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Cylinder head valve...

Paintballpsyco2369

NAXJA Forum User
Location
Memphis, Mi
Long story short, I am reconditioning a newer head for my Jeep build. One of the intake valves had some rust on it around the sealing surface. The head itself is all good now, cleaned up real nice so the final issue to put it all back together is this: In cleaning the valve up, I found some pitting on towards the base of the stem. Not too deep and not close to the "sealing band" towards the edge of the valve. The rest of the valve is in pretty good shape too so I am wondering if I just clean the valve good, and lap it for a better seal (doing that to ALL the valves anyway) can I still use it? OR should I just replace it with a new one? My only worry is running into an issue of some sort with the ONE new valve vs. all the other "OLD" valves...

Any input is greatly appreciated, and I thank you in advance.

Paint
 
Pitting of the back side of the valve is not unusual. Just lap the valves and call it good.
 
Pitting of the back side of the valve is not unusual. Just lap the valves and call it good.

It was from a bit past the beginning of the flare from the stem, to a bit before where the valve seals to the head. Based on what I got from here and another forum, I am just going to re-use the valve. Clean it good, wire wheel/scotchbriting any heavy stuff and give it a good de-greasing, then go and lap everything good... Taking the head in to get 2 manifold bolts removed that snapped off in a few minutes here...

Thanks again for your help, greatly appreciated,

Paint
 
Yeah valves are dirt cheap, why re-use it? I just got my head rebuilt this week and had one pitted valve from water intrusion that had to be replaced while the others all looked fine. RUnning just one new valve will be fine. I have a 4cyl yota head that i had rebuilt w/ just 2 new valves and it runs great.

One shiny new valve, 11 old cleaned up vavles...
Need to get it on tomorrow night.
57265f6b.jpg
 
I may still replace it, I got the head back today from getting the 2 bolts extracted (outer 2 exhaust manifold bolts snapped flush with the head) and started cleaning up the valves and bridges and such. Only got the first 2 cylinders worth cleaned up before work, but in wire brushing the valves, the pitting really isn't bad at all. They all do have a tiny amount, but not enough to worry about.

The best price I could find on a new valve is $10 locally, and I want to get the thing done so I did get it when I bought my last batch of parts... I still may not use it as the old valve cleaned up REAL nice. I'm not building a performance engine or anything like that so I don't think I'm going to worry about it... My main worry was just how the one new valve may effect everything else being newer and possibly changing spring rates or something... Will just see how it goes once I start lapping everything... Next year or so I may go through and do a complete rebuild on the engine and head and possibly the trans too maybe bore it and possibly stroke it and of course port and polish everything too... Though I'm not too worried about it all right now...

This may be a long shot here, but is there any sort of fluid I could use to check the valve cylinders for leaks? I used water when I power washed it and found the one leak, hence the lapping and going through the whole valvetrain... It checked out to just be some rust, so all is good now that it is cleaned up...

Anyhow, will keep you all updated with progress, thanks again.

Paint
 
Alcohol, wiper fluid, etc all work as a checking solution. I wouldn't worry about leaks. They are leaks when cold and once you clamp the head on the block and it heats up that will all change. Some leaks when cold might seal up when hot, then there may be new leaks when hot. Checking for leaks when cold is merely academic.
 
Alcohol, wiper fluid, etc all work as a checking solution. I wouldn't worry about leaks. They are leaks when cold and once you clamp the head on the block and it heats up that will all change. Some leaks when cold might seal up when hot, then there may be new leaks when hot. Checking for leaks when cold is merely academic.

Cool, thanks. Just wanted something to make sure it is good at least in the "Bench stage" To make sure they are lapped good. Think denatured alcohol is ok? Got that by the gallon lol. Thanks again for the help on this.

Paint
 
Denatured Alcohol is fine. It's just ethanol with a % of methanol added to make it poisonous.
 
Denatured Alcohol is fine. It's just ethanol with a % of methanol added to make it poisonous.

Cool thanks. In that case, one could conceivably distill it to make moonshine! lol. Though at those concentrations of both parts it would be beyond dangerous and just pure stupidity lol. That and the danger of an improper process can still result in blindness...BTW DON'T TRY THIS AT HOME KIDS!!

Paint.
 
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