6.9 IDI valve train questions + head gasket job

[8769bigred]

I put in a full shift today on the engine project. Today was one of those shop days where you clean up and look around and it looks like you made no progress. Spent all day cleaning the heads. Chasing threads, cleaning threads, cleaning head bolt holes and meticulously scraping carbon off the head around the valve seats. I also was able to get the block cleaning started. The block thankfully is very flat. Only could get then.0015 feeler under the straight edge in the middle. The .002 would not fit. I was able to get the front damper off and front cover and begin cleaning those areas as well. It is such a messy operation. I started inspecting the valves and found most all of the exhaust valves to have some putting. I’m not sure what my move will be on those yet.

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[8769bigred]

Been doing some closer inspecting and I’m hung up on this gasket and pre cup situation. I have the one crack that’s really close to the fire ring that makes me nervous. Iv been inspecting the gasket and it almost appears that the combustion gasses were leaking into the metal cut out on the gasket for the pre cup. This is apparent on all the cylinders. Does any one know if this is normal? I was looking at the CDD gasket I got and it appears to not have the metal fire ring extension for the pre cups. Maybe the head gasket was simply failing and this is what that looks like? Would hate to put it back together and have combustion gasses eating the cooling system. I never noticed any problems with that before disassembly.

another thought I had is that if the previous has a ‘fire ring’ of its own I’m not sure why the cracks even matter unless the clamp force in that particular area is not high enough to seal combustion gasses

 

[8769bigred]

Ok I just did a bit of an experiment. I cleaned up the pre cup and put the gasket on. I’m sure the ring will crush out on a new gasket but it appears I’m in the clear but it sure is close. If any has any thoughts I’d love to hear them.

 

[IDIBRONCO]

All precups will crack like that. It's just a matter of time. It's something that we have to live with. It's possible that some of the gasses were barely leaking by on your old head gaskets, but they would have been at an absolute minimum. With the compression that these engines run, it won't take very long for a leak to start pushing coolant out of the cooling system.

 

[8769bigred]

Wrapped up today with a few decisions being made and a shocking discovery. All my exhaust valves are pitted pretty bad so I’m going to replace them with factory ‘turbo’ rated valves from a 7.3 idi. If wanted to fix my valves I would need a machine shop and if I wanted to put new valves in I would also need a machine shop. So I’m going with the upgraded valves. I took the oil cooler apart and was horrified to find 16 out of the 26 coolant passages were completely plugged!! I have never once had an over heating problem but I’m a bit concerned about what my oil temperatures have been. Some one must have put some stop leak crap in the radiator at some point or used hard water to mix coolant. Going to get the heads cleaned up at work tomorrow and then I can sit down and properly measure all the guides to determine if they need done.

 

[IDIBRONCO]

I’m a bit concerned about what my oil temperatures have been.

It looks like you have an idea on an aftermarket gauge.

 

[8769bigred]

More inspecting today. My exhaust valves are pitted so I will be installing the upgraded 7.3 idi valves. I noticed it appears my valve stems are cracked at the tip. Has any one seen this type of wear before? It is more pronounced on the exhaust valves but still visible on the intake valves

 

[IDIBRONCO]

I believe that they are designed to spin while they are opening and closing. There should have been rotators beneath the valve springs. The wear in the 8988 picture would then probably be pretty normal.

 

[Nero]

I don't know... I've never seen a valve stem with wear like that... I wouldn't use it.

 

[Olds64]

Did you measure the valve guide wear with a dial indicator and the valves in the head?

 

[8769bigred]

Did you measure the valve guide wear with a dial indicator and the valves in the head?

I have not measured them that way yet. The heads are filthy I need to run them through the parts washer at work. Then I will have a clean work space to measure. I did take some preliminary measurements with a hole Gauge and micrometer. Most exhaust valve clearance’s were .0025-.0030

 

[Olds64]

Let us know what the measurements are once you get the heads clean.

 

[8769bigred]

More cleaning today. I got all my intake valves cleaned up and inspected. I will be the re- using them. All the valve rotators are smooth and all the springs have been tested. Every spring was square and tested at 70-80 pounds @1.790 inches according to the ford spec book. the ford spec is 60 pounds with a 10% service allowance.

I did notice most my valve spring ‘caps’ or ‘retainers’ were missing a small hard plastic ( I assume it used to be soft) seal of some sort. Going to need to hunt for replacements.

 

[rreegg]

More cleaning today. I got all my intake valves cleaned up and inspected. I will be the re- using them. All the valve rotators are smooth and all the springs have been tested. Every spring was square and tested at 70-80 pounds @1.790 inches according to the ford spec book. the ford spec is 60 pounds with a 10% service allowance.

I did notice most my valve spring ‘caps’ or ‘retainers’ were missing a small hard plastic ( I assume it used to be soft) seal of some sort. Going to need to hunt for replacements.

Does that mean your springs are “heavier” than spec? I’m not familiar but possibly recall reading about different spring weights

 

[8769bigred]

It would think they would be heavier than spec. Your question prompted me to do a quick google and it seem stock is 78-80 pounds. I was looking at the spec book on ‘the bull nose forum’ in their documentipn library. Maybe there are different weights for different years? I will do some more research.