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NeedMoreSpeed
11-25-2002, 06:42 AM
I have a 94 Advantage 22.3 454 Carb. about 300 hp. Bravo one 3 blade stainless. I was advised to remove the water pump and install a bypass with no thermostat. The first test run, showed less then 100 degrees temp. At wide open trottle, 58 mph. 4800rpm. spun a barring :( What did I do wrong??? Or is the lower end due at 300 hrs? Thanks any comments greatly appreciated.
[ November 26, 2002, 06:40 PM: Message edited by: NeedMoreSpeed ]

Spirit of Discovery
11-27-2002, 12:10 PM
Call James at Extreme Marine in Los Alamitos. The guy is brilliant!! 562-431-0577

NeedMoreSpeed
11-27-2002, 12:31 PM
THANKS, I WILL GIVE THIS GUY A CALL. BOB :)

gnarley
11-27-2002, 12:35 PM
Should of had no effect on the lower end with the stat out, sounds like something else. How was the Engine & oil before you did the last test?

NeedMoreSpeed
11-27-2002, 12:57 PM
Everything was always very well maintained, I just did a valve job on the motor. I was trying to cut corners by not doing the lower end. Obvisosly it was a costly mistake. It made 2 passes at 60mph and the thrid pass it lost oil pressure. I was concerned it was caused by running to cold. I think it was just due to be done. Thanks

wsm9808
12-08-2002, 08:42 PM
Most of the jet boats run a real low temp, usually somewhere around 120degrees. Some of those boats have been running around on the same motor for 20 years. I wouldn't think the cold temp was what damaged the bottom end. Check the oil pump drive shaft, if you suddenly dropped to zero oil pressure, the shaft may have broken.

NeedMoreSpeed
12-09-2002, 08:26 AM
Thanks for the input. I definitly spun a barring. And I guess I will tear into it in a couple of weeks. Thanks again. Bob :)

Ian
12-11-2002, 04:04 PM
I don't know why you would want to run such low temp, my friend is an engine builder and does extensive dyno testing, and with some heat in the motor 160-180 the engines typically make more power. I know on my flat I make more power and get more rpm's with some temperature in the motor. A motor with three hundred hours should not spin a bearing (my dad's Mastercraft has over 1200), 300 hours in a car would probably equal well less than 18,000 miles. It's possible you spun a bearing because the oil didn't have time to thin out. In my cruiser I let it warm up to at least 140 before I get on it too hard. Just my 2 cents. PM me if you want the number of a good engine builder/machine shop.

NeedMoreSpeed
12-11-2002, 07:48 PM
Thank you for your reply. I'm a mechanic with 41 years experience and have always believed that engines were designed and perform better at 160 to 180 degress just like you said. I took the advise of a performance marine shop, against my better judgment. I also believe thats what happened to my motor. When I rebuild it, I will have to design a bypass because I took out the water pump and I will put back in the thermostat, probally a 160. Thank you Bob :rolleyes:

SilyDevil
12-11-2002, 09:55 PM
Ive been running my boat 18 yrs with same motor and never gets the gauge to move. I have tried every way to get the temp up, but you will lose something, like being able to idle for long time without overheating. there is always something, so i gave up yrs back and run it wide open,and never had a prob,and i run a BBC with NOS in the 110 range..only 2 freshups in the 17 yrs. just did # 3. And if you restrict the water to much, you run the chance of lifting the heads by excess water pressure...... WSM was right on the nose..
[ December 11, 2002, 09:57 PM: Message edited by: SilyDevil ]

Ian
12-11-2002, 10:53 PM
I agree that too much water pressure can be a problem with the heads, especially running copper head gaskets. That's why you restrict the water coming in, not going out. Think how much presure builds up at 70 mph, when you leave it wide open. On my flat we restricted the inlet and cut a couple viens off the impellor and have had no problems over heating. I'm not saying low temp is the reason he spun a bearing, but it is a good possibility, especially if the motor was put together with real tight clearances on the bearings. I think their is a reason almost everyone builds up heat in their motors before racing. Like I said this is just my 2 cents, I'm sure the majority of you have forgotten more about motors than I've learned.

NeedMoreSpeed
12-12-2002, 06:53 AM
Thanks very much for all the input. I was good friends with Kenny Lane--HTM---(and miss him greatly)and it's nice to find knowledgable people to talk with. Thank you again Bob :D