baronbob

I don't mean to jump on the band wagon but go back and read my response related to a procharger application. I tested my block with 20#s pressure as I too thought I might have a cracked block (winter temps are often below 0 here @ Tahoe) . No leaks even though I had a blown intake at the time. You should make a fresh run with the thermostat out!!! the pressure spec for a closed cooling system on my engine is a 16# cap. That is why I only tested to 20#s. I know you are frustrated but please listen to the experience with the circ pump out. I have only a little experience with water in the exhaust from a Leakey center rise gasket. It takes a while for water to make its way into the oil as it has to go through the rings. Please try this as it may just work.

Dirthead

Bartonbob, I will and I did not mean to ignore any advise, I must have missed it. Are you telling me to remove the thermostat? If so, I am ok with that. I have been considering removing the thermostat to reduce the water pressure. I know it is not ideal to not have the oil at a higher temp, however I need to fix the milkshake first and wory about oil temp second, in my opinion. I am going now to get a gage to test the water pressure. Are you saying nothing more than 20 PSI at idle or WOT? Would putting the circ pump back on lower the PSI? IF you like you can call me at 641-919-3406. THANKS!!!

Dirthead

I checked my water pressure at the block and at the top of the intake manifold. Both of them were 2-3 PSI at idle and about 8 PSI at 4000 RPM. From these numbers it does not appear that water pressure from the crossover is the problem. Any other ideas?

Dirthead

These readings were done while on the hose. However our shop hose is at a fairly high PSI for that it has a booster pump on it.

50boat

ih ive ben away for awhile reeding your problem, i have a 622 lift , 244 dur . i extend the tail pipes 12in. and use no flappers. i did this my slef , you need to cut the outer and inner pipes , use a small gringer, to do this. cut theouter one in. longertourds the riser, then cut the inner one in. longer. remove the inner and outer tail pipes and seperat them so you can wield the extions, inner first , then outer. atthe bottem of tail pipe , out flow end drill 3 half in. holes, about 3/4 in from end, do not pirce the inner pipe. weildthe inner and outer pipe to gather at end. you have just made a dry pipe but i dont think this is your prpblem,,, you must dicth the capations call and through prop smoker pipe also these water out let holes can not coverd buy a slip on muzzler

birdog

Thats not right....I never could show water pressure on the hose either. Put her in the water & try...Try removing the thermostat..Who Knows ?..I drilled holes in mine {new boat}
My Bullet had Blowers & the pumps..Never a problem..
Like Scott said...He is an idiot...ooops....Not That.....
Steam Pockets are another possible problem with crossovers
For 3-5 hp ?...Not worth it to me...............


Scott......You are SOOOO correct about some of my "Choices"

Dirthead

I just completed a test. 30 min with the exhaust going out the transom and got milkshake. 60 min with the exhaust going out the prop, and the oil looks great. The test was done on the hose, 700 rpm. I have done this test 4 times now and every time I get the same results. Any ideas? I know that this is completely opposite than what one would think with reversion happening when the exhaust has a clear shot out the rear and not when it is going out the prop. Any ideas??? THANKS!!!!

jspeeddemon

Ok here is my take on this and I have fought the same problem before as others have in this thread. The holes in the thermostat are to feed water to the Lightning headers while the thermostat is closed so they do not overheat.
Are you coming from the thermostat housing to the Lightning headers? Or does the thermostat housing have the four exits like from mercury? You have to figure a way to cut water out of the exhaust like has been mentioned here, that is paramount. I am assuming that you don't have a lot of slope to the exhaust. You can can run one side of the thermostat housing to a bulkhead dump out the side of the boat and then split the other exit from the thermostat housing and run those two hoses to each lightning header. This should be enough water to keep the lightning headers and rubber hoses cool enought that they don't burn. This will effectively cut your water in half and I would be surprised if that doesn't solve your problem. You simply have too much water in the exhasut and the boat cannot blow it out fast enough. This is how i solved mine and this is easy with a bulkhead fitting and a tee. The ultimate fix would be to seal the holes in the lightning headers, have a connection tube welded in the tips and headers, then drill holes in the end of the tips for it to dump, this is how the water exits on my lightnings, and mine is called the dry system.

Hot Boat

For you to get the proper reading of water pressure in the block you need to test the pressure before the thermostat.

I am running a crossover on my supercharged motor. I do not run a thermostat in it. Instead I run a restrictor plate in its place. I drilled out the plate to get the water pressure that I was looking for at WOT. My motor never gets above 100 degrees. My water pressure is at 18 psi at WOT. I want a cold water temp in order to cool the excessive heat caused by the blower. I run an oil thermostat to be sure that my oil temp is at 220 - 240 degrees. I also have to run a very large oil cooler to keep the oil temp below 250 when I am at WOT. So in short Because of my excessive cylinder heat caused by the blower I need to run the block very cold. Even with the cold water temps I need to run an over sized oil cooler to keep the oil temp down.

This is the ideal situation of a crossover to be used.

Using a thermostat with out the use of the recreating pump will cause unequal heating of the block. If you are running a crossover with a thermostat that is not drilled out water will not pump through the block until the thermostat is hot enough to open. Until this happens you will have very high water pressure and un equal temps in the block. This is a very bad thing. You will also not be pumping water into the exhaust until the thermostat is open.

If you are running a crossover with a thermostat this will add a constant variable to your trouble shouting. Depending on when the thermostat is open you will have UN equal heating and high and low water pressure.

Let’s just say you are running the boat and all is good. The thermostat is open and water is passing through the block. Some where along the way the block cools and the thermostat closes. Then you run the boat hard and build high water pressure in the block and it leaks in the block. Then after a few minutes the thermostat opens and the water flows freely again and the block dose not leak again until the thermostat closes and you run the boat hard again.


Food for thought.

Dirthead

jspeedemon,

I am using a crossover with a thermostat housing which has 3 fittings on it. 1 for the bypass from the crossover, and then 1 for each header to feed water too. I have done exactly what you are suggesting, that is the have both headers share one fitting and dump the other fitting out the side of the boat, thus getting rid of half of my water. Unfortunately this did not solve the reversion problem. With this setup, under about 5 min of running on the lake I got a milkshake. Does anyone have an opinion on what an OK temp is for the external part of the header to be at ?