Q-40 Racing Discuss AMA 422 and any other variants of Quarter 40 racing

Telling difference between Nelson Q40 LS & Q40 SS

Reply

Old 05-25-2012, 06:43 AM
  #1  
Vbuynfly
Thread Starter
My Feedback: (8)
 
Join Date: Nov 2002
Location: Rixeyville, VA
Posts: 35
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Telling difference between Nelson Q40 LS & Q40 SS

Hi Folks, I picked up a Nelson Q40 at a swap meet. It has an RC carb on with an firewall bolt-on backplate. I am trying to find out what version engine this is, if it's an LS Long Stroke, or an SS Short Stroke.

Does anyone know how to tell the difference just by looking at them, or is there some measurement I have to make to see just how far the piston travels up and down in the cylinder (stroke)?


I tried uploading some pics and get a 500-internal server error message from RCU.

Cheers,
Vince.

Vbuynfly is offline  
Reply With Quote
Old 05-25-2012, 12:05 PM
  #2  
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 RE: Telling difference between Nelson Q40 LS & Q40 SS

Does the muffler have "LS" engraved on it near where it connects to the motor?
daven is offline  
Reply With Quote
Old 05-25-2012, 01:30 PM
  #3  
Vbuynfly
Thread Starter
My Feedback: (8)
 
Join Date: Nov 2002
Location: Rixeyville, VA
Posts: 35
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Telling difference between Nelson Q40 LS & Q40 SS

No, there is no marking on the muffler at all. The only marking on anything is the "N" on the motor itself. Does this mean it is the earlier Short Stroke version? Thanks for any help.

Cheers,
Vince.
Vbuynfly is offline  
Reply With Quote
Old 05-25-2012, 07:00 PM
  #4  
garys
Senior Member
 
Join Date: Jan 2002
Location: Stansbury Park, UT
Posts: 937
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Telling difference between Nelson Q40 LS & Q40 SS

Most of my "LS" mufflers aren't engraved as they didn't do that for long. I'm out of town for the weekend and don't have one around to measure, and the differences are hard to describe, but if you post a pic, most people familiar with both could tell.
garys is offline  
Reply With Quote
Old 05-25-2012, 08:24 PM
  #5  
Vbuynfly
Thread Starter
My Feedback: (8)
 
Join Date: Nov 2002
Location: Rixeyville, VA
Posts: 35
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Telling difference between Nelson Q40 LS & Q40 SS

Pics do not seem to want to post. RCU is getting some bugs worked out of the BETA pic posting option and I keep getting the 500-internal server error message every time I try to post a pic. I'll keep working at it. Thanks, Vince.
Vbuynfly is offline  
Reply With Quote
Old 05-25-2012, 09:02 PM
  #6  
Duncan
Senior Member
 
Duncan's Avatar
 
Join Date: Oct 2008
Location: Coventry, Warwickshire, UNITED KINGDOM
Posts: 1,313
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Telling difference between Nelson Q40 LS & Q40 SS

My exhaust doesn't have LS engraved on it, but there are tiny letters scratched onto the mounting lugs if I remember correctly.

For the photos, sign up to photo bucket and then paste the links from there into a message, it sounds like hassle, but works everything so less frustrating than posting in RCU
Duncan is offline  
Reply With Quote
Old 05-26-2012, 10:11 AM
  #7  
Vbuynfly
Thread Starter
My Feedback: (8)
 
Join Date: Nov 2002
Location: Rixeyville, VA
Posts: 35
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Telling difference between Nelson Q40 LS & Q40 SS

http://s1149.photobucket.com/albums/o600/vbuynfly/

This should do it. I did as you suggested and here is the link. 10 pictures from all angles of engine and muffler.

Thanks,
vince
Vbuynfly is offline  
Reply With Quote
Old 05-26-2012, 10:30 AM
  #8  
Duncan
Senior Member
 
Duncan's Avatar
 
Join Date: Oct 2008
Location: Coventry, Warwickshire, UNITED KINGDOM
Posts: 1,313
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Telling difference between Nelson Q40 LS & Q40 SS

You can copy the image link below the photos on photo bucket and paste them here so they embed into the post.

The motor looks a fair bit older and different to my LS (below is yours, I'll take a pic of mine in a bit)

Duncan is offline  
Reply With Quote
Old 05-26-2012, 10:31 AM
  #9  
djlyon
Senior Member
 
Join Date: Dec 2001
Location: Castaic, CA
Posts: 2,492
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Telling difference between Nelson Q40 LS & Q40 SS

It's an SS. The throttle (choke) indicates it is a Q500 motor not a Q40. The casting intake is short and would indicate it may be a very old ABC.

Denis
djlyon is offline  
Reply With Quote
Old 05-26-2012, 10:59 AM
  #10  
garys
Senior Member
 
Join Date: Jan 2002
Location: Stansbury Park, UT
Posts: 937
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Telling difference between Nelson Q40 LS & Q40 SS

Agreed, it's a very early SS Q500 engine. Doesn't have the counter-balanced thrust washer, and the prop nut looks like what came on the early engines. Could possibly be AAC, but if it's the original piston/sleeve, it's probably ABC.
garys is offline  
Reply With Quote
Old 05-26-2012, 12:35 PM
  #11  
Vbuynfly
Thread Starter
My Feedback: (8)
 
Join Date: Nov 2002
Location: Rixeyville, VA
Posts: 35
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Telling difference between Nelson Q40 LS & Q40 SS

You guys are great!!! Thanks a lot. What fuel and propellor would I put on this to fly Quickie 500?

Keep in mind I'm not an experienced racer and would start out a bit slower than all you faster guys, then, work my way up to faster speeds.

I know these engines didn't use the standard 10x6 or 9x7 props.

I have some 8x8's, some 9x9's and few 7x8's in the prop box.

There is light carbon build up around the middle of the piston, so it's definitely been broken in. The guy I got these from, got out of RC due to advanced age. He had a couple of Rossi 40/46's as well, and it looked like he was into racing at one time.

Cheers,
Vince.
Vbuynfly is offline  
Reply With Quote
Old 05-26-2012, 12:57 PM
  #12  
djlyon
Senior Member
 
Join Date: Dec 2001
Location: Castaic, CA
Posts: 2,492
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Telling difference between Nelson Q40 LS & Q40 SS

Run it on 15% nitro. What looks to you like a carburetor is not. It is a choke only. It does not have a low speed needle. The engine will not run below 12000 rpm and probably not below 15000. It will just flood and shut down. That black thing is just for shutting the engine down at the end of a heat. It can also be used for dropping the rpm to about 16.5 to 17 on the start line to keep the engine from over heating. The props you have I would worry about using. They are not designed for the power and rpm this engine will put out and may break. You need a pylon prop. 8.8*8.75 or in that range APC. With this prop this engine should run in the mid 19s. Dub Jett makes or used to make a carburetor that fits that engine nicely and works quite well down to 3000 rpm.

Denis
djlyon is offline  
Reply With Quote
Old 05-26-2012, 03:36 PM
  #13  
Vbuynfly
Thread Starter
My Feedback: (8)
 
Join Date: Nov 2002
Location: Rixeyville, VA
Posts: 35
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Telling difference between Nelson Q40 LS & Q40 SS

Thanks guys for all the help. I'm getting the very distinct feeling I'm way outta my league with this engine. I think I would be much safer putting the Rossi 45 on the Quickie and selling this motor. Judging by your comments about about precautions and performance, I would probably give the old biddys at the field coronaries. The safety office already twice had bouts of insanity when one of our new guys came out with Hotliner gliders that did 140mph.

I fly Electric Ducted Fan Jets and they do around 80-100mph easily. I can see the safety officer sweating after my flight.

I'd rather be cautious and safe for now, so it's going up on the bay tomorrow night. I know when something is too much for me to handle if the choke is only there to cut off the motor and the thing is designed for firewalled flight!

Cheers,
Vince.
Vbuynfly is offline  
Reply With Quote

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service