Exhaust valves

gollygeemister · **Posted:** Sun Jun 16, 2019 10:11 pm

https://www.ebay.com/itm/8-Jeep-Liberty ... SwU2tc5JQT

geordi · **Posted:** Mon Jun 17, 2019 12:40 am

I am highly suspicious of those... No markings on the "packaging" to speak of, and just a paper wrapper? The coatings on the stems appear unevenly applied, like they have been sprayed with something to hide possible wear on the contact areas. I don't know if these are used or new, but the uneven coating is a major problem for me. None of the actually-new valves I have seen have looked like that.

The tips of the stems (where the rocker sits) also is different. Ours are flat with only the barest nip of the corner, these look practically tapered at the top. That may not affect performance, but then again it might.

Rabbit566 · **Joined:** Wed Mar 21, 2018 9:45 am **Posts:** 9

I've reached out to the Ebay seller and he's going to provide us specs.... he wouldn't offer up the manufacture :banghead:

geordi · **Posted:** Mon Jun 17, 2019 2:46 pm

Yeah... No manufacturer just makes me MORE suspicious. I don't know of ANYONE making valves for this engine other than the OEM factory, and that factory is in Turkey. Every valve I have ever unwrapped (and that has been quite a lot now as you may guess) has been from the same place in Turkey.

layback40 · **Posted:** Mon Jun 17, 2019 6:18 pm

geordi wrote:

I am highly suspicious of those... No markings on the "packaging" to speak of, and just a paper wrapper? The coatings on the stems appear unevenly applied, like they have been sprayed with something to hide possible wear on the contact areas. I don't know if these are used or new, but the uneven coating is a major problem for me. None of the actually-new valves I have seen have looked like that.

The tips of the stems (where the rocker sits) also is different. Ours are flat with only the barest nip of the corner, these look practically tapered at the top. That may not affect performance, but then again it might.

Does any one know of a valve manufacturer in Italy?
If you look at the base around where the valve seals against the seat, it looks like new as its upstanding a little from the valve body.
The top of the stem has the angled edge like many other valves.
The weld area is definitely undercut a little.
Maybe the Turks have upgraded their valve manufacturing process & this is the result.
I wonder who is manufacturing the valves for the Chinese LDV that uses a variant of this engine?
Are the valves different on the replacement (KK CRD) engine?

Rabbit566 · **Joined:** Wed Mar 21, 2018 9:45 am **Posts:** 9

Ebay Seller got back to me....

I quote

"Finally made it back to town and did my best to translate from Italian...

they match OE specs, but I was able to ascertain
That they are:

-induction hardened grooves
-welded with stellite alloy
-induction hardened stem
- made of Chrome silicon steel "

I also reached out to Manley..http://www.manleyperformance.com/

$40 each. for their STREET SERIES

Still debating what to purchase....

WWDiesel · **Posted:** Wed Jun 19, 2019 12:31 pm

Rabbit566 wrote:

Ebay Seller got back to me....
I quote
"Finally made it back to town and did my best to translate from Italian...
they match OE specs, but I was able to ascertain
That they are:
-induction hardened grooves
-welded with stellite alloy
-induction hardened stem
- made of Chrome silicon steel "
I also reached out to Manley..http://www.manleyperformance.com/
$40 each. for their STREET SERIES
Still debating what to purchase....

That's very good news on the Manley Valves! They make some really good valves. We used them exclusively when building high performance drag race engines when I worked at a machine shop.

Based on Manley's "EXHAUST VALVE TEMPERATURE RANGE CHART in their online catalog; the CRD engine at a minimum would need either severe duty or extreme duty series valves.

Rabbit566 · **Joined:** Wed Mar 21, 2018 9:45 am **Posts:** 9

If the temps are that high than the price from Manley would probably increase. It was just a quick conversion with Johnny at Manley. I think I'm just going to go with OEM.

GordnadoCRD · **Posted:** Wed Jun 19, 2019 4:07 pm

The most heat resistant are Titanium. That's what they use in Nitromethane drag engines. How they would wear over time, though, I have no idea. They are all removed and measured any way they can be after every race day.

SJBrooks · **Joined:** Tue Mar 11, 2014 11:01 am **Posts:** 91

geordi wrote:

IDparts has the VM valve seals, but you will need professional assistance to replace them b/c of how they are installed. To date out of the 40 or so heads I have worked on and over a hundred more that others have done, I have not heard of a single case of any issue with the seats or seals. Only the valves themselves have been an issue.

I'm about to remove a head and replace the exhaust valves. Along with all the other needed parts, I did get all new valve seals. Considering the time that's lapsed since Geordi's input (above), has anybody replaced their valve seals themselves or is there no choice but to have a machine shop do that task?

Regards,

Steve

WWDiesel · **Posted:** Fri Nov 29, 2024 2:52 am

No need to replace the valve seals unless somehow one got damaged.
Valve seals don't cause any issues unless the valve guide gets worn out and eats the seal up.
Valve seal leak by is only an issue on gas engines and then only on the intake valves due to vacuum in the intake manifold which allows oil to be sucked by a bad seal.
Diesel engines do not have vacuum in the intake, they are under pressure from the turbo most of the time. + pressure.

Just reuse your OEM seals and be careful not to damage them when removing and replacing the exhaust valves.

SJBrooks · **Joined:** Tue Mar 11, 2014 11:01 am **Posts:** 91

Thanks WW, I've always appreciated your timely input on matters. Considering the low amount of annual miles I expect to my on my much-beloved Liberty in the future, I'm expecting this job to (perhaps) be the last time I do it before I give the keys to my daughter and quit driving. That in mind, since it'll be apart anyways, I'd still like to replace those seals. Is it true that can only be done by a machine shop/etc?

Steve

WWDiesel · **Posted:** Sun Dec 01, 2024 4:07 pm

I see no need for a machine shop to be involved in valve seal replacement. They just slip off the the top of the valve guides and then slip the new ones on.
The Factory Service Manual does not list any special instructions or tools needed as to valve seal replacement requirements and / or procedures.
But you certainly need to lap the new exhaust valves to the seats for a good positive tight leak proof seal.
This can be done at home with a little valve lapping compound and a drill or a valve lapping tool. This could be done before you install the new valve seals.
There are some YouTube videos on how to do this if you are not familiar with the process.

SJBrooks · **Joined:** Tue Mar 11, 2014 11:01 am **Posts:** 91

Thanks again WW! I'm underway with getting everything out of the way of doing the timing belt and head gasket jobs, so I'll be tackling the valve seals soon...

Steve

SJBrooks · **Joined:** Tue Mar 11, 2014 11:01 am **Posts:** 91

I ended up not replacing the valve seals. Rationale was: 1. The original seals' rubber and springs were all intact, the rubber was still pliable, and all seals tightly gripped the valve stems when the valves were pushed in and out, and 2. With the body of the seals being metal, if they were removed, it appeared there would be a socket-like device needed to tap the seals down onto the top of the valve guides and I didn't have that tool or a basic socket that fit well enough to use as a substitute.

Thought somebody might find this info useful...

Steve

WWDiesel · **Posted:** Wed Jan 15, 2025 1:49 am

Most never replace the valve seals on this engine when replacing the exhaust valves. They just don't wear out on this engine!

Exhaust valves

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