Milling head w/out valve job

[kirkallen143]

Currently I am waiting on the E0EB-**** head, they are chasing cracks from welding the low/fill spots. What I am asking is it OK to mill the head that's on the engine now w/out doing a valve job. There are no problems with it now, and compression is good in all cylinders as I know of. I am milling the intake for the 2-barrel direct fit and then go ahead and mill .025 off the bottom to raise the CR while it is there. I am probably running 7.5 to 1 now with the Fel-pro gasket installed (D5 head, 7cc dished pistons, etc...) I will confirm the combustion chamber size of each cylinder before it goes to be on the safe side.

"Every .010 milled is approx. 2cc...every 10cc is approx. 1 number increase in the CR."

This will be on a turbo application, so 8.0 to 1 ratio max. Any responce is very much appreciated, Thank You.

Kirk ' 73 bronco

 

[addo]

No problem to mill it! You will need to tear it down and just be sure to remove all the swarf after.

Regards, Adam.

 

[Guest]

Why not just grind the valves, without guides, and use teflon valve seals? This way you also know if a valve is bent. Grinding just a bit doesnt mean you have to have them "seated", they probably sit fine. The only time I would say someone that doesnt have access to a machine shop for free would seat the valves would be in a 3 angle or 5 angle new valve job, or if the seats have wear or pocking.

They can also mic the stems for cheap, if you dont have a micrometer. Should be no more than .003 difference between the stem and the upper stem for a good seal. Heck, if you know the guys at the shop, theyd probably mic the valve stems for free, takes 5 minutes, 10 minutes to grind all of them. Better valve stems=more compression, less oil running down the stem and past the guide into motor, burning oil at startup. Also lets valves run tighter, tighter motor.

Anyways, grinding the valves just a bit costs very little. If the head is clean and so are the valves to some extent, Id invest a little into the valve grind. If youre going turbo, its a little to invest to make sure those valves seal better. Higher compression without any leaking of the valves on a "valve closed" condition.

 

[kirkallen143]

Well, after the thought of it, you just might as well do it right the first time. Yeah I am going to do the 3 angle valve job, backcut the intakes, install bonze guides with teflon seals only on the intakes. Basically do what the Ford Falcon Handbook suggests to the heads.
I was trying to get the bronco ready early to test before I need pics for a calender that our clubs puts out each year, The LoneStar Early Bronco Club. August 31st is my deadline. Oh well, there is always next year, too.

Kirk ' 73 bronco

ps. appreciate the suggestion, though.

 

[wsa111]

Kirk, also backcut the exhaust valves, the gain you receive on the intakes is also gained on the exhaust side. the exhaust needs all the help it can get from better cfm flow.

If you have headers also install the teflon seals on the exhaust valves to.
William

 

[kirkallen143]

William,
I was going the turbo route, so I need all the extras I can get on the exhaust side. The extra metal will help with heat, and having no seals on the exhaust valves, for what oil passes in, will only add to help cool the valve. Besides, the bronze guides do a pretty good job themselves to seal the valve stem. This has been done before with no really measurable loss/burning of the oil, in fact some engine manufactures do this same technique...either subaru or volvo, one of them. Yet, as always sure do appreciate the info, thank you sir.

Kirk ' 73 bronco

 

[wsa111]

Kirk, If you use quality valves, such as the ones from FSPP I see no reason not to also backcut the exhausts.

The extra flow can't hurt. Wiliam

 

[kirkallen143]

Yes, I will have the SS valves from FSPP, so then it is a done deal and you are right, the extra flow couldn't hurt a thing. Thanks William.

Kirk ' 73 bronco