Started to rebuild head

1966_l6

1966_l6

Well-known member
Hi,
I have 66 mustang, stock motor with DSII from CI and 32/36 weber with Clifford adapter and in few days CI headers.
I buyed last C9 Head, I want to rebuild it before to put it on my mustang.

I have many questions:
- I have red and green spring, why?
Their lengths are 1.832 inch (46.5mm), Is it good?


- I have 2 models of retainers, 1 piece and 2 pieces, why?


Thanks for your help
 
Howdy Fred:

And welcome to THe Forum. Yes, it is that good. That's a good looking ride. I'm sure we can help you.

On the valve springs, some evidence suggesting that the Green springs are on the intake side. Red on the exhaust. In my experience, they are the same in height, tension, coil width and coil diameter. The thought for the color id is that springs on the exhaust side experience a great deal more heat than the intake side, which may cause those springs to sag or lose tension more quickly. After measuring many springs tension at open and closed height, I have never found a difference.

On the retainers, the two piece is the stock type for a '66 engine. One piece retainers from several sources have been used over the years; most recent from a 4.0 Ford V6. The two piece design was supposed to rotate the valve to reduce pattern wear. THe one piece retainers are lighter and thinner, causing less interference with the umbrella type stock valve stem seals.

FYI- Check you hood clearense on using an adapter to mount the Weber carb.

What Transmission is in your car?

Again, Welcome to The Forum

Adios, Davdi
 
Hi, yes, kind of weird to mis match the retainers. I would just get new valve springs if you don't know how old they are. Get the Falcon Performance Handbook for great advice on getting the most out of your Ford 6. Good luck
 
WELCOME!
(seems we have another 'Fred.' from France)
Yes the "Handbook" is great (Matt from vintage inlines dot com), while waiting for delivery check out the CI archive (4th horozontal line above) for another extensive compedium of info on these engines.
Let us know if needing info on parts (USA) however much more ease the net lends to the rebuild/mod process.
Doing what U do, we have found plenty less expensive & more reliable parts than a random net search...
 
Howdy Again Fred:

I took a second look at your photo of the '73 head and cannot tell, for sure, but the valve springs don't appear to be placed intake/exhaust consistently. I can't tell which springs have the one piece retainers either.

Have you pulled the valve cover off of your engine to inspect? Let us know what you find there in reference to the valve springs.

So long as old valve springs measure up to lb specifications I would not be afraid to reuse them. I would reccommend that you shim them up .030" to add a little more tension- even with a stock cam.

Are you having a valve job done on this head while it's off?

Keep it coming. The more we know about what you are working with and what you plan the better we will be able to help with suggestion, ideas and pitfalls. So keep it coming.

Adios, David
 
CZLN6":2bnarbla said:
...I would reccommend that you shim them up .030" to add a little more tension- even with a stock cam...Keep it coming. The more we know about what you are working with and what you plan the better we will be able to help with suggestion, ideas and pitfalls. So keep it coming.
Adios, David
Click to expand...
How's that done? & what material is used?
Not needed w/higher ratio rockers?
Thnx David~
 
Chad - shims are available for relatively cheap online. Think I got some from rockauto for 10-15 cent/piece. I would definitley use them if you're running stock springs on high ratio rockers. I ended up going with high ratio rockers and dual springs.
 
Thanks, Cat. So only W/high ratio rockers & stock springs? No, haven't I've seen that recommendation W/ the stock?
not with high ratio rockers and dual springs?
I'm missing several things here, I think…

I know they go under the springs & give advantage on lift? Not sure what I know :oops: ~
Is'nt there cam considerations?
(again, it's all bout low rev tq 4 me, not lookin 4 build recommendations, just understanding - sorry 2 bust in "1966_i6")

Thanks ALL.
 
Hi, the main purpose for the shims is this. As I learned many years ago, the shim restores the factory "closed spring height" meaning the distance between the seat for the spring on the head and the bottom of the retainer. When the machinist grinds a few thousands off the valve, and a few thousands off the seat, the valve is sitting deeper in the head and the distance between the spring seat and bottom of the retainer is more than before, so the shim takes that up. They will also to a small degree increase spring pressure. The machinist will also grind the top of the valve stem to make it flat again, and restore the total valve height back to factory specs.
 
So if U shim it's important to have the length of the valve stem shortened?
Guess I need 2 read that hischool auto shop manuel FF recommended…
:rolflmao:
 
Howdy Back All:

Hey Chad- If you want to start your own thread on valve spring shims I'd be glad to share with you what I know about their uses. Hijacking Fred's thread isn't very nice. I'm just saying-

Hey Fred, how is your head rebuild coming along?

Adios, David
 
Yup,
Sorry,
Thanks.
 
Hi ,
I have the Handbook, it's very interesting book.
Thanks for your answer .
CZNL6 , I have automatic transmission with 2.80 rear end .
I buyed the head only . The cast number is C9DE 6090-M
There is no reference on parts.
I don't know any thing on this head , the saler say me , The head was removed en 80' of breaking motor .
Cous you said me if the springs have the good lengh ?
I would like to rebuilt the head for to put it on my 66 block.
But I am going to rebuilt the head during my spare time, it is possible that it takes some time
I would like to put direct mount adapter for to put my weber in first time , an autolite in second time.
Actually , the head is very dirty
 
That's a great head for the direct mount (compaired to some other years). One of the more knowledgables will B along shortly w/more info but I don't think U need an adapter (even less sure for a weber). Adding anything between the 'log' intake and the hood can get into violation of tight space. :shock:
The "M" head U have is very flat taking an excellent mill for this purpose, larger runners and nice volumn. One of the best (& many of the worse) machinings of these heads is seen right on this forum of the site. (there's a search function above) I think the good one was done because material was added BEFORE the milling passes were made.
Glad U have the "Handbook", make sure you click the above link for the Classic Inlines archive, more great info. If U C a mag article by AK Miller try'n read all of it 2!

Your English is better than mine! Hate to C my french!

I'd swear there wuz nother "Fred" from France here (may B Belgium?). sorry
:oops:
 
Howdy Back Fred:

THe C9xx- M casting is from 1969. The "M" casting was a big step up for its time. The plus is the flatter surface on the top of the log and more intake tract volume than previous casting. The flat top make it easier to modify for direct mounting two barrel carb. These are the 1st small block Ford sixes with a 1.75" carb hole. Your '66 head has a carb hole of 1.5".

The down side of this head is it still has 1.65" intake valves and no hardened seats. Later heads from D7xx (1977) came with 1.75" intake valves and hardened valve seats. These later heads {including your "M" head} have combustion chamber volume of 62 ccs while your '66 head chambers measure 52 cc giving your head an advertised combustion ratio of 9:1. The later heads have advertised CR ratings of 8:1 to 8:5 due to the larger combustion chamber volume.

You can upgrade your "M" head to the bigger intake valves and the compression ratio can be restored by milling.

I hope all this is not over whelming to you. It's alot to take in. Keep reading, planning and budgeting. Have you found a machinist to help you yet? It may be worth your time to shop for the right one. Prices, quality and a willingness to support your project. Having a machine shop disassemble and clean your new {old} head will make it a lot more enjoyable to work on. How much of the work will be doing and how much will you need to have done?

So, get a plan, ask questions and enjoy your adventure.

The 2.80 rear gear will be a disadvantage is the stop light sprints but will shine while highway cruising.

Once you get a plan in mind for this head share it here to give us an opportunity to make suggestions.

Adios, David
 
Fred, before you spend a lot of money on the head get it magnafluxed for cracks. If ok proceed as David mentioned.
 
I have totally disassembled the head , I cleaned it actually .
It have no crack , I 'm happy :D
Where can find freeze plugs for the head ?
 
You often wont see cracks just looking at it. Spend the 50 or 60 bucks to have it magnafluxed. You are about to spend some money on that head, and I think you said it came off of a bad motor. Magnafluxing can save you a ton of money and effort.
 
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