Pressue relief valves?
 

Who makes a good one and where can I buy them?

Re: Pressue relief valves?
 

water pressure????

Re: Pressue relief valves?
 

Yes.

Re: Pressue relief valves?
 

The ones from Mercury must be good. At least for over $200 for a peice of plastic, one would assume so.

Re: Pressue relief valves?
 

back for more, i have two i can sell. pm me if you're interested, rm

Re: Pressue relief valves?
 

The Merc ones?

Re: Pressue relief valves?
 

whats the purpose, or need for these? is there a problem to correct or what? ive heard of them and never really knew what the situations were.
thanks
kevin

Re: Pressue relief valves?
 

Used for motors running crossovers with t-stats to help control water pressure. And also for stock motors since the t-stat housing was redesigned w/o the brass tee, mid late 90's??
You need to know your WP 1st.

Re: Pressue relief valves?
 

Same as above...
I went to the new CMI's and they are a bit more restrictive in the water exits.
It pushes 30 at WOT. :(

Re: Pressue relief valves?
 

back for more, yes i have the mercs. rm

Re: Pressue relief valves?
 

I am running 30psi on my Hustler at wfo. for 3 years with out any problems .Whipple recommends at least 25psi in the motor for the super chargers ,

Re: Pressue relief valves?
 

that was my next question,
whats recommended? through out the power range? is there a rule of thumb,or a guidline from merc for stock? then, is there any guide for modified.
im running a water circ pump so maybe it doesnt pertain to me now but if i ever do a crossover............

Re: Pressue relief valves?
 

I bought adjustable brass ones from McMaster-Carr for about $40 apiece.

Re: Pressue relief valves?
 

What is the "rule of thumb" on water pressure?? Minimum?? Maximum?? I have heard 15lbs was ideal. In what situation might a higher pressure be an advantage?

Re: Pressue relief valves?
 

would happen to have a pick???

Re: Pressue relief valves?
 

Here's the one I bought from McMaster-Carr for ~$40. Probably the same one pachangalpina bought.

www.mcmaster.com

Re: Pressue relief valves?
 

Is that a pop off valve .or do you adjust it like a fuel regulator where it bypasses all the time ?

Re: Pressue relief valves?
 

From what I saw on a section view....it sets the spring preload.

Re: Pressue relief valves?
 

That is the one that I use. Just set the spring pressure to bypass at the desired pressure. I would call it a pop off valve.

Re: Pressue relief valves?
 

where is the best place for a pop off valve w/871 blowers ,crossovers no thermostst. i have one between the sea strainer and the oil cooler now,not sure if that is the best place to have the pop off valve.at high speed the water pressure drops way down to 5to8 on the guage.

Re: Pressue relief valves?
 

What size hose is used for the dump?

Thanks,

Kurt

Re: Pressue relief valves?
 

kurt the mercs use a 1" hose to bleed off the water pressure quickly, the other vaalves are for biolers and are not the best setup the mercs work prefectly

Re: Pressue relief valves?
 

Thanks Ratman!!!!

Re: Pressue relief valves?
 

:d

Re: Pressue relief valves?
 

Ok Fred,
what is the deal on these??? New item?? What psi? How big are they (hose size)? Etc... Oh yeah the big question... $$?

Thanks
Dick

Re: Pressue relief valves?
 

Fuel filter?? :eek:

Re: Pressue relief valves?
 

those are the kpm valves i think sterling is using them and the kpm 2 stage pumps on their supercharged engine packages. they use a 3/4 hose i think

Re: Pressue relief valves?
 

Looks like you have to "Tee it in" somewhere along the water circuit and discharge overboard.
It is pretty.

Re: Pressue relief valves?
 

Do you still have these?
I tried to e-mail you and PM you but you have blockers inplace.

Re: Pressue relief valves?
 

I just had the Mercury valves installed. The builder said they fit better than the others would? They were $290 each! He cut the springs to allow about 12 psi through. I hope this will be enough?

Re: Pressue relief valves?
 

Mark,
I did the bypass hose and drilled the thermostat on ours. Configuration is #8AN bypass hose to top of thermostat housing, 140deg thermostat.

Intial setup 2 - 1/8" holes in thermostat, temp 160-170, water pressure 30psi at 3000 rpm.

2nd test was 2 - 3/16" holes, temp 140, water pressure 25 psi at 3000-3200.

3rd test was 4 - 3/16" holes, temp 100, water pressure 25 psi at 4200 rpm.

4th test remove thermostat and ran the rest of the day at 12-15psi.

I need larger bypass hose.

Has anyone tried the 4 port thermostat housing with a spring valve inside? See CP performance web site:
http://www.cpperformance.com/detail.aspx?ID=697

I would be interested to hear who has tried these.

Rick

Re: Pressue relief valves?
 

Thats the road I'm lookin to head down....12psi and a little water temp would be great.
I want to eventually run some 140 stats.

rv, You could still use the ports off your strainers with some KPM's and softer springs.
I'm having Dan make me some up for a test.

Re: Pressue relief valves?
 

Fred need info.......

Re: Pressue relief valves?
 

From what I have read and gleaned from conversations the over pressure issue is caused more by the drive or transom pickup, not to say some after markets do not fall into the. Closed cooled rigs do not have much to worry about where as raw cooled engines can suffer from weeping head gaskets ( I know many have seen the rust on the side of the block just below the head) with closed cooling that is not an issue most of us run a 14psi cap. I had no over pressure problems with the Blackhawk drive but when I went to the dual pickup BravoX my sea strainer leaked a fair bit at speed, I crank the cover tighter for now but am working on a new idea. When you think about the pressure remember 30psi is a little over double what is run in an automotive app, the gaskets and hoses are getting better BUT!

Phil

Re: Pressue relief valves?
 

I'm goin with the Merc's....

Re: Pressue relief valves?
 

Mark, I just installed a set of the Merc valves this weekend on my 100% stock 502 MPI's, other than SM exhaust. At 3500 rpm, my pressure WP gauges where pegged at 40psi. Been limiting myself to 3000 rpm this summer so far. Kinda boring, but saved some fuel. :D

Now with the Merc valves installed, my pressure is 30 psi at WOT. They start flowing at 25PSI. I'm going to order a batch of springs from McMaster Carr tonight and try cutting to different spring lengths to get my WOT pressure down to 15-20, saving the original springs just in case I need to put them back in.

As of a couple weeks ago when I was looking for 2, Ratman had 1 and T/Motorsports had 1 left, (I bought his other 2).

Jerry

Re: Pressue relief valves?
 

I have also heard that 15 psi is more deireable. I installed one from Arizona Speed and Marine while having a head gasget problem. I run a crossover with a Pro Charged motor. At the end of the day it was a head gasket and not a water pressure problem but at 15 psi I have never dumped because of over pressure through the valve.

Re: Pressue relief valves?
 

I just had an e-mail from Tyler C. regarding this issue. My water pressure had been cut to 12, which he claims is way too low. He said that I should be running 20-25 so that I don't damage any head work that has been done.

How do I get my pressure back to that range?

Re: Pressue relief valves?
 

Yep...I also mentioned 15psi to a performance engine builder and he said 20psi would be better.

Re: Pressue relief valves?
 

Replace your springs back to original. I placed an order last night from McMasterCarr for 6 springs that are the same as the original to experiment with. $11 .

I will say that at 25psi, my water pump hose really swells up, along with the supply hose coming from the coolers gets rock hard. I see no way it needs that kind of pressure. Maybe that is one of the reasons we hear of water pumps leaking past the weep hole?? I've done replaced 1 of my pumps with less than 150 hrs. No salt water use either. Just a thought.
I'm going for under 20psi. My previous boat had the stock t-stat housing with the brass tee for the bypass hoses and the pressure was 18psi max. Trouble free!