Is theese valves wasted?

Hey guys.

2 questions.

#1. On the attached pictures, there are 2 valves. Would you say that they are wasted? They could not move at all, had to tap them with a hammer. One of them is totally sooded, and the other one.. well decide for yourself. If not wasted, then how to clean?

#2. How do i clean my cylinder head? The exterior parts will be glassblasted, but how do i clean the sooded parts inside the cylinder head, on top of the pistons, erc. ?

Best regardds MIkkel

Valve1:






Valve 2

 

Valves are cheap, replace 'em. It's not so much the valve head you have to worry about, it's the wear on the stem, and those look pretty galled up (look at the areas on the stem/shaft above the carbon, where the valves ride in the guides). Don't forget to have the valve guides looked at closely too. The valve heads are usually fine, unless one kisses a piston and gets bent, or some Bubba screws up re-grinding one.

You can clean up the valve heads all you want, but if the stems and guides are hosed that motor's gonna suck oil and smoke like a forest fire. My own personal policy is to always replace valves and guides, it's cheap insurance. But that's just me, I'd rather spend a little more for the confidence of having new parts in my engine, than go the cheap route and always wonder/worry about an old, tired part breaking.

And once all the parts are completely degreased, it won't hurt to have everything beadblasted. Aluminum parts like pistons and brass things are better done with walnut shell media, glass beads are too harsh for soft metals. Just be sure and WASH everything afterwards with hot soapy water and dry thoroughly. Blasting grit is NOT your friend.

 

There's no automotive machine shop in your neighborhood that can recondition your cylinder head? Proper rebuilding of a cylinder head requires quite a lot of special equipment, and it's not economical for individuals.

The shop will evaluate the valves and tell you whether they need to be replaced or not. The usual criteria is the thickness of the edges after they are ground.

Reconditioning the cylinder head is one job I would absolutely leave to the professionals.

 

BTW the valves look fine to me - just normal dirt. The soot has more to do with the fuel mixture and temperature in the valve pocket than anything else. The exhaust valves will have that tan-brown scale. Normal.

Bead blast the valves to clean them. The shop would do that for you. They would hot-tank the head (immerse in corrosive cleaner, NaOH solution), or some modern shops have a washer, like a big automatic dish washer.

 

You can take care of most of the heavy deposits with a wire wheel on a pedastal grinder.
Some carb cleaner or laquer thinner should clean it up enough to mic it to check that it's whithin specs.

A good professional head reman is money well spent. Have you shopped around for one up there ?

 

Excellent point Tim! I concur. I might dink with 'em a little because I just like to, but in the end it'll go to a pro to be done right. Same with the rest of my engine. If my trans and t-case give any guff, off they'll go too.

 

Well, I think if I had the machines needed to do valve work, I would do them myself. It's not rocket science. But I don't, and it's just too expensive to buy the equipment I'd need to fix one or two cylinder heads.

I could write a couple of pages on what's involved, but I think it would be better for the interested reader to pick up a book or two and read about it there. There's a nice chapter in Tom Monroe's book http://www.amazon.com/Engine-Builde...=sr_1_1?ie=UTF8&s=books&qid=1288690924&sr=1-1 - this book is both cheap and very informative.

About the valves, as I understand, the stems don't wear much, so measuring the stems won't tell you much. The steel stems ride in the iron head, which is softer and wears away. When the head is reconditioned, it's the hole the stem rides in (the valve "guide") that is repaired. There are several ways to recondition the guides, including knurling and several types of inserts.

The other major wear point is the faces of the exhaust valves. The exhaust valves are much more susceptible to oxidation and erosion because of the high temperature of the corrosive exhaust gases. The valve seats don't suffer as much damage because they are part of the larger cylinder head, and the temperature of the seat does not rise like valve temperature does. But the seats need to be reconditioned when the valves are replaced. A leaky exhaust valve will erode the seat, which must be reground.

So there's a lot to it, but 1) it's not very complicated in total, and 2) both evaluation and reconditioning requires several special tools and some equipment. In the USA, you'd just drop the head(s) at the shop and let them deal with it.

Another job the shop can do that you can't is to check for cracks. That's the first thing to do (after cleaning), since you don't want to spend a lot of money on a junk head.

 

Heee hehe, you are right, But the salary here in denmark is really high compared to USA. That means, to get a head renovated, we are talking 1000-1200 dollars.

I will take all the **** off the valves.
Replace valve stem seals.
clean entire block
Clean valve seats and use this tool: http://www.ajengros.dk/shop/am-pro-ventil-sugekop-925p.html at the valves

That is what i will currently do to the head.

 

Holy crap, I think you could send the heads to the U.S. and have them done and shipped back and save money in the deal.

 

Oh wow, I didn't realize you were on the other side of the planet! Sorry about that.