170 head on a 200 block?

[ElTejano]

I have not posted here in a while, actually only twice. I am a semi-regular member on TFFN.net but any help here would be appreciated.

I have a rebuilt 68 200 block. I also have a fresh built 170 head that I have had for a while. I cannot track down a 200 head and would like to use this one while I find something off a 200 or 250. I am not too concerned with performance right now, my Falcon is my daily driver. I am wondering if the compression will be much too high doe to the smaller combustion chambers.

Any help would be greatly appreciated.

 

[bubba22349]

The compression could be higher with the smaller combustion chambers or it may be close to right you would need to measure the CC's of the chambers to know for sure. If the head has not been milled much over the years and was close to the largest size as cast chamber you would be all right. You can also use the thickest composition head gasket that is .055 thick more than twice the thickness of a stock steel gasket this will drop compression a little too. And then you could do some grinding in the chamber by the intake and exhaust valves (check porting posts) you could gain a CC or 2

 

[rbohm]

8) here is a list of websites that have compression ratio calculators. any one of them can be used to figure what your compression ratio will end up being.

http://search.yahoo.com/search?fr=ffds1 ... calculator

 

[CZLN6]

Howdy All:

Hey Tejano, post the casting numbers of the 170 head. The 170 was used into the early 70s. From a C4xx casting on 170 and 200 used the same heads ( with some differences from 1969 to '72).

The other variable is the head gasket. All OEM head gaskets were a steel shim type of .025". All later composite gaskets are thicker. Depending on the thickness of the head gasket you use ou could lose CR.

Keep it coming.

Adios, David

 

[ElTejano]

The casting numbers are C1UE, I believe. I am not sure about the last number but I do know that the first 3 acre C1U.

The head on the current engine in the car is C8DE and if its the case that its the same head that would be used on a 200, then I can have that one rebuilt later.

For now, if its do-able, I would like to use this C1UE head because it is already built.


Thank you to all of you for your responses, BTW.

 

[CZLN6]

Howdy Again:

The casting is likely a C1VE. Which were used in the 1st 170s built in 1961 & 1962. It is virtually the same as the C3DE casting of the 1963 model year, with the major changes relating to carb mounting and exhaust manifold. Chamber volume varied from 48 to 53 ccs. Advertised CR in '61 on a 170 was 8.7:1.

It is doable to use this head on a 200. The big differences between a C1 and a C8 head is valve size and intake tract volume.

C8 casting, 200- Intake valve size 1.64", exhaust valve size 1.38", Intake tract volume- 1100 ccs.
C1 casting, 170- Intake valve size 1.52", exhaust valve size 1.266", Intake tract volume- 890 ccs.

Performance wise, it may draw a little more vacuum, and yield good economy, but loose higher rpm performance. What carb and distributor will you be using on the engine?

Adios, David

 

[ElTejano]

Hey David, I will be using a Carter YF with a Duraspark II.

I am not too worried about performance, I am more worried about economy.

Thank you so much, BTW.

 

[CZLN6]

Howdy back:

It sounds like a good plan. One more question- What head gasket will you be using?

Maintaining a CR of around 9:1 would be good for economy. Was the C1 head milled when it was rebuilt? How much?

Adios, David

 

[ElTejano]

See, I am not sure if it was milled, I got it already rebuilt. I am going to have to measure the combustion chambers per Falcon Performance Hand Book instructions and also check the cylinders cause the block was decked when I had a sleeve installed.

I will try to get to that today.

The gasket I have is the Fel Pro 7916PT-1 which I see at .055 and .050 compressed on the hand book. I will measure it with the mic when I get in the garage to make sure.

I am also transferring the adjustable rockers off my 70 and replacing the non-adjustable ones.