[dci]

I thought I would share with everyone how I saved an other wise scrap or thought to be scrap set of heads. These particular castings are early 1968 number 16 castings. The casting date is H107 and are very hard to find. You will see in the pic's that these castings are very rusty from sitting in or under water. In the past I would have thrown these away and looked for another set, but with the muscle car craze and the rarity we are going to salvage these. This same process could also be used to save other rare heads as well, like Ram Air 2's,3's, and 4's.
We started by milling the combustion out approximately .030. This done two things, one we got rid of the rust and pits, and two we now have a new clean surface to grind new valve seats. If we would have tried to grind the seats before doing this the valves would have been sunk to much. Another popular option is replacing the seats, but this in my opinion is a better more economic solution. The deck will need resurfacing as well and this opens up an opportunity to some degree for picking a lower or higher compression ratio. We can now mill just a small amount from the deck surface lowering our compression, or of course mill what is needed to regain our stock compression ratio. Remember we removed at least .030 from the floor of the chambers, and close to the same amount from the open side of the chamber. These heads also had allot of pitting and rust in the ports as well. So we are porting the heads which will give us performance gain while we are at it. Stock most D-port castings flow right around 190 cfm. After porting these particular heads will flow around 270 plus cfm.

In the past I would have thought nothing of scrapping castings this bad, but today with parts getting harder and harder to find. I am looking for new and more creative ways to salvage these old relics.







Don Johnston
DCI MOTORSPORTS INC.
330-628-3354 cell
330-850-5050 shop
Designer of the DCI Tiger heads and the NEW DCI Ram Air V heads !!!!!

[Region Warrior]

Not bad so far!
Bridgeport? Been look'n for a affordable used one.
Have a YS with 16's that sat outside for yrs i got on a trade. Been debating fix, sell, or scrap.
Never seen pistons so froze. Crank is excellant. Even has nylon cam sprocket with little stretch.

[69Customs]

Cool!!

Just curious will you have to do anything to the spark plug hole threads?

[Nicks67GTO]

cool thread!

[dci]

Thanks Guys!! The spark plug threads are ok and I removed very little material around them. So they will be ok in this particular situation.



Don Johnston
DCI MOTORSPORTS INC.
330-628-3354 cell
330-850-5050 shop
Designer of the DCI Tiger heads and the NEW DCI Ram Air V heads !!!!!

[gene simmons]

Interesting thread.
Do you have an idea what the nominal thickness of the chamber floor is?

[steve25]

In stock form the thinest parts of the chamber floor are .180" ( Some area`s way thicker), so after the mill job and years of normal rust loss I would have to guess at .140".
.140" is about the minimum for a piston top, so a cast iron chamber will hold up just fine if thats what your concern is in regard to.

[dci]

Like Steve25 said, the nominal thickness is usually around .190 before modification. There is plenty of material there for structural strength. We have run piston tops which of course are aluminum as thin as .180 thick in mild applications with no problems.


Don Johnston
DCI MOTORSPORTS INC.
330-628-3354 cell
330-850-5050 shop
Designer of the DCI Tiger heads and the NEW DCI Ram Air V heads !!!!!

[Half-Inch Stud]

Don, I'm spellbound. There is much skill applied therein. What do you drink for courage?


Today's listing: 16's for sale $125

[77 TRASHCAN]

Originally Posted by Region Warrior

Not bad so far!
Bridgeport? Been look'n for a affordable used one.
Have a YS with 16's that sat outside for yrs i got on a trade. Been debating fix, sell, or scrap.
Never seen pistons so froze. Crank is excellant. Even has nylon cam sprocket with little stretch.

I used to get a Sears tool catalog in the mail, at work. I think they targeted businesses w/ buying potential, not sure. They had a mill in a catalog not too long ago, I think around $2200.00. Looked like something a common working guy could use in his garage. The problem w/ a used one from a shop, is they weight so stink'n much, it would be nearly impossible to move it easily, and would my concrete garage floor be strong enough to support the weight???

There's a company call Wholesale Tool, they have many locations in the U.S. They have all kinds of equipment and prices. OF COURSE most equipment like this is import. Bridgeport is a name brand, I've never seen one of that brand....Thre might be something of interest to you.....
Jeff

[gene simmons]

Would there be any problem installing hardened seats and retaining the 1.77 ext. valve?

Nice work,keep posting photos,i have a machinist friend who would like to see this.
Right now he is working on 191 455 H.O. heads for a 71 firebird.

[dci]

You could put seats in with no problem, but I have found with Pontiac heads that they used more nickel in their iron. So hardened seats are not required, but you do need to run stainless steel valves. I have many customers that I have been doing work for 30 years now, and I have not seen or had any issues with valve seats in Pontiac heads. Chevy's and Ford's are whole different story. So unless a seat has been damaged to the point I cannot grind it to fix it. We just do our normal valve seat work and install stainless steel valves. Some may disagree with that, but I am talking from 30 years of experience. Not something I read in a magazine.



Don Johnston
DCI MOTORSPORTS INC.
330-628-3354 cell
330-850-5050 shop
Designer of the DCI Tiger heads and the NEW DCI Ram Air V heads !!!!!

[Region Warrior]

My father said exact same thing about Pontiac metal.
Was a shearman at U.S. Steel 1930's-1970's.
Years later my chevy buddy(engine machinist) told me same thing.

[Bob Eiler]

Originally Posted by 77 TRASHCAN

I used to get a Sears tool catalog in the mail, at work. I think they targeted businesses w/ buying potential, not sure. They had a mill in a catalog not too long ago, I think around $2200.00. Looked like something a common working guy could use in his garage. The problem w/ a used one from a shop, is they weight so stink'n much, it would be nearly impossible to move it easily, and would enoumy concrete garage floor be strong gh to support the weight???

There's a company call Wholesale Tool, they have many locations in the U.S. They have all kinds of equipment and prices. OF COURSE most equipment like this is import. Bridgeport is a name brand, I've never seen one of that brand....Thre might be something of interest to you.....
Jeff

77 Trashcan

Your floor should be able tp support a knee mill. I have two that weigh a total of 4400/4500 lbs placed in an app. 9x9 area. The floor hasn't cracked yet.

[Bob Eiler]

Don, I've repaired a lot of rusty heads. I've had heads that the exhaust seats were partially missing, but nothing like the set you have. I hope people can appreciate the hours you'll have invested in those heads.

I'm presently fixing a set of 48's. Whoever performed the last valve job sunk the seats, used a flat stone to narrow the seats which left a pronounced ridge just outside the valve seats. I used a radius cutter to remove the ridge as shown in the pics.

Thanks for thread.

[71 Ventura II]

Definite concern with port failure from rust coming from both sides. There will be as much or more rust from the coolant passages as what's seen in the runners. Between the two eating in towards each other the odds are good with any porting of the runners and behind the guide there could be a "Break Through" not in a good way. .02 JD

[dci]

I was concerned about that to. So I pressure tested them before we began and they tested OK. The water jackets themselves don't appear to be any rustier than any of the other heads we have done work on. It appears that these heads may have been on an engine that was assembled judging from the head gasket surfaces.

Nice work Bob!! We see allot of heads come in with sunken seats as well. It doesn't seem to effect performance, but it sure looks bad. It seems that the shops with Serdi's and sunnen's sink allot of their valve jobs, and in my opinion limits the life of the heads for future valve jobs. We try at all cost to avoid doing this!!!!


Don, I'm spellbound. There is much skill applied therein. What do you drink for courage?

Ice cold beer!!!!

Don Johnston
DCI MOTORSPORTS INC.
330-628-3354 cell
330-850-5050 shop
Designer of the DCI Tiger heads and the NEW DCI Ram Air V heads !!!!!

[Half-Inch Stud]

Originally Posted by dci

...Don, I'm spellbound. There is much skill applied therein. What do you drink for courage?

Ice cold beer!!!!

Don Johnston
DCI MOTORSPORTS INC.
330-628-3354 cell
330-850-5050 shop
Designer of the DCI Tiger heads and the NEW DCI Ram Air V heads !!!!!

If & when you are up to it; I know a Shop sitting on a pair of 455 SD heads; Casting Exteriors look great. All looks decent except they feature several Valve bowls ported past their life by an unconscious grinder operator. They flow coolant. Wasn't me

[dci]

If & when you are up to it; I know a Shop sitting on a pair of 455 SD heads; Casting Exteriors look great. All looks decent except they feature several Valve bowls ported past their life by an unconscious grinder operator. They flow coolant. Wasn't me.


Give me a call and fill me in. I think I can save them.


Don Johnston
DCI MOTORSPORTS INC.
330-628-3354 cell
330-850-5050 shop
Designer of the DCI Tiger heads and the NEW DCI Ram Air V heads !!!!!

[gene simmons]

Originally Posted by dci

You could put seats in with no problem.

We just do our normal valve seat work and install stainless steel valves. Some may disagree with that, but I am talking from 30 years of experience. Not something I read in a magazine

How wide should the seat angle be on the Intake and exh. seats?