Bajapred

iTrader: (1)

Ok here it goes..I know this subject was beat to death and I have read all the posts on water pressure issues..I have installed a 250 B&M on my HP500..I was told to run a 1/2" disc in the t-stat housing...well i blew a gasket on the first test run, got water in the oil....I had a deteriorated intake so I got a new intake from my mechanic and went back to the boat with new intake gaskets and intake and put it all back together..same problem again...so I started reading posts on the wtare pressure issues..I checked my pressure, with no disc my pressure barely changes, when I install a disc the pressure jumps imediately to 12ish just revving the engine so I am sure it is crazy high when out running, I am sure this is my problem..so, do i just leave the housing open and run it or do I get some kind of bypass..I do have an oil tstat so maybe that will help with no water stat...I am heading to the lake on Monday nite to pressure test and see if I have just intake gasket blown or head gasket blown...hoping just intake.... Please just reply if you build and run blower engines and have experience with this issue, I don't want a war of ideas and guesses...thanks!

H2Xmark

you need pressure to keep hot spots out of your cooling system, try to shoot for around 20 lbs give or take a few

monstaaa

pending on your speed , you should be able to achieve 20 as said above, which is target.

pressure is not the critical mass, but volume is. you do need restriction however so keep investigating. remember , the best way to relieve the engine of hot spots is to purge the water at the back of the intake.

US1 Fountain

iTrader: (1)

Are you going around the intake tighening the bolts until the
1st bolt is still tight after you tighten the last one, or just going around twice and calling it done? On my BM 250 intake, it took me at min 6X around the torque sequence until all bolts were tight. I also chased water problems around until I stumbled on the intake not being tight, to the point of have the heads fluxed and decked & block pressure checked.

Bajapred

iTrader: (1)

Monstaaa, could you be a little more detailed please. send me an email with some ideas on how to set it up correctly..I have read about the dumps but I have no idea how to install them or even where they would go..pictures would be even cooler, no punn intended. thank you

My mechanic has been doing the torque job....I have watched, he goes around a few times...but we ran the engine again after the new inmtake gaskets with the disc in, so I thionk we blew out the intake again..then removed the disc and still had water in oil....I have done the easy stuff...comp check..no cylinders with odd compression...so I am leaning toward the intake gasket...this time I am taking mechanic with me to tear the engine down so he can look for signs of water penatration...but we will do a leakdown first. What I really am looking for is how to set this thing up correctly so as not to have this problem anymore

ghittner

I run a B&M 420 on a 489. Through Stainless Marine manifolds w/ No restrictors at all. Ran perfect @ 170 Deg.. and still does. Raw water pump only, volume is the key, lose the washer.....

fstboater

I run the washer if you take it out is should drop a little pressure what is your exhaust like. That is where it will build pressure from rust or trash. Or reverson because of cam shaft overlap that will put water in the oil sucking water back in while running.

Bajapred

iTrader: (1)

My exhaust is brand new CMI..no reversion..just running the two 1" lines from front on intake to each manifold, elbow inlets are plugged off

ghittner

HP 500 should have no reversion issues unless you changed the cam....

Bajapred

iTrader: (1)

Ok guys, I am having a hellofa time here...went to the boat and pressurized the water system, no apparent leaks..so we figured oil cooler..removed and checked, no leaks...... so we are thinking maybe we didn't get enough air pressure in the water system to reveal the leak..we are going back with more firepower....anyone have any ideas, I am bout out of options...boat was fine until this blower install, I am thinking maybe since I ran the new intake with the disc in the tstat housing that I blew out the new intake again, but just not sure...it makes oil fast, a 5 minute boat ride and I get 3 quarts of water in the oil..but weird how it did not show with 20psi of air through the intake and heads.maybe the engine needs to be hot for it to show up, we hope to get about 40psi this time....no reversion issues, cylinders do not get any water in them...my cam is stock HP500.... I sure would like to see a picture of the dumps that some of you are using, along with the pressure relief valve and how you plumbed it all...thanks