why is there water in my manifold?

[tahiti79]

Hi, I am new to the website and a new and proud owner of a 79'tahiti jet boat. It has a 454 and a panther jet and water cooling system. It has headers that run up and out of the engine compartment with two water injection lines on it. (at least I think they are) anyway, i noticed the other day that there is water dripping out of small holes on the exhaust pipe just after the manifold(water-jacket) and right before it upsweeps into a ninety degree angle out of the engine compartment. I dont know that the exhaust comes in direct contact with water however I may be incorrect. It would seem that it is though. If anyone has any suggestions, let me know. The two water lines connected to the exhaust pipe are just before the 90degree up-sweep and at the top of the ninety, the darn things keep flooding my bilge....please help if you can. thanks so much

[BIGA]

from what you describe i believe that you have a set of single jacketed headers. the water lines inject water into the headers as coolant. there are small holes in the bend of the tubes to allow this water to weep or leak out at low rpm. it is normal that there will be some small amount of water coming out at low rpm. as rpm rises this should be expelled thru the pipe as the velocity of the exhaust picks up. you should not be getting a large amount of water into your bildge compartment. most of these headers if i am understanding your problem correctly came with a t-valve witha low pressure spring to limit the amount of water that is injected into the exhaust. also on a jet it is possible that the coolant source is overpowering the valve. check the valve and check the corrrect plumbing. there is a diagram on the www.bassettracing.com site that will show how to plumb the system.

[tahiti79]

What you wrote makes good sense, the water didnt start dripping from my header until after I hooked my garden hose to the water intake line just after the pickup on the jet..HMMMMM, perhaps I applied to much water pressure and the T-valve is stuck in an open position. I will check the valve..You seem very knowledgable!! By the way, my 454 loves to run at 16 degrees advanced, people tell me that this is to far and I could damage my pistons by doing so..Anything lower than 10 degrees and it sputters and hesitates before the secondaries open...Any suggestions? thank you, sincerely, Tahiti79

[Darkside's Calling]

For the high initial timing, it could be as simple as a slipped outer ring on the balancer, do a TDC chck using a piston stop to verify that first.

Other possibilities are low compression, either mechanical or cranking. Run a compression check and see what your cranking compression is. Should be around 120 ish someplace. If it's low then you'll have to figure out if its due to mechanical compression ratio (Piston to head clearance and head volume) or cam lift/duration or cam phasing (possibly retarded, allows compression to bleed off before teh intake valve closes).

[BIGA]

thanks for the kind words, have done this a long time, try to be accurate in the answers, now with more info ii will zoom in on the water source. the t-valves are designed to operate on sigle digit lb sof pressure. a jet at idle will only put out 2-6 lbs. your water hose is probably in the 20 lbs or greater, i am sure that there is most of your problem. if you run your jet on the water hose , which i do not advise, be sure that you start the engine before engaging the water as it may,will ,enter excessively into the exhaust and can hydro lock the engine, ie, bending rods or worse. thanks john

[SS-201]

Check your full timing at 2500-3000 rpm. 32-34 that's the important one

The idle timing is starting and running until you get to 25-34 RPM. Your 16 degree is the inital but is the difference between full - idle so for the sake of obtaining full timing would be 18 + 16 full timing would be total 34

[tahiti79]

That would make perfect sense, so that is why it seems to run so well at 16 degrees! hmmm, do you believe that to be to far advanced as an initial timing setting? thanks for your input, its comforting to hear from individuals that know how these motors work. Tahiti