Part #C9DE-6051-C what is this???

Hello, i have been looking for one of the thinner head gaskets for the 200. I was told by one source he had a gasket available part #C9DE-6051-C. I was looking for the composite type but i thought it was part #C9DZ-6051-C or AC. Anyone know what the head gasket offered to me is? Want to get back to seller asap if it is what i am looking for. Thanks for the help. Mark

same thing i believe. The intake would say c9de the gasket should be c9db. I THINK they are the same part

Like some falcon parts a C4DB OR C4DZ

Bax;
The ones I have are the C9DE6051C.
I don't know what the C9DZ units are, though.

MarkP":38xt8uzp said:

I don't know what the C9DZ units are, though.

Click to expand...

General FYI - fourth position code "Z" denotes the item to be a Ford service part. If the gasket has C9DZ on it, then someone replaced the original with a factory Ford service part as opposed to one from the local parts store.

For more on decoding Ford part numbers: http://www.hammar.dyndns.org/~djhamma/partnumb.htm

Thanks everyone I found 2 of the thin composite type and just wanted to make sure they were what i wanted before i bought them. Thanks again your help, you all are the best 8) Mark

Howdy All:

Phil hit the nail on the head wigh code deciphering. Here's some more info. I gathered up all the head gaskets I had and measured for myself. Here's what I got.
Bore thickness
NOS OEM steel shim, D3DE 6051AA= 3.75" .028"
FoMoCo Composite, C9DE 6051 C = 3.81" .037"
Victor Composite, #3910 VC = 3.81" .046"
Fel Pro, #7916PT-1 = 3.81" .046"

Note that the "Thickness" referred to here is new, before torquing. For complete accuracy, measurements should be taken from an old torqued head gasket.

Those of you who have played with the Compression Calculator on our website please note that one of the variables is the bore of the head gasket. For greater accuracy be sure to insert the correct number for you situation.

Once again proof positive that the only way to know, for sure, what you have is to measure for yourself.

This is different than info previously posted by us and MarkP as to the thickness of the FelPro gasket. If anyone has a new or used Felpro, please mic and post the dimensions. As always we are still gathering information.

Adios, David

More FYI stuff from my collection: thicknesses & torques used -

1. The used steel FoMoCo head gasket out of my engine = .018".
2. The used Victor gasket out of my engine (75 ft-lbs) = .044"
3. The installed-but-not-fired-up FelPro gasket (70 ft-lbs) = .055"
4. The installed NOS FoMoCo steel now in the engine (measured by slipping a feeler gauge between the edges of the castings while assembled and torqued, so might be slightly off) = .021" at 70 ft-lbs.

The manuals I have for the Fairmont all show 70 ft-lbs for head torque, but my old 1964-68 Chilton shows 60-65 ft. lbs. torque required on Mustangs and Comets. I don't know why they changed specs, but I've been using the 70 figure on mine.

David,

Here are our measurements to add to the list.

Measured two Fel Pro, #7916PT-1 head gaskets that we have removed from two different 200 ci engines, heads torqued to 70 lb/ft. One gasket had been in an engine for at least 20 years, the other for 8 months. They both produced equal numbers.

Ten measurements taken per gasket at the rim of the bore using a Starrett No. 230 micrometer.

The measurements ranged from 0.045 to 0.048, the median was .046 inches.

I guess we will recalculate our decking and compresion calcullations.

Regards, Dave

how much of a difference will the reproduction gaskets make in a rebuilt engine? just lower the CR some? how much would this affect performance? thanks guys.

Howdy BRHero and All:

Thanks for the additional info. It's in the data bank.

The difference in a stock OEM '65 200 will be a loss of CR, from 9:1 to 8.6:1, assuming a .010 mill cut to true the head surface, typical in a standard valve job. Quench would go from about .045", assuming a .025" deck height and a .020" OEM steel shim head gasket to .075", assuming the same deck height of .025" and a Felpro composite gasket of .046".

The original quench height of .045" is tight enough to have a positive effect on turbulance and combustion efficiency. The new quench height of .075" is too great to have much effect at all.

Note- Quench is not effected by milling the head. It's factors are deck height and gasket thickness.

Between the loss of CR and combustion efficiency the difference would be noticeable in performance, economy and possibly in ability to resist pre-ignition. Mark P can give you some real life experiences.

As always, the devil is in the details.

Adios, David

David, planning the folloing biuld upon my 200. Hoping to get a compression of somewhere between 8:8 and 9:2. For improved daily driving in Maine. I was hoping not to have to pull the engine block, but I will if absolutely necessary. I have cast dished pistons. Adding oz head w/ complete re-build over sized valves 3 angle valve job and mild port. Plan to mill to reach 52cc on the chambers. Going to use NOS C9DE head gasket bore size of 3.81 and thickness of .037 according to your calculations thanks. Using your compression calculator that puts me at 9:1. Would this be accurate or am i missing some things? Would it be absolutely necessary to .000 deck the block? Just rather not pull the engine if not necessary. Thanks for any and all help. Mark

Howdy Back Mark:

No, zero decking the block is not necessary, but it is the ideal. Assuming you have a .025" piston to deck height, you'll be on the verge of having very little quench effect. But, you will not be alone. Ideal and reality, are sometimes the same. You do wnat you have to.

Adios, David

David thanks for the input. This car has been a work in progress since i rescued it from a field on my way home from college about 7 years ago. I parted out most of the work. Took the common cost cuts but I do not want to take any short cuts this time through. I would really like your opinion on the build up i should be looking at shooting for a summer daily driver. Read that a compression in the 9:0, 9:2 range is what i should be looking for. I have a 200. These are some of the upgrades i am going w/
dizzy2, blaster coil, msd box
260 cam
header w/ 2 or 2 1/4 single exhaust not decided yet
roller tipped rockers
cast dished pistons
Oz head
new valves 1.75 intake 1.50 exhaust, new hardened seats, guides
mild port
head resurface
holley 2300 series 350 cfm carb
.037 NOS headgasket 3.81 bore
Your opinion on the best build up to go w/ from here would be greatly appreciated. Just like to do it up right instead of going half way
Thanks for the help, Mark

Howdy back Bax:

Are you rebuilding the whole engine? Or just the head and doing bolt ons. The reason I ask is because if you doing the whole engine then it makes sense to deck the block to zero when your boring and adding the new cam and bearings. Boring and decking will alter your combustion chamber volume goals for a 9:1 cr goal.

If you're going this far, serioulsly consider a balance job on the rotating and reciprocating mass. It is money well spent.

I do not know anything about Oz 2V head volume or a formula for reducing volume. Sorry.

Adios, David

Call it "things I learned by reading about Smokey Yunick", but .040" is probably a good figure to shoot for on quench distance. Effective, but safe.

Don't forget that these measurements are usually done cold and that at operating temps the rod and piston will be measurably longer, closing the gap several thou. Add in some rod stretch (a thou or so), increasing bearing clearance over the life of the engine (another thou or so), and you soon start to get very, very close to smacking the heck out of a head with a piston that might be moving 3000 fps if you cut it too close.

Unless you can really carefully control the quench distance, most of us are safe with a zero deck and a .040-.045" gasket. Zero deck and a steel shim might be asking for a problem.

Typical 2V chambers were 58-60cc new. You'll be milling a little...

Picking up on Jack's comments, do your decking after resizing the rods.

Thanks to all for the help. As you can tell this is all quit new for me and i am attempting to take in as much info as possible. Just want to get my whole engine plan together before I take the head in for the re-build. Have a couple more questions. 1)If i do zero deck the block which head gasket should i use, the new .045 or the .035 nos replacement i have (sounds like w/ a .000 deck height i should use the .045) 2) to what size should i cc the chambers of the Oz head? Again looking for about 9:2 compression. It is starting to come together Thanks again for all the help.
Mark

Howdy Again:

To add to Jack and Addo's comments about decking, be sure to measure after boring and using the exact replacement pistons and new parts you are planning to use on assembly. Replacement piston pin height can vary.

Bax, If you haven't already, click on my signature, which will take you to the Falcon Performance Handbook website. There, on the left, you'll find "Compression Calculator". Click on it. That will bring up a table with the necessary dimensions to figure your CR. The defaults figures can be changed by erasing and adding your specifics. Once you have the inputs the way way you want them, click on "calculate". When the screen returns, scroll down for your data.

On a US 200/250 head you can estimate the amount you need to mill to achieve your desired volume. That formula is .010"=2cc. I do not know of a formula for the OZ head. It is best to cc each chamber both before and after milling changes.

Adios, David

David, thanks i use your book and site quit often I have input several diff. calculations just attempting to get an idea as i know measure measure is the key. I do have a couple of questions however. When using the calculator i have been keeping the following at the default calculations. cylinders, bore diameter, stroke length, piston to deck clearance .015, pistons dihed, dish/valverelief 7, volumetric efficiency 80%, 4500 RPM. I have changed the combustion chamber to 52, head gasket .035 w/ a bore of 3.81. Comes out at 9:1 Am i going about this correctly? Just got a feeling i am not adjusting some things that need to be. I replaced the pistons last year w/ stock spec replacements. Should the deck clearence be changed? If this is correct it gives me basically the compression i am looking for, but possibly very little quench. Would this be in danger of pre-ignition w/ such low quench? Lastly it seems like measurements need to be taken carefully from the block and then re-build the head to suit the needs. I ask because my car is now in storage here in Maine and the fellow who i wanted to have re-build the head is getting ready to move. Not really anyone else in my area i would trust w/ my head w/. I do not want to put the cart before the horse if i have him rebuild the head w/ only a general idea what my plans for the block are.
Thanks Mark

Howdy vBack bax:

Was the block overbored when rebuilt? If so input the thew bore dia. If it was Overbored .030" then the bore data would go from 3.68" to 3.71".

Most replacement pistons have a lower pin height to compensate for machining. At the very least, I'd use .025" for deck height input. do you know what aftermarket pistons were used on the rebuild?

Replacement pistons come in several dish configurations. Small dish Sil-Vo-lite pistons #1120 have a 6.5 cc dish. To be accurate you must know what you have.

Your quench dimension is dependent on your deck height and gasket thickness. Jack's mention of .040" as a worthy goal is a good one. Even a stock '66 200 with a steel shim gasket and .025" deck height will be over that. They ran 9:1 CR and were still fairly knock resistant. Closer to .040" is better, but you have to do what you have to do. Street engines are a statement of compromise.

Yes, it would be best to know exactly what you have for dimensions in your block before planning your head mill cut. It is possible to build everthing, block and head, but not mill until you can mock assemble. Then, if you need to dissassemble the head for a final mill cut to achieve your CR goal. It adds and additional dissassembly, but you'll be exact. You can estimate, but err on the caustious side. This is not uncommon.

Adios, David