[357ford]

I have the heads apart, thought I would clean them.

The intake valves have a little carbon buildup..I can take care of that.

The exhaust valves have a little surface rust as I would expect, any thoughts on cleaning those. Steel wool? I thought about soaking them in vinegar and let it eat the rust off but will use that as a last resort.

Thanks

 

[NAIRB]

Buy some muriatic acid, dillute it with water and pour some in a bucket, (just enough to cover the head of the valve up to where the carbon stops. Carefully place your valves in the solution (just the heads as the acid will eat up the chrome plated stem if you soak it). Be careful with the acid, it's very caustic, do not use it indoors, do not use it around equipment and metal tools(the vapor will rust your stuff). Don't breath the crap, use a respirator or mask and eye protection.

Leave them in there for a few minutes, remove the valves and rinse them with water. You can then buff them up by chucking each one in either a drill press or a portable drill in a vice. I used to use scotch brite to clean them as they turned in a lathe, but a drill or drill press will do the job. You can polish the stems with some fine 400 grit or finer paper and wd-40.

 

[357ford]

Appreciate it.

 

[machine shop tom]

Forget the toxic stuff. Just wire wheel them or use a wire brush. You can use a knife to scrape off any large carbon build up.

tom

 

[357ford]

Sounds like a plan...I am not a fan of harsh chemicals (acid)...still leaning towards soaking them in vinegar...believe it or not it works when it comes to taking rust off parts....just takes a little more time than most would wanna waste. Put an exhaust manifold bolt off a 100,000 mile engine in a cup of off the shelf white vinegar (5%acidic), four hours later the rust completely flaked off. However, it flash rusts real quick, have to rinse and put some type of primer or wd-40 on it real quick.


Might have to use the wire wheel, thanks

 

[302 Z28]

Why complicate things, just wire brush them?

Vince

 

[357ford]

Not trying to complicate things but it does appear so. I just think it would be easier to let the valves soak and wipe with a towel/rag, than hold the valve and go at it with a wire wheel in the other hand. Maybe I am just lazy. I will try steel wool and put the valves in a drill and see how that goes if thats not cutting it, the sandpaper, then wire wheel. Luckily I have each so thats not a problem.

Thanks for the reply

 

[brainsboy]

Muriatic acid will etch the metal not to mention it doesnt take off carbon. I have used it many times for cleaning frames and engine compartments and I can tell you that after you use it, metal rusts even faster. I have used muriatic acid, then cleaned with thinner, then ospho, then lacquer thinner again, then a coat of urethane paint. After 3 weeks I removed some paint and rust had formed under the paint. Parts will start to rust with in the first hour no matter how much you clean it or rinse with water. Now I know your not painting but the stuff is nasty, the best way is to just use a wire wheel on a bench grinder.


Ben

 

[Super Streeter]

Put them into a drill press and spin them around,and knock the heavy stuff off with a sharp tool.When done,keep them spinning and use some emory paper on them while they are spinning and squirt it down with some WD40 while you do this.If you want to really step it up,wipe them down with a towel while they spin,and blob some Mother's polish on a cloth and polish them.I had a set of valves that looked like they were chromed.They made interesting shelf fodder among all my other hot rod parts.A few actually made it into one of my engines as second string players after some nitrous related injuries of my first string valves.If you had a lot of free time on your hands,you could lap them in,then remount them in the drill press and do a back cut by hand using a course cutting stone.A hand drill could even be used oif all you want to do is clean them up a bit.Good luck.

 

[4 Jaw Chuck]

Using acid will hydrogen embrittle your valves, you must bake at 300 degrees for 6 hours to get the hydrogen out of the metal matrices it also preferentially removes the ferrite.

Be careful using acid, a short exposure is probably safe. I use a wire wheel mounted on a 6 inch grinder, you have to grind the face anyway.

 

[machine shop tom]

Here in the shop we solvent wash the valves then rinse them in hot water and then blow them dry with compressed air. We then glass bead blast the carbon and crud off of them. After that, we wire wheel them to polish them and to clean the keeper grooves.

tom

 

[k-star]

valves

I slide a piece of rubber hose over the stem and glass bead mine to remove the carbon. Another option is just getting a new set. Stock replacement valves are only like $3.50/ $4.00each... save you alot of work. Just a thought..

keith

 

[machine shop tom]

Re: valves

I slide a piece of rubber hose over the stem and glass bead mine to remove the carbon. Another option is just getting a new set. Stock replacement valves are only like $3.50/ $4.00each... save you alot of work. Just a thought..

keith

Yup, we do just that, +.003" or .005" o/s alot of the time and just ream the guide. But many replacement valve are far more expensive so cleaning and re-using them is still cost effective. We work on almost any damn thing!

tom

 

[k-star]

valves

Yep you are right Tom, I guess i should have put small block chevy behind the price,,, L.O.L. i am stuck in that mode, just assuming that is what everybody is working on if you know what i mean..... He....He.....He....

Keith