questions for when I get to the machine shop

Positively Ralf

Well-known member
Since I'm finally taking the head off to take it to a machine shop, what should I tell them to do when it comes to shaving the head to gain the 9:1 compression I keep seeing being suggested? Is that the referred ratio for everyone or are there any other suggestions? Cause I know I will be asking for a 3 angle valve job and cleaning of the rocker assembly when I give it to them. Anything else to add?

Also, can I put on any ford 6 cylinder head gasket I can find at an autoshop? Or is there a specific one I have to get?

And if there is any additional info I need to know to tell them, would someone be kind to list them for me? I want to try to get this done as smoothly as possible without any questions being asked.
 
Depends on bore size you have, the pistions, and the heads chamber size (CC) that you have now. :| This all varieys by the years, differant engine sizes ie 144,170, 200, or 250. :nod: What are the parts and years you working with? :unsure:
 
As far as I know, its a completely stock 74 200. Although I really need to find out how to identify the heads since I found a carter rbs on it for a carb and the maverick 200s of that year did not have an rbs.
 
Check the casting numbers to get in ball park and than the date code will give you exact date
 
Depends on what head gasket you end up using.
If you can find a steel shim gasket you can mill about .050 to get up around 9:1.
If you use something new like this:
http://cgi.ebay.com/ebaymotors/1960-83- ... 2ead7f5b2b
you might have to go another .010-.020 to compensate for the extra thickness of the gasket.

It's a good idea to cc the chambers so you know what you've got.

Are you re-using the valves or getting some new?
Larger valves might require unshrouding.
Backcut 30° on the intake valves.
You could ask about pocket porting the valve guide bosses.

I took a copy of the Falcon Six Handbook and left it with the head.
I had highlighted all the most important stuff, and it came back well-thumbed and the head was beyootifull! :nod:
 
Howdy Back Ralf and All:

You'd be money ahead to buy a gasket set for a valve job. The gasket set will include a head gasket plus all the other gaskets you'll need to reassemble. Specify that you want a gasket set for a '74 200 and the head gasket will be right. FYI- the set for 144 and 170 engines has a head gasket with a smaller diameter bore. A '74 head, either 200 or 250 will have a casting code of D3DE or D4DE. They are basically identical.

A '74 200 is rated @ 8:1. It will have a stock chamber volume of aproximately 62 ccs. To get to a 9:1 CR you will need to reduce chamber volumes to 52 ccs. That is aproximately a mill cut of .050". The other critical dimension is the thickness of the new head gasket compared to the old one. Measure both. For instance, if the old one measures .025 and the new one .045", the difference is .020". You will need to mill the head .020" to compensate for the difference. A sharp machinist will have no trouble ciphering this out for you.

Adding a 30 degree back-cut to the intake valves, as Jack suggests, is good advice. A '74 200/250 head will still have 1.69" intake valves. If you have to replace any, I'd replace all with 1.75" valves that became standard on later heads.

Post the code on you head and keep us posted on your progress.

Adios, David
 
Actually I was coming here to ask you guys where exactly on the head is the casting code. I removed the air filter assembly and was looking around but couldn't find it. I think I may actually need to get a new head considering the head on the motor right now seems to have a dark brown color to it. Hopefully it's nothing really bad.
 
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