BBC running "warm"
+ Reply to Thread
Page 1 of 2 1 2 LastLast
Results 1 to 14 of 19

Thread:
BBC running "warm"

  1. #1
    Senior Member
    Join Date
    Aug 2008
    Posts
    357

    Default BBC running "warm"

    I have had these same symptoms on 2 engines, old mostly stock 454 and the new 476. With the pump outlet valve all the way open the engine runs at 150 idle and 130 cruising, if I close the valve at all it gets hotter. I have checked everything but the wear ring. Turning the pump over by hand it sounds totally normal, no rubbing or grinding sounds, jet seems to be running fairly efficiently. I pulled the pump outlet pipe off and there was nothing gumming up the hole, can't really see anything. Is this definitely a shifted wear ring? My dash gauge reads 150 when my manifold mounted gauge reads 120, but this is the second dash mount gauge and second sending unit reading the same thing. Is it at all possible that the wire could cause this?? My experience tells me know, but I've seen some weird shit happen before...

  2. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  3. #2
    Senior Member bc18's Avatar
    Join Date
    Jul 2008
    Posts
    950

    Default

    Quote Originally Posted by nos1967 View Post
    I have had these same symptoms on 2 engines, old mostly stock 454 and the new 476. With the pump outlet valve all the way open the engine runs at 150 idle and 130 cruising, if I close the valve at all it gets hotter. I have checked everything but the wear ring. Turning the pump over by hand it sounds totally normal, no rubbing or grinding sounds, jet seems to be running fairly efficiently. I pulled the pump outlet pipe off and there was nothing gumming up the hole, can't really see anything. Is this definitely a shifted wear ring? My dash gauge reads 150 when my manifold mounted gauge reads 120, but this is the second dash mount gauge and second sending unit reading the same thing. Is it at all possible that the wire could cause this?? My experience tells me know, but I've seen some weird shit happen before...
    I don't know why your worried about that temperature, that's all normal operating temp for a jet boat.

  4. #3
    Senior Member jetjunky's Avatar
    Join Date
    Jul 2008
    Location
    Diamond Bar, Big River
    Posts
    1,145

    Default temps

    what pump are you running? If a berk. style pump, I don't see any way a wear ring could "shift" and interrupt the water flow. If the w.r were to move it would be on the impeller and making noise. As mentioned those temps aren't really anything to be overly concerned with. I am more concerned with my oil temps than water temps. although I monitor both carefully. I trust my mechanical location gages more than elec. gages. What size and type of plumbing are you running? Are you running a t-valve for headers with the ball and spring for idle water control? Maybe it's sticking? Where has the boat been used for the previous years? If in a sandy water area like the lower colorado, such as blyth, yuma etc. the block may be filling with sand and need to be flushed if the problems worsen. Kinda graspen at straws on the last one but just a potential issue/thought. When your gage reads 250+, you can hear the water boiling in the block and it's steaming violently out the dump line then you should get worried.

  5. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  6. #4
    Senior Member
    Join Date
    Aug 2008
    Posts
    357

    Default

    I figured the old engine had sand in it, but the fresh engine is doing the same thing. It's just a valve at the pump followed by the normal log setup. I also just ultra sonic cleaned my logs and snails and got a crap ton of sand and zebra snail chicks out. I'm not worried about these temps, just curious as to why it's happening. Previously in every boat I have ever had, including this boat when I first got it, with the valve wide open the temp gauges wouldn't even read above 110 no matter what the speed. I guess I should hook up a pressure gauge and see what's up.

  7. #5
    Senior Member jetboatperformance's Avatar
    Join Date
    Dec 2007
    Location
    Atascadero Calif
    Posts
    7,463

    Default

    Quote Originally Posted by nos1967 View Post
    I have had these same symptoms on 2 engines, old mostly stock 454 and the new 476. With the pump outlet valve all the way open the engine runs at 150 idle and 130 cruising, if I close the valve at all it gets hotter. I have checked everything but the wear ring. Turning the pump over by hand it sounds totally normal, no rubbing or grinding sounds, jet seems to be running fairly efficiently. I pulled the pump outlet pipe off and there was nothing gumming up the hole, can't really see anything. Is this definitely a shifted wear ring? My dash gauge reads 150 when my manifold mounted gauge reads 120, but this is the second dash mount gauge and second sending unit reading the same thing. Is it at all possible that the wire could cause this?? My experience tells me know, but I've seen some weird shit happen before...
    Might have missed this but are you routing the water thru the logs first before the water precedes into the block ?

  8. #6
    Senior Member
    Join Date
    Aug 2008
    Posts
    357

    Default

    Yes the water goes through the logs first.

  9. #7
    Senior Member jetjunky's Avatar
    Join Date
    Jul 2008
    Location
    Diamond Bar, Big River
    Posts
    1,145

    Default

    well since the old block and exhaust manifolds were clogged with sand and z. muscles it seems safe to assume one or both is also clogging every other item associated with that system so it seems a complete replacement or thorough cleaning of all cooling sys. components, hoses, fittings etc. would be necessary. Maybe the new motor is just tighter and not fully broke in yet and causing more heat from tighter tolerances? Is the new motor turning more rpm's?

  10. #8
    Senior Member
    Join Date
    Aug 2008
    Posts
    357

    Default

    Hoses are all new or inspected, logs and snails were sonic cleaned and water runs through them like butter, temperature is at idle and same cruising speed/rpm. I can easily squeeze the pump outlet hose with two fingers, feels like there's barely any pressure. I haven't taken the jet apart, but looking through the intake and hand hole everything looks fine.

    the only thing that is the same on the boat is the pump and the outlet valve, and I took the outlet valve apart to inspect it. What kind of direct mount pressure gauge is readily available at lowes or Home Depot?
    Last edited by nos1967; 05-16-2016 at 10:53 AM.

  11. #9
    Senior Member
    Join Date
    May 2012
    Posts
    109

    Default

    pull your bowl and check the area behind impeller. I had a thrust bearing failure that caused overheating from it eating up the area by the water inlet for motor, destroyed the impeller and did not really hear or feel it. I bought the boat apparently with this issue and did not know it
    1990 ultra 21' open bow. 509, American turbine Jet

  12. #10
    Senior Member
    Join Date
    Aug 2008
    Posts
    357

    Default

    Did you have any play in the shaft to let you know the thrust bearing had failed?

  13. #11
    Senior Member
    Join Date
    May 2012
    Posts
    109

    Default

    not that I felt by hand, but I think the packing held it tight. just seen the backend of impeller wasn't looking right thru clean out
    1990 ultra 21' open bow. 509, American turbine Jet

  14. #12
    Senior Member
    Join Date
    Aug 2008
    Posts
    357

    Default

    I measured from the water outlet opening to the impeller on two pumps, the one in my boat and one I have sitting in the garage and the distance was the same.

  15. #13
    Senior Member jetboatperformance's Avatar
    Join Date
    Dec 2007
    Location
    Atascadero Calif
    Posts
    7,463

    Default

    Quote Originally Posted by nos1967 View Post
    Hoses are all new or inspected, logs and snails were sonic cleaned and water runs through them like butter, temperature is at idle and same cruising speed/rpm. I can easily squeeze the pump outlet hose with two fingers, feels like there's barely any pressure. I haven't taken the jet apart, but looking through the intake and hand hole everything looks fine.

    the only thing that is the same on the boat is the pump and the outlet valve, and I took the outlet valve apart to inspect it. What kind of direct mount pressure gauge is readily available at lowes or Home Depot?
    Good Investment is a small handheld IR temp sensor (Pep boys, Oriellys ect) ,you can use it for a multitude of things like checking oil temp on the pan surface as well as actual block and head temp. The temps you describe are close to what everyone seems to want (but normally cant obtain ) for their Jet I would first verify that the temp your seeing is actually true , if you want it to run cooler you could re plumby running raw water to a T , then into the block , then out of the intake (no T stat) and then to your logs and then the second log nipple loops back to your rizer and finally out thru the tips

  16. #14
    Senior Member
    Join Date
    Aug 2008
    Posts
    357

    Default

    Tanks Tom. I spent a few years of of life carrying one of those around a ship, I probably have one at work I can borrow for a day. I'm happy with the temps, just a little worried that I have these temps with the valve all the way open. I'll just monitor both gauges next week, knowing that the impeller hasn't shifted gives me more of a warm and fuzzy.

+ Reply to Thread
Page 1 of 2 1 2 LastLast

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