Page 2 of 2 FirstFirst 12
Results 11 to 20 of 20

Thread: Race 92 update...The quest for 400 mph

  1. #11
    Join Date
    Jun 2011
    Location
    Reno, Nevada
    Posts
    2,015

    Default Re: Race 92 update...The quest for 400 mph

    Quote Originally Posted by CubersWrist View Post
    Are there any good pictures of the old Rare Bear exhaust system?
    I've heard about it, but haven't seen an explanation of why it was supposed to be better?

    Baffling is annoying. I wish the cowling/plenum could be clear so we could blow smoke through it and get some flow visualization. Especially when it comes to spray bars. Or I wish that CFD was easier to use and more reliable...

    Not to get too off topic, but reminds me of a story. A couple of years ago we had some cooling issues with the plenum (I think it was cylinder 3) and the new intake tube layout. We figured we could troubleshoot and fix the airflow inside the plenum or add another spray bar nozzle above that cylinder. We decided we would be lazy and add another nozzle. Next test flight we found the messed up airflow caused our new nozzle to cool cylinder 1 instead! So we had to fix the plenum....
    Heres one from 2012

    Click image for larger version. 

Name:	HWR_2128.jpg 
Views:	672 
Size:	315.8 KB 
ID:	24066

  2. #12

    Default Re: Race 92 update...The quest for 400 mph

    Quote Originally Posted by Desertdawg View Post
    Heres one from 2012

    Click image for larger version. 

Name:	HWR_2128.jpg 
Views:	672 
Size:	315.8 KB 
ID:	24066
    Oof, that's even uglier than I remember. Trying to get all of those tubes to align, and not be pretensioned, after who knows how many heat cycles could be an exercise in frustration. In the picture you can see where it's off a little bit on the lower exit pipe, it shouldn't be pointed at that fairing, but I bet whoever installed it spent many hours trying to get it perfect and finally had to be satisfied with what was possible.
    Last edited by knot4u; 12-28-2018 at 09:29 AM.

  3. #13

    Default Re: Race 92 update...The quest for 400 mph

    Quote Originally Posted by CubersWrist View Post
    Are there any good pictures of the old Rare Bear exhaust system?
    I've heard about it, but haven't seen an explanation of why it was supposed to be better?

    Baffling is annoying. I wish the cowling/plenum could be clear so we could blow smoke through it and get some flow visualization. Especially when it comes to spray bars. Or I wish that CFD was easier to use and more reliable...

    Not to get too off topic, but reminds me of a story. A couple of years ago we had some cooling issues with the plenum (I think it was cylinder 3) and the new intake tube layout. We figured we could troubleshoot and fix the airflow inside the plenum or add another spray bar nozzle above that cylinder. We decided we would be lazy and add another nozzle. Next test flight we found the messed up airflow caused our new nozzle to cool cylinder 1 instead! So we had to fix the plenum....
    Baffling stinks, and Greg Shaw was adamant that we'd get it completely sealed. It was either the first or second Phoenix race and we were still working on the baffles in the pits. I was up on a ladder with a caulking gun full of sealant filling the gaps, one of my best friends to this day was working below me on the lower cylinders. I came across a gap I could not fill regardless of the amount of silicone I pumped into it, then I looked down and saw a saucer sized pool of goop on top of my friends head. He was not pleased, but we managed to endeavor to persevere. Years later he had lost a lot of his hair and suggested to me it might be my fault, I once again profusely apologized. But then I reminded him that every time he would come to the house and sit on the couch my Jack Russel would jump onto the back of the couch and lick the top of his head so it might have been her fault. I have tact, I'm tactful.

  4. #14
    Join Date
    Nov 2004
    Location
    Napa Ca
    Posts
    1,301

    Default Re: Race 92 update...The quest for 400 mph

    With everything sealed up, and with so little space around the cylinders, how did the air get out of the cowling area? Both Rare Bear and 232 have some of the tightest fitting cowlings out there, but I don't see an obvious way for the hot air to escape aside from the exhaust stack exits. I'd imagine that even with a cylinder spraybar setup, Id guess you are still going to run into stagnant non moving air which neither assists cooling, or drag. I know Pete Law has looked at both 77 and 232 and offered ideas to make them both cool better.

    Will

  5. #15

    Default Re: Race 92 update...The quest for 400 mph

    Quote Originally Posted by RAD2LTR View Post
    With everything sealed up, and with so little space around the cylinders, how did the air get out of the cowling area? Both Rare Bear and 232 have some of the tightest fitting cowlings out there, but I don't see an obvious way for the hot air to escape aside from the exhaust stack exits. I'd imagine that even with a cylinder spraybar setup, Id guess you are still going to run into stagnant non moving air which neither assists cooling, or drag. I know Pete Law has looked at both 77 and 232 and offered ideas to make them both cool better.

    Will
    It did exit through the same opening as the exhaust, that's why the fact that it acted as an augmenter for the pressure cowl was so important. The small gap between the cowl and spinner would only allow a certain amount of air in, everything else just blew away (tee hee). That's what made the baffles so important, the air that was sucked out needed to be used properly to keep CHTs in a reasonable range. The cowl came off of a DC-7, as did the majority of the baffling, but no airline ever tried to push their 3350s as hard as the bearcat did, and it required special attention. I'm still pretty sure it has the capacity to be the fastest piston powered contraption that's been conceived yet, but it's going to take a lot of work to simply climb back up to the lofty heights it used to frequent.

  6. #16
    Join Date
    Jul 2013
    Location
    KSBP
    Posts
    958

    Default Re: Race 92 update...The quest for 400 mph

    Anybody know if Dusty will be bring Polar Bear also or just the yak?

  7. #17
    Join Date
    Sep 2013
    Location
    SYRACUSE, KANSAS
    Posts
    27

    Default Re: Race 92 update...The quest for 400 mph

    HI GUYS....... AS WILL SAID IN A THREAD A WHILE AGO, POLAR BEAR WON'T BE RACING. IT HAS A LIST OF OVER 50 ITEMS TO BE ADDRESSED BEFORE FLYING AGAIN AND I'M TRYING TO PAY OFF A LOAN AT THE BANK THAT I HAD TO DO '
    TO SEE IT FINISHED. AS USUAL, I'M SPENDING MOST OF MY TIME ON SPRAY PLANES TO MAKE A LIVING AND WORKING ON THE YAK EVENINGS TILL THE WEE HOURS ON THE EXHAUST AND INTAKE SYSTEMS. WILL POSTED PICTURES OF THE DUMMY STACKS THAT SAM DAVIS WILL COPY IN STAINLESS AS SOON AS I GET THE EXIT DUCTS DONE. SORRY FOR NOT POSTING, BUT I ALWAYS LOOK AT MY FAVORITE WEBSITE TO SEE WHAT PEOPLE WILL SAY. SOME GOOD, SOME BAD.
    I WISH ALL THE HAPPIEST OF NEW YEARS AND IF I GET THE YAK TO RENO, I HOPE YOU WILL COME BY THE PITS AND SAY HI......
    BEST,
    DUSTY
    PS: FIND ME A SPONSOR ;-))

  8. #18
    Join Date
    Aug 2007
    Location
    San Diego, CA
    Posts
    1,991

    Default Re: Race 92 update...The quest for 400 mph

    Quote Originally Posted by Dusty View Post
    HI GUYS....... AS WILL SAID IN A THREAD A WHILE AGO, POLAR BEAR WON'T BE RACING. IT HAS A LIST OF OVER 50 ITEMS TO BE ADDRESSED BEFORE FLYING AGAIN AND I'M TRYING TO PAY OFF A LOAN AT THE BANK THAT I HAD TO DO '
    TO SEE IT FINISHED. AS USUAL, I'M SPENDING MOST OF MY TIME ON SPRAY PLANES TO MAKE A LIVING AND WORKING ON THE YAK EVENINGS TILL THE WEE HOURS ON THE EXHAUST AND INTAKE SYSTEMS. WILL POSTED PICTURES OF THE DUMMY STACKS THAT SAM DAVIS WILL COPY IN STAINLESS AS SOON AS I GET THE EXIT DUCTS DONE. SORRY FOR NOT POSTING, BUT I ALWAYS LOOK AT MY FAVORITE WEBSITE TO SEE WHAT PEOPLE WILL SAY. SOME GOOD, SOME BAD.
    I WISH ALL THE HAPPIEST OF NEW YEARS AND IF I GET THE YAK TO RENO, I HOPE YOU WILL COME BY THE PITS AND SAY HI......
    BEST,
    DUSTY
    PS: FIND ME A SPONSOR ;-))
    I will say even though the A model is one of the most beautiful planes I’ve seen race, I LOVE Lylia on the course. She has a distinct sound to her, somewhat of a more “refined” Wildcat. Can’t wait to hear what she sounds like with the new exhaust. Good luck Dusty!!!! Hope you can make it!
    *My Air Race Site*

    Reno from '99 to '19

  9. #19
    Join Date
    Jul 2013
    Location
    KSBP
    Posts
    958

    Default Re: Race 92 update...The quest for 400 mph

    Thanks for chiming in Dusty! That would be awesome if you could find a sponsor!

  10. #20
    Join Date
    Nov 2004
    Location
    Napa Ca
    Posts
    1,301

    Default Re: Race 92 update...The quest for 400 mph

    From Dusty's post under the Chino Bearcat thread...
    "I SENT A COUPLE PICTURES OF THE YAK EXHAUST MODS TO WILL CAMPBELL TO POST AS I HAVEN'T BEEN ABLE TO
    ACCOMPLISH THAT ON MY OWN. THANK GOD I CAN FLY A LITTLE BETTER THAN I AM AN I.T. GUY......
    I COUPLE YEARS AGO, I WAS DOING LATE-NIGHT NACA SEARCHING AND FOUND A STUDY ON A P-41 WITH AN 1830 ENGINE SIMILAR TO MINE. THE ORIGINAL AIRCRAFT HAD A COLLECTOR LIKE I HAD, AND THEY INSTALLED 14 INDIVIDUAL
    "JET STACKS". DON'T REMEMBER THE EXACT NUMBERS CURRENTLY, BUT THEY ACHIEVED 18MPH INCREASE AT 350MPH
    AT 18,000' IF MY MEMORY SERVES ME. SO, SEEING HOW THE DC-3 COLLECTOR STACK WAS IN SORRY CONDITION, IT WAS ON "THE LIST" TO DO. THE OTHER ITEM TO ATTACK IS THE CARB INTAKE TRUNK, WHICH DID MAKE TWO 90 DEGREE BENDS FOLLOWED BY A 120 DEGREE BEND GOING INTO THE CARB. WUFFFF. ANYWAY, SO THAT WILL BE ADDRESSED
    AND HOPEFULLY ANOTHER NOSE SPINNING I WILL MAKE OUT OF GRAPHITE. THE NEW GOAL IS 400 ON THE COURSE. I TOLD OUR FEARLESS LEADER ( AND I MEAN THAT LITERALLY), ONE SHERMAN SMOOT, THAT I INTENDED TO COME BACK AND DO 400 AND HE SAID "NO WAY". WELL, YOU CAN'T TELL AN OLD IRISH GUY "NO WAY" AND NOT EXPECT TROUBLE.
    SO THE MUSTANG.......STILL BANGING AWAY ON SOME STUFF ON IT BEFORE IT FLIES AGAIN. MANY ITEMS TO
    ADDRESS, BUT SPRAYING HAS BEEN SLOW, SO I HAVE DONE SOME WORK ON IT.......
    UNFORTUNATELY, NEITHER MACHINE CAN BE MADE READY FOR RENO 2020 IF IT HAPPENS. HOWEVER, BILL SHEPHERD, WHOM I GOT THE YAK FROM, HAS PURCHASED AN ALLISON POWERED YAK AND ASKED IF I WOULD
    FLY IT AT RENO. SO, IF IT CAN ME READY FOR RENO, I MIGHT GET TO DRIVE IT AROUND CONSERVATIVELY.
    BEDTIME GUYS. DON'T LET YOUR DREAMS DIE. I WENT TO MY FIRST AIR RACE IN 1958 WHEN I WAS 7 YRS YOUNG, AND DECIDED I WAS GOING TO RACE. 21 YEARS LATER, RACED FORMULA AT CLEVELAND IN '79. BEEN THE LUCKIEST GUY I KNOW AND HAVE THE BEST FRIENDS A PERSON COULD EVER ASK FOR. NITE......
    DUSTY"

    Here are the pics of the new exhaust system. Well, one at least. I tried to upload the other two and got a "image failed to upload" They are both about 2.62 mb. The one that did upload is just under 2mb. Isn't the size restriction 5mb for an image?





    I hosted the images elsewhere and linked them over. It really would be awesome to have a little more file size so I can save theme here.

    Will
    Last edited by RAD2LTR; 04-22-2020 at 11:17 AM.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •