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Cylinder Head

 
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ProtegeJunkie
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PostPosted: Fri Mar 25, 2011 5:40 pm    Post subject: Cylinder Head Reply with quote

I recently purchased a used DOHC cylinder head. The cylinder head was rebuilt and all machining had been done before I bought it. However, it did not come with journal caps for the camshafts. I was told that I needed a cam bore alignment to ensure that the camshafts spun freely during engine operation. Is cam bore alignment the proper terminology here? Some people seem to not know what I'm talking about.
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af2
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1933 Willys Coupe

PostPosted: Fri Mar 25, 2011 7:55 pm    Post subject: Re: Cylinder Head Reply with quote

ProtegeJunkie wrote:
I recently purchased a used DOHC cylinder head. The cylinder head was rebuilt and all machining had been done before I bought it. However, it did not come with journal caps for the camshafts. I was told that I needed a cam bore alignment to ensure that the camshafts spun freely during engine operation. Is cam bore alignment the proper terminology here? Some people seem to not know what I'm talking about.


You could buy a machined block without main caps also and be told you need a crank to finish the job?? WTF????

Can you throw the head at the guy that told you that??
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ProtegeJunkie
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PostPosted: Fri Mar 25, 2011 8:59 pm    Post subject: Reply with quote

Im not sure I follow you. Do I need the additional work done?
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Big Dave
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PostPosted: Fri Mar 25, 2011 9:36 pm    Post subject: Reply with quote

I suspect that he bought a head without the caps to hold the cam in place just like some nice guy at a swap meet will make you a smoking deal on a used block without main caps.

In either case once the missing part of the circle is located the caps are cut (making the clamping part thinner in the process) and new holes are machined to center the rotating part (which often throws off other dimensions which may or may not negate the value of the head).

If this example occurred with a Mercedes head you would be buying a new head from Germany as you can not move the cam without putting the valves into the pistons (though I suppose if you remachined every part in the motor to take out what ever you cut out of the top I suppose you could get by).

Big Dave
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10sec.et
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PostPosted: Sat Mar 26, 2011 12:46 am    Post subject: Reply with quote

no matter what you need the caps. i doubt you can just buy them separately so you will need another head to get them off of. once you do theres a better than good chance you will need to have the "new" caps machined (line bored) to fit your existing head. what head/engine is this ?
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af2 wrote:
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ProtegeJunkie
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PostPosted: Sat Mar 26, 2011 1:10 am    Post subject: Reply with quote

I already bought the caps off another cylinder head from the same engine(FSDE). That is why I was told that an alignment(machining)would need done. I'm just trying to find out exactly the name of the procedure that the machine shop would need to do. Is the line bore you speak of a common thing done what most shops do? Is that what I need done? I assume thats a different procedure than the cam bore alignment I mentioned?
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10sec.et
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PostPosted: Sat Mar 26, 2011 2:20 am    Post subject: Reply with quote

i would just call what machine shops you have available, tell them what youre dealing with and find out if they can do it. if they cant figure out from your description (which seemed pretty accurate to me) what needs to be done then you probably dont want them working on it anyway. just out of curiousity, have you tried torquing the caps on to see how far off they were ? i have actually seen heads that were damn near perfect and you could mix up the caps and everything would still mic out good (dont ask me how i know Embarassed ).
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ProtegeJunkie
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PostPosted: Tue Mar 29, 2011 9:18 pm    Post subject: Reply with quote

I did do a quick test, but the cams did not spin. Altho, nothing had oil on it so maybe that was why. Its hard to do work in my garage cuz its almost as cold in there as it is outside. I will try to do a more thorough test soon. I was actually hoping it didn't need the machining, but was gonna get it done just incase. My current cylinder head is leaking coolant bad and thats why I bought another.
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Big Dave
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PostPosted: Sat Apr 02, 2011 3:13 pm    Post subject: Reply with quote

Sounds like a blown head gasket. Is the surface deck of the head and the block free of corrosion and still showing machined surface marks, or is it rusty and pitted? If it is corroded both will have to be machined.
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ProtegeJunkie
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PostPosted: Sun Apr 03, 2011 10:38 am    Post subject: Reply with quote

The head gasket and deck are all fine. I had an exhaust manifold bolt break and had to drill it out. I then tapped the hole but could not get the new bolt to screw in properly. So I drilled out the hole to the next size up and somehow ended up drilling too far in and thats where I have coolant shooting out at
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Big Dave
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PostPosted: Sun Apr 03, 2011 7:55 pm    Post subject: Reply with quote

Once you get it resized with a thread insert I would JB weld the insert in place. After the epoxy has set then don't forget to use some thread sealer on your manifold bolt or it will weep coolant.

Big Dave
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af2
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PostPosted: Mon Apr 04, 2011 9:35 pm    Post subject: Reply with quote

Big Dave wrote:
I suspect that he bought a head without the caps to hold the cam in place just like some nice guy at a swap meet will make you a smoking deal on a used block without main caps.

In either case once the missing part of the circle is located the caps are cut (making the clamping part thinner in the process) and new holes are machined to center the rotating part (which often throws off other dimensions which may or may not negate the value of the head).
).

Big Dave


That is what i was trying to say. Without words I failed!!
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10sec.et
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PostPosted: Tue Apr 05, 2011 1:33 am    Post subject: Reply with quote

af2 wrote:
That is what i was trying to say. Without words I failed!!


Adams brain moves faster than his fingers. until someone invents a keyboard that reads minds, hes doomed to type in broken english Laughing .

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