Major Score on Head

[66200i6]

The main question here is, what log size does the C9DE-6090-M head have.

A little history:
I had finally pulled the C6 200 head from the Coupe. I have needed to have the exhaust surface machined for some time now because of the leak on number six. Once pulled and delivered to the shop, the machinist went right to the carb base on the intake and pointed to the crack. Now what?

I had run into on old Inliner at a car show last weekend that happened to have some extra heads. Long story short, I picked up a head Friday night that has the above casting numbers. This head also came with the adjustable valve train and proper pushrods. Score!!

So back to the question, according to the Falcon Book the 65’ – 73’ 200’s had the 1100cc log. The log on this “Mâ€￾ head is defiantly the larger flat top 1.75 intake log. Does this mean that this head has the 1240cc intake?

Does anyone have any words of wisdom? Thanks in advance, Ric.

 

[simon]

howdy Ric,

I have the same type head.
C9DE means engine from the falcon group (falcon, mustang, ranchero) cast in 1969, used on both 200ci and 250ci engines. head chamber volume should be around 62cc.
all 200ci and 250ci engines had the stock nonadjustable valvetrain only; but all the rocker arms , including the 144-170 adjustable ones, shafts and pedestals are interchangeable.

compared to yer olde 200ci head the intake log of C9DE should have a flatter and wider surface, and the carb mounting flange should be wider for Carter YF and Carter RBS carburetters (btw, how is this written right? seems everybody, inc. dictionaries, writes that word in another way...)

Unfortunately I haven´t cc´d the intake runners and log when I still had all the valves in place; but should be around 1200-1300cc.

I´m a bit worried about my own cylinder head because the last of the upper rear exhaust manifold bolt bosses doesn´t look that beefy... any chances to add some strength at this point?

 

[Anonymous]

HI Ric,

To the best of my knowledge, and my understanding of the info in the Falcon Performance Handbook, the C9-M and all of the "D" series heads have the 1.75" carb bore, the the "flat top" log, and intake volume of 1240 / 1245 with the exception of a D5 (AA or AB??), which has 1365. The D7 and later also have the 1.75" intake valve, but this valve can be installed in the pre D7 head. I recently purchased a D7 for my 66 and I am still amazed at how much difference there is between the 2 manifolds (C6 vs. D7). By the way, if you are going to rebuild your head I think you should consider the 1.75" intakes and a set of 1.468" 170ci head intake valves for the exhaust side while your at it. Also, as you are probably already aware, you will need to mill the new head to keep your CR up, i.e., the C6 is about 10cc smaller than the C9. But, as the book says, be sure to measure the chambers before you start milling.

Steve

 

[CobraSix]

The only problem with the larger combustion chamber is that you will need to recalculate your compression ratio. All else being stock your compression ratio will be about 8:1.

Slade

Here is the calculator:

http://falconperformance.sundog.net/compcalculator.asp

Slade

 

[CZLN6]

Howdy All:

Ric- all of the C9 heads that we've been able to measure for intake volume come out to about 1365 plus ccs. As usual, check thoroughly for cracks and weaknesses before investing in a used head.

If you're going to go for bigger valves make the 1.75" intakes a 1st priority. If you're thinking of bigger exhaust, consider the 1.5" SSI valves make for this engine rather then the "Old tech" 144, 1.467" intakes. So far, the 144s haven't let us down but they are just as expensive to buy new as the SSI "New tech" ones. That will be my choice for my next head.

Heed the good advice about compensating for the difference in cc between the two heads.

That's my two cents.

Adios, David