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223 compression ratio increase

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peeeot
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Joined: Thu Feb 07, 2008 5:07 pm

223 compression ratio increase

Post #1 by peeeot » Thu Mar 23, 2017 8:56 am

I need to replace the head gasket on my 223 and am considering having the head milled while it is off to increase compression. It is my understanding that higher compression increases combustion efficiency, improving power, torque, and economy.

I don't know what a good target would be--perhaps 9.0-9.5? I'd like to stay with regular gas.

It looks like the head gasket available now is a multi-layer steel gasket. Do we know the compressed thickness of this gasket, or how it compares to original?

Has anyone done this on a 223?

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bubba22349
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Re: 223 compression ratio increase

Post #2 by bubba22349 » Fri Mar 24, 2017 5:15 pm

:hmmm: you didn't mention which brand of head gasket so can't be of help on its crush thickness but it probally can be looked up on their web site. But for sure you will need to at least mill the head the differance of the orginal steel shim head gasket thickness (their roughly about .025) and whatever the new head gasket thickness is just to get back to your years stock 8.4 to 1 compression ratio that you had. The top of the heap in 223 performance was the 1957 and 58 223 engines (145 HP and 212 Foot Pounds of Torque) their compression ratio was at a higher 8.60 to 1. If you still want to run regular gas than 9.0 to 1 is about the limit. Finding out the true compression ratio would require CCing the combustion chamber size, togeather with the head gasket thickness, plus the amount the pistion is at TDC is from the top of the block. If your having a fresh valve job done on your head consider having the valve bowls opened up and blended, three angle valve job with the valves back cut for better flow too. Some adistional porting work could also help gain some more power. Good luck :nod:
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

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B RON CO
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Re: 223 compression ratio increase

Post #3 by B RON CO » Fri Mar 24, 2017 6:17 pm

Hi, X2. If you are planning on milling the head you should find out the original combustion chamber size and cc check at least one or two other cylinders. Then you will see if the head has already been milled by a previous owner doing a valve job. Good luck
B RON CO. Still workin' on it!

1933 Ford Pickup - 59A Flathead V8
1966 Ford Bronco - U14 - 170/200 Straight 6
1966 Ford Mustang - 289 V8

peeeot
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Posts: 134
Joined: Thu Feb 07, 2008 5:07 pm

Re: 223 compression ratio increase

Post #4 by peeeot » Sat Mar 25, 2017 11:25 am

I'm sorry, Felpro is the only brand I have seen for sale at the sites I usually use for parts. Here is a link to the Felpro site listing for the gasket:
http://www.fme-cat.com/overlays/part-de ... RLANE&vin=

It lists a manufactured thickness, but not a crush thickness.

I am not planning to do a valve job, but I will consider it. In order to check the combustion chamber volume, I was thinking I could use a calibrated dropper and see how much liquid it takes to fill the chamber. Would that be an acceptable method?

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bubba22349
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Re: 223 compression ratio increase

Post #5 by bubba22349 » Sun Mar 26, 2017 8:40 am

:thumbup: FelPro head gaskets are great I have used them for many years. Use that manufacturing thickness that will be close enough subtract the thickness of your orginal head gasket as the amount to get back to the stock 8.4 compression ratio. Yes any way that you are able to measure the chamber sizes accurately will be fine, to go even further a to 8.6, 8.8, or 9.0 compression ratio. I use a 100 CC Buret and a piece of thick plexiglass, a little white grease to seal it around the combustion chamber with a 3/8 hole drilled in it that I place at the top in corner. If you don't need to do a valve job right now that's ok too. Good luck :nod:
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

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