Blower snout getting hot
+ Reply to Thread
Results 1 to 12 of 12

Thread:
Blower snout getting hot

  1. #1
    Senior Member
    Join Date
    Feb 2009
    Location
    SF Bay Area
    Posts
    204

    Default Blower snout getting hot

    8-71 16% over, tension is 1 1/2" total deflection hot, oil is Red Line Shockproof. By hot I mean 150+ degrees. Blower case stays cool until the snout starts to heat up the gear case area. Rotor area of case and rear bearings both stay cool.
    Guys, any idea why?
    Last edited by SFOcean; 07-14-2013 at 08:19 PM.

  2. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  3. #2
    gn7
    gn7 is offline
    Senior Member gn7's Avatar
    Join Date
    Jan 2008
    Posts
    25,975

    Default

    Quote Originally Posted by SFOcean View Post
    8-71 16% over, tension is 1 1/2" total deflection hot, oil is Red Line Shockproof. By hot I mean 150+ degrees. Blower case stays cool until the snout starts to heat up the gear case area. Rotor area of case and rear bearings both stay cool.
    Guys, any idea why?

    I take it by the question you don't want to hear its normal.

    Keep in mind the blower has gas vaporizing inside it. Mine will get frost on the top near the carbs under the right conditions. Heat from a roots is made in the manifold, not the blower itself like many think it is. Its why intercoolers for roots aren't nearly as effiicient as a with a turbo, centrif, or a Whipple screw. The air passing thru the roots chiller doesn't see nearly the heat of compression that happens with the others. If the roots was run at 10,000 rpm off the manifold with alcohol, it would damn near discharge ice cubes. It does not compress air, it simply moves air. The others compress air.


    The rear plate is nothing more than two bearings support the rotors and pretty much along for the ride. Not a lot of load there, and the thin bearing plate is in direct contact with the inside of the blower.

    If you can hold you hand on the snout for even a couple seconds, its not that hot.

    Now the front. Two ball bearings on the rotors, two helical cut gears with the thrust forces as well as the force trying to seprate them (which is a huge force), plus two ball bearings supporting the snout shaft and the belt forces they deal with, all spinning at XX% faster than the crank, add in the heat of the belt transmitting heat into the pulley, and a oil splash for lube, and most of all this is not in direct contact with the inside of the blower.
    Remember, the snout and everything attached to it is dealing with roughly 200-300HP transmitted thru it.

    Imagine a v drive in a boat without a water jacket, or an outdrive without the shower.

    there is a lot of power transmitted between the pulley and the blower case, and power is heat.



    100% free webcam site! | Awesome chicks and it is absolutely free! | Watch free live sex cam - easy as 1-2-3
    Last edited by gn7; 07-14-2013 at 10:14 PM.

  4. #3
    Senior Member
    Join Date
    Feb 2009
    Location
    SF Bay Area
    Posts
    204

    Default

    Actually, that is really good news to me!
    Thanks for taking the time to explain, my experience with roots blowers before this boat is with alcohol funny car and nostalgia top fuel drag racing. This gas endurance engine is a totally different animal.
    Greg

  5. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  6. #4
    Thrasher187 Steve Slostad's Avatar
    Join Date
    Sep 2012
    Posts
    102

    Default

    My first real high speed run trying to get 100 mph on my 28 Daytona ended with a very hot snout too. I even went as far as changing the oil in the blower to check for signs of a bad bearing. All was fine. I guess it just gets hot. Loosened the belt tension to 2" of deflection as it was a little tight. The belt has never got tight all summer at cruising speed but when I was WFO for several speed runs playing with different trim settings the belt definitely got tight. Ended up only getting 85 mph at 4500 rpm 5 lbs boost,so I have to figure out where I am leaving hp on the table.

  7. #5
    Senior Member
    Join Date
    Feb 2009
    Location
    SF Bay Area
    Posts
    204

    Default

    My belt was a bit tight also, have to set it 2.5" cold, I think the belt is a 1600 length due to the 4" intercooler. I have made a simple but very effective cooler for the snout, now I can run for 30 or more minutes at 5500 for 85mph.

  8. #6
    Thrasher187 Steve Slostad's Avatar
    Join Date
    Sep 2012
    Posts
    102

    Default Cooler

    Quote Originally Posted by SFOcean View Post
    My belt was a bit tight also, have to set it 2.5" cold, I think the belt is a 1600 length due to the 4" intercooler. I have made a simple but very effective cooler for the snout, now I can run for 30 or more minutes at 5500 for 85mph.
    I gotta see this cooler !

  9. #7
    Senior Member
    Join Date
    Feb 2009
    Location
    SF Bay Area
    Posts
    204

    Default

    Quote Originally Posted by Steve Slostad View Post
    I gotta see this cooler !
    It is just 1/4" aluminum tubing wrapped around the snout behind the swing belt adjuster. It is plumbed from the intercooler sand strainer and out into a header drain.

  10. #8
    gn7
    gn7 is offline
    Senior Member gn7's Avatar
    Join Date
    Jan 2008
    Posts
    25,975

    Default

    You guys figure that snout is getting hotter than the rear end in your truck towing to the water?



    100% free webcam site! | Awesome chicks and it is absolutely free! | Watch free live sex cam - easy as 1-2-3

  11. #9
    New here Beer:30's Avatar
    Join Date
    Feb 2008
    Location
    Bakersfield, CA
    Posts
    4,219

    Default

    Quote Originally Posted by gn7 View Post
    You guys figure that snout is getting hotter than the rear end in your truck towing to the water?
    Every now and then, you actually say something that is correct.

    Anytime you guys think your blower snout it hot....crawl under and look at a stock rear-end cover on your PU. The paint will be FLAKED OFF from heat. I just serviced the wife's rear end () and her normal-street-driven Yukon has COOKED the coating on the cover and about an inch out from it. No wonder GM started spec'ing synthetics in these units.

    Mine are filled with TORCO SGO now, so I know I am covered.
    Quote Originally Posted by gn7 View Post
    EFI is the wave of the future. There can be no denying it. Electronics have been on the leading edge of our entire lives. Not only os the magneto dead, but the standard issue CDI is wavering. Its all about total fuel, air AND spark control. Anybody that thinks its not has their head up their ass.


    2001 SleekCraft 30' Heritage SSB, open-bow mid-cuddy. 496HO / Bravo-I.

  12. #10
    Senior Member
    Join Date
    Feb 2009
    Location
    SF Bay Area
    Posts
    204

    Default

    Quote Originally Posted by gn7 View Post
    You guys figure that snout is getting hotter than the rear end in your truck towing to the water?
    Maybe not but I figured that heat has to be getting into the intake charge especially since not a lot of air goes by the front of the blower like it does on GN7's deal, mine's under a hatch, okay, there is a scoop on it but that is mostly full of carbs . My 'heat mitigation device' costs almost nothing, was easy to do and does not look bad (I have had to replace snout bearings that were only 50 hrs old).

  13. #11
    gn7
    gn7 is offline
    Senior Member gn7's Avatar
    Join Date
    Jan 2008
    Posts
    25,975

    Default

    Quote Originally Posted by SFOcean View Post
    Maybe not but I figured that heat has to be getting into the intake charge especially since not a lot of air goes by the front of the blower like it does on GN7's deal, mine's under a hatch, okay, there is a scoop on it but that is mostly full of carbs . My 'heat mitigation device' costs almost nothing, was easy to do and does not look bad (I have had to replace snout bearings that were only 50 hrs old).
    You did replace then snout bearing because it got too hot. You replaced them because your belt was too tight.
    Keep on mind that on the other end of the too tight belt was the crank snout, which by the way, the oil there is hotter than the blower snout.

    140* is about the limit you can hold you hand on for any period of time.
    Gear oil, CHEAP gear oil, isn't in trouble until over 250*. That's hot enough to steam water on contact.



    100% free webcam site! | Awesome chicks and it is absolutely free! | Watch free live sex cam - easy as 1-2-3

  14. #12
    Senior Member
    Join Date
    Feb 2009
    Location
    SF Bay Area
    Posts
    204

    Default

    "You replaced them because your belt was too tight"

    Most likely true; my real concern is not the blower, it is the intake charge temperature. The front of the blower case went from 155 to 115 or so, I will be running it tomorrow for a ways after which I will shoot it and see exactly what the new temperature is. I know, splitting hairs, but it all adds up.
    Last edited by SFOcean; 08-09-2013 at 06:06 PM.

+ Reply to Thread

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Please select your insurance company (Optional)

Log-in

Tags for this Thread

Digg This Thread

Posting Permissions

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

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95