Homemade relief valve

[MILD THUNDER]

Wondering if anyone has made a homemade type of relief valve tied in to the water system. Was thinking of a brass gate valve, installed in the water hose going to the crossover, plumbed to a 45* dump that would be installed so that it dumps directly onto the drive. Kind of manually control water psi?

My setup is crossovers, no stats. I dont have much water psi, but tons of volume. Was thinking of adding restrictors, and a relief valve. Never see water temp at all on gauge. Would like to see at least 120* while running. Even with oil stats, oil temps are still cold. Would get some condensation under the valve covers. im thinking with no stats, 10qt pans, cold lake michigan water, the block temp may be the reason the oil is runnin so cold. So thinkin restrictors to help slow the water flow down a bit in the block, and a relief to make sure water psi is in line.

 

[Richard Crainium]

I have a pressure relief valve that i bought at McMaster Carr I think it was like $120.00 about 5-6 years ago. I made the T fitting and mounting bracket. It works great ,
20-25 lbs at any speed. you can see it in this picture it is brass colored.


Here is the McMaster Carr Part # and Description
Part #4703K562

Extended-Life Adjustable Relief Valve Bronze Body, 1" NPT, 15 - 25 PSI
In stock at $130.59 Each

 

[Chris]

Depending on your exhausts, you might try routing your water thru the manifolds and then into the engine. This pre-heats it a bit.

A little restriction wouldn't hurt either.

 

[Biggus]

I've also rigged up my own using a Mc Master-Carr pressure relief valve.

I've also had great success with the Merc plastic relief valve (have one on my 18 Donzi) but they are now stupid money...

 

[Chris]

I know several of the "California" guys has them. Rex lists two different one's. You probably don't need pressure relief with a full open system and low pressures. If you restrict, look out for pressure spikes- especially on re-entry.

 

[MILD THUNDER]

Not to be a tight ass, but what about something like this? Preset at 30psi blow off, 3/4 connections, spring inside is stainless??? What does the merc one blow off at? I found this one for $8.50 cents on another site

http://www.houseneeds.com/Shop/heatingproducts/HydronicHeating/cashacme/safereliefvalvebuypage.asp

 

[Chris]

You have no water pressure now so it's a waste of $8.50.

If you're planning on using it as a restrictor- controlling the output of your cooling system, keep in mind, it was designed as an emergency valve- to be used maybe once in a blue moon. It's likely not made for continual use.

And there's no need to have 30 PSI in your cooling system. It's going to put unnecessary load on your pump impeller, drive belt, hoses and most importantly your intake manifold gaskets.

 

[MILD THUNDER]

You have no water pressure now so it's a waste of $8.50.

If you're planning on using it as a restrictor- controlling the output of your cooling system, keep in mind, it was designed as an emergency valve- to be used maybe once in a blue moon. It's likely not made for continual use.

And there's no need to have 30 PSI in your cooling system. It's going to put unnecessary load on your pump impeller, drive belt, hoses and most importantly your intake manifold gaskets.

Only thinking of this if i was to add water restrictors in the thermostat housing, to slow the water flow thru the block down. I would think with the restrictors, i would see a PSI increase, and would like a safety blowoff for like you said, re-entry.

Current setup was zero water psi at idle, and barely 10psi at 65-70mph. Water temp gauge pegged to the cold side at all times. Exhaust is stelling headers with full length dry tails...

 

[PatriYacht]

Why not just buy new crossovers and thermo housings. From Eddie Marine it's about 200.00 per engine. They have 1" dia. bypass hoses or -12 fittings so they will bypass plenty of water to keep pressure down. I used them on stock 400 Cyclones that were 10 years old and never had a problem. I have a similar set-up on the Black Thunder but it's from Stainless Marine and a tad more money. No problems there either. Btw, if you don't have a bypass and you try to run a thermostat, you will have to do some strange plumbing to cool the exhaust manifolds. The bypass is there to send water to the manifolds when the thermostat is closed. There's really no need to reinvent the wheel here.

 

[MILD THUNDER]

My stat housings are actually stainless marine with bypasses, but capped off. My crossovers do not have the bypass. I supposed i can just have my guy weld some stainless bungs onto the crossovers, and run a 120 deg stat with a few holes drilled?

 

[Chris]

Are your engines normally aspirated?

 

[MILD THUNDER]

Are your engines normally aspirated?

They are basically hopped up 525SC with alum heads, bigger cams, headers...177 weiands

 

[PatriYacht]

My stat housings are actually stainless marine with bypasses, but capped off. My crossovers do not have the bypass. I supposed i can just have my guy weld some stainless bungs onto the crossovers, and run a 120 deg stat with a few holes drilled?

Yes, that would work well. Make the bypass 1" hose barb or -12 hose fitting. Arizona Speed and Marine has the 120 thermostats. That's what I am using with a couple of holes drilled. My temps are steady never vary more than a couple degrees.

 

[Chris]

I'm not fond of tstats in anything blown.

 

[Bad Idea Baja]

I made one, actually 2 out of PVC. They are big & bulky & I'm really not all that happy with them, but it cost me zero $$ so I'm gonna try them out soon. You can adjust the pressure via a knob & it has a lock nut on it so it should be ok. I'd like to change out the barbed fittings but like I said it was a freeebie deal.

 

[Elite Marine]

I have a used Merc unit with literally less tahn 15 hours on it. It cost something crazy like $ 250+ It was used in fresh water only on my Pantera.

Will sell $ 100.00

There are Bronze units out tehre from Mcmaster and Grainer that are about $ 50.00 or so, but you then need to add a tee and nipples. Works great, but looks kind of ****ty.

Kirk