Well this is my first attempt at doing a bit of head work. Nothing major, just some smoothing out of the air flow. Just look at this picture that Darkhorse took of a stock head, mine looked just like it.

https://www.evolutionm.net/forums/at...chmentid=30005

Anyway, I am going to have my machine shop cut the seats for 1mm larger valves, press in new valve guides, and line bore the camshaft journals. Actually a member on this board sold me the head, but it had no camshaft journal caps and they are bored out while on the head from the factory so my old ones do not match up exactly. They were not ther on the eBay add, I just did not notice, however several of the valves were bent and there was no mention made of that in the add. I am trying to get ahold of him to see if I can at least get the caps, God only knows why someone else would want them. Here are some pics (if they attach) so tell me what you think, and I know that I am no Darkhorse so you do not have to tell me! I had to work around the valve guides beacause I have no way to press them out. I have thought about polishing the ports very thoroughly, but some people say to leave them a bit rough. Anyways......

 

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Not bad at all! Looka pretty damn good! it isnt as easy as it looks is it? esp with the guides installed, its tough to work around them. Dont be so concerned with the surface finish as much as removeing any rough casting and factory maching areas, like the ridges left next to the seat in the combustion chamber, those will disturb the air entering past the seat, and kick it up, so you may want to go back and try and knock those down- carefully, you dont want to knick the valve seat. It looks great though, nice job. Also, while you have it off, I woudl have the gasket surfcae at least checked and at best, take a light clip off it just to be sure its flat and the new gasket can get as much surface area as possible.

 

Nice work... how much time you have in it?

 

Thanks Darkhorse, coming from you that is a complement, and I will go back and address the area's around the seats. And I was planning on having the surface lightly decked, not to lower the compression ratio but just to make sure it is straight like you said. I do have a question for you, but it may be difficult to answer. The seller kept the caps for some odd reason, can I have my machine shop take a bit off of the feet of the caps and re-line bore them? I have no idea why the guy kept the old ones, but mine do not line up exactly on the new head. They are not off by much, but I can feel it with my fingers. Zeus, I have about 6-8 hours in it. The hardest part was learning what dremel bits to use, and how to use them. It sounds strange, but I ended up using odd bits in odd places. After that just being patient and not knicking anything or digging too deep is the next hardest part, but your having worked in the aerospace industry I am sure that you would have the patience and precision needed. Maybe some cool bits too! It has actually been kind of fun, I just wish I had a lathe and some of the equipment that Darkhorse has, but then my fiance woud hurt me due to lack of attention.

 

The reason I asked is do to the fact that I didn't see any "rushed" mistakes. Pretty impressive for a "first timer".

I did win a bet with a pneumatic hand grinder once... with half of two teams watching (and betting), I hand fit an "out of spec" Ti part (about twenty centimeters worth, about half a mil over) in about two minutes without "burning" it. Tolerance when fitted between the spar and skin was plus or minus a few ten thousandths (I've long forgotten the actual spec). Of course it "couldn't be done" and I was too young to believe that. The watching inspectors couldn't believe it after checking it over and over... I'd give anything to still have hands like that...

 

It's good to know we can count on joeycoates for a good head job. nice work!

 

LMAO. Joey good work .

 

let us know how it turns out for power gains...

when you port the head, does that help bottom end or top end?

 

both! but it really depends on how much and how (shape) you port it. you can do things to increase torque and you can just hog it out to improve high flow. however, there is such thing as too much. it is a science.

 

More like an Art...

 

I did not really take any material out of the ports as I do not want to loose velocity, I just smoothed out all of the rough edges. I would not know where I needed to take material out anyway, so instead of screwing it up I am not even going to mess with it. I am hoping that 1mm larger valves will help with the flow but leaving the ports alone will help with velocity. Once it is on the dyno I will see what the difference is.

 

the classic debate of the balance between art and science. just like life.

 

If you can take the caps you have, have the feet cut- the same way you rebuild a main cap or the big end of a rod. Better yet, if you can find someone with a Sunnen cap grinder, you can have the cap squared, thats what I do them on, clip about .004 off the feet, and them hand lap each cap in to be sure is DEAD flat, then set it up and slip the top purcahse area where the bolt head clamps, this way you maximize the surface contact. Pull all of the dowels from the head, and set up and have the top flange clipped to make sure its flat as well, clean all of the threaded holes, install new dowels, install the cut caps and torque and then I hone them back to size. Honing is nice becasue you can sneak up on it, I have never bored them- not to say it cant be done. I like the crosshatch left by the hone since it holds more oil that way also. Plus the honing bar gets the housing all straight with one another. You are going to have to at least bore or dress the seal housings at the end caps and the cam sensor flange since if you shorten the caps, the opening becomes oval

 

That's doesn't sound right.