Bad Valve Stems?
Moderator: Team
Bad Valve Stems?
I came across something a little unusual for the second time today. The valve stems on all 8 intake valves were worn beyond recognition. I didn't measure, but think .030" wear! The middle of the stem was worn away. This is only the second time I have ever seen this. The first time both intake and exhaust valves were bad. This time only the intakes (exhaust were good). I measured the guides and to my surprise they are all straight with 0.0014" clearance and about 0.0002" taper at the chamber side (both intake and exhaust)(measured with a Sunnen P300). In both instances they were +0.100" small block Chevy valves in Edelbrock heads. Did Edelbrock receive a bad run of valves in the past? What could have caused this?
Re: Bad Valve Stems?
Sounds like the stem material was wrong for the guides ??SRS_Chris wrote: ↑Wed Jan 18, 2023 11:54 pm I came across something a little unusual for the second time today. The valve stems on all 8 intake valves were worn beyond recognition. I didn't measure, but think .030" wear! The middle of the stem was worn away. This is only the second time I have ever seen this. The first time both intake and exhaust valves were bad. This time only the intakes (exhaust were good). I measured the guides and to my surprise they are all straight with 0.0014" clearance and about 0.0002" taper at the chamber side (both intake and exhaust)(measured with a Sunnen P300). In both instances they were +0.100" small block Chevy valves in Edelbrock heads. Did Edelbrock receive a bad run of valves in the past? What could have caused this?
Ignorance leads to confidence more often than knowledge does.
Nah, I'm not leaving myself out of the ignorant brigade....at times.
Nah, I'm not leaving myself out of the ignorant brigade....at times.
Re: Bad Valve Stems?
In both instances they are the valves that came in the heads from Edelbrock. Stainless valves with bronze guides. Beyond that, I'm not sure what specific stainless steel or bronze materials Edelbrock would use.
-
- Guru
- Posts: 4607
- Joined: Sun Sep 18, 2011 11:31 am
- Location: Heading for a bang up with Andromeda as we all are.
Re: Bad Valve Stems?
Sounds like a issue of little to none of the needed chrome plating on the stems.
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
Re: Bad Valve Stems?
Not sure I've ever seen chrome plating on the stems of aftermarket Stainless valves. They rely on proper material and heat treatment.
Re: Bad Valve Stems?
Are you sure the valves are not STRETCHING... which would thin them out in the middle?
-
- Guru
- Posts: 4607
- Joined: Sun Sep 18, 2011 11:31 am
- Location: Heading for a bang up with Andromeda as we all are.
Re: Bad Valve Stems?
4 of the 7 series of SS valves that Manley makes have chrome plated stems, but it does not seem like you can say the same for Ferrea valves which is odd to me!
You do not have the required permissions to view the files attached to this post.
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
Re: Bad Valve Stems?
I have run into this situation a few times with E heads.
I’ve only seen it happen on heads that were run “ootb”.
One set of SBC heads, a few sets of BBM heads.
Heads that I have prepped/sold, when they come back in for freshening have essentially no wear on the valves.
My summation was/is, the guide clearance was too tight(I open them up a few tenths), and wonder about how well Ede cleans out the guides after sizing.
That might allow honing grit to get embedded in the guides........ and wear out the stems.
I don’t feel the tight clearances and white lithium grease assy lube helps in getting oil flowing into the guides early on.
Like the OP, when I’ve come across this worn stem condition, the guides still measure good.
I’ve only seen it happen on heads that were run “ootb”.
One set of SBC heads, a few sets of BBM heads.
Heads that I have prepped/sold, when they come back in for freshening have essentially no wear on the valves.
My summation was/is, the guide clearance was too tight(I open them up a few tenths), and wonder about how well Ede cleans out the guides after sizing.
That might allow honing grit to get embedded in the guides........ and wear out the stems.
I don’t feel the tight clearances and white lithium grease assy lube helps in getting oil flowing into the guides early on.
Like the OP, when I’ve come across this worn stem condition, the guides still measure good.
Last edited by PRH on Fri Jan 20, 2023 5:05 pm, edited 2 times in total.
Somewhat handy with a die grinder.
Re: Bad Valve Stems?
I thought it was pretty standard to chrome plate the stems on most valves, although it's not very thick.
You do not have the required permissions to view the files attached to this post.
Channel About My diy Projects & Reviews https://www.youtube.com/c/BOOTdiy
I know as much as I can learn and try to keep an open mind to anything!
If I didn't overthink stuff I wouldn't be on speedtalk!
I know as much as I can learn and try to keep an open mind to anything!
If I didn't overthink stuff I wouldn't be on speedtalk!
Re: Bad Valve Stems?
Ferrea chrome plates the stems for 5000 & 6000 series and may others, i just googled it quick.
https://www.ferrea.com/5000-series-hi-p ... alves/c165
https://www.ferrea.com/6000-series-comp ... alves/c166
Channel About My diy Projects & Reviews https://www.youtube.com/c/BOOTdiy
I know as much as I can learn and try to keep an open mind to anything!
If I didn't overthink stuff I wouldn't be on speedtalk!
I know as much as I can learn and try to keep an open mind to anything!
If I didn't overthink stuff I wouldn't be on speedtalk!
Re: Bad Valve Stems?
All Chrome plated stems
https://www.milodon.com/valves/street-s ... valves.php
https://www.compcams.com/sportsman-stai ... 001-1.html
http://www.pbm-erson.com/Catalog/PBM/Va ... _V/PBM1001
For the eddy ones scroll down it's in the details, not saying all are, just these from a quick search
https://www.edelbrock.com/intake-valves ... -9366.html
https://www.edelbrock.com/intake-valves ... 93775.html
https://www.milodon.com/valves/street-s ... valves.php
https://www.compcams.com/sportsman-stai ... 001-1.html
http://www.pbm-erson.com/Catalog/PBM/Va ... _V/PBM1001
For the eddy ones scroll down it's in the details, not saying all are, just these from a quick search
https://www.edelbrock.com/intake-valves ... -9366.html
https://www.edelbrock.com/intake-valves ... 93775.html
Channel About My diy Projects & Reviews https://www.youtube.com/c/BOOTdiy
I know as much as I can learn and try to keep an open mind to anything!
If I didn't overthink stuff I wouldn't be on speedtalk!
I know as much as I can learn and try to keep an open mind to anything!
If I didn't overthink stuff I wouldn't be on speedtalk!
Re: Bad Valve Stems?
Interesting, but why only the intake and not exhaust valves in my most recent case? The first time I saw this happen it was both. In any case, I've ordered a new set of Manley intake valves and will be honing the guides to create some cross hatch. Hopefully this helps with oil retention and stem lubrication.PRH wrote: ↑Fri Jan 20, 2023 4:57 pm I have run into this situation a few times with E heads.
I’ve only seen it happen on heads that were run “ootb”.
One set of SBC heads, a few sets of BBM heads.
Heads that I have prepped/sold, when they come back in for freshening have essentially no wear on the valves.
My summation was/is, the guide clearance was too tight(I open them up a few tenths), and wonder about how well Ede cleans out the guides after sizing.
That might allow honing grit to get embedded in the guides........ and wear out the stems.
I don’t feel the tight clearances and white lithium grease assy lube helps in getting oil flowing into the guides early on.
Like the OP, when I’ve come across this worn stem condition, the guides still measure good.
- Caprimaniac
- Guru
- Posts: 1062
- Joined: Fri Nov 18, 2011 1:17 pm
- Location: NORWAY
Re: Bad Valve Stems?
FYI- my edel Vic jr’s 11/32 stems, after 10 years of abuse, 2-3 with stud rockers, after that a shaft setup, all the valves had stems worn out, and in need of replacement.
All except one guide were good to go.
One or another need to go- guide or stem- the time it takes have to do with seats, geometry, material, etc
All except one guide were good to go.
One or another need to go- guide or stem- the time it takes have to do with seats, geometry, material, etc
How to turn GURU in an instant.....