Water problems after blower install..help
 

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!

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

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.

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.

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

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.....

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.

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

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

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

Monstaaa is 100% correct... did you do a normal "by the book" torquing sequence or did you physically check the forward bolts??? You may also have an issue with the intake... have you checked it with a flat edge?? Was the motor overheated?
I know it sounds dumb.. but we have run into intakes that were used AND already machined requiring thicker gaskets.
good luck with it.

Also handy is utilizing a dial indicator type torque wrench on the bolts... make sure they are uniform as a whole AFTER you feel like they are all tight.

Did you recheck your intake bolts? Check it yourself. Go around the sequence until they are all tight. even if it requires 20 rounds. For chits and grins, recheck the bolts before you do anything or tear into it.

Keep in mind, this all started with the simple intake swap, not a head removal. Stick with looking at the changes done.
Been there done that. Exactly the same problems as you.

I had under 20# PSI at WOT using the 3/4" disc. The 1/2" was to restrictive, as you found out.

I also drilled and tapped the rear water jackets and connected them to the front jackets to bleed off any chance of hot spots.

Or you can simple run a hose from each rear passage and dump it over board. Have you considered the Merc relief valve? They are pricey, but they work! My current all stock 502 MPI motors were pegging the WP gauges at over 40 PSI. Now they are right at 20 PSI at WOT.

The relief route is not the fix for your problem. Doesn't appear your pressure is that high. Fix the problem then dial in your pressure.

ok, thanks to all you guys for your help..US1 & Monstaaa I think I get how the dumps work now..I am still leaning toward the intake again, only because I ran the 1/2" disc after I replaced the gaskets over the weekend & my guess is I blew out the intake again...my pump and impeller is all new so I could be running some high pressure at WOT...one thing I did not mention...when I first intalled this blower I had the 5/8" disc in..but I had the larger pulley and was only making 1# boost....no water problems then...when I changed out the pulley to 3 1/4" I made 3# boost with no problems....then I changed out pulley to 3" and installed 1/2" disc to try to get some temp...6# of boost but started making oil...now I have removed the disc but am still making oil, I guess once the gasket is blown it is blown....yes I have tighten and retightend the intake bolts..they are SNUG now....I will replace intake gasket again and run no disc and see what happens...THANKS AGAIN FOR THE HELP EVERYONE! I will keep you all posted on my progress.

It's very possible you have a bad head gasket too. Is it running okay? I also guaranty you are running some serious water pressure. A friend of mine had the same problem. Turn up the air to about 35-40# and I promise you'll find your leak.(Or create one,He,He).

Well, I got the water problem taken care of...it was the intake gasket...I used 3M 5200 fast cure to seal it this time..it seems to have worked very well.....however; I have a knock in the engine now..I am guessing it to be a rod bearing, with all the water in the engine I was expecting this to happen. I am pulling the engine tonight and will drop the pan to see what I can do..with any luck I can just roll in some new bearings and be on my way...man, what a mess! Thanks to all of you that helped me out,...btw, I am not running any t-stat or any disc...we checked the head gaskets again and they were fine, put about 30psi air to them and they were solid....so we knew it had to be the intake again....that 5200 adhesive is some bad as$ stuff, I hope I do not have to tear the engine down, I may need to chip the intake off!

had this happen to me using felpro intake gaskets.2 different sets leaked.used mr.gaskets ultra seal and never had a problem