverta, CA
Posts: 5,295
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Re: What engine will make my p-51 scream??

Originally posted by Steven H
I have a .40 size modeltech p-51. Currently running a .61fx. I need to pick up the pace. what engine and prop combo should I use to reach the absolute max speed with this plane? I really, really, want it to scream!
steve H
Hang a YS 91 or the new 110 on your Mustang. We race these and WM Mustangs with the YS Engines. The .60 size two strokes don't even come close to the YS four stroke in this application.

13/12N APC @ 10K on 45% nitro will provide the speed your looking for.
mglavin is offline  
Reply With Quote
Old 08-04-2003, 05:39 AM
  #11  
Razor-RCU
Senior Member
My Feedback: (50)
 
Razor-RCU's Avatar
 
Join Date: Mar 2002
Location: Mira Mesa, CA
Posts: 5,405
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Nice!

That sounds good too huh?

YS-91 with a 13x12 APC? That would be awesome-

I have flown a TF P-51 that was equipped with a YS-120! Simply awesome performance, and SOUND!

Hadn't thought about the 4 cy.'s for all out speed - but what you lose in RPM's (Rossi, Jett, etc..) you make up with all that pitch....(?)

Now this thread should get interesting?

Whatever you decide- keep us posted so we can live vicariously through you!

james
Razor-RCU is offline  
Reply With Quote
Old 08-04-2003, 10:24 AM
  #12  
Flyboy Dave
My Feedback: (21)
 
Join Date: Mar 2002
Location: Pinon Hills, CA
Posts: 13,775
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Yo, Razor....

....Michael is correct on the .91 four strokes. Many
would think that the .91's are way too much motor, but
in fact they are the perfect set-up. They fit perfectly.

I mean....what were the real Mustangs all about ? A
huge supercharged engine, surrounded by a haggle
of .50 caliber machine guns (heh heh heh).

I have the "Dago Red starter set" with the OS .90, but
I had the presence of mind to snag a couple .91 FZ's
from the last batch....for a rainy day...( )....
Attached Thumbnails Click image for larger version

Name:	98966_5977.jpg
Views:	11
Size:	38.7 KB
ID:	56216  
Flyboy Dave is offline  
Reply With Quote
Old 08-05-2003, 02:59 AM
  #13  
Steven H
Member
Thread Starter
 
Join Date: Apr 2002
Location: Longview, WA,
Posts: 71
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default What engine will make my p-51 scream??

I just tached it. Current set up is a .61FX with a Macs? short pipe. It will turn a APC 10/7 14,700 RPM's max, but I turn the needle back to 14,500.

Oh yeah, this is a World Models, not a ModelTech like I said in the original post. I'm getting to the age where I forget anything that is not written down. (Just turned 40)

What type of RPM's would I get with a Jett 50? Or the Tower 75? I don't mind doing a little work or spending some dough, I just want it to scream!

Steve H
Steven H is offline  
Reply With Quote
Old 08-05-2003, 03:07 AM
  #14  
Flyboy Dave
My Feedback: (21)
 
Join Date: Mar 2002
Location: Pinon Hills, CA
Posts: 13,775
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Steve....

....my Tower .75 will turn an 11-7 1/2 MAS at 14K...
....bone stock, on 15% Powermaster....

....that's pretty stout.... ....not spectacular, but
whaddaya want for a hundred bucks....
Flyboy Dave is offline  
Reply With Quote
Old 08-05-2003, 03:18 AM
  #15  
Steven H
Member
Thread Starter
 
Join Date: Apr 2002
Location: Longview, WA,
Posts: 71
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default What engine will make my p-51 scream??

I tried to post a pic and gave up, maybe I'll try again tommarrow. The file is too big.
Steven H is offline  
Reply With Quote
Old 08-05-2003, 03:20 AM
  #16  
Flyboy Dave
My Feedback: (21)
 
Join Date: Mar 2002
Location: Pinon Hills, CA
Posts: 13,775
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default What engine will make my p-51 scream??

Is that one of those "Stealth jobbers''...?
Flyboy Dave is offline  
Reply With Quote
Old 08-05-2003, 03:51 AM
  #17  
Razor-RCU
Senior Member
My Feedback: (50)
 
Razor-RCU's Avatar
 
Join Date: Mar 2002
Location: Mira Mesa, CA
Posts: 5,405
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default well-

That is actually pretty good for the 61FX-

Is the WM Mustang the same size as the other stang?

There are many directions you could head toward-

Jett-50 on a 9x8? Dunno- but it WILL SCREAM-
Razor-RCU is offline  
Reply With Quote
Old 08-05-2003, 03:54 AM
  #18  
mglavin
My Feedback: (31)
 
Join Date: Nov 2001
Location: Elverta, CA
Posts: 5,295
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default What engine will make my p-51 scream??

Steven

If you want to go fast and don't mind spending a few bucks go with a four-stroke. Been here done this several times, you cannot beat this combo with THIS model! No special work is required and the engine fits nicely in the cowl inverted with the head protruding slightly..

The secret is pulling the high pitch prop down the straight away and carrying it threw the turns. These models have considerable drag and a very thick symmetrical wing. Typical weight with a YS 91 is 7.0lbs.

13/12 APC @10K is making around 8.57lbs thrust at 113mph theoretically at 2.5hp

11/8 APC @ 14K is making around 8.61lbs of thrust at 106mph at 2.3hp. If you could pull 11/10 at 14K you'd see 132mph theoretically at 2.9hp.

A large glow engine will make this model scream, something like a Webra 1.20 might work well... I have seen one of these beasts in action, don't remember the prop used and the model was slightly smaller but it was fast.
mglavin is offline  
Reply With Quote
Old 08-05-2003, 04:39 AM
  #19  
Razor-RCU
Senior Member
My Feedback: (50)
 
Razor-RCU's Avatar
 
Join Date: Mar 2002
Location: Mira Mesa, CA
Posts: 5,405
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default okay...?

I flew a TF Mustang with a YS-120 (wish I could remember the prop. :stupid: ) it was quick but not compared to your numbers there...

What prop. would you recommend for pure speed on the 120?

Anyhow, I am not as familiar with 4 strokes as I am with 2- but do you think any 4 cycle could pull faster than a Jett-90?

All these big strokers add alot of weight-
Razor-RCU is offline  
Reply With Quote
Old 08-05-2003, 05:47 AM
  #20  
Flyboy Dave
My Feedback: (21)
 
Join Date: Mar 2002
Location: Pinon Hills, CA
Posts: 13,775
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Yo, Razor....

....me thinks the Jett would get smoked... ....

...they only pull an 11-8 prop....
Flyboy Dave is offline  
Reply With Quote
Old 08-05-2003, 11:34 AM
  #21  
ewspears
Senior Member
My Feedback: (12)
 
Join Date: Sep 2002
Location: Ocala, FL
Posts: 242
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Jett 90 vs Any 4 Stroke 120

Flyboy Dave,
You Stated; "....me thinks the Jett would get smoked... ...."

You said that in response to Razor's comment; "Anyhow, I am not as familiar with 4 strokes as I am with 2- but do you think any 4 cycle could pull faster than a Jett-90?

Either you didn't understand the Ouestion or just don't know the engines in question.

I am a YS lover and have two 140L's and a DZ, but on their best day they're not in the same class with the Jett 90 (which I also have) as far as "could pull faster" is concerned.

The Jett 90 is about 6shp, the DZ is the hottest 4 stroke and is under 4shp!
ewspears is offline  
Reply With Quote
Old 08-05-2003, 08:47 PM
  #22  
Steven H
Member
Thread Starter
 
Join Date: Apr 2002
Location: Longview, WA,
Posts: 71
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default What engine will make my p-51 scream??

....my Tower .75 will turn an 11-7 1/2 MAS at 14K...
....bone stock, on 15% Powermaster....


Flyboy Dave,

According to the Jett website you are pretty close to the Jett .75 performance with your hundred dollar engine! I might have to give it a try.

Besides the firewall, what other airframe issues should I be paying attention to? This will be new speed territory for me. I don't want it to start crappin parts at the bottom of a full throttle dive.

Steve H
Steven H is offline  
Reply With Quote
Old 08-05-2003, 11:55 PM
  #23  
Erik R
My Feedback: (32)
 
Erik R's Avatar
 
Join Date: Jan 2002
Location: Fogelsville, PA
Posts: 1,024
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default What engine will make my p-51 scream??

I have a modeltech 60 size P-51(the old ARC no longer in production)with an OS 108 2 stroke turning a 13x8 apc,that is almost as fast as my yellow a/c ducted fan starfire. I'd try that tower 75,and run some higher nitro,and it'll be snotty enough for you!
Erik
Erik R is offline  
Reply With Quote
Old 08-06-2003, 12:20 AM
  #24  
Razor-RCU
Senior Member
My Feedback: (50)
 
Razor-RCU's Avatar
 
Join Date: Mar 2002
Location: Mira Mesa, CA
Posts: 5,405
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default What?

Your P-51 is almost as fast as the Starfire?

What engine fan combo. you runnin'?

Sounds pretty impressive- Must be alot of pitch in that prop.

I still say get a Rossi-60, YS-60 or Jett somethin'

A 1.08 on a 40 sized plane would be silly
Razor-RCU is offline  
Reply With Quote
Old 08-06-2003, 12:28 AM
  #25  
mglavin
My Feedback: (31)
 
Join Date: Nov 2001
Location: Elverta, CA
Posts: 5,295
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Re: okay...?

Originally posted by Razor
I flew a TF Mustang with a YS-120 (wish I could remember the prop. :stupid: ) it was quick but not compared to your numbers there...

What prop. would you recommend for pure speed on the 120?

Anyhow, I am not as familiar with 4 strokes as I am with 2- but do you think any 4 cycle could pull faster than a Jett-90?

All these big strokers add alot of weight-
I have T/F and the Modeltech 1/7 scale Mustangs. These are bigger heavier rmodels, 775 plus sqaure inches and they weigh in at 10-11lb. full house... The WM Mustang is a splash of Great Planes .40 size Mustang. Typical weight with two strokes is around 6-1/2lbs. Great flying models, their a little draggy and they have fully symetrical wings.

We use APC 14/12 - 14/13N at 10,500 with YS SC-120's.

YS four strokes out perform all others CC to CC, hands down. Different kind of power for sure. Much more torque and low end grunt.

I have a Jett 76, Dub modified it for warbird racing with a bigger carb and changed the timing slightly. Were limited to displacement on our models, .75 two strokes need 575 square inches while .91 four stokes can be as little as 440 square inches.

The Jett 76 and 91 pull an APC 12/6 at 14,300 and 14,700 according to Jett. Lot's of static thrust but not much in speed, around 83 mph theoretically.

Anyway I have tried the Jett .76 on the same WM Mustang, the Jett makes a lot of noise and sounds like its busting a move but it's not as fast as the YS powered model.

The two strokes won't carry the pitch, so they don't go as fast. These engines are port timed for RPM, lugging them down with high pitch props cooks em, smaller props with high pitch to maintain RPM requires a lighter less draggy airframe to work as less static thrust is available. Not really feasable with this Mustang...

YS 91-100's weigh in at 25ozs.
YS 120's weigh in at 32ozs.

OS61-91 weigh in at 19ozs. less the mufflers.
Jett .76/91 RTF weighs 25ozs.
mglavin is offline  
Reply With Quote

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service