[Dragncar]

Originally Posted by catc

curious .what is the max flow you can get out of a cast iron 722 cyl head...286 back in 1978 was pretty strong i'd say....

300cfm was generally about as high as you could get without them p!ssing water with a normal no epoxy/no welding port job. Dan did one set slightly over that but thought they would leak one day.
Butler brazed up a set of RAIVs and made "wide port" versions out of them for class racing. Got 800HP out of a 400 I believe.
Wilcox has got 300 cfm out a some of the "X" d ports. But I am sure they had epoxy too.
Then you have the Robertson 320cfm raised port 48s with a bunch of epoxy in the roof. Awesome heads in their own right.
I think a new cast steel RAIV head would sell. Make it with extra materiel in key spots for porting. Cast steel (not freaking iron) so it is easily welded for repairs or to make a set of wide ports out of them. LS chamber while you are at it too.
Iron heads make more power than their aluminum counterparts because they hold the heat and heat is energy. And its not like you are taking 100lbs off the front of your car going aluminum like a BBC either.

[steve25]

With a extremely tall port height at the flange Pete McCarthy says they go into the high 320s @28", I forget what lift that was at.

If the issue of flow turbulence/ sheer goes away when bolting on a Manifold then it's due to the Intake not being able to pass 100% of the air mass that the head is capable of.

[mjm421]

If I were going to send them out, I would strongly consider Jim Robertson in Abilene Texas. Tough to beat with the iron stuff.

[Jim Robertson]

Great Find! Bob Maxey was a legend. Hope you put some heat back in those heads soon...they deserve to be run and will run hard.

[1969400HO]

I’ve got a set of the 722’s in the machine shop now waiting to measure out the vlv length.
I think the standard OEM vlv length is 4.98”, guessing on that ..
My roller cam choice has a lift of .510/.521 possibly require a longer vlv to obtain the longer spring length to accommodate for then lift & bind clearance specs.
Maybe the 5.213/5.230 length valves, not 100% yet.
One of the issues I might be up against is the Geometry might be off on the RA tip~vlv stem surface area to allow adequate surface area to function.
I’m would like to avoid cutting the spring seat down to increase longer spring piece so prefer the longer vlv and maybe offset retainers/keepers, that is if this is even available on these 722 type heads.
I’t can be MFG just the co$st is the issue.

[Jim Scites]

I was talking to Mike Minno (Indian Uprising Car) several years ago who told me that when GM stopped selling RAIV heads they called Bob Maxie and sold him every head they had left, Bob and Mike bought pallets of them and sold them over the years until they ran out.

[steve25]

There are valve bowl differences between the heads cast up for the first production run for use on production motors and inventory stock, and those cast up later down the road for just over the counter sales!

[PAUL K]

Originally Posted by 1969400HO

I’ve got a set of the 722’s in the machine shop now waiting to measure out the vlv length.
I think the standard OEM vlv length is 4.98”, guessing on that ..
My roller cam choice has a lift of .510/.521 possibly require a longer vlv to obtain the longer spring length to accommodate for then lift & bind clearance specs.
Maybe the 5.213/5.230 length valves, not 100% yet.
One of the issues I might be up against is the Geometry might be off on the RA tip~vlv stem surface area to allow adequate surface area to function.
I’m would like to avoid cutting the spring seat down to increase longer spring piece so prefer the longer vlv and maybe offset retainers/keepers, that is if this is even available on these 722 type heads.
I’t can be MFG just the co$st is the issue.

I'm not understanding what you are asking but the stock length RAIV valves are the 5.230 ish long valves.