are BB #516 good for performance?

So I popped a pair of big block #516 heads for sale on another forum and checking my email this morning, I found I had half dozen guys have reached out to buy them. I know the close chamber helped bring up compression, but is there anything else about these heads that makes them desirable?

The closed chamber is the big selling point , especially since they can be had cheaper than 915's. they need the exh valve upgraded to at least 1.74 and porting to come alive .

thanks John. Yeah that tiny ex valve looks restrictive.

http://www.moparts.org/Tech/Archive/bb/62.html

There is nothing desirable about them other than the cheap price.
If you can sell them great. I've thrown away a lot of those heads in the past since there wasn't a market for them. I used to take them to swap meets and try to sell them for $100 a pair with no takers. Lowered my price to $50 a pair and still not takers so they all went in to the recycle place.

I went 10.40’s with them back in the late 1970’s with a set in my 69 dart. I wouldn’t scrap them.

if you want good improvements from swapping heads step up to a cheap set of aftermarket aluminum heads with the bigger, better flowing valves and ports

Some guys on a budget want them.
Some regions of the U.S. are pretty lean on old cast iron cylinder head cores.
I ran a set on my 69 RR, added the 1.74 exh valve, bowl ported them with the MP templates, gained 2-3 mph through the traps.
It ran low 13's @ 105 mph. Just a warmish 383 B-motor, 833, 284/484, TM6, 750 AFB, 4.30:1, 10" slicks, 1.99 60'.

If you're on a budget, they're great in my opinion. Big exhaust valve, a little porting, and they will run decent numbers. Not aluminum head numbers, but not aluminum head $$$$ either.

For me to consider them, there would be two key questions to answer first:
1. What do I have to spend to make them usable in the first place (e.g., valves, seat & guide work, milling)?
2. If I want more than as-cast performance, how much do I have to pay to have someone do enough porting to reach my goals (assuming I can't do it myself)?

I wouldn't want to put much money into 60 year-old castings in this day and age...

I look at it as……. How much less than a set of aluminum heads would the “all in” price for any old iron heads have to be for you to go down that path?
And……. Can that be realistically done(price wise) in your area?

Machine shop labor prices keep going up……… but so have new aluminum heads.

By the time you put hard seats in, new 1.74 valves, port them, guides and a valve job you could just as well buy a new set of aluminum heads. Having said that years ago I did a set for myself, plus I shaved them .060. I ran 12.19@106 in my old truck with them. I put a lot of work into them but they guy worked real cheap (me).

Yeah, 50 years ago they weren't a bad choice

My days of sitting in a cold garage learning to port on a set of OEM iron heads are decades behind me

My expected combo (65 426 wedge) is the 516, 452 or Eddy head with 1.60 ex valve. Cam is limited to .431 lift and any duration no porting but any valve job. I’m thinking of running 40 degree or less seats (more flow in overlap with the low lift). What about nail head vs tulip valve shape? I have a few extra 516 heads to experiment on but still looking for the 67 small valve heads.

30deg, & a nailhead valve, works great on a low lift setup

Ahhhhh one of many “boneyard performance” upgrades of our youth. Grabbing a set of those was akin to crawling under a van or truck and scoring some 3.9 or 4.1 gears.

Some of these guys don’t understand the fun we had making this stuff go fast. Lol

My scores were 915 casting.big or small exhaust valve

Thanks

i agree with the area under lift with 30 degree but I don't think they seal as well as a 45. I would just stay with a 45. my 2 cents.

A race engine only. I’d never do that on the street.

For what it cost me to have some basic machine work done on a pair of 915s last year, I'd say it's only worth it to fix iron heads if you can do some of the work yourself.
I had the heads shaved (just a light cleanup cut), 16 bronze guide liners, 8 hardened exhaust seats, opened up for 2.14"/1.81" valves, and a 3 angle valve job. That was a little over $700.
I did the bowl porting, general port cleanup, cut the guides for positive style seals, assembled the heads w/ new valves, springs, retainers, locks. Just the parts will run you another $600+ depending on what you need.

A decent port job will be in the $1000 ballpark or so I'd say? I'm definitely no Dwayne Porter, so blending the bowls is about as much as I do. Then again, I'm not expecting 700 hp out of these heads either, lol.

Granted, a lot of aluminum heads (not all) need to be torn apart and checked out before using them, so the new cost needs that added to the bottom line.
The cheap heads have cheap parts installed in them which are a gamble.

Pontiac used a lot of 30* intake seats in their street cars way back when, so I don't view that as a "race only" thing

The last customer who insisted on original cast iron heads for his big block ended up paying a ton of money for them. He had to buy 4 sets of heads before he found a pair of castings that were in good enough shape to be rebuilt. Then the heads had be fully rebuilt with new seats, guides, valves, etc. No porting was done. All surfaces machined, decked, all threads chased, cleaned or helicoiled, etc. Well over $2000 just to get a set of good 906 heads for a resto project.

The AMC did also but I'm telling ya they don't seal to well. Some even mod the valve with a conformation groove in the valve face

Years ago I swapped a pair of decent, no magic parts or work on them ,906 heads onto my bracket car motor at that time to remove the 516 heads with 1.74 exhaust valves in them to sell them to a customer who wanted them for his build.
The bracket motor had the old TRW 11.5 to 1 compression forged (CRS Pt.#. now ) "race pistons" in it with a solid lifter camshaft, Isky rockers and so on. I didn't measure both heads combustion chambers while they were both on my bench, I was thinking the 906 heads would lower it but I didn't make sure,. Bottom line is that motor ran faster and quicker by about.200 ET and 2.+ MPH with the 906 heads on it with no other changes
My message is sale them old 516 rascal and buy a new set of better aluminum heads with bigger valves and better ports

“My message is sale them old 516 rascal and buy a new set of better aluminum heads with bigger valves and better ports up scope work twocents“

Exactly what we’re not allowed to do, rules, has to be the 1.60 ex valve, no port work. I don’t think I’ve seen an open chamber aluminum head, all closed chamber, quench is nice.
I’ll do the work so no money just time.

The 88 CC Eddy RPM heads have a CNC machine open chamber in them