RE: NEW NELSON Q-40  
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RE: NEW NELSON Q-40 - 2/26/2007 11:49:52 PM   
Ed Smith


 

Posts: 2837
Joined: 12/29/2001
From: Brantford, ON, CANADA
Status: offline 		Just lately, to preserve my sanity I have dispensed with the Coke!

Ed S

(in reply to garys)
       Post #: 101

RE: NEW NELSON Q-40 - 2/27/2007 1:19:29 AM   
Tony Pacini


 

Posts: 266
Joined: 1/11/2002
From: Prescott Valley, AZ, USA
Status: offline 		I have a unique perspective in that I broke-in and ran two of the LS engines last week (1 for me, 1 for my son). I started, needled, and maintained both for the whole weekend. We ended up running them as originally assembled (no changes to head or liner shims).

Know one thing for certain: I am NOT an engine guy. I am not a (wood) prop guy, either.

I would have preferred to run the 7.6 or 7.7 pitch props. One engine pulled the 7.8 and needled fine. The other, not so fine. Again, I am not an engine guy.

I'll figure it out eventually. I still need to pull them down and take some measurements to see why the two are behaving so differently. Maybe one is just a bit tighter than the other. When running the 7.8, there just wasn't enough margin to be able to back it off enough and still keep it on the pipe.

There is enough of a performance difference, though, that I personally would not want to race using the old motor (unless everyone else had to). I need all the help I can get, and the LS is definitely faster.

Once this prop issue is sorted out, I hope that all will be well again in the land of Q40.







(in reply to Jim Duda)
       Post #: 102

RE: NEW NELSON Q-40 - 2/27/2007 1:21:19 AM   
bl10


 

Posts: 303
Joined: 12/29/2001
From: Chatsworth, CA,
Status: offline 		As Gary said the LS engine has been in development for at least a year. I believe the “long stroke” is an offshoot of the FAI Nelson developed for the 2007 Worlds. The 7.6 & 7.7 props, on the other hand, are recent developments done independently of the engine. The 7.5 has been around for quite a while. One of the differences in the LS is the muffler. It’s got a shorter tuned length which would cause the engine to reach its HP peak at a higher RPM. My own LS would peak the 7.8 on the ground at 24.8 K. My best old style was 23.8. My engine would peak the 7.5 at almost 27K and the 7.6 was 26K or so. With the 7.8 the engine would run like crazy for the first 5 or 6 laps then start slowing down like it was going lean. The plug came out way lean. I was setting it over 2k down and it still did it. I believe the problem I had was different from the others. Dave took the engine to analyze what went wrong.

At this point, due to the prop issue, no one knows what prop will be best.

I don’t believe any rules were broken with the release of either the engine or props. This is racing and it’s pretty much the standard for new and better equipment to supersede the old designs. It’s also pretty common for a new weak link to show up.

This next part is just my opinion:
There were 73 entries from 8 countries at the PHX race. I firmly believe that without the APC props only half as many would have been there and I probably would have been one of the ones not there. I am hopeful this issue can be resolved in the near future without a huge impact on the Q40 community.

Take care,
Barry

(in reply to Ed Smith)
       Post #: 103

RE: NEW NELSON Q-40 - 2/27/2007 2:23:31 AM   
BUDMAN27



Posts: 1133
Joined: 3/28/2006
From: Galveston, TX, USA
Status: offline 		No davin it was not me. To tell you the truth I have read all this stuff you guys are saying about the new nelson and I couldn,t make heads or tails of it all.

(in reply to bl10)
       Post #: 104

RE: NEW NELSON Q-40 - 2/27/2007 3:45:01 AM   
daven



Posts: 6911
Joined: 12/7/2001
From: Andover, MN, USA
Status: offline 		LOL

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(in reply to BUDMAN27)
       Post #: 105

RE: NEW NELSON Q-40 - 2/27/2007 1:30:44 PM   
luv to race


 

Posts: 465
Joined: 12/10/2002
From: Liquored, FL,
Status: offline 		Like I said earlier, my situation was just as Barry described. The only difference was I launched at about 2,200 down from peak and made it about 6 or 7 laps then went lean and basically melted for 3 laps. Then I watched my teammate Travis stay about 15 to 1,800 down and have not one problem. Very puzzling? Some might think it's a tank position thing? I flew the new GR7 which has the tank in perfect alignment behind the engine. if anything the tank is slightly above the needle, which would be better than having the tank below the needle. Some might think it's a break-in time issue? I broke mine in as much as the next guy.. about 15 tanks through mine before the prop switch.. Freeman Jr had the same problem as Barry and I... he flew a polecat? who knows.... What I do know is the only thing I changed between Thursday's practice day and Saturday morning was prop.

I think Dave Shadel is a great guy. He spent more than enough time with me, rebuilt my motor on the spot, came out and needled it once to see for himself... not too many guys go that extra mile. And I guarantee that he will adjust piston fits and find the sweet spot as the year progresses...

Lastly... Schmidty, Shadel, Seaholm, and I had a FREAKING BLAST at the drag races. And the wife is super excited that I got Ashley Forces autograph on my JR jacket. We will be going to Gator Nationals in Gainsville... we say 4.43, at 331mph... that's better than FAI anyday!

RB....
SuperT's caller...

(in reply to daven)
       Post #: 106

RE: NEW NELSON Q-40 - 2/28/2007 12:10:24 AM   
burgster


 

Posts: 110
Joined: 6/19/2005
From: Lockport, NY, USA
Status: offline 		could they be over compressed?

Jeff

(in reply to luv to race)
       Post #: 107

RE: NEW NELSON Q-40 - 2/28/2007 11:27:26 AM   
BUDMAN27



Posts: 1133
Joined: 3/28/2006
From: Galveston, TX, USA
Status: offline 		It would seem like no one wants to answer your Q. burgster.

(in reply to burgster)
       Post #: 108

RE: NEW NELSON Q-40 - 2/28/2007 12:46:10 PM   
luv to race


 

Posts: 465
Joined: 12/10/2002
From: Liquored, FL,
Status: offline 		We played with that as much as possible. We all raised the head .003, .004, .005.. then back down again. My answer would be no.

RB

(in reply to BUDMAN27)
       Post #: 109

RE: NEW NELSON Q-40 - 2/28/2007 11:10:15 PM   
burgster


 

Posts: 110
Joined: 6/19/2005
From: Lockport, NY, USA
Status: offline 		Then must be a fit issue, maybe too tight. Had problems like that when I raced snowmobiles. Thing would run like stink then either haze a piston or lock up solid. i always thought it was a lean conditon or lack of oil, but it was a clearance issue. The piston would expand too much too quickly ie faster then the cylinder. I am sure that Dave will figure it out what ever it may be.

Jeff

(in reply to luv to race)
       Post #: 110

RE: NEW NELSON Q-40 - 3/1/2007 4:29:55 AM   
BUDMAN27



Posts: 1133
Joined: 3/28/2006
From: Galveston, TX, USA
Status: offline 		Sounds like everone is getting uptight over this new engine. life is to short to worry over such small things. If you can,t handle the presure than set on the side lines with me. Its not that bad from here. I get to watch a bunch of ritch guys fret over nothing.

(in reply to burgster)
       Post #: 111

RE: NEW NELSON Q-40 - 3/1/2007 4:48:17 PM   
DHG


 

Posts: 896
Joined: 4/24/2002
From: Arvada, CO, USA
Status: offline 		That's why I like football. Our millionaires can beat up your millionaires!

(in reply to BUDMAN27)
       Post #: 112

RE: NEW NELSON Q-40 - 3/1/2007 7:11:58 PM   
BUDMAN27



Posts: 1133
Joined: 3/28/2006
From: Galveston, TX, USA
Status: offline 		Me too

(in reply to DHG)
       Post #: 113

RE: NEW NELSON Q-40 - 3/1/2007 8:08:58 PM   
HighPlains


 

Posts: 2669
Joined: 3/2/2003
From: Over da rainbow, KS, USA
Status: online 		Does the earlier tuned muffler still fit on the LS? Perhaps that would allow it to have enough torque to turn the 7.8 props.

Also, since the liner shims from the earlier Nelsons still fit, will the older P/S set and head fit into the LS for added displacement, giving something close to a .45 or more?

< Message edited by HighPlains -- 3/1/2007 8:09:34 PM >

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(in reply to bl10)
       Post #: 114

RE: NEW NELSON Q-40 - 3/1/2007 8:17:01 PM   
luv to race


 

Posts: 465
Joined: 12/10/2002
From: Liquored, FL,
Status: offline 		The old muffler will fit. I watched Rusty helping Frank Wong in Phx... Frank accidently put the old muffler on the new motor. Would even hardly run, coughing rich in the air. Not sure about your next question... But I'm sure Dave tried all the combinations, before settling with this one.

(in reply to HighPlains)