Oil relief valve - what should I do?

[mungus]

I bought one of Doug's Melling HV pumps to go in my 390 (bored to 401) project.
I've discovered that my block is missing any kind of separate factory relief valve.
I can't seem to find any FE oil relief valve kits for sale except for the 406HP 427 kit at POP.
Googled, eBayed looked at Summit, nothing!

Now I've seen some talk about running no valve, plugging the hole in the block or some such.
Sounds a bit extreme to me! Is that practice for my GT390 or something more exotic?
So whats the deal? Fit the factory one? If so where can I get one?
Shim it out? Plug it? What should I do?

Advice appreciated.

[Barry_R]

What vintage is the 390.  I do not think I have seen a 390 that used a relief valve.  Might not be a big deal because it might not really "be there"?

[mungus]

1969. So do they just use the pump for relief function? Is the relief valve part of it?
I saw one in a 427 is all, and I think I've never built an engine that didn't have one (first FE).
So I just assumed they must have one somewhere...

[blykins]

No 390's with block relief valves....

[mungus]

Thanks Brent, so should the pumps come with one?
Sorry for my ignorance, I havent got the block here to look at right now, it's in the hot tank.

[WConley]

Yes the pump you get from POP will have an integral pressure relief.  You should be good to go on that 390!

- Bill

[mungus]

Yes the pump you get from POP will have an integral pressure relief.  You should be good to go on that 390!

- Bill

Thanks Bill. Yes I had a look at the Melling HV pump today, and I can see a plug on the end of a gallery, maybe 1/2" diameter.
From the pump drawings I've seen I'm guessing the relief valve is hiding inside there...

[troublemaker427]

A 390 Hipo block has a relief valve.....

[Ranch]

Are you saying that your block is drilled and taped for a relief valve at the back just below the main galley?   I think the '401' 390's had them pre 406-427s so POPs relief valve kit should work, that back plug is not a  1/2-20 thread. You are gonna need something to fill that hole other wise you will just blow all your oil over your cam and down to the sump.  I was not aware that later 390 had this valve, is it a solid lifter block?...  JMO 

[mungus]

Perhaps amongst the confusion of the conversation we are jumping to conclusions a little bit here...

No it's not solid lifter block.
No it has no drilled or tapped cavity in the casting, never implied so. Although from a bit of reading and web searching over the last week I now know what that method was for.

The plug in the Melling HV pump from POP has what looks like a cup style steel expansion plug approx 1/2 diameter capping off a gallery. From the pump drawings I'm guessing that's where the valve is.
And in truth it looks like there's nowhere else it could be!

I was simply asking where it is and what folks do as the is my first FE build.

Thanks for all the input guys. Much appreciated and better informed now.

[Drew Pojedinec]

Mungus,
When buying a pump from Doug, he normally sends a new plug and a large shim.  You *can* install it for High pressure, but honestly, his HV pump is darn near perfect as is.

On my car it's 80psi cold idle
25psi hot idle
and pressure jumps the second you hit the throttle right up to 65psi.  Works like it should, I wouldn't really want any more pressure for a street car.

[mungus]

Mungus,
When buying a pump from Doug, he normally sends a new plug and a large shim.  You *can* install it for High pressure, but honestly, his HV pump is darn near perfect as is.
On my car it's 80psi cold idle
25psi hot idle
and pressure jumps the second you hit the throttle right up to 65psi.  Works like it should, I wouldn't really want any more pressure for a street car.

Thanks Drew, if mine does those figures I'll be a happy man. No need for anything more.
I can't recall seeing any spare parts in the pumps box, although there is a lot of packing paper scrunched up in there, I'll have another look tomorrow. Can't hurt to have a spare plug...